阅读说明：本技术 加工对象物切断方法 (Method for cutting processing target ) 是由 坂本刚志 于 2018-04-12 设计创作，主要内容包括：加工对象物切断方法包含：第1步骤,准备加工对象物；第2步骤,在第1步骤之后,通过对加工对象物照射激光,分别沿着多个切断预定线,在加工对象物的单晶硅基板的内部形成至少1列的改质区域,并以跨越至少1列的改质区域与加工对象物的第2主面之间的方式形成龟裂；以及第3步骤,在第2步骤之后,对加工对象物从第2主面侧实施干式蚀刻,由此分别沿着多个切断预定线形成在第2主面开口的槽。在第2步骤中,以使龟裂未连接的未龟裂区域形成于加工对象物中的厚度方向的规定位置的方式形成改质区域。(Method for cutting processing target includes: step 1 is rapid, prepares workpiece；Second step, after step 1 is rapid, by irradiating laser to workpiece, respectively along multiple cutting preset lines, the modified region of at least 1 column is formed in the inside of the monocrystalline silicon substrate of workpiece, and to form cracking across the mode between the modified region of at least 1 column and the 2nd interarea of workpiece；And third step implements dry-etching from the 2nd main surface side to workpiece after second step, and the slot of the 2nd interarea opening is thus formed in respectively along multiple cutting preset lines.In second step, modified region is formed in a manner of the specified position for the thickness direction that the non-polygonal area for keeping cracking not connected is formed in workpiece.)

1. a kind of method for cutting processing target, which is characterized in that

Include:

Step 1 is rapid, prepares the workpiece with monocrystalline silicon substrate and the functional element layer that the 1st main surface side is arranged in；

Second step, after the step 1 is rapid, by irradiating laser to the workpiece, to be cut respectively along multiple Disconnected preset lines form the modified region of at least 1 column in the inside of the monocrystalline silicon substrate, and pre- respectively along the multiple cutting Alignment, in the workpiece across between the modified region of at least 1 column and the 2nd interarea of the workpiece Mode form cracking；And

Third step implements dry-etching from the 2nd main surface side to the workpiece after the second step, by This is formed in the slot of the 2nd interarea opening respectively along the multiple cutting preset lines, in the workpiece,

In the second step, so that the non-polygonal area that the cracking is not connected with is formed in the thickness in the workpiece The mode for spending the specified position in direction forms the modified region.

2. method for cutting processing target as described in claim 1, which is characterized in that

The modified region closer to the 1st modified region of the 1st main surface side and compares including at least than the specified position The specified position closer to the 2nd main surface side the 2nd modified region,

In the second step, in the inside of the monocrystalline silicon substrate, changed with being formed in the specified position from the described 1st Non- polygonal area described in the cracking that matter region extends and the cracking extended from the 2nd modified region are not connected or The cracking extended from the either side of the 1st modified region and the 2nd modified region and the 1st modified region and the 2nd The mode of the not connected non-polygonal area of any other party of modified region, forms the 1st modified region and the described 2nd Modified region.

3. method for cutting processing target as claimed in claim 1 or 2, which is characterized in that

In the second step, by forming multiple modification luminous points respectively along the multiple cutting preset lines arrangement, thus The modified region of at least 1 column is formed, and respectively along the multiple cutting preset lines to cross over the multiple modification luminous point In mode between adjacent to each other modification luminous point form the cracking.

4. method for cutting processing target according to any one of claims 1 to 3, which is characterized in that

In the third step, described in from the slot reaches the 2nd main surface side of the non-polygonal area until reaching Terminate the etching between until the 1st main surface side of non-polygonal area.

5. method for cutting processing target as described in any one of claims 1 to 4, which is characterized in that

In the third step, by implementing the etching, so that being formed in the position of the non-polygonal area has bending section V-shaped section or U-shaped section the slot.

6. such as method for cutting processing target according to any one of claims 1 to 5, which is characterized in that

Have: step 4 is rapid, after the third step, expanded film is attached in the 2nd main surface side, by making the expansion Film expansion, so that the workpiece is cut to multiple semiconductor chips respectively along the multiple cutting preset lines.

Technical field

One aspect of the present invention is related to method for cutting processing target.

Background technique

As the technology of current method for cutting processing target is related to, a kind of technology is recorded in patent document 1, Pass through implementation after workpiece forms modified region along cutting preset lines and to workpiece irradiation laser It etches and carries out etching along modified region.

Summary of the invention

The technical problems to be solved by the invention

However, in method for cutting processing target in recent years, it is sometimes desirable to using dry-etching by workpiece Cutting.In the case, such as in order to manage the quality of the semiconductor chip as obtained from cutting, it is desirable that control dry-etching Progress.

Therefore, one aspect of the present invention is to provide a kind of workpiece cutting of progress that can control dry-etching For the purpose of method.

Technical means to solve problem

Method for cutting processing target involved in one aspect of the present invention, include: step 1 is rapid, prepares have monocrystalline Silicon substrate and be arranged in the 1st main surface side functional element layer workpiece；Second step passes through after step 1 is rapid Laser is irradiated to workpiece, respectively along multiple cutting preset lines, forms changing at least 1 column in the inside of monocrystalline silicon substrate Matter region, and respectively along multiple cutting preset lines, in modified region and processing object of the workpiece to be arranged across at least 1 Mode between 2nd interarea of object forms cracking；And third step, after second step, to workpiece from the 2nd interarea Dry-etching is implemented in side, thus respectively along multiple cutting preset lines, is formed in the slot of the 2nd interarea opening in workpiece； In second step, so that the non-polygonal area that cracking is not connected with is formed in the specified position of the thickness direction in workpiece Mode form modified region.

In the method for cutting processing target, to main with the 2nd of the modified region and workpiece that are arranged across at least 1 the Mode between face is formed with the workpiece of cracking, implements dry-etching from the 2nd main surface side.Dry-etching can be from as a result, 2nd main surface side is selectively carried out along cracking, and the narrow and deep slot of the width of opening is formed respectively along multiple cutting preset lines. Here, it has been found that dry-etching in the not connected non-polygonal area of cracking in workpiece is carried out than along the dry of cracking The progress of formula etching is slower.Therefore, to form modified region in such a way that specified position forms non-polygonal area, at it In dry-etching afterwards, dry-etching can be reliably set delay in the specified position.Thereby, it is possible to control dry type erosion The progress at quarter.

In one aspect of the invention in related method for cutting processing target, it is also possible to modified region and at least wraps Containing changing than specified position closer to the 1st modified region of the 1st main surface side and than specified position closer to the 2nd of the 2nd main surface side Matter region, in second step, in the inside of monocrystalline silicon substrate, to form the tortoise extended from the 1st modified region in specified position Split the non-polygonal area not connected with the cracking that extends from the 2nd modified region or from the 1st modified region and the 2nd modified region The cracking that extends of the either side non-polygonal area not connected with any other party of the 1st modified region and the 2nd modified region Mode, form the 1st modified region and the 2nd modified region.According to this structure, it can be realized the shape of specific non-polygonal area At.

In one aspect of the invention in related method for cutting processing target, it is also possible in second step, shape At multiple modification luminous points respectively along multiple cutting preset lines arrangements, thus formed at least respectively along multiple cutting preset lines The modified region of 1 column, and to form cracking across the mode between modification luminous point adjacent to each other in multiple modification luminous points.By This, can make dry-etching more efficiency good and selectively carry out.

In one aspect of the invention in related method for cutting processing target, it is also possible in second step, In Until terminating dry type between until the 1st main surface side of the non-polygonal area of arrival from slot reaches the 2nd main surface side of non-polygonal area Etching.According to this structure, dry-etching can be made terminate in specified position.

It is dry by implementing in second step in one aspect of the invention in related method for cutting processing target Formula etching, the position for being formed in non-polygonal area have the section V-shaped of bending section or the slot of section U-shaped.According to this structure, It is capable of forming the section V-shaped of the shape of the position corresponding to non-polygonal area or the slot of section U-shaped.

