阅读说明：本技术 浸没装置上孔洞堵塞的检测方法 (Method for detecting blockage of holes in immersion device ) 是由 林辉 吴长明 葛斌 高中原 于 2021-06-17 设计创作，主要内容包括：本申请公开了一种浸没装置上孔洞堵塞的检测方法,涉及半导体制造领域。该浸没装置上孔洞堵塞的检测方法包括获取N片涂布有光刻胶的硅片；利用表面扫描装置扫描N片硅片,获取N片硅片对应的初始缺陷图；针对N片硅片,令浸没装置相对硅片按预定方向遍历硅片的四个象限；利用表面扫描装置扫描N片硅片,获取N片硅片对应的浸没缺陷图；根据初始缺陷图和浸没缺陷图,检测浸没装置上的孔洞是否存在堵塞；解决了目前对浸没装置进行堵塞检测耗费大量人力和时间的问题；达到了快速检测浸没装置的孔洞是否发生堵塞,降低检测成本的效果。(The application discloses a method for detecting blockage of a hole in an immersion device, and relates to the field of semiconductor manufacturing. The method for detecting the blockage of the hole in the immersion device comprises the steps of obtaining N silicon wafers coated with photoresist; scanning N silicon wafers by using a surface scanning device to obtain initial defect maps corresponding to the N silicon wafers; aiming at N silicon wafers, the immersion device traverses four quadrants of the silicon wafers relative to the silicon wafers in a preset direction; scanning N silicon wafers by using a surface scanning device to obtain immersion defect maps corresponding to the N silicon wafers; detecting whether the holes on the immersion device are blocked or not according to the initial defect map and the immersion defect map; the problem that a large amount of labor and time are consumed for detecting the blockage of the immersion device at present is solved; whether the hole of short-term test submergence device takes place to block up has been reached, reduces the effect that detects the cost.)

1. A method of detecting plugging of a hole in an immersion device, the method comprising:

obtaining N silicon wafers coated with photoresist, wherein N is a positive integer;

scanning the N silicon wafers by using a surface scanning device to obtain initial defect maps corresponding to the N silicon wafers;

aiming at the N silicon wafers, enabling an immersion device to traverse four quadrants of the silicon wafers relative to the silicon wafers in a preset direction;

scanning the N silicon wafers by using the surface scanning device to obtain immersion defect maps corresponding to the N silicon wafers;

and detecting whether the holes on the immersion device are blocked or not according to the initial defect map and the immersion defect map.

2. The method of claim 1, wherein the detecting whether the holes on the immersion device are blocked according to the initial defect map and the immersion defect map comprises:

obtaining a defect comparison diagram according to the initial defect diagram and the immersion defect diagram;

detecting whether the defect comparison graph has track defects or not;

if the defect comparison graph is detected to have track defects, determining that holes in the immersion device are blocked;

and if the defect comparison graph is detected to have no track defect, determining that the hole on the immersion device is not blocked.

3. The method according to claim 1 or 2, characterized in that the method further comprises:

when the holes on the immersion device are detected to be blocked, determining the positions of the blocked holes according to a defect comparison graph; the defect comparison map is obtained from the initial defect map and the immersion defect map.

4. The method according to any one of claims 1 to 3, wherein for the N silicon wafers, the immersion device traverses four quadrants of the silicon wafer in a predetermined direction relative to the silicon wafer;

fixing the immersion device aiming at N/2 silicon wafers, driving the silicon wafers to move through the silicon wafer bearing device, and enabling the immersion device to traverse four quadrants of the silicon wafers in a clockwise direction and stay for a preset time in each quadrant; n is a positive even number;

and fixing the immersion device aiming at the rest N/2 silicon wafers, driving the silicon wafers to move through the silicon wafer bearing device, and enabling the immersion device to traverse four quadrants of the silicon wafers in an anticlockwise direction and stay for a preset time in each quadrant.

5. The method of claim 1 or 4, wherein N-10.

6. The method of claim 4, wherein the predetermined time is 30 s.

7. The method of claim 2, wherein said deriving a defect comparison map from said initial defect map and said immersion defect map comprises:

and comparing the defects on the initial defect map with the defects on the immersed defect map to obtain a defect comparison map.

8. The method of any one of claims 1 to 7, wherein the hole is at least one of a void water outlet, a gas knife hole, an outside water outlet.

Technical Field

The application relates to the field of semiconductor manufacturing, in particular to a method for detecting blockage of a hole in an immersion device.

