A method for edge deviation positioning

Abstract

The present application provides a method for edge-finding deviation positioning, which relates to the field of wafer processing technology. The edge-finding mechanism includes a positioning base and a detection mechanism; the positioning base is provided with a first detection hole and a second detection hole; the line between the center of the first detection hole and the center of the second detection hole is a positioning reference line; the method includes the following steps: the wafer completely blocks the first detection hole and the second detection hole to obtain the detection value #imgabs0# in the first detection hole and the second detection hole in the above case; the wafer is moved so that the positioning edge is tangent or intersected with the first detection hole and intersected with the second detection hole, and the detection value #imgabs1#, #imgabs2# and the detection value #imgabs3# of the first detection hole in the above case are obtained; the angle #imgabs4# formed by the positioning edge and the positioning reference line is calculated; the first point of the positioning edge is selected as a fixed point, and the first point is taken as the center of the circle, and the wafer is driven to rotate around the first point by an angle #imgabs5#, so that the positioning edge is parallel to the positioning reference line. The defect of long wafer positioning time in the related art is solved.

Description

Technical Field

[0001] The present application relates to the field of wafer processing technology, and in particular to a method for edge deviation positioning. Background Art

[0002] A wafer is the substrate used to manufacture semiconductor transistors or integrated circuits. Due to precision requirements for wafer processing, some wafers are cut with a notch. This notch is used to precisely locate the wafer, a process known as wafer edge finding.

[0003] During the wafer manufacturing process, wafers need to be frequently transferred between different carriers and wafer boxes. Since the position of the wafers may be offset by millimeters when the robot takes and places the wafers from the slots of the wafer box, the direction of the positioning edge of the wafer will not be fixed when the wafer is moved to the carrier.

[0004] The existing centering device usually places the wafer on a vacuum suction cup so that the center of the wafer and the center of the vacuum suction cup are located on the same axis. The vacuum suction cup can drive the wafer to rotate, and the wafer is rotated to the desired position by the vacuum suction cup.

[0005] Since the size of the wafer needs to be extremely precise during processing, it is also necessary to accurately position the positioning edge of the wafer. In the existing technology, in order to ensure that the positioning edge can be accurately rotated to the expected position, the wafer needs to be rotated several times in small increments until the positioning edge of the wafer completely coincides with the expected position. However, this operation undoubtedly takes a lot of time to position the wafer, reducing the processing efficiency of the wafer. Summary of the Invention

[0006] The purpose of this application is to provide an edge deviation positioning method, which aims to solve the defect in the related art that the wafer positioning time is long and the wafer processing efficiency is low.

[0007] Additional aspects and advantages of the present application will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the present application.

[0008] According to a first aspect of the present application, a method for edge-finding deviation positioning is provided. The method is applied to an edge-finding mechanism, wherein the edge-finding mechanism includes a positioning base and a detection mechanism; a wafer is placed on the positioning base, and a first detection hole and a second detection hole are provided on the positioning base; the first detection hole and the second detection hole are of the same size and are both connected to the detection mechanism, and a line connecting the center of the first detection hole and the center of the second detection hole serves as a positioning reference line; the detection mechanism is used to detect a detection value of a set detection substance passing through the first detection hole and the second detection hole, wherein the detection value is proportional to the area of ​​the first detection hole and the second detection hole blocked by the wafer;

[0009] The method comprises the following steps:

[0010] Place the wafer on the positioning base and completely cover the first detection hole and the second detection hole, and obtain the detection values ​​in the first detection hole and the second detection hole under the above situation ;

[0011] Move the wafer so that the positioning edge of the wafer is tangent to or intersecting with the first detection hole and intersecting with the second detection hole, and obtain the detection value of the first detection hole in the above situation 、 and the detection value of the second detection hole ;

[0012] According to the detection value The detection value of the first detection hole 、 and the detection value of the second detection hole , the radius of the first detection hole , and the center distance between the first detection hole and the second detection hole , calculate the angle between the positioning edge of the wafer and the positioning reference line ;

[0013] Select the first point of the positioning edge as the fixed point, take the first point as the center of the circle, and drive the wafer to rotate around the first point by an angle , so that the positioning edge of the wafer is parallel to the positioning reference line.

