阅读说明：本技术 一种化学机械抛光保持环和化学机械抛光承载头 (A kind of Retaining Ring in Chemical Mechanical Polishing Process and chemically mechanical polishing carrier head ) 是由 赵德文 刘远航 孟松林 于 2019-09-30 设计创作，主要内容包括：一种化学机械抛光保持环,包括环形主体,所述环形主体由环状的上部和下部组成,所述上部由金属制成,所述下部由塑料制成并且具有用作抛光液通道的凹槽,所述上部和下部通过结合层结合为一体,所述结合层含有吸波材料以防止保持环反射电磁波或产生电涡流。(A kind of Retaining Ring in Chemical Mechanical Polishing Process, including annular body, the annular body is made of cricoid upper and lower part, the top is made of metal, the lower part is made of plastics and has the groove as polishing fluid channel, the upper and lower part is combined as a whole by binder course, and the binder course contains absorbing material to prevent retaining ring reflection electromagnetic wave or generate current vortex.)

1. a kind of Retaining Ring in Chemical Mechanical Polishing Process, including annular body, the annular body is made of cricoid upper and lower part, The top is made of metal material, the lower part be made of plastics and have as polishing fluid channel groove, it is described on Portion and lower part are combined as a whole by binder course, and the binder course contains absorbing material to prevent retaining ring reflection electromagnetic wave or production Raw current vortex.

2. retaining ring as described in claim 1, which is characterized in that the absorbing material is magnetic medium type absorbing material, electricity Jie Matter type absorbing material and/or resistor-type absorbing material.

3. retaining ring as claimed in claim 2, which is characterized in that the absorbing material is ferrite micropowder and/or is coated with nickel- The graphene micro mist of phosphorus alloy.

4. retaining ring as claimed in claim 2, which is characterized in that the absorbing material accounts for the ratio of the binder course total weight It is 2% to 20%.

5. retaining ring according to any one of claims 1 to 4, which is characterized in that the lower surface on the top, which has, strengthens Engaging portion, the reinforcing engaging portion can be circular protrusion, annular recess, radial projection or radial groove.

6. retaining ring as claimed in claim 5, which is characterized in that it is described strengthen combine cross section can be rectangle, it is trapezoidal, Triangle, taper or semicircle.

7. retaining ring as claimed in claim 5, which is characterized in that the height for strengthening engaging portion is 0.1mm to 2mm.

8. retaining ring as claimed in claim 1 or 5, which is characterized in that the lower surface on the top of the retaining ring has through laser Roughening structure made of processing, sandblasting, shot-peening, grinding and/or machining.

9. retaining ring as claimed in claim 8, which is characterized in that the roughness Ra of the lower surface is 0.8 to 6.3.

10. a kind of chemically mechanical polishing carrier head, which is characterized in that the carrier head includes such as any one of claims 1 to 9 institute The retaining ring stated.

Technical field

The invention belongs to chemical Mechanical Polishing Technique field more particularly to a kind of Retaining Ring in Chemical Mechanical Polishing Process and chemical machine Tool polishes carrier head.

Background technique

Chemically mechanical polishing is a kind of mainstream substrate polishing method in chip manufacturing field.This polishing method usually will Substrate is pull-in on the lower part of carrier head, and substrate is connected on the polishing pad of rotation on one side with sedimentary, and carrier head is driving Under the drive of component with polishing pad rotating Vortex and give substrate downward load；Meanwhile polishing fluid is supplied in the upper of polishing pad Surface is simultaneously distributed between substrate and polishing pad, so that substrate completes global polishing under chemistry and mechanical comprehensive function.