Method for cutting processing target involved in one aspect of the present invention can also have: step 4 is rapid, in step 3 After rapid, attach expanded film in the 2nd main surface side, respectively along multiple cutting preset lines, will be added by expanding expanded film Work object is cut to multiple semiconductor chips.According to this structure, workpiece can be reliably divided into and multiple is partly led Body chip.

The effect of invention

One aspect of the present invention it is possible to provide a kind of workpiece of progress of controllable dry-etching is cut off Method.

Detailed description of the invention

Fig. 1 is the schematic structural diagram for being used to form the laser processing device of modified region.

Fig. 2 is the top view of the workpiece of the formation object as modified region.

Fig. 3 is the sectional view along the III-III line of the workpiece of Fig. 2.

Fig. 4 is the top view of the workpiece after laser processing.

Fig. 5 is the sectional view along the V-V line of the workpiece of Fig. 4.

Fig. 6 is the sectional view along the line VI -- VI of the workpiece of Fig. 4.

Fig. 7 is the sectional view for illustrating experimental result relevant to method for cutting processing target.

Fig. 8 is the sectional view for illustrating experimental result relevant to method for cutting processing target.

Fig. 9 is the sectional view for illustrating experimental result relevant to method for cutting processing target.

Figure 10 is the sectional view for illustrating experimental result relevant to method for cutting processing target.

Figure 11 is the figure for illustrating experimental result relevant to method for cutting processing target.

Figure 12 is the figure for illustrating experimental result relevant to method for cutting processing target.

Figure 13 is the figure for illustrating experimental result relevant to method for cutting processing target.

Figure 14 is the figure for illustrating experimental result relevant to method for cutting processing target.

Figure 15 is the figure for illustrating experimental result relevant to method for cutting processing target.

Figure 16 is the figure for illustrating experimental result relevant to method for cutting processing target.

Figure 17 is the figure for illustrating experimental result relevant to method for cutting processing target.

Figure 18 is the figure for illustrating experimental result relevant to method for cutting processing target.

Figure 19 is the figure for illustrating experimental result relevant to method for cutting processing target.

Figure 20 is the figure for illustrating experimental result relevant to method for cutting processing target.

Figure 21 is the perspective view for illustrating the workpiece of experimental result relevant to method for cutting processing target.

Figure 22 is the sectional view for illustrating method for cutting processing target involved in an embodiment.

Figure 23 is the sectional view for illustrating method for cutting processing target involved in an embodiment.

Figure 24 is the sectional view for illustrating method for cutting processing target involved in an embodiment.

Figure 25 is the sectional view for illustrating method for cutting processing target involved in an embodiment.

Figure 26 is the sectional view for illustrating method for cutting processing target involved in an embodiment.

Figure 27 is the sectional view for illustrating method for cutting processing target involved in an embodiment.

Figure 28 is the sectional view for illustrating method for cutting processing target involved in an embodiment.

Figure 29 is the sectional view for illustrating method for cutting processing target involved in an embodiment.

Figure 30 is the sectional view for illustrating method for cutting processing target involved in an embodiment.

Figure 31 is by the vertical of the semiconductor chip obtained of method for cutting processing target involved in an embodiment Body figure.

Figure 32 is the figure for illustrating method for cutting processing target involved in an embodiment.

Specific embodiment

Hereinafter, embodiment is described in detail referring to attached drawing.In addition, in the various figures, to same or equivalent part The same symbol is assigned, the repetitive description thereof will be omitted.

In the method for cutting processing target involved in present embodiment, by by laser focusing in workpiece, Modified region is formed in workpiece along cutting preset lines.Then, firstly, formation to modified region, referring to Fig.1~figure 6 are illustrated.

As shown in Figure 1, laser processing device 100 has laser emitting portion, the i.e. laser light for making laser L carry out impulse hunting Source 101, by by the direction of the optical axis of laser L (optical path) change 90 ° in a manner of configure dichronic mirror 103, for light-concentrating laser L's Optically focused lens 105.In addition, laser processing device 100, which has, is used to support illuminated swashing by 105 optically focused of optically focused lens The supporting table 107 of the workpiece 1 of light L, the platform 111 for keeping supporting table 107 mobile, the output in order to adjust laser L (pulse energy, luminous intensity) or pulse width, impulse waveform etc. and control laser light source 101 laser light source control unit 102, control The platform courses portion 115 of the movement of platform 111 processed.

In laser processing device 100, the laser L being emitted from laser light source 101 is made the side of its optical axis by dichronic mirror 103 To change 90 °, by optically focused lens 105 the workpiece 1 being placed in supporting table 107 inside optically focused.It is same with this When keep platform 111 mobile, and relatively move workpiece 1 along cutting preset lines 5 relative to laser L.It is processing as a result, Object 1 forms the modified region along cutting preset lines 5.In addition, here, making platform 111 to relatively move laser L It is mobile, but it is mobile to make optically focused lens 105, or the both sides can also be made mobile.

As workpiece 1, the semiconductor substrate comprising being formed by semiconductor material can be used or by piezoelectric material shape At piezoelectric substrate etc. plate component (for example, substrate, wafer etc.).As shown in Fig. 2, being set useful in workpiece 1 In the cutting preset lines 5 of cutting off processing object 1.Cutting off preset lines 5 is the imaginary line linearly extended.In workpiece 1 Inside formed modified region in the case where, as shown in figure 3, by focal point (spot position) P alignment workpiece 1 it is interior In the state of portion, make laser L along cutting preset lines 5 (that is, direction arrow A of Fig. 2) relative movement.As a result, such as Fig. 4, Fig. 5 and Shown in Fig. 6, modified region 7 is formed in workpiece 1 along cutting preset lines 5, is formed by modification along cutting preset lines 5 Region 7 becomes cutting starting area 8.

Focal point P is the position of laser L optically focused.Cutting preset lines 5 are not limited to linearly, can be curve-like, Shapes can be tieed up to combine their 3, or the specified line of coordinate.Cutting preset lines 5 are not limited to imaginary line, can also be with For be actually plotted in workpiece 1 surface 3 line.The case where modified region 7 is also formed continuously also has and to be intermittently formed Situation.Modified region 7 can be column-shaped, or it is dotted, as long as modified region 7 is at least formed in workpiece 1 Portion.In addition, having with modified region 7 is the case where starting point forms cracking, even if cracking and modified region 7 are exposed to processing pair As the outer surface (surface 3, the back side or outer peripheral surface) of object 1 can also.Form the laser entrance face and non-limiting when modified region 7 It, can also even if the back side for workpiece 1 in the surface of workpiece 13.

That is, in the case where the inside of workpiece 1 forms modified region 7, laser L through workpiece 1 and It is especially absorbed near the focal point P of inside for being located at workpiece 1.Modified region is formed in workpiece 1 as a result, 7 (that is, absorbed inside type laser machines).In the case, due to hardly being inhaled in 3 laser L of the surface of workpiece 1 It receives, thus the surface 3 of workpiece 1 will not melt.On the other hand, modification is formed on the surface of workpiece 13 or the back side In the case where region 7, laser L is especially absorbed near the focal point P for being located at surface 3 or the back side, is melted from surface 3 or the back side And be removed, form the removing unit (laser processing of Surface absorption type) of hole or slot etc..

Modified region 7 refers to as density, refractive index, mechanical strength or other physical characteristics state different from surrounding Region.As modified region 7, such as there is fused region (to refer to after melting re-solidified region, in molten condition Region and from the region melted in re-solidified state at least any one), slit region, insulation breakdown region, refractive index Region of variation etc., the region for also thering are them to be mixed.Further more, having in the material of workpiece 1 as modified region 7 The density of modified region 7 region changed or the region for being formed with lattice defect compared with the density of non-modified region.Adding In the case that the material of work object 1 is monocrystalline silicon, modified region 7 is referred to as high dislocation density region.

