Wafer edge annular cutting deviation rectifying method and system

Abstract

The invention discloses a deviation rectification method and system for wafer edge annular cutting, and the method comprises the following steps: placing a wafer on a workbench, and obtaining data through an image recognition system; the algorithm calculation system calculates a deviation distance and a rotation angle according to the identification data; coordinates of cutting in the front-back direction are calculated; the motion control system controls the workbench to move; and the system judges whether the deviation is continuously corrected until the T shaft rotates to the target position. According to the wafer edge annular cutting deviation rectifying method, the rotating position of the current cutting position is read in real time, the position of the Y axis is calculated in real time according to the rotating position, meanwhile, position deviation rectifying is conducted on the Y axis, annular cutting is achieved, and cutting precision and performance are improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor device processing, and in particular to a wafer edge annular cutting deviation correction method and system. Background Art

[0002] During the dicing process, the blade angle is always parallel to the horizontal direction of the workbench (i.e., the X direction), which has no effect on horizontal cutting. However, it is different when performing circular cutting. The workbench performs circular cutting by constantly changing the circular cutting T (rotation) angle. The cutting position of the blade and the wafer is no longer the initial tangent direction but forms an uncertain angle, which needs to be corrected in time to reduce the angle. It is difficult to achieve the required accuracy while achieving circular cutting.

[0003] The traditional approach is to divide the ring into several equal parts, use fixed value correction, transform the circle into a certain number of polygons, and calculate the Y (front and back) and T (rotation) positions of each division in advance. However, the movement is not uniform, but fluctuates around the set speed. This method of operation will cause large ring errors and edge collapse due to the uncertainty in the movement process. Not only is it difficult to guarantee accuracy and performance, it will also cause damage to the wafer. Summary of the invention

[0004] The purpose of the present invention is to solve the above problems existing in the prior art and provide a method for correcting the wafer edge circular cutting. To achieve the above purpose, the present invention provides the following technical solutions:

[0005] A method for correcting the wafer edge circular cutting, the method at least comprising:

[0006] Placing a wafer on a workbench, identifying the wafer, and collecting wafer data;

[0007] Acquire the actual movement position of the T-axis of the worktable, determine the deviation correction position through the actual movement position and wafer data, and determine the cutting position through the deviation correction position;

[0008] The workbench moves longitudinally to the cutting position;

[0009] All actual motion positions are traversed and corrected until the T axis rotates to the target position.

[0010] In an alternative embodiment, it further comprises:

[0011] Get the center position of the microscope;

[0012] The edge of the wafer is identified, an identification image of the wafer is obtained, the center position of the wafer is determined, and wafer data is collected.

[0013] In an alternative embodiment, the collecting wafer data further includes:

[0014] Collecting the deviation distance and rotation angle of the wafer, wherein the deviation distance at least includes a first deviation, a second deviation and a center deviation;

[0015] The first deviation is determined by the longitudinal difference between the center position and the circle center position;

[0016] The second deviation is determined by a lateral difference between the center position and the circle center position;

[0017] The center deviation and the rotation angle are determined by the first deviation distance and the second deviation distance respectively, wherein the center deviation is the straight-line distance between the center position and the center position of the circle, and the rotation angle is the angle between the line connecting the center and the center of the circle and the horizontal direction of the workbench.

[0018] In an alternative embodiment, determining the rotation angle further comprises:

[0019] Comparing the lateral values ​​of the circle center position and the center position;

[0020] If the lateral value of the center position is greater than the lateral value of the circle center position, the rotation angle is directly determined by the first deviation and the second deviation;

[0021] If the lateral value of the center position is not greater than the lateral value of the circle center position, performing secondary processing on the result directly obtained by the first deviation and the second deviation, and determining the rotation angle according to the result after the secondary processing;

[0022] After the radian result is obtained by the first deviation and the second deviation, the radian is converted into a rotation angle.

[0023] In an alternative embodiment, the step of obtaining the actual movement position of the T-axis of the worktable, determining the deviation correction position through the actual movement position and wafer data, and determining the cutting position through the deviation correction position further comprises:

[0024] Acquiring an actual movement position of the T-axis, and determining an actual position of the T-axis in the recognition image according to the actual movement position;

[0025] Calculating the size of the pre-cut wafer by using the collected wafer data, wherein the wafer data includes the original wafer size and the annular cut portion size;

[0026] According to the actual position of the T-axis, the actual longitudinal position of the wafer is corrected to obtain the position deviation and determine the cutting position.

