Thinning method, indexing table compensation parameter determination method, system and thinning machine

Abstract

The present invention discloses a thinning method, a method for determining compensation parameters of a dividing table, a system and a thinning machine, wherein the thinning method grinds a sample to obtain the corresponding dividing table compensation angle when there is no center spot problem on the workpiece on each wafer stage after grinding. Therefore, in the subsequent actual grinding, when each dividing table needs to be rotated to a second grinding mechanism, the rotation of the dividing table is controlled by the dividing table compensation angle corresponding to each wafer stage, which can effectively ensure that the angle of rotation of the dividing table satisfies the requirement that there will be no center spot on the wafer on each wafer stage after thinning by the second grinding mechanism, thereby effectively ensuring the thinning quality. At the same time, the dividing table compensation angle corresponding to each wafer stage can be automatically obtained without manual debugging, and is easy to implement.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor device processing, in particular to a thinning method, a method for determining compensation parameters of a dividing table, a system and a thinning machine. Background Art

[0002] Thinning machine is a special equipment used for grinding and thinning semiconductor devices such as wafers.

[0003] The invention patent application with application publication number CN115338717A discloses a usable thinning device. In this structure, a dividing table is used to drive three wafer carriers to rotate in sequence under two grinding wheels of the thinning assembly for thinning.

[0004] In order to avoid the occurrence of a center spot (center boss) on the wafer, the invention patent with application publication number CN116810528A discloses a method for thinning by keeping the edge of the grinding wheel tangent to the axis of the wafer stage below it.

[0005] However, in the actual thinning process, due to factors such as the rotation accuracy and assembly accuracy of the dividing table, the axis of the wafer table often cannot be effectively rotated to a state tangent to the edge of the grinding wheel. Therefore, the existing solution still has a center spot during actual processing. Summary of the invention

[0006] The purpose of the present invention is to solve the above-mentioned problems existing in the prior art and to provide a thinning method, a method for determining the compensation parameters of a dividing table, a system and a thinning machine.

[0007] The purpose of the present invention is achieved through the following technical solutions:

[0008] The thinning method comprises the following steps: when a wafer on a wafer stage needs to be rotated to a second grinding mechanism for thinning after being thinned at a first grinding mechanism, controlling the indexing table to rotate by a predetermined angle, wherein the predetermined angle is determined according to the indexing table compensation angle and the compensation rotation direction corresponding to the wafer stage;

[0009] The compensation angle and the compensation direction of the indexing table corresponding to each of the wafer carriers are determined according to the following process:

[0010] S01, after determining that a sample is concentrically placed on the wafer table at the loading and unloading position, the sample is rotated to the first grinding mechanism and the second grinding mechanism in sequence according to the fixed rotation angle for thinning;

[0011] S02, after thinning, controlling the indexing table to rotate according to the fixed rotation angle so that the wafer carrier rotates to a loading and unloading position;

[0012] S03, determining whether there is a center spot on the top of the sample on the wafer stage by image recognition, if not, executing S04, if yes, executing S05;

[0013] S04, determining that the compensation angle of the indexing table corresponding to the wafer holding table is 0°;

[0014] S05, determining the current compensation angle according to the size parameters of the central spot and determining the compensation direction, and then executing S06;

[0015] S06, after unloading the thinned sample on the wafer stage, place a sample concentrically on the wafer stage again and rotate the sample to the first grinding mechanism for thinning according to the fixed rotation angle. After the thinning is completed at the first grinding mechanism, the indexing table is controlled to rotate according to the fixed rotation angle and the current compensation angle and compensation steering determined by the last image recognition so that the sample is rotated to the second grinding mechanism for thinning. After thinning, execute S07;

[0016] S07, controlling the indexing table to rotate so that the wafer table rotates to the loading and unloading position, and determining whether there is a center spot on the top of the sample on the wafer table by image recognition again, and when it is determined that there is no center spot, executing S08, and when it is determined that there is a center spot, executing S09;

[0017] S08, determining that the compensation angle and compensation direction of the indexing table corresponding to the wafer stage are the current compensation angle and compensation direction determined by the last image recognition;

[0018] S09, determining the current compensation angle and compensation direction according to the size parameters of the central spot determined by the current image recognition and executing S06.

[0019] Preferably, the optical axis of the lens of the image acquisition device used for the image recognition is concentric with the wafer stage at the loading and unloading position.

[0020] Preferably, in S05, the current compensation angle θ is calculated according to the following formula:

[0021] θ=arctan(D / 2L) / 2 or θ=arctan(r / L) / 2;

[0022] Wherein, D is the diameter of the center spot, r is the radius of the center spot, and L is the distance between the axis of the wafer stage and the axis of the dividing table.

[0023] Preferably, in S09, the compensatory steering is determined according to the diameter of the central spot determined by the current image recognition and the diameter of the central spot determined by the previous image recognition.

[0024] Preferably, when the diameter of the central spot determined by this image recognition is larger than the diameter of the central spot determined by the previous image recognition, the compensation direction corresponding to the current compensation angle determined by this image recognition is determined to be opposite to the compensation direction corresponding to the current compensation angle determined by the previous image recognition; otherwise, the compensation direction corresponding to the current compensation angle determined by this image recognition is determined to be the same as the compensation direction corresponding to the current compensation angle determined by the previous image recognition.