Fused region, refractive index change regions, the density of modified region 7 become compared with the density of non-modified region The region of change and the region for being formed with lattice defect further have in the inside in these regions or modified region 7 and non-modification area The interface in domain includes the case where cracking (rupture, micro-crack).The cracking included has comprehensive situation or only throughout modified region 7 In a part or the case where multiple portions are formed.Workpiece 1 includes to be made of the crystalline material with crystal structure Substrate.For example, workpiece 1 includes by gallium nitride (GaN), silicon (Si), silicon carbide (SiC), LiTaO₃And sapphire (Al₂O₃) at least either formed substrate.In other words, workpiece 1 including, for example, gallium nitride base board, silicon substrate, SiC substrate, LiTaO₃Substrate or sapphire substrate.Even if crystalline material is in anisotropy crystallization and isotropism crystallization Any one can also.Furthermore even if workpiece 1 is comprising by the amorphous material structure with noncrystalline construction (noncrystalline construction) At substrate can also, such as even if can also comprising glass substrate.

It in the present embodiment, can be with by forming multiple modification luminous points (spot) (process trace) along cutting preset lines 5 Form modified region 7.In the case, modified region 7 is become by the aggregation of multiple modification luminous points.So-called modification luminous point is The modification part formed by the transmitting (shot) (that is, the laser irradiation of 1 pulse: Laser emission) of 1 pulse of pulse laser.As Luminous point is modified, crackle luminous point, melt process luminous point or variations in refractive index luminous point or their at least one mixing can be enumerated Existing luminous point etc..About modification luminous point, required cutting precision, the flatness of required section, processing pair are considered It, can be with its size of suitable control or the length of the cracking of generation as the thickness of object 1, type, crystal orientation etc..Furthermore in this reality It applies in mode, modification luminous point can be formed using as modified region 7 along cutting preset lines 5.

[experimental result relevant to method for cutting processing target]

Firstly, an example about method for cutting processing target, is illustrated referring to Fig. 7~Figure 10.In addition, Fig. 7~figure Each structure shown in 10 is schematical structure, aspect ratio of each structure etc. and actual difference.

As shown in (a) of Fig. 7, prepare the functional element layer 12 that there is monocrystalline silicon substrate 11, be set to the 1st side interarea 1a Workpiece 1, and protective film 21 is attached to the 1st interarea 1a of workpiece 1.Functional element layer 12 includes along the 1 interarea 1a is configured to such as rectangular multiple function element 12a (hair such as light receiving element photodiode, laser diode Optical element or the circuit element etc. formed as circuit).In addition, the 2nd interarea 1b of workpiece 1 is (with the 1st interarea 1a The interarea of opposite side) it is the surface with 12 opposite side of functional element layer in monocrystalline silicon substrate 11.

Then, as shown in (b) of Fig. 7, by swashing using the 2nd interarea 1b as laser light incident in face of the irradiation of workpiece 1 Light L, respectively along multiple preset lines 5 of cutting off in the modified region 7 of the inside of monocrystalline silicon substrate 11 formation multiple row, and respectively along Multiple cutting preset lines 5 form cracking 31 in workpiece 1.Multiple cutting preset lines 5 are to pass through the thickness from workpiece 1 The mode between function element 12a adjacent to each other when the observation of direction is spent, such as clathrate is set as.Respectively along multiple cuttings The modified region 7 for the multiple row that preset lines 5 are formed arranges on the thickness direction of workpiece 1.Cracking 31, which is at least crossed over, to be located at Between the modified region 7 and the 2nd interarea 1b of 1 column of the 2nd side interarea 1b.

Then, as shown in (a) of Fig. 8, dry-etching is implemented from the 2nd side interarea 1b to workpiece 1, thus such as Fig. 8 (b) shown in, respectively along multiple cutting preset lines 5 workpiece 1 formation slot 32.Slot 32 is open in the 2nd interarea 1b Such as V slot (slot of section V-shaped).Slot 32 by dry-etching from the 2nd interarea 1b lateral edge cracking 31 (that is, respectively along Multiple cutting preset lines 5) it selectively carries out and is formed.Then, the modified region 7 for being located at 1 column of the 2nd side interarea 1b is passed through Thus dry-etching removal forms relief region 9 in the inner face of slot 32.Relief region 9 is in correspond to the 2nd side interarea 1b The concaveconvex shape of the modified region 7 of 1 column.About their details, it is described below.

Dry-etching is implemented from the 2nd side interarea 1b to workpiece 1 refer to and pass through by the 1st interarea 1a in addition, so-called The covering such as protective film, and the 2nd interarea 1b is made (or to be formed with gas by region respectively along multiple cutting preset lines 5 Etch protection layer 23 (following)) it is exposed in the state of etching gas, dry-etching is implemented to monocrystalline silicon substrate 11.Especially exist In the case where implementing reactive ion etching (plasma etching), refers to and the reaction kind in plasma is exposed into the 2nd master Face 1b (or being formed with the etch protection layer 23 (following) that gas passes through region respectively along multiple cutting preset lines 5).

Then, as shown in (a) of Fig. 9, expanded film 22 is attached to the 2nd interarea 1b of workpiece 1, and such as Fig. 9 (b) shown in, by protective film 21 from the 1st interarea 1a of workpiece 1 remove.Then, as shown in (a) of Figure 10, make to expand It opens film 22 to expand, workpiece 1 is thus cut to multiple semiconductor chips 15 respectively along multiple cutting preset lines 5, And as shown in (b) of Figure 10, semiconductor chip 15 is picked up.

Then, implement dry type erosion after modified region for being formed as an example of above-mentioned method for cutting processing target The experimental result of the case where quarter is illustrated.

The 1st experiment (1 and Figure 12 referring to Fig.1) in, 400 μm of thickness of monocrystalline silicon substrates with 2mm spacer bar zonally Multiple cutting preset lines are set, respectively along multiple cutting preset lines, are formed in the thickness of monocrystalline silicon substrate in monocrystalline silicon substrate The modified region of the multiple row arranged on direction.(a) of Figure 11 be the cross-section photograph of the monocrystalline silicon substrate after modified region is formed (just It is the photo of section when cutting off monocrystalline silicon substrate before implementing following reactive ion etchings for really), (b) of Figure 11 is the planar picture of the monocrystalline silicon substrate after modified region is formed.Hereinafter, by the thickness direction list of monocrystalline silicon substrate It is single to be known as " thickness direction ", the table of the side in the case where implementing dry-etching from the surface side of a side to monocrystalline silicon substrate Face (being the surface of the upside of monocrystalline silicon substrate in (a) of Figure 11) is only known as " surface of a side ".

In Figure 11, " standard finished surface: HC " be by nature spherical aberration (due to make laser focusing in processing Object, in the spontaneous aberration of the spot position due tos snell law etc.) by laser focusing in the case where, be located at a side Surface side 1 column modified region from the surface of a side separate and be cracked from this 1 column modified region reach a side surface State, that is, the state that the cracking stretched from each modified region towards thickness direction is connected to each other." (tact-up) is processed when contracting Surface: HC " is incited somebody to action in the length of the focal point on optical axis direction mode more shorter than nature spherical aberration due to lens error correction In the case where laser focusing, separates and be cracked from 1 column from the surface of a side positioned at the modified region of 1 column of the surface side of a side Modified region reach a side surface state, that is, the cracking stretched from each modified region towards thickness direction is not by Figure 11 (a) seen in black line part connection state.

" VL pattern finished surface: HC " be with the length of the focal point on optical axis direction because aberration assign due to than nature ball In the case that the longer mode of surface aberration is by laser focusing, positioned at the surface side of a side 1 column modified region from the table of a side Face separation and the state being cracked from the surface of 1 modified region one side of arrival arranged." VL pattern finished surface: ST " is with light The length of focal point in axis direction is in the case that longer than nature spherical aberration mode is by laser focusing due to aberration assigns, It separates and is cracked from the surface of a side positioned at the modified region of 1 column of the surface side of a side and do not reached from the modified region of 1 column The state on the surface of one side." VL pattern finished surface: ablation " be with the length of the focal point on optical axis direction because aberration assign Give and mode longer than nature spherical aberration by laser focusing in the case where, positioned at a side surface side 1 column modification area Domain is exposed to the state on the surface of a side.