[0014] In an exemplary embodiment of the present application, any other point on the positioning edge is selected as a driving point, the distance between the first point and the driving point is a radius, and the driving point of the positioning edge is driven to rotate the positioning edge around the first point by an angle , so that the positioning edge of the wafer is parallel to the positioning reference line.

[0015] In an exemplary embodiment of the present application,

[0016] When the positioning edge of the wafer is tangent to the first detection hole and intersected with the second detection hole, according to the detection value The detection value of the first detection hole and the detection value of the second detection hole , the radius of the first detection hole , and the center distance between the first detection hole and the second detection hole , calculate the angle between the positioning edge of the wafer and the positioning reference line include:

[0017] Using the detection value and test values Calculate the arc of the blocked portion of the second detection hole ;

[0018] Using radians , the radius of the second detection hole and the center distance between the first detection hole and the second detection hole Calculate the angle between the positioning edge of the wafer and the positioning reference line .

[0019] In an exemplary embodiment of the present application, the distance between the two intersection points of the positioning edge and the second detection hole is calculated as follows: :

[0020] .

[0021] In an exemplary embodiment of the present application, the distance between the tangent point formed by the positioning edge and the first detection hole and the farther one of the two intersection points formed by the positioning edge and the second detection hole is calculated according to the following method: :

[0022] .

[0023] In an exemplary embodiment of the present application, the angle is calculated as follows: :

[0024] 。

[0025] In an exemplary embodiment of the present application,

[0026] When the positioning edge of the wafer intersects the first detection hole and the second detection hole, according to the detection value The detection value of the first detection hole and the detection value of the second detection hole , the radius of the first detection hole , and the center distance between the first detection hole and the second detection hole , calculate the angle between the positioning edge of the wafer and the positioning reference line include:

[0027] Using the detection value and test values Calculate the arc of the blocked portion of the first detection hole ;

[0028] Using the detection value and test values Calculate the arc of the blocked portion of the second detection hole ;

[0029] Using radians ,radian , the radius of the first detection hole , and the center distance between the first detection hole and the second detection hole , calculate the angle between the positioning edge of the wafer and the positioning reference line .

[0030] In an exemplary embodiment of the present application, the radian is calculated as follows and radians :

[0031] ;

[0032] .

[0033] In an exemplary embodiment of the present application, the chord-center distance of the first detection hole is calculated according to the following method: and the chord-center distance of the second detection hole :

[0034] ;

[0035] .

[0036] In an exemplary embodiment of the present application, when the positioning edge of the wafer and the secant line of the first detection hole, and the secant line of the positioning edge of the wafer and the second detection hole are located on the same side of the connecting line between the center of the first detection hole and the center of the second detection hole, then the extension line of the positioning edge of the wafer and the extension line of the line segment corresponding to the center distance L have an intersection.

[0037] In an exemplary embodiment of the present application, if the distance between the intersection point and the center of the first detection hole is less than the distance between the intersection point and the center of the second detection hole, the distance between the intersection point and the first detection hole is calculated in the following manner: and angle :

[0038] ,

[0039] or .

[0040] In an exemplary embodiment of the present application, if the distance between the intersection point and the center of the second detection hole is less than the distance between the intersection point and the center of the first detection hole, the distance between the intersection point and the second detection hole is calculated in the following manner: and angle :

[0041] ,

[0042] or .

[0043] In an exemplary embodiment of the present application, the secant line between the positioning edge of the wafer and the first detection hole and the secant line between the positioning edge of the wafer and the second detection hole are located on the opposite sides of the connecting line between the center of the first detection hole and the center of the second detection hole, then the distance between the positioning edge of the wafer and the center is The corresponding line segments have an intersection, and the intersection is located between the first detection hole and the second detection hole.

[0044] In an exemplary embodiment of the present application, the distance y and the angle from the intersection to the second detection hole are calculated as follows: :

[0045] ，

[0046] .