[0027] In an alternative embodiment, determining the actual position of the T axis in the recognition image further comprises:

[0028] The actual position of the T-axis on the recognition image is determined according to the center position of the circle, the actual movement position of the T-axis and the rotation angle.

[0029] In an alternative embodiment, the position deviation includes a first position deviation and a second position deviation, wherein the first position deviation is a longitudinal distance between the center position and a preset coordinate origin, and the second position deviation is a longitudinal distance between the center position and the blade.

[0030] In an alternative embodiment, the determining the cutting position further comprises:

[0031] Determine the deviation correction distance according to the center deviation, the wafer size after pre-cutting and the actual position of the T-axis;

[0032] The correction distance is converted into a cutting distance through the first position deviation, and the cutting distance is converted into a cutting position through the second position deviation.

[0033] In an alternative embodiment, traversing all actual motion positions and correcting the deviation until the T-axis rotates to the target position further includes:

[0034] Moving the wafers to actual movement positions in sequence;

[0035] Identifying the wafer and acquiring the current center position of the wafer;

[0036] According to the current center position of the circle, the current rotation angle is calculated to determine whether the T axis has rotated to the target position;

[0037] If it is not rotated to the target position, the actual moving position is corrected and the wafer is longitudinally moved to the corrected cutting position;

[0038] If the wafer is rotated to the target position, the circular cutting of the edge of the wafer is completed.

[0039] The present invention also provides a wafer edge annular cutting deviation correction system, the wafer edge annular cutting deviation correction system comprising:

[0040] An identification module, the identification module is used to identify the wafer and obtain wafer data;

[0041] A correction module, which is used to determine the actual position of the T-axis, determine the correction position according to the actual position of the T-axis, and determine the cutting position according to the correction position;

[0042] The motion control module is used to control the longitudinal movement of the workbench to the cutting position to complete the cutting.

[0043] The judgment module is used to traverse all cutting positions and correct the deviation until the center of the wafer rotates to the target position corresponding to the T axis.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] The wafer edge circular cutting correction method of the present invention aims at the shortcomings of the prior art, collects the current actual movement position in real time, calculates the position of the wafer on the Y-axis according to the actual movement position, determines the correction position, and determines the cutting position through the correction position, and controls the workbench to move along the Y-axis to the cutting position, and realizes circular cutting through continuous position correction and position judgment until the T-axis finally rotates to the target position, thereby realizing circular cutting, solving the problem of uncertainty in movement and greatly improving the accuracy of compensation and correction. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 The flowchart of the wafer edge circular cutting correction method is as follows;

[0047] Figure 2 This is a schematic diagram of the wafer edge circular cutting correction;

[0048] Figure 3 A specific schematic diagram of the wafer edge circular cutting deviation correction method;

[0049] In the figure: X-axis, horizontal direction of the workbench; Y-axis, front-to-back direction of the workbench; Point O, center of the microscope; Point A, center of the image recognition wafer; T, rotation angle; Point B, intersection of the wafer and the Y-axis; Point C, intersection of the cutting ring and the Y-axis; Point D, point where the wafer center point A intersects vertically with the Y-axis. DETAILED DESCRIPTION

[0050] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0051] Embodiments of the present invention, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The terms "first", "second", "third", etc. (if any) in the specification and claims of the present invention and the accompanying drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the objects described in this way can be interchanged where appropriate. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. The directional terms mentioned in the present invention, such as: up, down, left, right, front, back, inside, outside, side, etc., are only reference directions of the accompanying drawings. The embodiments described below by reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention. In addition, the present invention repeats reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides examples of various specific processes and materials, but a person of ordinary skill in the art can recognize the application of other processes and / or the use of other materials.