Background

Photolithography is a critical process in the semiconductor manufacturing process, and in the submicron process era, the minimum line width is already smaller than the wavelength of an exposure light source, and the photolithography process is more and more complex with the reduction of the line width. Since the conventional lithography machines cannot meet the requirements for the fabrication of small line width devices, immersion lithography techniques have been introduced. Immersion lithography is the replacement of air with water between the projection lens and the silicon wafer, using the greater refractive index of water to increase resolution.

In the immersion lithography process, a layer of liquid is fixed between the projection lens and the silicon wafer, so that exposure light is emitted from the lens to the liquid and finally reaches the surface of the silicon wafer. In order to ensure that a layer of liquid is always between the projection lens and the silicon wafer, an immersion device is arranged between the projection lens and the silicon wafer. As shown in fig. 1, the immersion device 11 is provided with a plurality of gap water outlets (12), gas knife holes (13), and outer water outlets (14), and the liquid maintained by the immersion device is mainly pumped out through the gap water outlets (12) to form CO through the gas knife holes (13)₂The gas knife prevents the flow of water, draws excess water through the outboard water outlet 14 and prevents CO₂And (4) leakage.

If the gap water outlet, the air knife hole and the outer side water outlet on the immersion device are blocked, redundant water possibly remains on the surface of the silicon wafer, and then the water stain defect is caused. Since the gap water outlet, the air knife hole and the outer side water outlet are all micron-level cavities, whether the immersion device is blocked or not can be detected only by a microscope at regular intervals at present, each detection consumes a large amount of time, and particles in the environment can be introduced.

Disclosure of Invention

In order to solve the problems in the related art, the application provides a method for detecting the blockage of a hole on an immersion device. The technical scheme is as follows:

in one aspect, an embodiment of the present application provides a method for detecting blockage of a hole in an immersion device, where the method includes:

obtaining N silicon wafers coated with photoresist, wherein N is a positive integer;

scanning N silicon wafers by using a surface scanning device to obtain initial defect maps corresponding to the N silicon wafers;

aiming at N silicon wafers, the immersion device traverses four quadrants of the silicon wafers relative to the silicon wafers in a preset direction;

scanning N silicon wafers by using a surface scanning device to obtain immersion defect maps corresponding to the N silicon wafers;

and detecting whether the holes on the immersion device are blocked or not according to the initial defect map and the immersion defect map.

Optionally, detecting whether a hole on the immersion device is blocked according to the initial defect map and the immersion defect map includes:

obtaining a defect comparison diagram according to the initial defect diagram and the immersion defect diagram;

detecting whether the defect comparison graph has track defects or not;

if the defect comparison graph is detected to have the track defect, determining that the hole on the immersion device is blocked;

and if the defect comparison graph is detected to have no track defect, determining that the hole on the immersion device is not blocked.

Optionally, the method further includes:

when the blockage of the holes on the immersion device is detected, determining the positions of the blocked holes according to the defect comparison graph; the defect comparison map is obtained from the initial defect map and the immersion defect map.

Optionally, for N silicon wafers, traversing four quadrants of the silicon wafer by the immersion device relative to the silicon wafer in a predetermined direction;

fixing an immersion device aiming at N/2 silicon wafers, driving the silicon wafers to move through a silicon wafer bearing device, and enabling the immersion device to traverse four quadrants of the silicon wafers in a clockwise direction and stay for a preset time in each quadrant; n is a positive even number;

and fixing the immersion device aiming at the rest N/2 silicon wafers, driving the silicon wafers to move through the silicon wafer bearing device, and enabling the immersion device to traverse four quadrants of the silicon wafers in an anticlockwise direction and stay for a preset time in each quadrant.

Optionally, N ═ 10.

Alternatively, the predetermined time is 30 s.

Optionally, obtaining a defect comparison map according to the initial defect map and the immersed defect map, including:

and comparing the defects on the initial defect map with the defects on the immersed defect map to obtain a defect comparison map.

Optionally, the hole is at least one of a gap water outlet, an air knife hole and an outer side water outlet.

The technical scheme at least comprises the following advantages:

scanning N silicon wafers coated with photoresist by using a surface scanning device to obtain initial defect maps corresponding to the N silicon wafers; aiming at N silicon wafers, enabling an immersion device to traverse four quadrants relative to the silicon wafers in a preset direction, scanning the N silicon wafers by using a surface scanning device, obtaining immersion defect maps corresponding to the N devices, and detecting whether holes in the immersion device are blocked or not according to the initial defect map and the immersion defect maps; the problem that a large amount of labor and time are consumed for detecting the blockage of the immersion device at present is solved; whether the hole of short-term test submergence device takes place to block up has been reached, reduces the effect that detects the cost.