[0025] Preferably, after the current compensation angle is determined each time, it is determined whether the current compensation angle is within a set threshold, if so, S06 is executed, if not, an alarm is issued.

[0026] Preferably, in S01, when a sample on an upstream wafer stage is thinned at the first grinding mechanism, a sample is placed concentrically on a downstream wafer stage at a loading and unloading position, and when the sample on the upstream wafer stage is thinned at the second grinding mechanism, the sample on the downstream wafer stage is thinned at the first grinding mechanism;

[0027] In the above 03, when it is determined by image recognition whether there is a center spot on the sample on the upstream wafer stage, the second grinding mechanism is controlled not to thin the sample on the downstream wafer stage; when it is determined that there is no center spot on the sample on the upstream wafer stage, it is further determined by image recognition whether there is a center spot on the sample on the downstream wafer stage, if not, S04 is executed; if so, the current compensation angle and compensation steering are determined according to the size parameters of the center spot of the sample on the downstream wafer stage determined by image recognition, and S06 is executed;

[0028] In the S06, the thinned samples on the upstream wafer stage and the downstream wafer stage are unloaded in sequence and then concentrically placed on the same sample; when the upstream wafer stage needs to be rotated to the second grinding mechanism, the indexing table is controlled to rotate according to the fixed rotation angle and the current compensation angle and compensation steering determined by the last image recognition so that the sample on the upstream wafer stage is rotated to the second grinding mechanism for thinning; after thinning, S07 is executed;

[0029] In S07, it is determined in turn whether the sample on the upstream wafer stage and the sample on the downstream wafer stage have a center spot. When it is determined that the sample on the upstream wafer stage and the sample on the downstream wafer stage do not have a center spot, the compensation angle and compensation direction of the indexing table corresponding to the upstream wafer stage are determined to be the current compensation angle and compensation direction determined by the last image recognition;

[0030] When it is determined that the sample on the upstream stage or the downstream stage has a center spot, the current compensation angle and compensation direction are determined according to the size parameters of the center spot of the sample on the upstream stage or the downstream stage, and S06 is executed.

[0031] The method for determining the compensation parameters of the indexing table includes the following processes:

[0032] S01, after determining that a sample is concentrically placed on a wafer table at a loading and unloading position, the sample is rotated to the first grinding mechanism and the second grinding mechanism in sequence according to a fixed rotation angle for thinning;

[0033] S02, after thinning, controlling the indexing table to rotate according to the fixed angle so that the wafer carrier rotates to a loading and unloading position;

[0034] S03, determining whether there is a center spot on the top of the sample on the wafer stage by image recognition, if not, executing S04, if yes, executing S05;

[0035] S04, determining that the compensation angle of the indexing table corresponding to the wafer holding table is 0°;

[0036] S05, determining the current compensation angle according to the size parameters of the central spot and determining the compensation direction, and then executing S06;

[0037] S06, after unloading the thinned sample on the wafer stage, place a sample concentrically on the wafer stage again and rotate the sample to the first grinding mechanism for thinning according to the fixed rotation angle. After the thinning is completed at the first grinding mechanism, the indexing table is controlled to rotate according to the fixed rotation angle and the current compensation angle and compensation steering determined by the last image recognition so that the sample is rotated to the second grinding mechanism for thinning. After thinning, execute S07;

[0038] S07, controlling the indexing table to rotate so that the wafer table rotates to the loading and unloading position, and determining whether there is a center spot on the top of the sample on the wafer table by image recognition again, and when it is determined that there is no center spot, executing S08, and when it is determined that there is a center spot, executing S09;

[0039] S08, determining that the compensation angle and compensation direction of the indexing table corresponding to the wafer stage are the current compensation angle and compensation direction determined by the last image recognition;

[0040] S09, determining the current compensation angle and compensation direction according to the size parameters of the central spot determined by the current image recognition and executing S06.

[0041] The indexing table compensation parameter determination system includes:

[0042] A thinning execution unit is used to, after a sample is concentrically placed on a wafer table at a loading and unloading position, rotate the sample to the first grinding mechanism and the second grinding mechanism in sequence according to a fixed rotation angle for thinning;

[0043] A dividing table control unit, used for controlling the dividing table to rotate according to the fixed angle after thinning so that the wafer carrier rotates to a loading and unloading position;

[0044] A first image recognition unit is used to determine whether there is a center spot on the top of the sample on the platen through image recognition, and communicate with the first compensation parameter determination unit when it is determined that there is no center spot, and communicate with the first calculation unit when it is determined that there is a center spot;

[0045] A first compensation parameter determination unit is used to determine that the compensation angle of the indexing table corresponding to the wafer stage is 0°;

[0046] A first calculation unit, used for determining a current compensation angle and a compensation direction according to the size parameters of the central spot and communicating with a re-execution unit;

[0047] a re-compensation unit, for unloading the thinned sample on the wafer stage, placing a sample on the wafer stage again concentrically and rotating the sample to the first grinding mechanism for thinning according to the fixed rotation angle, and after completing the thinning at the first grinding mechanism, controlling the rotation of the indexing table according to the fixed rotation angle and the current compensation angle and compensation direction determined by the last image recognition to rotate the sample to the second grinding mechanism for thinning, and communicating with the second image recognition unit after thinning;

[0048] A second image recognition unit is used to control the rotation of the indexing table so that the wafer table rotates to a loading and unloading position, and to determine whether there is a center spot on the top of the sample on the wafer table through image recognition again, and to communicate with the second compensation parameter determination unit when it is determined that there is no center spot, and to communicate with the second calculation unit when it is determined that there is a center spot;

[0049] A second compensation parameter determination unit, used to determine the compensation angle and compensation direction of the indexing table corresponding to the wafer stage to be the current compensation angle and compensation direction determined by the last image recognition;

[0050] The second calculation unit is used to determine the current compensation angle and compensation direction according to the size parameters of the central spot determined by the current image recognition and communicate with the re-compensation unit.