[0052] The present invention provides a method for correcting the wafer edge circular cutting, the method comprising the following steps:

[0053] S100, placing a wafer on a workbench, identifying the wafer, and collecting wafer data;

[0054] In this step, the horizontal direction of the workbench is set as the X-axis, the vertical direction is set as the Y-axis, the X-axis and the Y-axis intersect vertically at the coordinate origin, the rotation direction is the T-axis, the center of the microscope is point O, the center of the wafer is point A, point B is set as the intersection of the original wafer and the Y-axis, point C is the intersection of the wafer and the Y-axis after cutting, point D is the point through the wafer center point A and the Y-axis intersects vertically, and point D is the point through the wafer center point A and the Y-axis intersects vertically, forming a right triangle △ODA and a right triangle △CDA.

[0055] S110, obtaining the center position of the microscope, the coordinates are LensCenter (MicroCenXPos, MicroCenYPos);

[0056] S120, identifying the edge of the wafer, obtaining an identification image of the wafer, determining the center position of the wafer, the coordinates of which are CenterChipPos (PosX, PosY, PosT), and collecting wafer data;

[0057] S121. Collect wafer data including at least wafer deviation distance and rotation angle T.

[0058] The deviation distance of the wafer includes at least a first deviation, a second deviation and a center deviation;

[0059] S130, collecting wafer deviation.

[0060] Specifically,

[0061] Determine the first deviation by the longitudinal difference between the center position and the circle center position;

[0062] OffsetCenterPos.PosY=CenterChipPos.PosY-LensCenter.MicroCenYPos

[0063] Determine the second deviation by the lateral difference between the center position and the circle center position;

[0064] OffsetCenterPos.PosX=CenterChipPos.PosX-LensCenter.MicroCenXPos;

[0065] The center deviation is the straight-line distance between the center and the center of the circle. In the right triangle △ODA, according to the Pythagorean theorem, the center deviation is determined using the first deviation distance and the second deviation distance.

[0066] fCalcCenterPos=(OffsetCenterPos.PosX) 2 +(OffsetCenterPos.PosY) 2

[0067] Among them, OffsetCenterPos.PosY is the first deviation, OffsetCenterPos.PosX is the second deviation, and fCalcCenterPos is the straight-line distance OA between the center and the center of the circle.

[0068] S140: Collect the rotation angle T.

[0069] In this step, the rotation angle T is the angle (∠AOX) formed by the line connecting the center and the center of the circle and the horizontal direction of the workbench (ie, the X-axis).

[0070] S141. Compare the horizontal values ​​(i.e., the horizontal coordinates) of the circle center position and the center position, specifically LensCenter.MicroCenXPos and CenterChipPos.PosX.

[0071] S142: If the lateral value of the center position is greater than the lateral value of the circle center position, directly determine the rotation angle through the first deviation and the second deviation.

[0072] Specifically, when LensCenter.MicroCenXPos > CenterChipPos.PosX, directly substitute the first deviation and the second deviation into the arctangent operation to obtain the rotation angle T.

[0073]

[0074] If the horizontal value of the center position is not greater than the horizontal value of the center of the circle position, perform secondary processing on the result directly obtained from the first deviation and the second deviation, and determine the rotation angle according to the result after secondary processing.

[0075] Specifically, when LensCenter.MicroCenXPos < CenterChipPos.PosX, substitute the first deviation and the second deviation into the arctangent operation, and through secondary processing, add 180° to the calculated result to calculate the rotation angle T of the center of the crystal circle.

[0076]

[0077] In the formula, OffsetCenterPos.PosT is the rotation angle T of the center of the crystal circle.

[0078] Furthermore, after obtaining the radian result from the first deviation and the second deviation, convert the radian to the rotation angle.

[0079] S200. Obtain the actual movement position of the T-axis of the workbench, determine the deviation correction position through the actual movement position and the wafer data, and determine the cutting position through the deviation correction position.

[0080] In this step, the cutting position is calculated jointly by the actual movement position of the T-axis and the wafer data.

[0081] S210. Collect the actual movement position of the T-axis, and determine the actual position of the T-axis in the recognition image according to the actual movement position.

[0082] S211. Determine the actual position of the T-axis in the recognition image according to the center position, the actual movement position of the T-axis, and the rotation angle.