Drawings

In order to more clearly illustrate the detailed description of the present application or the technical solutions in the prior art, the drawings needed to be used in the detailed description of the present application or the prior art description will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a partial schematic view of an immersion apparatus in operation;

FIG. 2 is a method for detecting clogging of a hole in an immersion device according to an embodiment of the present disclosure;

FIG. 3 is a schematic diagram of an immersion apparatus traversing quadrants of a silicon wafer relative to the wafer according to an embodiment of the present application;

FIG. 4 is a schematic view of another immersion apparatus according to an embodiment of the present disclosure traversing quadrants of a wafer relative to the wafer;

FIG. 5 is a schematic diagram of a track defect provided by an embodiment of the present application;

fig. 6 is a schematic diagram of coordinates of a blocking hole on a positioning immersion device according to an embodiment of the present disclosure.

Detailed Description

The technical solutions in the present application will be described clearly and completely with reference to the accompanying drawings, and it is obvious that the described embodiments are some, but not all embodiments of the present application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; the connection can be mechanical connection or electrical connection; the two elements may be directly connected or indirectly connected through an intermediate medium, or may be communicated with each other inside the two elements, or may be wirelessly connected or wired connected. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

In addition, the technical features mentioned in the different embodiments of the present application described below may be combined with each other as long as they do not conflict with each other.

Referring to fig. 2, a flow chart of a method for detecting a hole blockage on an immersion device according to an embodiment of the present application is shown, the method at least includes the following steps:

in step 101, N silicon wafers coated with photoresist are obtained.

N is a positive integer.

And obtaining N silicon wafers with the same specification, and coating photoresist on the surfaces of the silicon wafers.

In step 102, scanning the N silicon wafers by using the surface scanning device to obtain initial defect maps corresponding to the N silicon wafers.

Before the silicon wafer is subjected to immersion lithography, photoresist needs to be coated on the surface of the silicon wafer, defects may exist on the surface of the silicon wafer after the photoresist is coated, and the defect condition of the silicon wafer after the photoresist is coated is obtained by scanning the silicon wafer through a surface scan tool.

And aiming at each silicon wafer in the N silicon wafers, scanning by using a surface scanning device to obtain an initial defect map corresponding to each silicon wafer.

The initial defect map is used for describing the defect condition of the silicon wafer after gluing.

In step 103, for N silicon wafers, the immersion device is made to traverse four quadrants of the silicon wafer in a predetermined direction with respect to the silicon wafer.

And aiming at each silicon wafer in the N silicon wafers, taking a certain quadrant as a traversal starting point, and enabling the immersion device to traverse four quadrants of the silicon wafer relative to the silicon wafer in a preset direction.

In one example, if the predetermined direction is clockwise and the second quadrant is set as the traversal starting point, the traversal order of the immersion device with respect to the silicon wafer is: the second quadrant, the first quadrant, the fourth quadrant and the third quadrant of the silicon chip.

In another example, if the predetermined direction is counterclockwise and the second quadrant is set as the traversal starting point, the traversal order of the immersion device with respect to the wafer is: the second quadrant, the third quadrant, the fourth quadrant and the first quadrant of the silicon chip.

Optionally, the traversal orders corresponding to the N silicon wafers are the same, or the traversal orders corresponding to some of the N silicon wafers are different, and the traversal orders corresponding to some of the silicon wafers are the same.

In step 104, scanning the N silicon wafers by using a surface scanning device to obtain an immersion defect map corresponding to the N silicon wafers.

And after traversing the surfaces of the silicon wafers by using the immersion device, scanning the N silicon wafers by using the surface scanning device again to obtain immersion defect maps corresponding to the N silicon wafers.

Each silicon wafer corresponds to one immersion defect map.

The immersion defect map is used for describing the defect condition of the silicon wafer coated with the photoresist after the silicon wafer is traversed by the immersion device.

It should be noted that the immersion devices traversing the N silicon wafers are the same immersion device.

In step 105, whether the holes on the immersion device are blocked or not is detected according to the initial defect map and the immersion defect map.

Each silicon wafer corresponds to an initial defect map and an immersion defect map.