[0047] In an exemplary embodiment of the present application, the set detection substance is gas, the first detection hole is a first air blowing hole, the second detection hole is a second air blowing hole, the detection value is the air pressure value passing through the first air blowing hole and the second air blowing hole, and the detection mechanism is configured to detect the air pressure value in the first detection hole and the second detection hole; or,

[0048] The set detection material is a light beam, the first detection hole is a first light-transmitting hole, the second detection hole is a second light-transmitting hole, the detection value is the light-shielding rate passing through the first light-transmitting hole and the second light-transmitting hole, and the detection mechanism is configured to detect the light-shielding rate passing through the first light-transmitting hole and the second light-transmitting hole.

[0049] The exemplary embodiments of the present application may have some or all of the following beneficial effects:

[0050] In the example embodiment of the present application, a method for edge deviation positioning is provided. By determining the connecting line of the center of the first detection hole and the center of the second detection hole as the positioning reference line, the final state to be achieved is to make the positioning edge of the wafer parallel to the positioning reference line. When the wafer position needs to be adjusted, the wafer is first placed on the positioning base so that the wafer is in a state of complete obstruction of the first detection hole and the second detection hole, and the detection value of the first detection hole and the second detection hole at this time should be detected by the detection mechanism. , and then the wafer is preliminarily moved. The wafer can be moved to a state where the positioning edge is tangent to the first detection hole and intersected by the second detection hole; or the wafer can be moved to a state where the positioning edge is intersected by both the first detection hole and the second detection hole. When the positioning edge is tangent to the first detection hole, the wafer does not block the first detection hole, making the first detection hole completely unobstructed. At this time, the detection value in the first detection hole should be , the detection value in the second detection hole should be When the positioning edge intersects the first detection hole and the second detection hole, the detection value in the first detection hole should be , the detection value in the second detection hole should be Then set any point on the positioning edge as the first point, and use the first point as a fixed point to drive the wafer to rotate. Before the wafer is driven to rotate, the detection value is , detection value , detection value , detection value , the radius of the first detection hole , and the center distance between the first detection hole and the second detection hole , the angle between the positioning edge of the wafer and the positioning reference line can be calculated ; That is to say, the wafer only needs to use the first point as the rotation center, and the wafer rotates at an angle , the positioning reference line can be made parallel to the positioning edge. Furthermore, the above structure provides a method for accurately rotating the wafer positioning edge to be parallel to the positioning reference line, eliminating the need for repeated adjustments by the operator. This shortens the time required for wafer positioning and improves wafer processing efficiency.

[0051] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] The accompanying drawings are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification, are used to explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0053] Figure 1 A top view of an edge-finding deviation positioning method in Example 1 of the present application is shown;

[0054] Figure 2 A method for finding and positioning an edge in Example 1 of the present application is shown when the positioning edge is tangent to the first detection hole and intersecting with the second detection hole;

[0055] Figure 3 Another edge-finding and positioning method is shown when the positioning edge in Example 1 of the present application is in a state of being tangent to the first detection hole and intersecting with the second detection hole;

[0056] Figure 4 A schematic diagram showing the positional relationship between the positioning edge, the first blowing hole, and the second blowing hole in Case 3 of Example 2 of the present application is shown;

[0057] Figure 5 A schematic diagram showing the positional relationship between the positioning edge, the first blowing hole, and the second blowing hole in Case 4 of Example 2 of the present application is shown;

[0058] Figure 6 A schematic diagram showing the positional relationship between the positioning edge, the first blowing hole and the second blowing hole in another implementation of Example 2 of the present application is shown.

[0059] Description of reference numerals:

[0060] 1. Wafer; 11. Positioning edge; 2. Positioning base; 21. First detection hole; 22. Second detection hole. DETAILED DESCRIPTION

[0061] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this application will be thorough and complete and will fully convey the concepts of the example embodiments to those skilled in the art. Like reference numerals in the figures represent like or similar structures, and thus their detailed descriptions will be omitted. Furthermore, the figures are merely schematic illustrations of the present application and are not necessarily drawn to scale.