[0083] Specifically,

[0084] fCalcTransTSPos = OffsetCenterPos.PosT + ParaCutOneLine.dTPos - CenterChipPos.PosT

[0085] Among them, fCalcTransTSPos is the actual position of the T axis on the recognition image, ParaCutOneLine.dTPos is the actual movement position of the T axis, and CenterChipPos.PosT is the T axis position of point A, the center of the wafer.

[0086] S220, calculating the wafer size AC after pre-cutting by using the collected wafer data, wherein the wafer data includes the original wafer size and the annular cutting portion size, and the wafer size AC after pre-cutting is the difference between the wafer radius and the annular cutting portion size.

[0087] Specifically, AC = 0.5 × WorkCharacter.WorkRoundDiameter - fRingSize,

[0088] Among them, WorkCharacter.WorkRoundDiameter is the original wafer size, and fRingSize is the size of the ring cutting part.

[0089] S230, according to the actual position of the T-axis, the actual longitudinal position of the wafer is corrected, the position deviation is obtained, and the cutting position is determined.

[0090] The position deviation includes a first position deviation and a second position deviation. The first position deviation is the longitudinal distance between the center and the preset coordinate origin, which is reflected as the longitudinal coordinate of the center. The second position deviation is the longitudinal distance between the center and the blade.

[0091] S231. Determine the deviation correction distance according to the center deviation, the wafer size after pre-cutting, and the actual position of the T-axis.

[0092] Specifically, in the right-angle △ODA, the distance OD from point O to point D is obtained using the sine trigonometric function according to the center deviation and the actual position of the T axis on the recognition image;

[0093] In the right angle △ODA, according to the center deviation and the actual position of the T axis on the recognition image, the distance AD ​​from point A to point D is obtained by using the cosine trigonometric function.

[0094] In the right triangle △CDA, the distance DC from point C to point D is obtained by using the Pythagorean theorem based on the wafer sizes AC and AD after pre-cutting;

[0095]

[0096] It is easy to obtain that the correction distance OC is the total length of the distance OD from point O to point D and the distance DC from point D to point C.

[0097] S232, converting the correction distance OC into a cutting distance through the first position deviation.

[0098]

[0099] Among them, LensCenter.MicroCenYPos is the longitudinal distance between the center and the preset coordinate origin, which is recorded as the first position deviation.

[0100] S233, converting the cutting distance into the cutting position through the second position deviation.

[0101] Y1CuttingPos=fCalcTransYPos+LengthFromMicroToZ1Blade,

[0102] Among them, LengthFromMicroToZ1Blade is the distance between the microscope and the blade, which is recorded as the second position deviation.

[0103] S300, the workbench moves longitudinally to the calculated cutting position.

[0104] Specifically, the system sends the calculated cutting position to the motion control module, and the motion control module controls the workbench to move longitudinally along the Y-axis to the calculated cutting position.

[0105] S400, traverse all actual motion positions and correct them until the T axis rotates to the target position.

[0106] S410, moving the wafers to actual movement positions in sequence.

[0107] S420, identifying a wafer and acquiring a current center position of the wafer.

[0108] S430, calculating the current rotation angle T according to the current center position, and determining whether the T axis has rotated to the target position.

[0109] S440, if it has not rotated to the target position, the actual moving position is corrected and the wafer is longitudinally moved to the cutting position after the correction; if it has rotated to the target position, the edge circular cutting of the wafer is terminated.

[0110] The present invention also provides a system for correcting the circular cutting of the wafer edge. The correction system includes an identification module, which is used to identify the wafer and obtain wafer data; a correction module, which is used to determine the actual position of the T-axis, determine the correction position according to the actual position of the T-axis, and determine the cutting position according to the correction position; a motion control module, which is used to control the longitudinal movement of the workbench to the cutting position to complete the cutting; and a judgment module, which is used to traverse all cutting positions and correct the deviations until the T-axis corresponding to the center of the wafer rotates to the target position.

[0111] What is described above is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for correcting the wafer edge circular cutting, characterized in that: The correction method at least comprises: Placing a wafer on a workbench, identifying the wafer, and collecting wafer data; Acquire the actual movement position of the T-axis of the worktable, determine the deviation correction position through the actual movement position and wafer data, and determine the cutting position through the deviation correction position; The workbench moves longitudinally to the cutting position; All actual motion positions are traversed and corrected until the T axis rotates to the target position.