If the hole on the immersion device is blocked, the difference exists between the initial defect image and the immersion defect image; if the holes on the immersion device are not blocked, the initial defect map and the immersion device map have no difference.

Detecting whether the initial defect map and the immersion defect map have difference or not aiming at each silicon chip; if the difference between the initial defect map and the immersion defect map is detected, indicating that the hole on the immersion device is blocked; and if no difference exists between the initial defect map and the immersion defect map, indicating that the holes on the immersion device are not blocked.

Whether holes in the immersion device are blocked or not is judged by using the initial defect maps and the immersion defect maps of the N silicon wafers, so that the situation of erroneous judgment is eliminated, and the detection result is more reliable.

In summary, according to the method for detecting the hole blockage on the immersion device provided by the embodiment of the present application, N silicon wafers coated with the photoresist are obtained, and a surface scanning device is used for scanning the N silicon wafers to obtain initial defect maps corresponding to the N silicon wafers; aiming at N silicon wafers, enabling an immersion device to traverse four quadrants relative to the silicon wafers in a preset direction, scanning the N silicon wafers by using a surface scanning device, obtaining immersion defect maps corresponding to the N devices, and detecting whether holes in the immersion device are blocked or not according to the initial defect map and the immersion defect maps; the problem that a large amount of labor and time are consumed for detecting the blockage of the immersion device at present is solved; whether the hole of short-term test submergence device takes place to block up has been reached, reduces the effect that detects the cost.

The holes on the immersion device comprise a gap water outlet, an air knife hole and an outer side water outlet, and the number of each hole is a plurality. When detecting whether the hole on the immersion device is blocked, the gap water outlet, the air knife hole and the outside water outlet can be detected simultaneously, and at least one of the gap water outlet, the air knife hole and the outside water outlet can also be detected.

In one example, when the immersion device is used for traversing N silicon wafers, the N silicon wafers are divided into 2 groups, each group corresponds to one traversal sequence, the traversal sequences of the two groups are different, the symmetrical comparison is realized through immersion defect maps corresponding to different traversal sequences, the misjudgment condition can be better eliminated, and the positions of holes blocked on the immersion device are determined. Another embodiment of the present application provides a method for detecting clogging of a hole in an immersion device, the method at least comprising the steps of:

in step 201, N silicon wafers coated with photoresist are obtained.

N is a positive integer.

And obtaining N silicon wafers with the same specification, and coating photoresist on the surfaces of the silicon wafers.

In step 202, the surface scanning device is used to scan N silicon wafers, and initial defect maps corresponding to the N silicon wafers are obtained.

And aiming at each silicon wafer in the N silicon wafers, scanning by using a surface scanning device to obtain an initial defect map corresponding to each silicon wafer.

The initial defect map is used for describing the defect condition of the silicon wafer after gluing.

In step 203, the immersion device is fixed for N/2 silicon wafers, and the silicon wafer is driven to move by the silicon wafer carrying device, so that the immersion device traverses four quadrants of the silicon wafer clockwise and stays in each quadrant for a predetermined time.

And in the process that the immersion device traverses the four quadrants of the silicon wafer, the immersion device is not moved, and the silicon wafer is driven to move by the silicon wafer bearing device.

Before the immersion device traverses four quadrants of the silicon wafer, a certain quadrant on the silicon wafer is set as a starting point, and N/2 silicon wafers take the set quadrant as a traversal starting point. Such as: and taking the second quadrant as a traversal starting point.

In one example, as shown in fig. 3, firstly, the immersion device 11 stays in the second quadrant of the silicon wafer 21 for a predetermined time, and then the silicon wafer is driven by the silicon wafer carrying device to move horizontally, so that the immersion device is located in the first quadrant of the silicon wafer 21 and stays in the first quadrant for the predetermined time; then, the silicon wafer is driven to translate through the silicon wafer bearing device, the immersion device 11 is positioned in the fourth quadrant of the silicon wafer 21, and the immersion device stays in the fourth quadrant for a preset time; and finally, driving the silicon wafer to translate through the silicon wafer bearing device, enabling the immersion device 11 to be located in the third quadrant of the silicon wafer 21, and staying for a preset time in the third quadrant.

The predetermined time is preset according to actual conditions. In one example, the predetermined time is 30 s.

In one example, N is 10, and 5 wafers are first processed, and the immersion device is moved clockwise relative to the wafers through four quadrants of each wafer.