[0062] While relative terms such as "upper" and "lower" are used in this specification to describe the relationship of one illustrated component to another, these terms are used for convenience only, such as in accordance with the orientation of the illustrations in the accompanying drawings. It should be understood that if the illustrated device were flipped upside down, the component described as "upper" would become the component "lower." When a structure is referred to as "on" another structure, this may mean that the structure is integrally formed with the other structure, that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure through the other structure.

[0063] The terms "a", "an", "the" and "at least one" are used to indicate the presence of one or more elements / components / etc.; the terms "including" and "having" are used to express open-ended inclusion and mean that additional elements / components / etc. may be present in addition to the listed elements / components / etc.; the terms "first" and "second" are used only as labels and do not limit the quantity of their objects. Example 1

[0064] like Figure 1 As shown, in an embodiment of the present application, a method for edge-finding deviation positioning is provided, which is applied to an edge-finding mechanism, and the edge-finding mechanism includes a positioning base 2 and a detection mechanism; the wafer 1 is placed on the positioning base 2, and the positioning base 2 is provided with a first detection hole 21 and a second detection hole 22; the first detection hole 21 and the second detection hole 22 have the same size and are both connected to the detection mechanism, and the line between the center of the first detection hole 21 and the center of the second detection hole 22 is the positioning reference line; the detection mechanism is used to detect the detection value of the set detection material passing through the first detection hole 21 and the second detection hole 22, and the detection value is proportional to the area of ​​the first detection hole 21 and the second detection hole 22 blocked by the wafer 1.

[0065] In the embodiment of the present application, no special restrictions are imposed on the first detection hole 21, the second detection hole 22, and the detection mechanism. The first detection hole 21 and the second detection hole 22 can be air blowing holes, in which case the first detection hole 21 is the first air blowing hole and the second detection hole 22 is the second air blowing hole. The first air blowing hole and the second air blowing hole are both connected to a gas source. The detection substance passing through the first detection hole 21 and the second detection hole 22 is gas. The detection mechanism can be configured as an air pressure sensor for detecting the air pressure value within the first air blowing hole and the second air blowing hole. The first detection hole 21 and the second detection hole 22 can also be light-transmitting holes. In which case the first detection hole 21 is the first light-transmitting hole and the second detection hole 22 is the second light-transmitting hole. The detection substance passing through the first light-transmitting hole and the second light-transmitting hole is a light beam. The detection mechanism can use a light sensor to detect the light-shielding rate of the first light-transmitting hole and the second light-transmitting hole.

[0066] like Figure 2 and Figure 3 As shown, the edge deviation positioning method provided in the embodiment of the present application includes the following steps:

[0067] Step S1: Place the wafer 1 on the positioning base 2 and completely cover the first detection hole 21 and the second detection hole 22, and obtain the detection values ​​in the first detection hole 21 and the second detection hole 22 under the above conditions. ;

[0068] First, the wafer 1 is accurately placed on the positioning base 2. At the same time, the wafer 1 needs to completely cover the first detection hole 21 and the second detection hole 22. At this time, the detection value in the first detection hole 21 and the second detection hole 22 is measured by the detection mechanism. , which is used as the reference value of the initial state;

[0069] Step S2, moving the wafer 1 so that the positioning edge 11 of the wafer 1 is tangent to the first detection hole 21 and intersected with the second detection hole 22, and obtaining the detection value of the first detection hole 21 in the above case and the detection value of the second detection hole 22 ;

[0070] In this state, the positioning edge 11 does not block the first detection hole 21. It can be understood that the detection material in the first detection hole 21 can pass through completely, so the detection value Then it is 0;

[0071] Step S3: according to the detection value The detection value of the first detection hole 21 、 and the detection value of the second detection hole 22 , the radius of the first detection hole 21 , and the center distance between the first detection hole 21 and the second detection hole 22 , calculate the angle between the positioning edge 11 of the wafer 1 and the positioning reference line ;

[0072] Step S4: Select the first point of the positioning edge 11 as a fixed point, and drive the wafer 1 to rotate around the first point with the first point as the center of the circle. , so that the positioning edge 11 of the wafer 1 is parallel to the positioning reference line.