It is formed after modified region as described above, on the surface of a side of monocrystalline silicon substrate, with the use of implementation in 60 minutes CF₄The reactive ion etching of (carbon tetrafluoride).As a result, as shown in figure 12.(a) of Figure 12 is to implement reactive ion The planar picture of monocrystalline silicon substrate after etching, (b) of Figure 12 are the monocrystalline silicon substrates implemented after reactive ion etching Cross-section photograph (perpendicular to cutting preset lines section photo).

Here, 3 being illustrated referring to Fig.1 for the definition of each term shown in Figure 12.So-called " groove width " is by dry Formula etches the width W of the opening for the slot to be formed.So-called " groove depth " is the depth D of the slot formed by dry-etching.So-called " slot Aspect ratio " is by D divided by the resulting value of W.So-called " Si etch quantity " is the thickness from the monocrystalline silicon substrate before dry-etching implementation (originally thickness) subtracts the resulting value E1 of thickness of the monocrystalline silicon substrate after dry-etching is implemented.So-called " SD etch quantity " is that E1 adds The upper resulting value E2 of D.So-called " etching period " is to implement the time T of dry-etching.So-called " Si etch-rate " is by E1 divided by T Resulting value.So-called " SD etch-rate " is by E2 divided by the resulting value of T.So-called " etch-rate ratio " is by E2 divided by obtained by E1 Value.

The 1st experiment as a result, knowing following situation shown in Figure 12.That is, if cracking reaches the surface of a side (to list Crystal silicon substrate from the surface side of a side implement dry-etching in the case where a side surface), then cracking connection range Interior, dry-etching selectively (that is, with high etch rates ratio) is carried out from the surface side of a side along being cracked, and is formed with opening Slot (" standard finished surface: HC " and " VL pattern finished surface: ST " and " the VL pattern of width narrow and deep (that is, slot aspect ratio is high) The comparison of finished surface: ablation ").Compared to modified region itself, cracking facilitates the selectivity of dry-etching more significantly It carries out (" standard finished surface: HC " is compared with " VL pattern finished surface: HC " and " VL pattern finished surface: ablation ").If The cracking stretched from each modified region towards thickness direction is not connected, then the progress of the selectivity of dry-etching is not connected in cracking Part (from the visible black line part (a) of Figure 11) stop (" standard finished surface: HC " and " when contracting finished surface: HC " Compare).In addition, the carry out speed reduction for carrying out stopping referring to dry-etching of the selectivity of so-called dry-etching.

In the 2nd experiment (4 and Figure 15 referring to Fig.1), in 100 μm of thickness of monocrystalline silicon substrates with 100 μm of interval clathrates Ground sets multiple cutting preset lines and is formed in monocrystalline silicon substrate in the inside of monocrystalline silicon substrate respectively along multiple cutting preset lines The modified region of 2 column arranged on the thickness direction of plate.Here, modified region adjacent to each other is set as each other in a thickness direction Isolated state, that is, the cracking stretched from each modified region towards thickness direction reaches the surface of a side and the surface of another party The state of the both sides on (surface with the surface opposite side of a side).Then, on the surface of a side of monocrystalline silicon substrate, implement to use CF₄Reactive ion etching.

2nd experiment the result is that as shown in Figure 14 and Figure 15.In Figure 14 and Figure 15, " CF₄: 60min " indicates to implement 60 Minute uses CF₄Reactive ion etching the case where, " CF₄: 120min " indicates to implement 120 minutes use CF₄Reaction The case where property ion(ic) etching.(a) of Figure 14 is a planar picture (side for the monocrystalline silicon substrate before reactive ion etching is implemented The photo on surface), (b) of Figure 14 is the bottom surface photo (table of another party of the monocrystalline silicon substrate after reactive ion etching is implemented The photo in face).(a) of Figure 15 is the monocrystalline silicon obtained and cutting off monocrystalline silicon substrate respectively along multiple cutting preset lines The side photo of chip, (b) of Figure 15 are the figures for indicating the size of the silicon single crystal wafer.In addition, Figure 15 (a) and (b) in, The surface of one side of monocrystalline silicon substrate becomes downside.

From Figure 14 and it is shown in figure 15 2nd experiment as a result, knowing following situation.That is, if cracking reaches the table of a side Face (to monocrystalline silicon substrate from the surface side of a side implement dry-etching in the case where a side surface), then cracking company, institute In the range of connecing, dry-etching selectively (that is, with high etch rates ratio) is carried out from the surface side of a side along being cracked, and is formed The slot of the width of opening narrow and deep (that is, slot aspect ratio is high).If the cracking stretched from each modified region towards thickness direction reaches The both sides on the surface on the surface and another party of one side then can only pass through dry-etching for the complete chip of monocrystalline silicon substrate.Separately Outside, in " CF₄: it, can if expanding the expanded film in the face for the another party for being attached at monocrystalline silicon substrate in the case where 60min " Enough monocrystalline silicon substrates by the rectangular plate-like of 50mm × 50mm are cut to the chip of 100 μm of 100 μ m with 100% ratio.

In the 3rd experiment (referring to Fig.1 6), zonally set in 400 μm of thickness of monocrystalline silicon substrates with 2mm spacer bar more A cutting preset lines are formed in the thickness of monocrystalline silicon substrate in the inside of monocrystalline silicon substrate respectively along multiple cutting preset lines The modified region of the multiple row arranged on direction.Here, being set as being located at by nature spherical aberration by laser focusing The modified region of 1 column of the surface side of one side, which is separated and is cracked from the surface of a side, reaches a side's from the modified region of 1 column The state on surface, that is, the state that the cracking stretched from each modified region towards thickness direction is connected to each other.Then, in monocrystalline silicon Reactive ion etching is implemented on the surface of one side of substrate.

The result of 3rd experiment is as shown in figure 16.In Figure 16, " CF₄(RIE) " it indicates to pass through RIE (Reactive Ion Etching (reactive ion etching)) device implement use CF₄Reactive ion etching the case where, " SF₆(RIE) " indicate logical RIE device is crossed to implement to use SF₆The case where reactive ion etching of (sulfur hexafluoride), " SF₆(DRIE) " it indicates to pass through DRIE (Deep Reactive Ion Etching (deep reaction ion etching)) device is implemented to use SF₆Reactive ion etching Situation.(a) of Figure 16 is the planar picture for implementing the monocrystalline silicon substrate after reactive ion etching, and (b) of Figure 16 is to implement The cross-section photograph of monocrystalline silicon substrate after reactive ion etching (perpendicular to the photo of the section of cutting preset lines).

The 3rd experiment as a result, knowing following situation shown in Figure 16.That is, the Si in order to ensure same degree is etched Amount, although using CF₄Reactive ion etching ratio use SF₆Reactive ion etching need longer time, but can be true Protecting high etch rates, when high slot aspect ratio uses CF at that point₄Reactive ion etching ratio use SF₆Reactivity from Son etching is advantageously.

In the 4th experiment (referring to Fig.1 7), zonally set in 400 μm of thickness of monocrystalline silicon substrates with 2mm spacer bar more A cutting preset lines are formed in the thickness of monocrystalline silicon substrate in the inside of monocrystalline silicon substrate respectively along multiple cutting preset lines The modified region of the multiple row arranged on direction.In Figure 17, " CF₄(RIE): the surface 30min: HC ", " CF₄(RIE): 60min table Face: HC ", " CF₄(RIE): the surface 6H: HC ", which refers to, to be set as being located at by nature spherical aberration by laser focusing The modified region of 1 column of the surface side of one side, which is separated and is cracked from the surface of a side, reaches a side's from the modified region of 1 column The state on surface, that is, the state that the cracking stretched from each modified region towards thickness direction is connected to each other."CF₄(RIE): 6H table Face: ST " refer to is set as by nature spherical aberration by laser focusing in the case where, positioned at a side surface side 1 column change Matter region separates and is cracked from the surface of a side does not reach the state on the surface of a side from the modified region of 1 column, that is, Cong Gegai The state that matter region is connected to each other towards the cracking that thickness direction stretches.