The interstitial water outlets 12 on the immersion device 11 are located inside the air knife holes 13, and the air knife holes 13 are located inside the outer water outlets 14.

In step 204, the immersion device is fixed for the remaining N/2 silicon wafers, the silicon wafer is driven to move by the silicon wafer carrying device, and the immersion device traverses four quadrants of the silicon wafer in the counterclockwise direction and stays in each quadrant for a predetermined time.

And in the process that the immersion device traverses the four quadrants of the silicon wafer, the immersion device is not moved, and the silicon wafer is driven to move by the silicon wafer bearing device.

Before the immersion device traverses four quadrants of the silicon wafer, a certain quadrant on the silicon wafer is set as a starting point, and N/2 silicon wafers take the set quadrant as a traversal starting point.

In one example, as shown in fig. 4, firstly, the immersion device 11 stays in the second quadrant of the silicon wafer 21 for a predetermined time, and then the silicon wafer 21 is driven to translate by the silicon wafer carrying device, so that the immersion device 11 is located in the third quadrant of the silicon wafer 21 and stays in the third quadrant for the predetermined time; then, the silicon wafer 21 is driven to translate through the silicon wafer bearing device, the immersion device 11 is positioned in the fourth quadrant of the silicon wafer, and the immersion device stays in the fourth quadrant for a preset time; and finally, driving the silicon wafer 21 to translate through the silicon wafer bearing device, enabling the immersion device 11 to be located in the first quadrant of the silicon wafer 21, and staying for a preset time in the first quadrant.

The predetermined time is preset according to actual conditions. In one example, the predetermined time is 30 s.

In one example, where N is 10, the immersion device is caused to traverse four quadrants of each wafer counterclockwise with respect to the wafer for the remaining 5 wafers.

It should be noted that step 204 may also be performed before step 203, which is not limited in this embodiment of the application.

In step 205, a surface scanning device is used to scan N silicon wafers, and an immersion defect map corresponding to the N silicon wafers is obtained.

This step is explained in step 104 above and will not be described here.

In step 206, a defect comparison map is obtained based on the initial defect map and the submerged defect map.

And comparing the defects on the initial defect map with the defects on the immersed defect map to obtain a defect comparison map. And acquiring N defect comparison graphs for the N silicon wafers, wherein each silicon wafer corresponds to one defect comparison graph.

Optionally, for each silicon wafer, the defect comparison map is obtained by subtracting the initial defect map from the immersion defect map.

In step 207, whether a track defect exists on the defect comparison map is detected.

If the holes in the immersion device are blocked, a defect comparison graph will show a track defect as shown by track 22 in FIG. 5.

The trace defect shown by trace 22 is formed by liquid remaining on the wafer surface due to hole plugging.

The starting point of the track defect can be determined according to the traversal direction, and the starting point of the track defect on the defect comparison graph is the position where the track defect is generated, so that the position coordinate of the hole blocked on the immersion device can be determined according to the track defect.

Therefore, whether the holes on the immersion device are blocked or not can be judged by detecting whether the defect comparison graph has track defects or not.

And if the defect comparison graph is detected to have the track defect, determining that the hole on the immersion device is blocked.

And if the defect comparison graph is detected to have no track defect, determining that the hole on the immersion device is not blocked.

In step 208, when a blockage of the hole on the immersion device is detected, the position of the blocked hole is determined according to the defect comparison map.

In one example, where the defect comparison map includes a track defect 22, as shown in FIG. 5, the combination of the track defect and the position of the hole in the immersion apparatus allows the location of the plugged hole on the immersion apparatus to be located; as shown in fig. 6, the coordinates of the blocked holes can be obtained by establishing a coordinate system according to the size of the immersion device, and the coordinates of the 4 blocked holes 23 in fig. 6 are as follows:

X(mm)	Y(mm)
		10.56	-25.31
30.78	-5.05
		25.12	10.96
-11.32	-29.18

the method comprises the steps of obtaining an initial defect map of a glued silicon wafer, traversing the glued silicon wafer by using an immersion device, obtaining an immersion defect map of the silicon wafer traversed by the immersion device, comparing the initial defect map and the immersion defect map to detect whether holes on the immersion device are blocked, and further determining the specific positions of the blocked holes according to the defect comparison map, so that the detection efficiency of the blocking condition of the immersion device is improved.

It should be noted that the silicon wafer is not exposed when the immersion device is used to traverse four boundaries of the silicon wafer.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications of this invention are intended to be covered by the scope of the invention as expressed herein.