[0073] In this embodiment, the wafer 1 is placed on the positioning base 2, and the detection value measured by the detection mechanism is and test values The arc of the blocked portion of the second detection hole 22 when the positioning edge 11 of the wafer 1 is tangent to the first detection hole 21 and intersected with the second detection hole 22 can be calculated. ; Then use radians , the radius of the second detection hole 22 The center distance between the first detection hole 21 and the second detection hole 22 Calculate the angle between the positioning edge 11 of the wafer 1 and the positioning reference line .

[0074] The specific operation can be as follows: When the included angle is obtained Then, any point on the positioning edge 11 of the wafer 1 is selected as the first point, the first point is set as the fixed point, and the wafer 1 is driven to rotate a specific angle with the first point as the rotation center. , so that the positioning edge 11 of the wafer 1 is completely parallel to the positioning reference line. This ensures the precise alignment of the positioning edge 11 of the wafer 1 and provides a high-precision positioning reference for subsequent wafer 1 processing operations.

[0075] It is important to emphasize that when using this method to determine positioning edge 11, there is no need to deliberately align the center of wafer 1 and the center of positioning base 2 on the same axis. Once positioning edge 11 is successfully located using this method, the center position of wafer 1 will be offset from its initial position. Therefore, this method is applicable to the following two situations:

[0076] Case 1: When the center of the wafer 1 and the center of the positioning base 2 do not need to be precisely aligned, that is, when there is no requirement for the center position offset of the wafer 1;

[0077] Scenario 2: Processing that requires strict alignment of wafer 1's center, requiring alignment of wafer 1 with the center of positioning base 2. In this scenario, this method is used to first align positioning edge 11 with the positioning reference line. Correction or compensation is then performed in subsequent processing steps. Specifically, the center of wafer 1 is adjusted during subsequent processing to align the center of wafer 1 with the center of the centering base.

[0078] It's important to note that in scenario 2, before centering, wafer 1's positioning edge 11 is already parallel to the positioning reference line. Therefore, wafer 1 can no longer rotate and can only translate. Before centering, the constraints on the first point should be released, allowing wafer 1 to translate freely in the horizontal plane until the center of wafer 1 and the center of positioning base 2 are perfectly aligned on the same axis, ensuring machining accuracy.

[0079] Furthermore, through the above method, the edge finding work of the positioning edge 11 can be completed with only two movements, without the need for repeated manual debugging, which significantly shortens the time required for positioning the wafer 1, thereby greatly improving the work efficiency of wafer 1 processing.

[0080] In the embodiment of the present application, the endpoint of one end of the positioning edge 11 is set as the first point, and the endpoint of the other end of the positioning edge 11 is set as the driving point. When the angle between the straight line where the positioning edge is located and the straight line where the positioning reference line is located is obtained, , drive the driving point on the positioning edge 11 with the first point as the rotation center and the positioning edge 11 as the rotation radius, so that the positioning edge 11 rotates toward the positioning reference line by an angle , so that the positioning edge 11 can be parallel to the positioning reference line.

[0081] Specifically, the center of the first detection hole 21 is recorded as , the center of the second detection hole 22 is recorded as , then the line segment The length is the distance between the centers of the circles The point where the positioning edge 11 of the wafer 1 is tangent to the first detection hole 21 is marked as point A, and the two points where the positioning edge 11 of the wafer 1 intersects with the second detection hole 22 are marked as points B and C respectively. is the length of the arc between points B and C. Then it is a line segment The angle formed by the extension line of the positioning edge 11 of the wafer 1 and the extension line of the positioning edge 11. Based on the above definition, it is not difficult to find that it is only necessary to set any point on the positioning edge 11 as the first point, and then use the first point as the rotation center to rotate the positioning edge 11 toward the direction of the first detection hole 21 by an angle of , the positioning edge 11 of the wafer 1 can be aligned with the line segment Parallel to each other, thereby achieving the effect of accurately positioning the positioning edge 11 of the wafer 1.