[0051] A thinning device includes a memory and a processor, wherein the memory stores a program executable by the processor, and when the program is executed, any of the above-mentioned thinning methods or the above-mentioned method for determining the compensation parameters of a dividing table is implemented.

[0052] The advantages of the technical solution of the present invention are mainly reflected in:

[0053] The method of the present invention grinds the sample to obtain the corresponding indexing table compensation angle when there is no center spot problem on the workpiece on each wafer stage after grinding. Therefore, in the subsequent actual grinding, when each indexing table needs to be rotated to the second grinding mechanism, the rotation of the indexing table is controlled by the indexing table compensation angle corresponding to each wafer stage, which can effectively ensure that the rotation angle of the indexing table satisfies the requirement that there will be no center spot on the wafer on each wafer stage after thinning by the second grinding mechanism, thereby effectively ensuring the thinning quality. At the same time, the indexing table compensation angle corresponding to each wafer stage can be automatically obtained without manual debugging, and is easy to implement.

[0054] The scheme of the present invention not only takes into account whether the workpiece has a center spot after thinning at the second grinding mechanism, but also takes into account whether the workpiece has a center spot after thinning at the first grinding mechanism when determining the compensation angle of the dividing table corresponding to the wafer table. This allows the determined compensation angle of the dividing table to simultaneously satisfy the requirement that there is no center spot after thinning at the first grinding mechanism and the second grinding mechanism. This can effectively avoid the influence of the center spot after thinning at the first grinding mechanism on the grinding wheel of the second grinding mechanism, thereby effectively improving the service life of the grinding wheel of the second grinding mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 It is a process schematic diagram of the thinning method of the present invention;

[0056] Figure 2 It is a schematic diagram of the process of determining the compensation angle and the compensation direction of the indexing table corresponding to the wafer holding table in the present invention;

[0057] Figure 3 It is a structural schematic diagram of identifying whether there is a central spot on the wafer table at the loading and unloading position by using an image acquisition device in the present invention;

[0058] Figure 4 It is a schematic diagram of the principle of determining the current compensation angle according to the size parameters of the central spot in the present invention;

[0059] Figure 5 It is a schematic diagram of the process of determining the compensation angle and compensation steering of the upstream indexing table according to whether the sample on the upstream wafer stage and the downstream wafer stage has a center spot. DETAILED DESCRIPTION

[0060] The purpose, advantages and features of the present invention will be illustrated and explained by the non-limiting description of the following preferred embodiments. These embodiments are only typical examples of the application of the technical solution of the present invention, and any technical solution formed by equivalent replacement or equivalent transformation falls within the scope of protection claimed by the present invention.

[0061] In the description of the scheme, it should be noted that the terms "center", "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience and simplification of description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0062] The thinning method disclosed in the present invention is explained below in conjunction with the accompanying drawings. The thinning method is based on a thinning machine. The specific structure of the thinning machine can refer to the thinning machine including three wafer carriers 100 disclosed in the patent application cited in the background technology. Of course, in other embodiments, the number of the wafer carriers 100 can also be more.

[0063] In the thinning machine with three wafer stages 100 , the three wafer stages 100 are distributed at 120°, so that the three wafer stages can be located at the loading and unloading positions, the first grinding mechanism 300 , and the second grinding mechanism 400 , respectively.

[0064] Correspondingly, as attached Figure 1 As shown, the thinning method includes the following steps: when a wafer on a wafer stage 100 needs to be rotated to the second grinding mechanism 400 for thinning after completing thinning at the first grinding mechanism, the dividing table 200 is controlled to rotate a predetermined angle, and the predetermined angle is determined according to the compensation angle and compensation direction of the dividing table corresponding to the wafer stage 100.

[0065] And when determining the predetermined angle corresponding to each wafer table 100, in addition to the compensating angle and compensating steering based on the dividing table corresponding to the wafer table 100, it is also necessary to compensate the angle and compensating steering based on the fixed angle of the dividing table 200 and the dividing table 100 corresponding to an upstream wafer table 100. The fixed angle is determined according to the number of wafer tables 100, that is, 360° is divided by the number of wafer tables 100 to obtain the fixed angle. In this embodiment, there are 3 wafer tables 100 and the fixed angle is 120°.

[0066] For the convenience of explanation, we define the three wafer tables 100 as the first wafer table, the second wafer table and the third wafer table in turn, assuming that the compensation angle of the indexing table corresponding to the first wafer table is 0.3° and the compensation direction is the same as the direction of the indexing table 200 during normal thinning, that is, the indexing table 200 needs to rotate 0.3° more on the basis of 120°, the compensation angle of the indexing table corresponding to the second wafer table is 0.2° and the compensation direction is opposite to the direction of the indexing table 200 during normal thinning, that is, the indexing table 200 needs to rotate 0.2° less on the basis of rotating 120°, and the compensation angle of the indexing table corresponding to the third wafer table is 0°, that is, no compensation is required on the basis of rotating 120°.