Carrier head is the important component of chemical mechanical polishing apparatus, and transaction capabilities are directly related to the chemistry of substrate Mechanically polish effect.United States Patent (USP) US20130065495A1 discloses a kind of carrier head comprising carrier and flexible membrane, it is soft Property film is removably disposed in the lower part of carrier；Carrier includes first part and second part, and first part is movably It is arranged concentrically in the upper grooves of second part and makes first part and second part each other can be along perpendicular to carrier The direction of bottom surface moves.Second part lower part be equipped with flexible membrane to be formed between second part and flexible membrane multiple air cavitys with Pressure by adjusting each independent air realizes the adjusting to substrate pressure outline.In the prior art, outside air is via The stomata of a part of upper surface enter the channel inside first part and from first part's side wall stomata outflow, then via Tracheae is delivered to the stomata of the upper surface for the second part being connected to respectively with independent air.

The lower part of carrier head is provided with retaining ring, plays a significant role in the chemically mechanical polishing of substrate.On the one hand, It can prevent the substrate of polishing process from slipping or flying out from the bottom of carrier head；On the other hand, the bottom of retaining ring is provided with Groove can provide fluid channel to update the polishing fluid between substrate and polishing pad；Furthermore retaining ring presses on polishing pad The adjustment for participating in substrate edges pressure, is advantageously implemented the global planarizartion of substrate and improves the consistency of planarization.

In CMP process, in order to adjust material removal rate in real time, on-line measurement material to be removed is needed The thickness of layer, when material to be removed is metal, current vortex film thickness measuring method is relatively applicable in.Existing current vortex film thickness measuring Device generates alternating electromagnetism field signal by signal generator, makes to form current vortex in the metal film of substrate, be examined by sensor The inductance variable signal as caused by the current vortex in the metal film is surveyed, and thereby determines that the thickness of metal film.

The detection accuracy of chemically mechanical polishing end point determination requires the continuous diminution with feature structural dimension parameter and improves, by In including metal parts or metal material in the components such as traditional retaining ring of chemically mechanical polishing carrier head, in current vortex film thickness Also current vortex can be generated in metal parts described in measurement, thus the letter generated by metallicity structure that can be obtained to sensor It number interferes, influences the precision of end point determination.Accordingly, it is desirable to be able to measuring the metal structure characteristic thickness of substrate to judge Guarantee that the metal structure of carrier head interferes the measuring signal as little as possible when chemically-mechanicapolish polishing emphasis.

Summary of the invention

The present invention provides a kind of Retaining Ring in Chemical Mechanical Polishing Process and chemically mechanical polishing carrier head, it is intended to a certain extent One of above-mentioned technical problem is solved, its technical solution is as follows:

A kind of Retaining Ring in Chemical Mechanical Polishing Process, including annular body, the annular body is by cricoid upper and lower part group At the top is made of metal material, and the lower part is made of plastics and has the groove as polishing fluid channel, described Upper and lower part is combined as a whole by binder course, the binder course contain absorbing material with prevent retaining ring reflection electromagnetic wave or Generate current vortex；

In above scheme, the absorbing material is magnetic medium type absorbing material, dielectric type absorbing material and/or resistor-type Absorbing material；

Further, the absorbing material is ferrite micropowder and/or the graphene micro mist for being coated with nickel-phosphor alloy.

Further, it is 2% to 20% that the absorbing material, which accounts for the ratio of the binder course total weight,；

In above scheme, the lower surface on the top, which has, strengthens engaging portion, the reinforcing engaging portion can be circular protrusion, Annular recess, radial projection or radial groove；

Further, described strengthen combines cross section to can be rectangle, trapezoidal, triangle, taper or semicircle；

Further, the height for strengthening engaging portion is 0.1mm to 2mm.

Further, the lower surface on the top of the retaining ring has through laser treatment, sandblasting, shot-peening, grinding and/or cutting Roughening structure made of processing；

Further, the roughness Ra of the lower surface is 0.8 to 6.3.

In addition, the carrier head includes any of the above-described kind of basis the invention also provides a kind of chemically mechanical polishing carrier head Retaining ring of the invention.

Existing beneficial effect includes: to reduce to survey in current vortex metal film thickness to the embodiment of the present invention compared with prior art During amount retaining ring generate current vortex to detection electromagnetic wave interference, improve detection accuracy.