[0082] Furthermore, regarding the radian The calculation method is as follows: the passing area of ​​the first detection hole 21 can be defined as , since the size of the first detection hole 21 is the same as that of the second detection hole 22, the passing area of ​​the second detection hole 22 is also When the positioning edge 11 of the wafer 1 is rotated to be tangent to the first detection hole 21 and intersecting with the second detection hole 22, the arc The corresponding center angle is set to , at this time the central angle The corresponding sector area is set to , central angle The corresponding triangle area is set to (That is, the line segment in the figure , line segment and line segments The area of ​​the triangle enclosed by the circle), at this time the central angle The area of ​​the area blocked by the positioning edge 11 of the wafer 1 is set to Based on the above definitions, the following mathematical relationship can be established:

[0083] ,

[0084] ,

[0085] ,

[0086] ,

[0087] Based on the above relationship, in step S2, the radian can be calculated as follows :

[0088] ,

[0089] Applying the radius to the above formula Uncertainty ,radian Uncertainty , center distance ,radian and radius Differentiate and calculate the area as follows Uncertainty .

[0090] ,

[0091] Among them, the radius Uncertainty Mainly related to manufacturing errors, this parameter can be obtained through repeatability measurements, parameters provided in relevant calibration certificates or parameters in the manual. The uncertainty caused mainly comes from fitting error and pressure gauge error, which is calculated by the ratio of the current pressure value of the pressure gauge to the total pressure value.

[0092] When the positioning edge 11 of the wafer 1 moves toward the first detection hole 21, the intuitive phenomenon is that the area of ​​the first detection hole 21 shielded by the positioning edge 11 of the wafer 1 gradually expands, while at the same time, the area of ​​the second detection hole 22 shielded by the positioning edge 11 of the wafer 1 gradually shrinks until the shielded areas of the two are equal. Specifically, when the detection values ​​of the first detection hole 21 and the second detection hole 22 reach the same value (this detection value should be between 0 and Within the interval of ), the locating edge 11 of wafer 1 covers the first inspection hole 21 and the second inspection hole 22 equally. Therefore, the locating edge 11 of wafer 1 is aligned parallel to the preset positioning reference line, ensuring accurate positioning of wafer 1 during subsequent processing. Furthermore, the fifth-order polynomial fitting function is:

[0093] ,

[0094] ,

[0095] In the embodiment of the present application, the radian and It can be accurately calculated by the fifth-order polynomial fitting method, or numerically solved by the ergodic method. It is worth noting that the central angle The size of is directly related to the angle between the positioning edge 11 of the wafer 1 and the positioning reference line Specifically, the central angle The larger the value, the greater the angle between the positioning edge 11 and the positioning reference line. At this time, in order to achieve accurate positioning of the wafer 1, the positioning edge 11 of the wafer 1 needs to be accurately adjusted toward the direction of the first detection hole 21 to reduce the central angle , until the positioning edge 11 of the wafer 1 is parallel to the positioning reference line.

[0096] like Figure 2 As shown, in one embodiment, a line segment is set that can be tangent to the first detection hole 21 and the second detection hole 22 at the same time. , set the length of the chord formed by the positioning edge 11 of the wafer 1 and the edge of the second detection hole 22 (i.e., the length of the line segment BC) to , set the distance between the tangent point of the wafer 1 positioning edge 11 and the first detection hole 21 and the farther one of the two intersection points of the wafer 1 positioning edge 11 and the second detection hole 22 (i.e., the length of the line segment AC) to be .

[0097] It is understandable that the line segment The length of the line segment are equal in length, that is, the line segments The length is equal to .but:

[0098] ,

[0099] ,

[0100] Based on the above correspondence, in step S3, the angle can be obtained as follows: :

[0101] ,

[0102] In seeking You can then determine the angle by looking up a trigonometric table or using an inverse trigonometric calculator. The numerical value of .