[0067] When the wafer on the first wafer stage needs to be rotated to the second grinding mechanism 400, the rotation angle of the indexing table 200 is 120°+0.3°; when the wafer on the second wafer stage needs to be rotated to the second grinding mechanism 400, the rotation angle of the indexing table 200 is 120°-0.3°-0.2°; when the wafer on the third wafer stage needs to be rotated to the second grinding mechanism 400 for thinning, the rotation angle of the indexing table 200 is 120°+0.2°±0°.

[0068] The compensation angle and compensation direction of the indexing table corresponding to each of the wafer carriers 100 are determined according to the following process. Since the determination process of the compensation angle and compensation direction of each indexing table 200 is the same, the first wafer carrier is taken as an example for explanation. Figure 2 As shown:

[0069] S01, after determining that a sample is placed concentrically on the first wafer carrier at the loading and unloading position, the sample is rotated to the first grinding mechanism 300 and the second grinding mechanism 400 in sequence according to the fixed rotation angle for thinning, that is, the dividing table 200 is first rotated 120° to rotate the first wafer carrier from the loading and unloading position to the first grinding mechanism 300 for thinning. After thinning, the dividing table 200 is rotated another 120° to rotate the first wafer carrier to the second grinding mechanism 400 for thinning.

[0070] S02, after thinning, the indexing table 200 is controlled to rotate according to the fixed angle so that the first wafer carrier is rotated to the loading and unloading position, that is, the indexing table 200 continues to rotate 120° so that the first wafer carrier is rotated to the loading and unloading position.

[0071] S03, determine whether there is a center spot 600 on the top of the sample on the first wafer stage through image recognition, if not, execute S04, if yes, execute S05. Figure 3As shown, the image acquisition device 500 used for image recognition can be a known feasible device. Preferably, the image acquisition device 500 can be a known microscope camera, which can acquire a local image of the top center area of ​​the sample. The image acquisition device 500 can be fixed, or can be set on a known mobile structure that can drive its translation. Preferably, the lens optical axis of the image acquisition device 500 is coaxial with the wafer stage 100 at the loading and unloading position. And image recognition can identify the size parameters of the center spot, such as radius and diameter. Specifically, the method is a known technology and will not be described here.

[0072] S04, when there is no center spot 600 on the sample, that is, no angle compensation is required, the compensation angle of the dividing table corresponding to the wafer stage 100 is determined to be 0°.

[0073] S05, determining the current compensation angle according to the size parameters of the central spot 600 and determining the compensation direction, and then executing S06;

[0074] As attached Figure 4 As shown, the current compensation angle θ is calculated according to the following formula:

[0075] θ=arctan(D / 2L) / 2 or θ=arctan(r / L) / 2;

[0076] Wherein, D is the diameter of the central spot 600 , r is the radius of the central spot 600 , and L is the distance between the axis of the wafer stage 100 and the axis of the indexing stage 200 .

[0077] When compensation is performed for the first time, the compensation direction can be determined as needed. The compensation direction can be the same as the direction of the indexing table 200 during normal thinning, or the compensation direction can be opposite to the direction of the indexing table 200 during normal thinning.

[0078] S06, after unloading the thinned sample on the first wafer stage, place a sample concentrically on the first wafer stage again and rotate the sample on the first wafer stage to the first grinding mechanism 300 for thinning according to the fixed rotation angle. After the thinning is completed at the first grinding mechanism 300, the indexing table 200 is controlled to rotate according to the fixed rotation angle and the current compensation angle and compensation steering determined by the last image recognition so that the sample on the first wafer stage is rotated to the second grinding mechanism 400 for thinning. After thinning, execute S07;

[0079] S07, controlling the indexing table 200 to rotate so that the first wafer stage rotates to a loading and unloading position (i.e., the first wafer stage rotates to a position coaxial with the lens optical axis of the image acquisition device 500), and determining again by image recognition whether there is a center spot 600 on the top of the sample on the wafer stage 100. If it is determined that there is no center spot 600, S08 is executed; if it is determined that there is a center spot 600, S09 is executed;

[0080] S08, determining that the compensation angle and compensation direction of the indexing table corresponding to the wafer stage 100 are the current compensation angle and compensation direction determined by the last image recognition;

[0081] S09, determine the current compensation angle and compensation direction according to the size parameters of the central spot 600 determined by the current image recognition and execute S06. The calculation method of the current compensation angle is the same as the calculation method in S05, which will not be described here.

[0082] In S09, the compensation direction is determined according to the diameter of the central spot 600 determined by the current image recognition and the diameter of the central spot 600 determined by the previous image recognition. When the diameter of the central spot 600 determined by the current image recognition is greater than the diameter of the central spot 600 determined by the previous image recognition, it is determined that the compensation direction corresponding to the current compensation angle determined by the current image recognition is opposite to the compensation direction corresponding to the current compensation angle determined by the previous image recognition; otherwise, it is determined that the compensation direction corresponding to the current compensation angle determined by the current image recognition is the same as the compensation direction corresponding to the current compensation angle determined by the previous image recognition.