Then, on the surface of a side of monocrystalline silicon substrate, implementation has used CF₄Reactive ion etching.In Figure 17, “CF₄(RIE): the surface 30min: HC ", " CF₄(RIE): the surface 60min: HC ", " CF₄(RIE): the surface 6H: HC ", " CF₄ (RIE): the surface 6H: ST " refers respectively to implement to use CF by RIE device with 30 minutes, 60 minutes, 6 hours, 6 hours₄It is anti- The ion(ic) etching of answering property.

4th experiment the result is that as shown in figure 17.(a) of Figure 17 is the monocrystalline silicon substrate implemented after reactive ion etching The cross-section photograph of plate (perpendicular to the photo of the section of cutting preset lines).

The 4th experiment as a result, knowing following situation shown in Figure 17.That is, if cracking reaches the surface of a side (to list Crystal silicon substrate from the surface side of a side implement dry-etching in the case where a side surface), then in the connected model of being cracked In enclosing, the progress of the selectivity of dry-etching does not stop (that is, maintaining high etch rates ratio).Even if cracking does not reach the table of a side Face, the etching on the surface of a side also carry out, and when cracking comes across the surface of a side, dry-etching starts along cracking selectivity Ground carries out.However, it is difficult to stop the stretching, extension of cracking with certain depth from the surface of a side, thus according to the progress of etching, Be cracked a side surface occur opportunity be easy it is different according to position, as a result, be formed by the opening of slot width and Depth is also easy different according to position.Therefore, when the modified region of 1 column for forming the surface side for being located at a side, with It is particularly important for so that the mode on the surface of cracking one side of arrival is formed the modified region.

In the 5th experiment (referring to Fig.1 8), set in 320 μm of thickness of monocrystalline silicon substrates with the interval 3mm clathrate more A cutting preset lines are formed in the thickness of monocrystalline silicon substrate in the inside of monocrystalline silicon substrate respectively along multiple cutting preset lines The modified region of the multiple row arranged on direction.Here, being set as being located at by nature spherical aberration by laser focusing The modified region of 1 column of the surface side of one side, which is separated and is cracked from the surface of a side, reaches a side's from the modified region of 1 column The state on surface, that is, the state that the cracking stretched from each modified region towards thickness direction is connected to each other.

Then, on the surface of a side of monocrystalline silicon substrate, implement reactive ion etching.In Figure 18, " CF₄(RIE) table Face: HC ", which refers to, to be implemented to use CF by RIE device₄Reactive ion etching."XeF₂Surface: HC " refers to be lost by sacrificial layer Engraving device is implemented to use XeF₂The reactant gas of (xenon difluoride) etches."XeF₂Surface: HC SiO₂Etch protection layer " refers to It is formed on the surface of a side of monocrystalline silicon substrate by SiO₂The etch protection layer that (silica) is constituted, and in cracking from positioned at one The modified region of 1 column of the surface side of side reaches the surface (outer surface with monocrystalline silicon substrate opposite side) of the etch protection layer Under state, implement to use XeF by sacrificial layer etching device₂Reactant gas etching.

5th experiment the result is that as shown in figure 18.(a) of Figure 18 is the monocrystalline silicon substrate before reactive ion etching is implemented Planar picture, (b) of Figure 18 be implement reactive ion etching after monocrystalline silicon substrate planar picture, (c) of Figure 18 It is to implement the cross-section photograph of the monocrystalline silicon substrate after reactive ion etching (perpendicular to the photograph of the section of cutting preset lines Piece).

The 5th experiment as a result, knowing following situation shown in Figure 18.That is, if not a side's of monocrystalline silicon substrate Surface (to monocrystalline silicon substrate from the surface side of a side implement dry-etching in the case where a side surface) formed by SiO₂ The etch protection layer of composition, then ensuring that high etch rates when in terms of high slot aspect ratio, use CF₄Reactive ion erosion Carve and use XeF₂Reactant gas etching there is no big difference.If monocrystalline silicon substrate a side surface formed by SiO₂The etch protection layer of composition, and be cracked and reach the etch protection layer from the modified region of 1 column of the surface side for being located at a side Surface, then when slot aspect ratio improves etch-rate tremendously.

In the 6th experiment (referring to Fig.1 9), it is formed on the surface of a side by SiO₂The thickness of the etch protection layer of composition 320 μm of monocrystalline silicon substrate sets multiple cutting preset lines with the interval 3mm clathrate, respectively along multiple cutting preset lines, The modified region of the multiple row arranged on the thickness direction that monocrystalline silicon substrate is formed in monocrystalline silicon substrate.Then, in monocrystalline silicon substrate The surface of one side of plate implemented to have used XeF with 180 minutes by sacrificial layer etching device₂Reactant gas etching.

In Figure 19, " standard finished surface: HC " is that modified region adjacent to each other in a thickness direction is separated from each other, and Modified region positioned at 1 column of the surface side of a side is separated from the surface of a side, is cracked and is reached etching from the modified region of 1 column The state on the surface (outer surface with monocrystalline silicon substrate opposite side) of protective layer, that is, stretched from each modified region towards thickness direction The state that the cracking of exhibition is connected to each other." standard finished surface: ST " be modified region adjacent to each other in a thickness direction each other Separation, and the modified region for being located at 1 column of the surface side of a side is separated from the surface of a side, cracking is not from the modification area of 1 column Domain reaches the state on the surface of a side, that is, the state that the cracking stretched from each modified region towards thickness direction is connected to each other.

" 1 surface: HC is processed when contracting " is that modified region adjacent to each other in a thickness direction is separated from each other, and is located at a side The modified region of 1 column of surface side separated from the surface of a side, be cracked and reach etch protection layer from modified region of 1 column The state on surface, that is, the state that the cracking stretched from each modified region towards thickness direction is connected to each other." 2 tables are processed when contracting Face: HC " is that modified region adjacent to each other in a thickness direction is separated from each other, and is located at the modification of 1 column of the surface side of a side Region is separated from the surface of a side, is cracked and is reached the state on the surface of etch protection layer from modified region of 1 column, that is, from each The state that modified region is not connected by a part towards the cracking that thickness direction stretches.

" VL pattern finished surface: HC " is that modified region adjacent to each other in a thickness direction is connected to each other, and is located at one The modified region of 1 column of the surface side of side is separated from the surface of a side, is cracked and is reached etch protection layer from the modified region of 1 column Surface state." VL pattern finished surface: ablation " is that modified region adjacent to each other in a thickness direction is connected to each other, and The state on the surface of etch protection layer is exposed to positioned at the modified region of 1 column of the surface side of a side.

6th experiment the result is that as shown in figure 19.(a) of Figure 19 is the monocrystalline silicon substrate implemented after reactive ion etching Plate cross-section photograph (perpendicular to cutting preset lines section photo), (b) of Figure 19 be implement reactive ion etching it The photo of the section of monocrystalline silicon substrate afterwards.

The 6th experiment as a result, knowing following situation shown in Figure 19.That is, if cracking reaches the table of etch protection layer Face, then in the range of being cracked connect, dry-etching is from the surface side of a side along cracking selectively (that is, with high etching Speed ratio) it carries out, form the slot of the width narrow and deep (that is, slot aspect ratio is high) of opening.If from each modified region towards thickness side It is not connected to the cracking of stretching, extension, then dry-etching isotropically carry out in the not connected part of cracking (" 2 surfaces are processed when contracting: The photo on column (a) in HC ").