[0103] Then, the first point on the positioning edge is used as the rotation center, so that the positioning edge 11 of the wafer 1 is rotated toward the reference line by an angle The positioning edge 11 of the wafer 1 can be made parallel to the positioning reference line, thereby achieving positioning of the positioning edge 11 of the wafer 1 .

[0104] like Figure 3 As shown, in another embodiment, the central angle is set The arc height of the corresponding sector area (i.e. the line segment in the figure DF )for , chord-center distance (i.e. the line segment in the figure )for . Arch height , chord-center distance and radians Has the following mathematical relationship:

[0105] ,

[0106] ,

[0107] ,

[0108] According to the above mathematical relationship, the angle can be calculated in step S3 as follows: :

[0109] ,

[0110] Measurement uncertainty assessment:

[0111] From the above relationship, we can see that Enough hours, at this time , then the above relationship can be approximated as:

[0112] ,

[0113] Applying the radius to the above formula Uncertainty , center distance Uncertainty ,radian Uncertainty , center distance ,radian and radius Differentiate and calculate the angle as follows Uncertainty .

[0114] ,

[0115] Among them, the radius Uncertainty and the distance between the centers of the circles Uncertainty Mainly related to manufacturing errors, this parameter can be obtained through repeatability measurements, parameters provided in relevant calibration certificates or parameters in the instruction manual.

[0116] angle The uncertainty caused mainly comes from fitting error and pressure gauge error. That is, it is calculated by the ratio of the current pressure value of the pressure gauge to the total pressure value. Assuming that the relative measurement error of the pressure gauge is 1%, the corresponding angle value at this time is The change is 1°. Example 2

[0117] like Figure 4-6 As shown, the difference from Example 1 is that when performing step S2, the wafer 1 is moved so that the positioning edge 11 of the wafer 1 intersects the first detection hole 21 and the second detection hole 22, and the detection value of the first detection hole 21 in the above case is obtained. and the detection value of the second detection hole 22 ;

[0118] Utilize detection value and test values Calculate the arc of the blocked portion of the first detection hole 21 ; Using the detection value and test values Calculate the arc of the blocked portion of the second detection hole 22 ;

[0119] Using radians ,radian , the radius of the first detection hole 21 (the second detection hole 22) The center distance between the first detection hole 21 and the second detection hole 22 Calculate the angle between the positioning edge 11 of the wafer 1 and the reference line ;

[0120] Then drive the wafer 1 to rotate with the first point on the positioning edge 11 as the rotation center, and rotate the angle , so that the positioning edge 11 of the wafer 1 is parallel to the positioning reference line.

[0121] In the embodiment of the present application, when the positioning edge 11 of the wafer 1 reaches a state of being cut simultaneously with the first detection hole 21 and the second detection hole 22, it means that the positioning edge 11 of the wafer 1 has reached a state of partially blocking the first detection hole 21 and the second detection hole 22 and partially exposing them. Whether the first detection hole 21 and the second detection hole 22 have reached the above-mentioned state can be determined by the detection value inside the two through the detection mechanism. When the detection value is 0, it means that the detection hole being detected is completely exposed and the positioning edge 11 of the wafer 1 does not block the detection hole; when the detection value is 0, it means that the detection hole being detected is completely exposed and the positioning edge 11 of the wafer 1 does not block the detection hole; Therefore, it can be understood that when the detection value is between 0- If it is within the range of , it means that the detection hole being detected has reached a state of being partially blocked and partially exposed, that is, the positioning edge 11 of the wafer 1 and the detection hole have reached a state of being cut off.

[0122] When the first detection hole 21 and the second detection hole 22 are both in a state of being cut by the positioning edge 11 of the wafer 1, the arc ,radian , the radius of the first detection hole 21 (the second detection hole 22) , and the center distance between the first detection hole 21 and the second detection hole 22 The angle between the positioning edge 11 of the wafer 1 and the reference line can be calculated. This means that the staff only needs to rotate the positioning edge 11 of the wafer 1 toward the reference line by an angle , the positioning edge 11 of the wafer 1 can be made parallel to the reference line. Through the above-mentioned control method for the wafer 1, the wafer 1 only needs to be moved twice to complete the edge finding work, without the need for manual repeated debugging, which significantly shortens the time required for wafer 1 positioning, thereby greatly improving the working efficiency of wafer 1 processing.