2. The method for correcting the wafer edge circular cutting according to claim 1, characterized in that: The collecting of wafer data further comprises: Get the center position of the microscope; The edge of the wafer is identified, an identification image of the wafer is obtained, the center position of the wafer is determined, and wafer data is collected.

3. The method for correcting the wafer edge circular cutting according to claim 2, characterized in that: The collecting of wafer data also includes: Collecting the deviation distance and rotation angle of the wafer, wherein the deviation distance at least includes a first deviation, a second deviation and a center deviation; The first deviation is determined by the longitudinal difference between the center position and the circle center position; The second deviation is determined by a lateral difference between the center position and the circle center position; The center deviation and the rotation angle are determined by the first deviation and the second deviation respectively, wherein the center deviation is the straight-line distance between the center position and the center position of the circle, and the rotation angle is the angle between the line connecting the center and the center of the circle and the transverse direction of the workbench.

4. The method for correcting the wafer edge circular cutting according to claim 3, characterized in that: Determining the rotation angle further comprises: Comparing the lateral values ​​of the circle center position and the center position; If the lateral value of the center position is greater than the lateral value of the circle center position, the rotation angle is directly determined by the first deviation and the second deviation; If the lateral value of the center position is not greater than the lateral value of the circle center position, performing secondary processing on the result directly obtained by the first deviation and the second deviation, and determining the rotation angle according to the result after the secondary processing; After the radian result is obtained by the first deviation and the second deviation, the radian is converted into a rotation angle.

5. The method for correcting the wafer edge circular cutting according to claim 1, characterized in that: The step of obtaining the actual movement position of the T-axis of the worktable, determining the deviation correction position through the actual movement position and wafer data, and determining the cutting position through the deviation correction position further includes: Acquiring an actual movement position of the T-axis, and determining an actual position of the T-axis in the recognition image according to the actual movement position; Calculating the size of the pre-cut wafer by using the collected wafer data, wherein the wafer data includes the original wafer size and the annular cut portion size; According to the actual position of the T-axis, the actual longitudinal position of the wafer is corrected to obtain the position deviation and determine the cutting position.

6. The method for correcting the wafer edge circular cutting according to claim 5, characterized in that: The determining the actual position of the T axis in the recognition image further comprises: The actual position of the T-axis on the recognition image is determined according to the center position of the circle, the actual movement position of the T-axis and the rotation angle.

7. The method for correcting the wafer edge circular cutting according to claim 6, characterized in that: The position deviation includes a first position deviation and a second position deviation, wherein the first position deviation is a longitudinal distance between a center position and a preset coordinate origin, and the second position deviation is a longitudinal distance between the center position and a blade.

8. The method for correcting the wafer edge circular cutting according to claim 7, characterized in that: The step of determining the cutting position further comprises: Determine the deviation correction distance according to the center deviation, the wafer size after pre-cutting and the actual position of the T-axis; The correction distance is converted into a cutting distance through the first position deviation, and the cutting distance is converted into a cutting position through the second position deviation.

9. The method for correcting the wafer edge circular cutting according to claim 8, characterized in that: The traversing all actual motion positions and correcting the deviation until the T-axis rotates to the target position further includes: Moving the wafers to actual movement positions in sequence; Identifying the wafer and acquiring the current center position of the wafer; According to the current center position of the circle, the current rotation angle is calculated to determine whether the T axis has rotated to the target position; If it is not rotated to the target position, the actual moving position is corrected and the wafer is longitudinally moved to the corrected cutting position; If the wafer is rotated to the target position, the circular cutting of the edge of the wafer is completed.

10. A system using the wafer edge circular cutting deviation correction method according to any one of claims 1 to 9, characterized in that: The system comprises: An identification module, the identification module is used to identify the wafer and obtain wafer data; A correction module, which is used to determine the actual position of the T-axis, determine the correction position according to the actual position of the T-axis, and determine the cutting position according to the correction position; The motion control module is used to control the longitudinal movement of the workbench to the cutting position to complete the cutting. The judgment module is used to traverse all cutting positions and correct the deviation until the center of the wafer rotates to the target position corresponding to the T axis.

Images