From experimental result relevant to above method for cutting processing target, it is known that following situation.That is, if with cracking From the surface (table to monocrystalline silicon substrate from the side in the case where the surface side of side implementation dry-etching for being located at a side Face) side 1 column modified region reach a side surface (be formed on the surface of a side of monocrystalline silicon substrate by SiO₂It constitutes Cracking reaches the surface of the etch protection layer in the case where etch protection layer) premised on, then in the range of being cracked connection, such as scheme Shown in 20, compared to using SF₆Reactive ion etching, use CF₄Reactive ion etching and use XeF₂Reaction Property gas etch can more ensure high etch rates ratio.Further more, if being formed on the surface of a side of monocrystalline silicon substrate by SiO₂Structure At etch protection layer, and be cracked and reach the surface of the etch protection layer from the modified region of 1 column of the surface side for being located at a side, Then etch-rate than tremendous improves.In addition, using CF if being conceived to slot aspect ratio₄Reactive ion etching it is special It is excellent.In addition, using XeF₂Reactant gas be etched in the strength reduction for preventing monocrystalline silicon substrate caused by plasma Aspect be advantageous.

It is illustrated for dry-etching along the principle that cracking selectively carries out.If making the laser L of impulse hunting Focal point P is located at the inside of workpiece 1, and relatively moves focal point P along cutting preset lines 5, then such as Figure 21 institute Show, forms the multiple modification luminous point 7a arranged along cutting preset lines 5 in the inside of workpiece 1.Along cutting preset lines 5 Multiple modification luminous point 7a of arrangement are equivalent to the modified region 7 of 1 column.

The modification area of the multiple row arranged on the thickness direction of workpiece 1 is formed in the inside of workpiece 1 In the case where domain 7, if (to implement across the 2nd interarea 1b for being located at workpiece 1 to workpiece 1 from the 2nd side interarea 1b The 2nd interarea 1b in the case where dry-etching) side 1 column modified region 7 and the 2nd interarea 1b between mode form cracking 31, then etching gas enters the cracking 31 (referring to the arrow of Figure 21) with the interval of number nm~several μm as capillary phenomenon. Thus, thus it is speculated that dry-etching is selectively carried out along cracking 31.

Therefore, if to form cracking across the mode between modified region 7 adjacent to each other in the modified region 7 of multiple row 31, then speculating makes dry-etching selectively carry out deeper.Further more, if with multiple across being arranged along cutting preset lines 5 Mode in modification luminous point 7a between modification luminous point 7a adjacent to each other forms cracking 31, then speculating makes dry-etching efficiency more It selectively carries out well.At this point, etching gas can be contacted with each modification luminous point 7a from surrounding, thus speculate that there are a several μm of left sides The modification luminous point 7a of right size is promptly removed.

In addition, so-called cracking 31 herein, the micro-crack that is included with each modification luminous point 7a, around each modification luminous point 7a The differences such as the micro-crack being randomly formed.So-called cracking 31 is along the thickness direction for being parallel to workpiece 1 and includes herein Cut off the cracking of the face stretching, extension of preset lines 5.In the case where monocrystalline silicon substrate is formed with so-called cracking 31 herein, pass through the tortoise The face (with the interval of several nm~several μm cracking face relative to each other) for splitting 31 formation becomes the face that monocrystalline silicon exposes.In addition, being formed Include polysilicon region, high dislocation density region etc. in the modification luminous point 7a of monocrystalline silicon substrate.

Then, it is illustrated for method for cutting processing target involved in an embodiment.In addition, Figure 22~Figure 31 Shown in each structure be schematical structure, aspect ratio of each structure etc. and actual difference.

Firstly, it is rapid as step 1, as shown in (a) of Figure 22, prepares that there is monocrystalline silicon substrate 11, is set to the 1st interarea 1a The workpiece 1 of the functional element layer 12 of side, and protective film 21 is attached to the 1st interarea 1a of workpiece 1.

After step 1 is rapid, as second step, as shown in (b) of Figure 22, by using the 2nd interarea 1b as laser light incident Laser L is irradiated in face of workpiece 1, forms multiple row in the inside of monocrystalline silicon substrate 11 respectively along multiple cutting preset lines 5 Modified region 7, and respectively along multiple cutting preset lines 5 workpiece 1 formed cracking 31.Respectively along multiple cuttings The modified region 7 for the multiple row that preset lines 5 are formed arranges on the thickness direction of workpiece 1.The modified region 7 of multiple row is distinguished It is made up of the multiple modification luminous point 7a arranged along cutting preset lines 5 (referring to Figure 21).Cracking 31 is across positioned at the 2nd interarea 1b Between the modified region 7 and the 2nd interarea 1b of 1 column of side, and at least across the multiple modification light for the modified region 7 for constituting 1 column (referring to Figure 21) between modification luminous point 7a adjacent to each other in point 7a.

However, reach the 2nd interarea 1b cracking 31 as described below between modified region 7 adjacent to each other in It is disconnected.That is, in second step, so that the non-polygonal area M that cracking 31 is not connected with is formed in the thickness direction in workpiece 1 The mode of specified position form the modified region 7 of multiple row.Non- polygonal area M is the single-crystal structural that modified region 7 is not formed Region, that is, be cracked 31 disconnecting region.Non- polygonal area M be cracking 31 stop towards thickness direction continuously into Capable region.Specified position is the depth location of preset desired (any).

In the example in the figures, the modified region 7 of multiple row includes that the central location of the thickness direction than workpiece 1 is Specified position is main closer to the 2nd closer to the modified region (the 1st modified region) 7 of the 1st side interarea 1a and than the specified position The modified region (the 2nd modified region) 7 of the face side 1b.In second step, in the inside of monocrystalline silicon substrate 11, so that main from the 1st The cracking 31 that the modified region 7 of the face side 1a extends is not connected not with the cracking 31 extended from the modified region 7 of the 2nd side interarea 1b The mode that polygonal area M is formed in the specified position forms the modified region 7 of multiple row.The formation sequence of the modified region 7 of multiple row It is not particularly limited, can be sequentially formed from the 1st side interarea 1a, can also be sequentially formed from the 2nd side interarea 1b.It can also be simultaneously Form at least part of the modified region 7 of multiple row.

Illustrate an example of the processing conditions in second step.When forming each modified region 7, impulse hunting wavelength 1064nm or more (is herein the laser L of 1342nm).The pulse width of laser L is set as 90ns, and frequency is set as 90kHz.Relative to Workpiece 1 makes the focal point P of laser L along cutting preset lines 5 with process velocity 340mm/s relative movement.Pass through 1 pulse Laser L irradiation and the modification luminous point that is formed between distance (processing spacing) be set as 3.78 μm.The energy of laser L is set as 4 μ J ~15 μ J.The width of modified region 7 on thickness direction is set as 20 μm~56 μm.So that the non-polygonal area M on thickness direction Width become monocrystalline silicon substrate 11 thickness 10%~30% mode, form each modified region 7.1st interarea 1a is set as (100) face.

After second step, as third step, as shown in (a) of Figure 23, to workpiece 1 from the 2nd side interarea 1b Implement dry-etching, thus as shown in (b) of Figure 23, forms slot in workpiece 1 respectively along multiple cutting preset lines 5 32。

Slot 32 is such as V slot (slot of section V-shaped) in the 2nd interarea 1b opening.Here, using XeF₂, to processing pair As object 1 implements dry-etching (that is, implementing to use XeF from the 2nd side interarea 1b₂Reactant gas etching).In addition, here, logical The modified region 7 for crossing 1 column in the modified region 7 by multiple row positioned at the 2nd side interarea 1b removes, can be in the inner face shape of slot 32 At in now correspond to be removed 1 column modified region 7 concaveconvex shape relief region 9 in a manner of, to workpiece 1 from Implement dry-etching in 2nd side interarea 1b.In addition, in the case where forming relief region 9, dry-etching also can be implemented until from Until the inner face of slot 32 completely removes modified region 7 (modification luminous point 7a).On the other hand, can not also to implement dry-etching straight Until relief region 9 completely removes.If cracking 31 reaches the 2nd interarea 1b, in the range of cracking 31 is connected, dry type erosion It carves and is selectively carried out from the 2nd interarea 1b along cracking 31, but the progress of the selectivity of dry-etching is interrupted not in cracking 31 Polygonal area M stops.In addition, the carry out speed reduction for carrying out stopping referring to dry-etching of the selectivity of so-called dry-etching.