Detailed description of the invention

It will be apparent and be easier to understand by made detailed description, advantages of the present invention in conjunction with the following drawings, But these attached drawings are only schematical, are not intended to limit protection scope of the present invention, in which:

Fig. 1 it is non-limiting show the organigram of typical chemically mechanical polishing unit；

The schematic diagram of Fig. 2 non-limiting structure for showing chemically mechanical polishing carrier head according to the present invention；

The signal of the structure of Fig. 3 non-limiting retaining ring for showing chemically mechanical polishing carrier head according to the present invention Figure；

The metal part of Fig. 4 non-limiting retaining ring for showing chemically mechanical polishing carrier head is to chemically mechanical polishing The influence of endpoint detection；

The binder course of Fig. 5 non-limiting retaining ring for enlargedly showing chemically mechanical polishing carrier head according to the present invention A kind of structure；

Fig. 6 it is non-limiting show the combination of the Retaining Ring in Chemical Mechanical Polishing Process according to the present invention with spacer structure Layer；

The part of Fig. 7 non-limiting upper metal structures for showing Retaining Ring in Chemical Mechanical Polishing Process according to the present invention Surface is coated with the structure of metal microwave absorbing coating；

The metal structure of Fig. 8 non-limiting variant for showing Retaining Ring in Chemical Mechanical Polishing Process according to the present invention it is complete Portion surface is coated with the structure of microwave absorbing coating；

Fig. 9 A and Fig. 9 B are respectively illustrated using current vortex when the retaining ring without containing absorbing material and containing absorbing material The comparison of the feature structure thickness for the substrate that measuring device and four-probe arrangement measurement obtain.

Specific embodiment

Combined with specific embodiments below and its attached drawing, technical solution of the present invention is described in detail.It records herein Embodiment be specific specific embodiment of the invention, for illustrating design of the invention；These explanations are explanatory With it is illustrative, should not be construed as the limitation to embodiment of the present invention and the scope of the present invention.Except the implementation recorded herein Exception, those skilled in the art can also be based on the claim of this application books and its specification disclosure of that using aobvious and easy The other technical solutions seen, these technical solutions include any obviously replacing using to making for the embodiment recorded herein The technical solution changed and modified.In order to illustrate technical solutions according to the invention, the following is a description of specific embodiments.

Fig. 1 is the stereoscopic schematic diagram for polishing the basic structure construction of unit 2A, and polishing unit 2A includes polishing disk 10, polishing Pad 20, substrate bearing device 30, trimming device 40 and polishing liquid supply unit 50；Polishing pad 20 is set to table on polishing disk 10 Face is simultaneously therewith synchronized along axis Ax1 rotation；Horizontally movable substrate bearing device 30 is set to 20 top of polishing pad, The lower surface sticking of the carrier head coupled has polished substrate W；Trimming device 40 includes conditioning arm 41 and finishing head 42, is repaired Whole arm 41 drives the finishing head 42 of rotation to swing to modify 20 surface of polishing pad and reach the Optimal State for being suitable for polishing；Polishing Polishing fluid is interspersed among the upper surface of polishing pad 20 by liquid supply unit 50；When carrying out chemically mechanical polishing operation, base plate carrying dress 30 upper surfaces that the polished face of substrate W is compressed to polishing pad 20 are set, polishing fluid distribution is between polishing pad 20 and substrate W, In The removal of completing substrate material under the action of chemistry and machinery.Substrate bearing device 30 includes carrier head 31 and top Pneumatic assembly 32 (UPA, Upper Pneumatic Assembly), carrier head 31 is coupled to pneumatic group of top by unshowned connection component Part 32.