[0083] For example, when the first sample on the first wafer stage is ground by the first grinding mechanism 300 and the second grinding mechanism 400, it is confirmed through image recognition that there is a center spot 600, and according to the size parameters of the center spot 600, the current compensation angle is determined to be 0.2° and the compensation direction is the same as the direction of the indexing table 200 during normal thinning. Then, when the second sample needs to be rotated to the second grinding mechanism 400 after thinning at the first grinding mechanism 300, the indexing table 200 rotates 120.2° (120°+0.2°). After the second sample is thinned at the second grinding mechanism 400, if it is determined that the diameter of the center spot 600 on the second sample is greater than the diameter of the center spot 600 on the first sample, and according to the diameter of the center spot 600 on the second sample, the current compensation angle is determined to be 0.3°, then the corresponding compensation direction is opposite to the direction of the indexing table 200 during normal thinning. Therefore, when the third sample needs to be rotated to the second grinding mechanism 400 after being thinned at the first grinding mechanism 300, the dividing table 200 rotates 119.7° (120°-0.3°), and after the third sample is thinned at the second grinding mechanism 400, if the current compensation angle determined according to the diameter of the center spot 600 on the third sample is 0.1°, it can be determined that the diameter of the center spot 600 on the third sample is smaller than the diameter of the center spot 600 on the second sample, then the corresponding compensation direction is opposite to the direction of the dividing table 200 during normal thinning. Therefore, when the fourth sample needs to be rotated to the second grinding mechanism 400 after being thinned at the first grinding mechanism 300, the dividing table 200 rotates 119.9° (120°-0.1°). After the fourth sample is thinned at the second grinding mechanism 400, if it is determined that there is no center spot 600, then the compensation angle of the dividing table corresponding to the first wafer table is finally determined to be 0.1°. The compensation direction is opposite to the direction of the wafer table 100 during normal thinning.

[0084] Further, after the current compensation angle is determined each time, it is determined whether the current compensation angle is within the set threshold. If so, S06 is executed, and if not, an alarm is issued. This can prevent the position of the wafer stage 100 from exceeding the grinding range of the first grinding mechanism 300 and / or the second grinding mechanism 400 after compensation, resulting in failure of thinning. The set threshold can be set as needed and is not limited here. Of course, an alarm can also be issued when there is still a center spot after a predetermined number of compensations. The predetermined number can also be set as needed and is not limited here.

[0085] Better, as attached Figure 5As shown, in S01, when a sample on an upstream wafer stage is thinned at the first grinding mechanism, the sample is placed concentrically on a downstream wafer stage at the loading and unloading position, and when the sample on the upstream wafer stage is thinned at the second grinding mechanism, the sample on the downstream wafer stage is thinned at the first grinding mechanism.

[0086] In 03, when it is determined by image recognition whether there is a center spot 600 on the sample on the upstream wafer stage, the second grinding mechanism 400 is controlled not to thin the sample on the downstream wafer stage; this is done because it is necessary to know whether there is a center spot on the sample on the downstream wafer stage after it is ground by the first grinding mechanism.

[0087] When it is determined that there is no center spot 600 for the sample on the upstream holding table, image recognition is further used to determine whether there is a center spot 600 for the sample on the downstream holding table. If not, S04 is executed; if so, the current compensation angle and compensation direction are determined based on the size parameters of the center spot 600 of the sample on the downstream holding table determined by image recognition, and S06 is executed.

[0088] In S06, the thinned samples on the upstream wafer stage and the downstream wafer stage are unloaded in turn and then a sample is placed concentrically; when the upstream wafer stage needs to be rotated to the second grinding mechanism 400, the dividing table 200 is controlled to rotate according to the fixed rotation angle and the current compensation angle and compensation steering determined by the previous image recognition so that the sample on the upstream wafer stage is rotated to the second grinding mechanism 400 for thinning; after thinning, S07 is executed.

[0089] In S07, it is determined in turn whether the sample on the upstream wafer stage and the sample on the downstream wafer stage have a center spot 600. When it is determined that the sample on the upstream wafer stage and the downstream wafer stage do not have a center spot 600, the compensation angle and compensation direction of the dividing table corresponding to the upstream wafer stage are determined to be the current compensation angle and compensation direction determined by the last image recognition.

[0090] When it is determined that the sample on the upstream wafer stage or the downstream wafer stage has a center spot 600, the current compensation angle is determined according to the size parameters of the center spot 600 of the sample on the upstream wafer stage or the downstream wafer stage, and S06 is executed.

[0091] For example, the first sample is placed on the first wafer stage (upstream wafer stage), and the second sample is placed on the second wafer stage (downstream wafer stage). When the first sample is thinned by the second grinding mechanism 400 and determined through image recognition that there is no center spot 600, the second sample on the second wafer stage that has only been thinned at the first grinding mechanism 300 is rotated to the image acquisition device 500 for image recognition. When it is determined through image recognition that there is no center spot 600 on the second sample, the compensation angle of the dividing table corresponding to the first wafer stage is determined to be 0°.

[0092] When it is determined through image recognition that there is a center spot 600 on the second sample, the current compensation angle is determined to be 0.2° according to the size parameters of the center spot 600 and the compensation angle is the same as the rotation angle of the indexing table 200 during normal thinning.

[0093] After unloading the sample on the first sample, place the third sample on the first wafer stage, rotate the indexing table 200 120°, take the second sample off the second wafer stage, and place the fourth sample on the second wafer stage 100 .