In third step, from slot 32 reaches the 2nd side interarea 1b of non-polygonal area M until reaching non-polygonal area M The 1st side interarea 1a until between terminate dry-etching.In other words, it in third step, hops to it for non-polygonal area M Formula be etched to end until (before all non-polygonal area M are removed) between, terminate the dry-etching.In third step, In the bottom for being formed by the slot 32 close to the tortoise extended from the modified region 7 of the 1st side interarea 1a from reaching non-polygonal area M Before splitting 31, terminate dry-etching.In third step, the position for being formed in non-polygonal area M has the section V word of bending section The slot 32 of shape.

It is rapid as step 4 after third step, as shown in (a) of Figure 24, expanded film 22 is attached at processing object 2nd interarea 1b of object 1, and as shown in (b) of Figure 24, protective film 21 is removed from the 1st interarea 1a of workpiece 1.It connects , as shown in (a) of Figure 25, expand expanded film 22, thus respectively along multiple cutting preset lines 5 by workpiece 1 Multiple semiconductor chips 15 are cut to, and as shown in (b) of Figure 25, pick up semiconductor chip 15.

It is illustrated for the method for cutting processing target semiconductor chip 15 obtained more than passing through.Such as the 31st figure Shown, semiconductor chip 15 has: monocrystalline silicon substrate 110, be set to monocrystalline silicon substrate 110 the 1st surface side 110a function The etching of element layer 120, the 2nd surface 110b (surface with the 1st surface 110a opposite side) for being formed in monocrystalline silicon substrate 110 is protected Sheath 230.Monocrystalline silicon substrate 110 is from the part that the monocrystalline silicon substrate 11 of workpiece 1 is cut out.Functional element layer 120 is It from the part that the functional element layer 12 of workpiece 1 is cut out, and include 1 function element 12a.Etch protection layer 230 be from The part that etch protection layer 23 is cut out.

Monocrystalline silicon substrate 110 includes part 1 111x, part 2 (part) 112.Part 1 111x is the 1st surface The part of the side 110a.Part 2 112 is the part of the 2nd surface side 110b.Part 2 112 is in more to leave the 1st surface 110a then Thinner shape.Part 2 112, which corresponds in the monocrystalline silicon substrate 11 of workpiece 1, is formed with the part of slot 32 (that is, dry The part that formula etching carries out).As an example, part 1 111x be in quadrangle plate (rectangular-shape), part 2 112 in more from Open part 1 111x then thinner quadrangular pyramid mesa-shaped.

In the side 111a of part 1 111x, modified region 7 is formed with band-like.That is, modified region 7 is bounded on each side face 111a extends along the direction that each side 111a is directed parallel to the 1st surface 110a.Positioned at the modification area of the 1st surface side 110a Domain 7 is separated from the 1st surface 110a.Modified region 7 is made of multiple modification luminous point 7a (referring to Figure 21).Multiple modification luminous point 7a exist Each side 111a is arranged along the direction that each side 111a is directed parallel to the 1st surface 110a.Modified region 7 (it is more specific and Speech modifies luminous point 7a) comprising polysilicon region, high dislocation density region etc..

In the side 112a of part 2 112, relief region 9 is formed with band-like.That is, relief region 9 is bounded on each side face 112a extends along the direction that each side 112a is directed parallel to the 2nd surface 110b.Embossed area positioned at the 2nd surface side 110b Domain 9 is separated from the 2nd surface 110b.Relief region 9, which passes through, leads to the modified region 7 for being located at the 2nd side interarea 1b of workpiece 1 It crosses dry-etching removal and is formed.Therefore, relief region 9 is in the concaveconvex shape corresponding to modified region 7, in relief region 9, Monocrystalline silicon exposes.That is, the side 112a of part 2 112 includes the male and fomale(M&F) of relief region 9, become the face of monocrystalline silicon exposing.

In addition, semiconductor chip 15 may not possess etch protection layer 230.Such semiconductor chip 15 for example with The mode for being removed etch protection layer 23 obtains in the case where implementing dry-etching from the 2nd side interarea 1b.

In (a) of Figure 13, upper section is the photo of relief region 9, and lower section is the dashdotted relief region 9 along upper section Concave-convex profile.In (b) of Figure 13, upper section is the photo of modified region 7, and lower section is the dashdotted modification area along upper section The concave-convex profile in domain 7.If being compared to them, knows in relief region 9, have and be simply formed with biggish multiple recess portions Tendency, in contrast, having in modified region 7 and not only forming biggish multiple recess portions, and has been randomly formed biggish multiple convex The tendency in portion.In addition, (c) of Figure 13 be not to workpiece 1 from the 2nd side interarea 1b implement dry-etching and by processing object The photo of " modified region 7 positioned at the 2nd side interarea 1b " in the case where the cutting of object 1 and concave-convex profile.In the modification of the situation In region 7, also have and not only form biggish multiple recess portions, and is randomly formed and has the tendency that biggish multiple protrusions.I.e., it is known that Have the tendency that being simply formed with biggish multiple recess portions is removed due to by modified region 7 by dry-etching in relief region 9.

As discussed above, in method for cutting processing target, to the modified region 7 to be arranged across at least 1 Mode between the 2nd interarea 1b is formed with the workpiece 1 of cracking 31, implements dry-etching from the 2nd side interarea 1b.By This, dry-etching 31 is selectively carried out from the cracking of the 2nd interarea 1b lateral edge, the slot 32 for keeping the width of opening narrow and deep edge respectively The formation of multiple cutting preset lines 5.Here, it has been found that dry in the non-polygonal area M that the cracking 31 in workpiece 1 is not connected with Carrying out for formula etching is slower than the progress of the dry-etching along cracking 31.Therefore, by form non-tortoise in specified position The mode of split plot domain M forms modified region 7, in dry-etching later, non-polygonal area M can be made to play what etching stopped Function, and so that dry-etching delay in specified position.

Therefore, according to method for cutting processing target, the progress of etching can be controlled.Can arbitrary position reliably So that the selectivity of dry-etching stop, being able to carry out the etching cutting of high quality.Etching gas can be prevented around entering function It can element layer 12.Compared with the case where non-polygonal area M is not formed, it is able to suppress respectively along multiple cutting preset lines 5 Each depth of slot 32 generates uneven.

In method for cutting processing target, be formed with than specified position closer to the modified region 7 of the 1st side interarea 1a and Closer to the modified region 7 of the 2nd side interarea 1b.In second step, in the inside of monocrystalline silicon substrate 11, so that from the 1st interarea The cracking 31 that the modified region 7 of the side 1a the extends non-tortoise not connected with the cracking 31 extended from the modified region 7 of the 2nd side interarea 1b The mode that split plot domain M is formed in specified position forms modified region 7.According to this structure, it can be realized specific non-polygonal area The formation of M.

In method for cutting processing target, in second step, formed respectively along multiple cutting preset lines 5 arrangements Thus multiple modification luminous point 7a form the modified region 7 of at least 1 column respectively along multiple cutting preset lines 5, and multiple to cross over Mode in modification luminous point 7a between modification luminous point 7a adjacent to each other forms cracking 31.Thereby, it is possible to make dry-etching more Efficiency is good and selectively carries out.

In method for cutting processing target, in second step, in the 2nd main surface side for reaching non-polygonal area M from slot 32 1b, which rises between until the 1st main surface side 1a for reaching non-polygonal area M, terminates etching.Thereby, it is possible to terminate in specified position The progress (being set as the state that etching is not gone on) of dry-etching.