Fig. 2 is the external structure schematic diagram of the carrier head 31 of substrate bearing device 30, and 31 bottom of carrier head, which is provided with, to be used for It is attracted and/or loads the flexible membrane 314 of substrate W and be coaxially disposed with the flexible membrane and positioned at its periphery for keeping limiting Determine the retaining ring 312 that substrate W does not skid off carrier head 31, wherein in the outer circumferential walls of flexible membrane 314 and the circumference of retaining ring 312 There is certain interval between wall.Fig. 3 individually illustrates the structure of Retaining Ring in Chemical Mechanical Polishing Process according to the present invention, from Fig. 2 It include top 3121, lower part 3123 and intermediate binder course with can be seen that retaining ring 312 in Fig. 3.

Fig. 4 is the partial sectional view with the carrier head 31 of retaining ring 312, and carrier head 31 includes carrier 313, flexible membrane 314, cyclic annular platen 315 and retaining ring 312, retaining ring 312 generally have metallic framework or metal architecture structure；Insertion setting exists Eddy current detection device 203 between polishing disk 10 and polishing pad 20 can be to the direction substrate W transmitting electromagnetic wave to measure substrate table The thickness of area structure character layer to capture polishing end point, the metallic framework or metal architecture of retaining ring 312 can generate current vortex and Reflection of electromagnetic wave in turn impacts the signal measurement precision of eddy current detection device 203, especially to close to the edge substrate W The polishing end point detection at place significantly affects, for this purpose, joined suction wave in the binder course 3122 of retaining ring 312 in the present embodiment Material is to reduce influence of the metal part of retaining ring to measurement electromagnetic wave.

Fig. 5 is the partial enlarged view that loop section is kept in Fig. 4, and wherein the annular body of retaining ring 312 includes the upper of annular Portion 3121 and lower part 3123, top 3121 can be made of metal materials such as stainless steel, titanium alloy or aluminium alloys, lower part 3123 It can be made of hard engineering plastic such as PPS, PEEK, polycarbonate, polyurethane, polyurethane or PET；3121 He of top The binder course 3122 that lower part 3123 passes through coaxially is combined as a whole, and the thickness of the binder course 3122 can be uniformly.In In some embodiments, lead to it since retaining ring 312 will receive the effect of shearing force in chemically mechanical polishing operation process Top 3121 and lower part 3123 are partly or entirely detached from, in order to increase retaining ring 312 upper and lower part bond strength, top 3121 lower surface may be provided with the reinforcing engaging portion (not shown) for reinforcing combining, which can be cyclic annular prominent It rises, at least one of annular recess, radial projection, radial groove, the lower surface on the top 3121 of retaining ring 312 or strengthens knot The surface in conjunction portion can carry out roughening processing to enhance the bond strength of itself and binder course 3122, to enhance top 3121 and lower part 3123 bond strength；Further, rubber polishing, Laser Surface Treatment, shot-peening, sandblasting and/or plasma spraying can be passed through The rugosity Ra of the bottom surface on top 3121 controlled between 0.8 to 6.3 etc. some column methods, be preferably controlled in 1.6 or 3.2 (point Dui Ying 7 grades and 6 grades of surface smoothnesses), it should be noted that excessive roughening may cause binder course just admittedly the time extend and/ Or the bottom surface on the top 3121 cannot be formed the binder of binder course 3122 and sufficiently infiltrate to reducing asking for bond strength Topic.

Similar, it can also refer to be handled using upper surface of the above method to lower part 3123 to increase it and combine by force Degree, at this point, the cross section of the circular protrusion, annular recess, radial projection, radial groove can be rectangle, trapezoidal, triangle Shape, taper, semicircle and/or any other regular shape or irregular shape, and the circular protrusion, annular recess, Radial projection, the height of radial groove and/or depth are 0.1mm to 2mm, preferably 0.3mm to 1mm, " height " herein and " depth " refers to the distance between lowest part and highest point of these protrusions or groove.