[0094] When the third sample needs to be rotated to the second grinding mechanism 400, the indexing table 200 rotates 120.2° (120°+0.2°), and when the third sample is thinned at the second grinding mechanism 400, the fourth sample is thinned at the first grinding mechanism 300. When the third sample has a center spot 600 through image recognition, and the current compensation angle is determined to be 0.3° based on the diameter of the center spot 600 on the third sample, at this time, when determining the compensation direction, it is determined based on the size of the center spot determined by image recognition of two consecutive samples on the same wafer stage, that is, the diameter of the center spot on the third sample on the first wafer stage is larger than the diameter of the center spot on the first sample on the first wafer stage (no center spot, diameter is 0), then the corresponding compensation direction is opposite to the direction of the indexing table 200 during normal thinning; at this time, the third sample is removed from the first wafer stage and the fifth sample is placed on it, and the indexing table 200 rotates 120 °, the fourth sample is removed from the second wafer stage, and the sixth sample is placed on the second wafer stage 100, when the fifth sample needs to be rotated to the second grinding mechanism 400, the dividing table 200 is rotated 119.7° (120°-0.3°), when the fifth sample is thinned at the second grinding mechanism 400, the sixth sample is thinned at the first grinding mechanism 300, when the fifth sample is found to have no center spot 600 after image recognition and the sixth sample is found to have no center spot 600 after image recognition, the compensation angle of the dividing table corresponding to the first wafer stage 100 is 0.3, and the compensation direction is opposite to the direction of the dividing table 200 during normal thinning.

[0095] If after a set number of compensations, it is still not possible to satisfy that both the sample on the first wafer stage and the sample on the second wafer stage after thinning at the first grinding mechanism have no center spot 600, then the current compensation angle and compensation direction corresponding to the time when the sample on the first wafer stage has no center spot 600 after thinning by the second grinding mechanism are selected as the compensation direction and compensation direction of the dividing table corresponding to the first wafer stage.

[0096] Example 2

[0097] This embodiment discloses a method for determining compensation parameters of a dividing table, including the following process:

[0098] S01, after determining that a sample is placed concentrically on the wafer stage 100 at the loading and unloading position, the sample is rotated to the first grinding mechanism 300 and the second grinding mechanism 400 in sequence according to a fixed rotation angle for thinning;

[0099] S02, after thinning, controlling the indexing table 200 to rotate according to the fixed rotation angle so that the wafer carrier 100 rotates to a loading and unloading position;

[0100] S03, determining whether there is a center spot 600 on the top of the sample on the wafer stage 100 by image recognition, if not, executing S04, if yes, executing S05;

[0101] S04, determining that the indexing table compensation angle corresponding to the wafer stage 100 is 0°;

[0102] S05, determining the current compensation angle according to the size parameters of the central spot 600 and determining the compensation direction, and then executing S06;

[0103] S06, after unloading the thinned sample on the wafer stage 100, a sample is placed concentrically on the wafer stage 100 again and the sample is rotated to the first grinding mechanism 300 for thinning according to the fixed rotation angle. After the thinning is completed at the first grinding mechanism 300, the indexing table 200 is controlled to rotate according to the fixed rotation angle and the current compensation angle and compensation steering determined by the last image recognition so that the sample is rotated to the second grinding mechanism 400 for thinning. After thinning, S07 is executed;

[0104] S07, controlling the indexing table 200 to rotate so that the wafer stage 100 rotates to the loading and unloading position, and determining again by image recognition whether there is a center spot 600 on the top of the sample on the wafer stage 100, and when it is determined that there is no center spot 600, executing S08, and when it is determined that there is a center spot 600, executing S09;

[0105] S08, determining that the compensation angle and compensation direction of the indexing table corresponding to the wafer stage 100 are the current compensation angle and compensation direction determined by the last image recognition;

[0106] S09, determining the current compensation angle and compensation direction according to the size parameters of the central spot 600 determined by the current image recognition and executing S06.

[0107] Example 3

[0108] This embodiment discloses a system for determining compensation parameters of a dividing table, including:

[0109] A thinning execution unit is used to, after determining that a sample is coaxially placed on the wafer stage 100 at the loading and unloading position, rotate the sample to the first grinding mechanism 300 and the second grinding mechanism 400 in sequence according to a fixed rotation angle for thinning;

[0110] An indexing table control unit, for controlling the indexing table 200 to rotate according to the fixed angle after thinning so that the wafer carrier 100 rotates to a loading and unloading position;

[0111] A first image recognition unit is used to determine whether there is a center spot 600 on the top of the sample on the wafer stage 100 through image recognition, and communicate with the first compensation parameter determination unit when it is determined that there is no center spot 600, and communicate with the first calculation unit when it is determined that there is a center spot 600;

[0112] A first compensation parameter determination unit is used to determine that the compensation angle of the indexing table corresponding to the wafer stage 100 is 0°;

[0113] A first calculation unit, configured to determine a current compensation angle and a compensation direction according to the size parameters of the central spot 600 and communicate with a re-execution unit;

[0114] a re-compensation unit, for unloading the thinned sample on the wafer stage 100, placing another sample concentrically on the wafer stage 100 again and rotating the sample to the first grinding mechanism 300 for thinning according to the fixed rotation angle, and after completing the thinning at the first grinding mechanism 300, controlling the rotation of the indexing table 200 according to the fixed rotation angle and the current compensation angle and compensation direction determined by the last image recognition to rotate the sample to the second grinding mechanism 400 for thinning, and communicating with the second image recognition unit after thinning;