In method for cutting processing target, in second step, by implementing dry-etching, it is formed in non-polygonal area M Position have bending section section V-shaped slot 32.Thereby, it is possible to form the shape for corresponding to the position of non-polygonal area M Section V-shaped slot 32.By the section V-shaped, become easy segmentation caused by the expansion of expanded film 22, Neng Gougai It is apt to its segmentation rate.

Method for cutting processing target has: step 4 is rapid, and after third step, it is thin to attach expansion in the 2nd side interarea 1b Film 22 respectively along multiple cutting preset lines 5, workpiece 1 is cut to and multiple is partly led by expanding expanded film 22 Body chip 15.Thereby, it is possible to workpiece 1 is reliably cut to multiple semiconductors respectively along multiple cutting preset lines 5 Chip 15.Further more, multiple semiconductor chips 15 are separated from each other on expanded film 22, it is thus possible to make picking up for semiconductor chip 15 Take facilitation.

In addition, in the present embodiment, in second step, do not etch non-polygonal area M and along cutting preset lines 5 By workpiece 1 cut off in the case where, can also be cut off workpiece 1 a pair of of section in, a side's At least part of the non-polygonal area M of section is formed with protrusion, another party section non-polygonal area M at least A part is formed with the mode of the recess portion corresponding to protrusion, forms modified region 7.It is so-called do not etch non-polygonal area M and along The case where cutting preset lines 5 cut off workpiece 1 can enumerate such as in order to confirm quality and temporarily second step it Do not implement third step afterwards and implements the rapid situation of step 4.According to this structure, cracking can reliably be made not in non-polygonal area M Connection.The height of protrusion is also possible to 2 μm~6 μm, and the width of the protrusion on thickness direction is also possible to 6 μm~17 μm.Cutting Face 12c is also possible to (110) face, and the face for forming protrusion is also possible to (111) face.In addition, such recess portion or protrusion are passing through It can be observed as black line when optical microphotograph sem observation, thus referred to as black line.

More than, embodiment is illustrated, but one embodiment of the present invention is not limited to above embodiment.

In the above-described embodiment, has reflective spatial in the laser processing device for implementing method for cutting processing target In the case where the spatial light modulator of optical modulator etc., in second step, can also replace it is above-mentioned or further, by suitable When the modulation pattern of setting spatial light modulator, to make non-polygonal area M form modified region in such a way that specified position is formed 7。

For example, it is also possible to formed the 1st side interarea 1a modified region 7 after and formed the 2nd side interarea 1b modification area Before domain 7, the laser L that irradiation is modulated using modulation pattern below by spatial light modulator, to be formed not in specified position The mode of polygonal area M forms modified region 7 between the position of the 1st side interarea 1a and the position of the 2nd side interarea 1b.Modulation figure Case also may include quality pattern, individual difference amendment pattern, spherical aberration amendment pattern, astigmatism amendment pattern as element pattern Deng at least either.Modulation pattern also may include: quality pattern, have towards the direction intersected with cutting preset lines 5 The 1st luminance area that extends and on the extending direction of cutting preset lines 5 adjacent to the 2nd bright of the two sides of the 1st luminance area Spend region.

It, can also be in specified position shape in the inside of monocrystalline silicon substrate 11 in the second step of above embodiment What the modified region 7 of the cracking 31 that the modified region 7 of 1 side interarea 1a Cheng Cong extends and the 2nd side interarea 1b was not connected with is not cracked Region M or the modified region 7 of the cracking 31 and the 1st side interarea 1a that extend from the modified region 7 of the 2nd side interarea 1b are not connected Non- polygonal area M mode, form these modified regions 7.

In the above-described embodiment, as protective film 21, such as pressure-sensitive adhesive belt, UV with vacuum-resistant are able to use Adhesive tape etc..Replace protective film 21, the wafer stationary fixture with etching patience also can be used.

It in the above-described embodiment, can also be before implementing dry-etching, in the 2nd interarea 1b shape of workpiece 1 Etch protection layer of the gas by region is formed at respectively along multiple cutting preset lines 5.Via etch protection layer to adding In the case that work object 1 irradiates laser L, the material of etch protection layer needs to be the material for having permeability relative to laser L. As etch protection layer, such as SiO can be formed by being vaporized on the 2nd interarea 1b of workpiece 1₂Film, or can lead to The 2nd interarea 1b formation etchant resist or resin film that rotation is coated on workpiece 1 are crossed, or can also be by sheet-like member (transparent resin film etc.), back-protective adhesive tape (IRLC adhesive tape/WP adhesive tape) etc. are attached at the 2nd interarea 1b of workpiece 1. As gas by region, such as can be by irradiating laser L to workpiece 1 via etch protection layer, thus in monocrystalline The inside of silicon substrate 11 forms modified region 7 and so that cracking 31 is reached the surface of etch protection layer (with monocrystalline from the modified region 7 The outer surface of silicon substrate opposite side), alternatively, can also implement to pattern to etch protection layer, being consequently formed makes workpiece 1 The 2nd interarea 1b expose slit, alternatively, can also by irradiate laser L form modified region (comprising multiple micro-cracks Region, ablated area etc.).

In the above-described embodiment, cracking 31 is with the modified region 7 arranged across at least 1 and the 2nd interarea of workpiece 1 Mode between 1b is formed.That is, if cracking 31 be it is local, the 2nd interarea 1b can not also be reached.Further more, if Cracking 31 be it is local, then can also be not across between modification luminous point 7a adjacent to each other.Cracking 31 can reach or not Reach the 1st interarea 1a of workpiece 1.

In the above-described embodiment, dry-etching can also be to remove the modified region 7 of multiple row, thus in slot 32 Face forms the concaveconvex shape in the modified region 7 for the multiple row for now corresponding to be removed and makes the relief region 9 of monocrystalline silicon exposing Mode is implemented from the 2nd side interarea 1b.The type of dry-etching is not limited to using XeF₂Reactant gas etching.As dry type Etching, such as also can be implemented using CF₄Reactive ion etching, use SF₆Reactive ion etching.

It in the above-described embodiment, can also be so that the cross sectional shape of slot 32 becomes V word shown in such as (a) of Figure 26 and (b) The mode of shape implements dry-etching, or as Figure 27 (a) and (b) shown in, can also be so that the cross sectional shape of slot 32 becomes U-shaped The mode of shape implements dry-etching, or as Figure 28 (a) and (b) shown in, can also be so that the cross sectional shape of slot 32 becomes I word The mode of shape implements dry-etching

In the above-described embodiment, above-mentioned step 1 can also be replaced rapid and second step, implements step 1 as described below Rapid and second step.That is, it is rapid as step 1, as shown in (a) of Figure 29, prepare workpiece 1, and protective film 21 is attached In the 2nd interarea 1b of workpiece 1.After step 1 is rapid, as second step, by entering using the 1st interarea 1a as laser It penetrates and irradiates laser L in face of workpiece 1, formed respectively along multiple cutting preset lines 5 in the inside of monocrystalline silicon substrate 11 more The modified region 7 of column, and cracking 31 is formed in workpiece 1 respectively along multiple cutting preset lines 5.Then, such as Figure 29 (b) shown in, other protective film 21 is attached at the 1st interarea 1a, and by the protective film 21 previously attached from the 2nd interarea 1b removal.Later the step of, is identical as the later step of above-mentioned third step.

It in the above-described embodiment, is phase in the material of the protective film 21 for the 1st interarea 1a for being attached at workpiece 1 It, as shown in figure 31, can also be via protective film 21 to workpiece in the case where the material for laser L with permeability 1 irradiation laser L.

The explanation of symbol

1 ... workpiece, the 1st interarea of 1a ..., the 2nd interarea of 1b ..., 5 ... cutting preset lines, (the 1st changes 7 ... modified regions Matter region, the 2nd modified region), 7a ... modify luminous point, 11 ... monocrystalline silicon substrates, 12 ... functional element layers, 15 ... semiconductor cores Piece, 22 ... expanded films, 31 ... crackings, 32 ... slots, L ... laser, the non-polygonal area of M ....