As shown in fig. 6, in some embodiments, spacer structure 3124 is provided in binder course 3122, binder course 3122 can It is formed by curing by such as epoxy resin adhesive, in its solidification process, because of the presence of spacer structure 3124, retaining ring top The distance between 3121 and lower part 3123 can maintain some definite value, so that it is guaranteed that 3122 thickness of binder course is uniform.Further, Spacer structure 3124 also has absorbing property, and its absorbing property is preferably close with the unit absorbing property of binder course 3122, Such as the carbon fiber skeleton of the spacer structure 3124 micro- coating of graphene that can be coated with nickel-phosphor alloy by such as surface is made, and And 3124 thickness of spacer structure in 0.2mm between 2mm, preferably 0.3 to 1mm.Spacer structure 3124 can be formed as ring Shape structure, block structure etc. can arbitrarily play a supporting role with formed certain thickness binder course 3122 and with binder course 3122 The structure of microwave absorbing property having the same.It should be noted that although the weight accounting of the absorbing material can be because of binder course 3122 thickness and change, and may change with concrete technology demand, it is however generally that, it is total that absorbing material accounts for binder course 3122 The 2 to 20% of quality, preferably 6% to 18%.

In some embodiments of the invention, wave is inhaled containing magnetic medium type absorbing material, dielectric type in binder course 3122 At least one of material and resistor-type absorbing material.Preferably, using having ferrite micropowder and/or be coated with nickel-phosphor alloy Graphene micro mist is as the absorbing material in binder course 3122.As shown in fig. 7, in some embodiments of the invention, retaining ring Wave coating 3121A is inhaled in the bottom surface on top 3121 and side setting, alternatively, can be only in the medial surface of retaining ring 312 and bottom surface shape Wave coating 3121A is inhaled at having.Preferably, nickel-phosphor-graphene coating, which can be used, as wave coating 3121A, the coating is inhaled not only has Excellent electromagnetic wave absorption performance also has stronger corrosion resistance, abrasion resistance and hardness.

As shown in figure 8, being another embodiment of retaining ring of the present invention, wherein retaining ring 312 is by cricoid metal inside 3125 and clad 3127 form, wherein inner core 3125 is made of metal materials such as stainless steel, titanium alloy or aluminium alloys, packet Coating 3127 is made of hard engineering plastic such as PPS, PEEK, polycarbonate, polyurethane, polyurethane or PET.One In a little embodiments, 3125 surface of inner core, which is coated with, inhales wave coating 3125A；Preferably, nickel-phosphor-graphene coating can be used as suction Wave coating 3125A.Alternatively, 3125 surface of inner core can be coated with one layer and have the nonmetallic coating for inhaling wave energy or pass through heat The mode of injection molding is formed with one layer of nonmetallic absorbent structure, and in order to enable this layer of nonmetallic absorbent structure and 3125 knot of inner core Fastening is closed, can be arranged on the surface inner core 3125A and be similar to the above-mentioned reinforcing engaging portion for reinforcing combining, it is then non-at this again The sacrifice plastic construction for chemically mechanical polishing is formed outside metal absorbent structure, which can be with chemical machine Tool polishing operation and be lost.Reinforcing engaging portion described herein can also be circular protrusion, annular recess, radial projection, radial direction At least one of groove；Further, rubber polishing, Laser Surface Treatment sandblasting, plasma spraying and/or shot-peening can be passed through The methods of the surface roughness Ra of inner core 3125A is controlled between 0.8 to 6.3, be preferably controlled to 1.6 or 3.2 and (respectively correspond 7 grades and 6 grades of surface smoothnesses), it should be noted that excessively time extension and/or the bottom are consolidated in roughening at the beginning of may cause binder course Face cannot sufficiently be infiltrated the phenomenon that reducing bond strength by binder；The circular protrusion, annular recess, radial projection, The cross section of radial groove can be rectangle, trapezoidal, triangle, taper, semicircle and/or any other regular shape or not Regular shape, and the height of the circular protrusion, annular recess, radial projection, radial groove and/or depth be 0.1 to 5mm, preferably 1.5 to 3mm.