[0115] The second image recognition unit is used to control the rotation of the indexing table 200 so that the wafer stage 100 rotates to the loading and unloading position, and determines whether there is a center spot 600 on the top of the sample on the wafer stage 100 through image recognition again, and communicates with the second compensation parameter determination unit when it is determined that there is no center spot 600, and communicates with the second calculation unit when it is determined that there is a center spot 600;

[0116] A second compensation parameter determination unit, used to determine that the compensation angle and compensation direction of the indexing table corresponding to the wafer stage 100 are the current compensation angle and compensation direction determined by the last image recognition;

[0117] The second calculation unit is used to determine the current compensation angle and compensation direction according to the size parameters of the central spot 600 determined by the current image recognition and communicate with the re-compensation unit.

[0118] Example 4

[0119] This embodiment discloses a thinning device, including a memory and a processor, wherein the memory stores a program executable by the processor, and when the program is executed, the thinning method described above or the method for determining the compensation parameters of a dividing table described above is implemented.

[0120] There are many implementation methods of the present invention, and all technical solutions formed by equivalent transformation or equivalent transformation fall within the protection scope of the present invention.

Claims

1. A thinning method, characterized in that: The method comprises the following steps: when a wafer on a wafer stage needs to be rotated to a second grinding mechanism for thinning after being thinned at a first grinding mechanism, controlling the indexing table to rotate by a predetermined angle, wherein the predetermined angle is determined according to the indexing table compensation angle and the compensation rotation direction corresponding to the wafer stage; The compensation angle and the compensation direction of the indexing table corresponding to each of the wafer carriers are determined according to the following process: S01, after determining that a sample is concentrically placed on the wafer table at the loading and unloading position, the sample is rotated to the first grinding mechanism and the second grinding mechanism in sequence according to the fixed rotation angle for thinning; S02, after thinning, controlling the indexing table to rotate according to the fixed rotation angle so that the wafer carrier rotates to a loading and unloading position; S03, determining whether there is a center spot on the top of the sample on the wafer stage by image recognition, if not, executing S04, if yes, executing S05; S04, determining that the compensation angle of the indexing table corresponding to the wafer holding table is 0°; S05, determining the current compensation angle according to the size parameters of the central spot and determining the compensation direction, and then executing S06; S06, after unloading the thinned sample on the wafer stage, place a sample concentrically on the wafer stage again and rotate the sample to the first grinding mechanism for thinning according to the fixed rotation angle. After the thinning is completed at the first grinding mechanism, the indexing table is controlled to rotate according to the fixed rotation angle and the current compensation angle and compensation steering determined by the last image recognition so that the sample is rotated to the second grinding mechanism for thinning. After thinning, execute S07; S07, controlling the indexing table to rotate so that the wafer stage rotates to the loading and unloading position, and determining whether there is a center spot on the top of the sample on the wafer stage by image recognition again, and when it is determined that there is no center spot, executing S08, and when it is determined that there is a center spot, executing S09; S08, determining that the compensation angle and compensation direction of the indexing table corresponding to the wafer stage are the current compensation angle and compensation direction determined by the last image recognition; S09, determining the current compensation angle and compensation direction according to the size parameters of the central spot determined by the current image recognition and executing S06.

2. The thinning method according to claim 1, characterized in that: The optical axis of the lens of the image acquisition device used in the image recognition is concentric with the wafer stage at the loading and unloading position.

3. The thinning method according to claim 1, characterized in that: In S05, the current compensation angle θ is calculated according to the following formula: θ=arctan(D / 2L) / 2 or θ=arctan(r / L) / 2; Wherein, D is the diameter of the center spot, r is the radius of the center spot, and L is the distance between the axis of the wafer stage and the axis of the dividing table.

4. The thinning method according to claim 1, characterized in that: In S09, the compensating steering is determined according to the diameter of the central spot determined by the current image recognition and the diameter of the central spot determined by the previous image recognition.

5. The thinning method according to claim 4, characterized in that: When the diameter of the central spot determined by the current image recognition is greater than the diameter of the central spot determined by the previous image recognition, it is determined that the compensation direction corresponding to the current compensation angle determined by the current image recognition is opposite to the compensation direction corresponding to the current compensation angle determined by the previous image recognition; Otherwise, it is determined that the compensation direction corresponding to the current compensation angle determined by the current image recognition is the same as the compensation direction corresponding to the current compensation angle determined by the previous image recognition.

6. The thinning method according to claim 1, characterized in that: After the current compensation angle is determined each time, it is determined whether the current compensation angle is within a set threshold. If so, S06 is executed; if not, an alarm is issued.