Further, absorbing material can be divided by technique:

1. applying (plating) stratotype: powder hybrid adhesive is solidificated in workpiece surface, or forms coating in workpiece surface, uses the longevity Life length；

2. structural type: while there is carrying and inhale the dual function of wave, it may be molded to various complicated shapes；

3. patch-type: versatility is good, easy to use；

The structure and use environment of retaining ring determine that patch-type is difficult to apply, and only consider first two form.

Further, absorbing material presses loss mechanism:

1. conduction loss type

2. dielectric loss type

3. magnetic loss type

Ferrite wave-absorbing material has above-mentioned 2 simultaneously, the characteristic of 3 two kind of material；In low-frequency range, mainly by hysteresis effect, The loss of eddy current effect and magnetic aftereffect causes the loss to electromagnetic wave；In high band, ferrite mainly carrys out the loss of electromagnetic wave Derived from natural resonance loss, domain wall resonance loss and dielectric loss, have the advantage that absorption frequency range is wide, absorptivity is high, cost It is cheap, preparation process is simple, matching thickness is thin, therefore pay the utmost attention to ferrite wave-absorbing material.

On the other hand, ferrite wave-absorbing material has the disadvantages that density is big, corrosion resistance is not good enough, cannot function as coating. Retaining ring needs certain corrosion resistance due to contacting polishing fluid, and clast pollutes wafer in order to prevent, to parts surface hardness and Wearability also there are certain requirements, in summary situation, be considered as the new material of graphite-like, as carbon fibre material or surface are coated with The grapheme material of nickel-phosphorus alloy.Carbon fibre material can be used as structural member, be applied to various positions；Nickel-phosphor-graphene coating With outstanding absorbing property, while there are also stronger wearability, corrosion resistance and hardness, and the combination of matrix are also more preferable.

The improvement of metal film thickness measurement accuracy is made in order to verify the retaining ring 312 of the binder course 3122 containing absorbing material With being respectively adopted in the retaining ring without absorbing material in the prior art and the present invention has the retaining ring of absorbing material to carry out to according to the facts It tests, as shown in fig. 9 a and fig. 9b, in figure 9 a, solid line is the environmental protection for being equipped with binder course 3122 and being free of absorbing material to experimental result When the carrier head held carries out the chemically mechanical polishing of 300mm substrate, surveyed online using metal film thickness of the electric vortex method to substrate The film thickness pattern measured, dotted line are the results for carrying out offline film thickness measuring to same substrate using four probe method；Due to There is no the interference of chemical-mechanical polisher when off-line measurement, result is more accurate, more credible than on-line measurement, can be used as ginseng Consider value.As can be seen that measurement error is more significant in the edge ± 150mm.

As control, in figures 9 b and 9, solid line is the carrier head for being equipped with ring of the binder course 3122 containing absorbing material and keeping The film thickness that on-line measurement obtains is carried out using metal film thickness of the electric vortex method to substrate when carrying out the chemically mechanical polishing of 300mm substrate Pattern, dotted line are the results for carrying out offline film thickness measuring to same substrate using four probe method.As can be seen that with existing skill Art is compared, and the measurement error of substrate edge part is obviously reduced.

In the above-described embodiments, it all emphasizes particularly on different fields to the description of each embodiment, each embodiment can combine in any combination The new embodiment formed afterwards is also within the scope of protection of this application.There is no the part for being described in detail or recording in some embodiment, It may refer to the associated description of other embodiments.

Embodiment described above is merely illustrative of the technical solution of the present invention, rather than its limitations；Although referring to aforementioned reality Applying example, invention is explained in detail, those skilled in the art should understand that: it still can be to aforementioned each Technical solution documented by embodiment is modified or equivalent replacement of some of the technical features；And these are modified Or replacement, the spirit and scope for technical solution of various embodiments of the present invention that it does not separate the essence of the corresponding technical solution should all It is included within protection scope of the present invention.