7. The thinning method according to any one of claims 1 to 6, characterized in that: In S01, when a sample on an upstream wafer stage is thinned at the first grinding mechanism, a sample is placed concentrically on a downstream wafer stage at a loading and unloading position, and when the sample on the upstream wafer stage is thinned at the second grinding mechanism, the sample on the downstream wafer stage is thinned at the first grinding mechanism; In the above 03, when it is determined by image recognition whether there is a center spot on the sample on the upstream wafer stage, the second grinding mechanism is controlled not to thin the sample on the downstream wafer stage; when it is determined that there is no center spot on the sample on the upstream wafer stage, it is further determined by image recognition whether there is a center spot on the sample on the downstream wafer stage, if not, S04 is executed; if so, the current compensation angle and compensation steering are determined according to the size parameters of the center spot of the sample on the downstream wafer stage determined by image recognition, and S06 is executed; In the S06, the thinned samples on the upstream wafer stage and the downstream wafer stage are unloaded in sequence and then concentrically placed on the same sample; when the upstream wafer stage needs to be rotated to the second grinding mechanism, the indexing table is controlled to rotate according to the fixed rotation angle and the current compensation angle and compensation steering determined by the last image recognition so that the sample on the upstream wafer stage is rotated to the second grinding mechanism for thinning; after thinning, S07 is executed; In S07, it is determined in turn whether the sample on the upstream wafer stage and the sample on the downstream wafer stage have a center spot. When it is determined that the sample on the upstream wafer stage and the sample on the downstream wafer stage do not have a center spot, the compensation angle and compensation direction of the indexing table corresponding to the upstream wafer stage are determined to be the current compensation angle and compensation direction determined by the last image recognition; When it is determined that the sample on the upstream wafer stage or the downstream wafer stage has a center spot, the current compensation angle and compensation direction are determined according to the size parameters of the center spot of the sample on the upstream wafer stage or the downstream wafer stage, and S06 is executed.

8. A method for determining compensation parameters of a dividing table, characterized in that: The process includes the following: S01, after determining that a sample is concentrically placed on a wafer table at a loading and unloading position, the sample is rotated to the first grinding mechanism and the second grinding mechanism in sequence according to a fixed rotation angle for thinning; S02, after thinning, controlling the indexing table to rotate according to the fixed angle so that the wafer carrier rotates to a loading and unloading position; S03, determining whether there is a center spot on the top of the sample on the wafer stage by image recognition, if not, executing S04, if yes, executing S05; S04, determining that the compensation angle of the indexing table corresponding to the wafer holding table is 0°; S05, determining the current compensation angle according to the size parameters of the central spot and determining the compensation direction, and then executing S06; S06, after unloading the thinned sample on the wafer stage, place a sample concentrically on the wafer stage again and rotate the sample to the first grinding mechanism for thinning according to the fixed rotation angle. After the thinning is completed at the first grinding mechanism, the indexing table is controlled to rotate according to the fixed rotation angle and the current compensation angle and compensation steering determined by the last image recognition so that the sample is rotated to the second grinding mechanism for thinning. After thinning, execute S07; S07, controlling the indexing table to rotate so that the wafer stage rotates to the loading and unloading position, and determining whether there is a center spot on the top of the sample on the wafer stage by image recognition again, and when it is determined that there is no center spot, executing S08, and when it is determined that there is a center spot, executing S09; S08, determining that the compensation angle and compensation direction of the indexing table corresponding to the wafer stage are the current compensation angle and compensation direction determined by the last image recognition; S09, determining the current compensation angle and compensation direction according to the size parameters of the central spot determined by the current image recognition and executing S06.

9. Indexing table compensation parameter determination system, characterized in that: include: A thinning execution unit is used to, after a sample is concentrically placed on a wafer table at a loading and unloading position, rotate the sample to the first grinding mechanism and the second grinding mechanism in sequence according to a fixed rotation angle for thinning; A dividing table control unit, used for controlling the dividing table to rotate according to the fixed angle after thinning so that the wafer carrier rotates to a loading and unloading position; A first image recognition unit is used to determine whether there is a center spot on the top of the sample on the platen through image recognition, and communicate with the first compensation parameter determination unit when it is determined that there is no center spot, and communicate with the first calculation unit when it is determined that there is a center spot; A first compensation parameter determination unit is used to determine that the compensation angle of the indexing table corresponding to the wafer stage is 0°; A first calculation unit, used for determining a current compensation angle and a compensation direction according to the size parameters of the central spot and communicating with a re-execution unit; a re-compensation unit, for unloading the thinned sample on the wafer stage, placing a sample on the wafer stage again concentrically and rotating the sample to the first grinding mechanism for thinning according to the fixed rotation angle, and after completing the thinning at the first grinding mechanism, controlling the rotation of the indexing table according to the fixed rotation angle and the current compensation angle and compensation direction determined by the last image recognition to rotate the sample to the second grinding mechanism for thinning, and communicating with the second image recognition unit after thinning; A second image recognition unit is used to control the rotation of the indexing table so that the wafer table rotates to a loading and unloading position, and to determine whether there is a center spot on the top of the sample on the wafer table through image recognition again, and to communicate with the second compensation parameter determination unit when it is determined that there is no center spot, and to communicate with the second calculation unit when it is determined that there is a center spot; A second compensation parameter determination unit, used to determine the compensation angle and compensation direction of the indexing table corresponding to the wafer stage to be the current compensation angle and compensation direction determined by the last image recognition; The second calculation unit is used to determine the current compensation angle and compensation direction according to the size parameters of the central spot determined by the current image recognition and communicate with the re-compensation unit.

10. A thinning device, comprising a memory and a processor, wherein the memory stores a program executable by the processor, characterized in that: When the program is executed, the thinning method as described in any one of claims 1 to 7 or the method for determining the compensation parameters of the indexing table as described in claim 8 is implemented.

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