[0123] Specifically, the center of the first detection hole 21 is recorded as , the center of the second detection hole 22 is recorded as , then the line segment The length is the distance between the centers of the circles The two points where the positioning edge 11 of the wafer 1 intersects the first detection hole 21 are marked as points A and B, and the two points where the positioning edge 11 of the wafer 1 intersects the second detection hole 22 are marked as points C and D. is the arc length between point A and point B, in radians is the length of the arc between points C and D. Then it is a line segment The angle formed by the extension line of the wafer 1 and the extension line of the positioning edge 11. Based on the above definition, it is not difficult to find that the wafer 1 only needs to be rotated with its own center as the center of rotation so that the positioning edge 11 is aligned with the line segment. Rotation angle , the positioning edge 11 of the wafer 1 can be aligned with the line segment Parallel to each other, thereby achieving the effect of accurately positioning the positioning edge 11 of the wafer 1.

[0124] Furthermore, regarding the radian and radians The calculation method is based on the arc corresponding to the first detection hole 21. Take calculation as an example. The passing area of ​​the first detection hole 21 can be defined as When the positioning edge 11 of the wafer 1 rotates to intersect with the first detection hole 21, the arc The corresponding center angle is set to , at this time the central angle The corresponding sector area is set to , central angle The corresponding triangle area is set to (That is, the line segment in the figure , line segment and line segments The area of ​​the triangle enclosed by the circle), at this time the central angle The corresponding area blocked by the positioning edge 11 of the wafer 1 is set to The area of ​​the second detection hole 22 blocked by the positioning edge 11 of the wafer 1 is set to Based on the above definitions, the following mathematical relationship can be established:

[0125] ,

[0126] ,

[0127] ,

[0128] ,

[0129] Based on the above relationship, in step S2, the radian can be calculated as follows :

[0130] ,

[0131] Similarly, the curvature of the second detection hole 22 is , detection value And the test value The relationship between them is:

[0132] ,

[0133] Applying the radius to the above formula Uncertainty ,radian Uncertainty , center distance ,radian and radius Differentiate and calculate the area of ​​the first detection hole 21 in the following way: Uncertainty .

[0134] ,

[0135] The uncertainty calculation method of the area of ​​the second detection hole 22 is also the same, and will not be described in detail.

[0136] Among them, the radius Uncertainty Mainly related to manufacturing errors, this parameter can be obtained through repeatability measurements, parameters provided in relevant calibration certificates or parameters in the manual. The uncertainty caused mainly comes from fitting error and pressure gauge error, which is calculated by the ratio of the current pressure value of the pressure gauge to the total pressure value.

[0137] When the positioning edge 11 of the wafer 1 moves toward the positioning reference line, the intuitive phenomenon is that the area of ​​one detection hole blocked by the wafer 1 gradually increases, while at the same time, the area of ​​the other detection hole blocked by the wafer gradually decreases, until the areas blocked by the first detection hole 21 and the second detection hole 22 become equal. Specifically, when the detection values ​​of the first detection hole 21 and the second detection hole 22 reach the same value (this detection value should be between 0 and Within the range of 1 / 4, the locating edge 11 of wafer 1 covers the first inspection hole 21 and the second inspection hole 22 equally. Therefore, the locating edge 11 of wafer 1 is aligned parallel to the preset reference line, ensuring accurate positioning of wafer 1 during subsequent processing.

[0138] Furthermore, the fifth-order polynomial fitting function is:

[0139] ,

[0140] ,

[0141] In the embodiment of the present application, the radian and It can be accurately calculated by the fifth-order polynomial fitting method, or numerically solved by the ergodic method. (Radians and The calculation method is the same as this, so I will not go into details here.) It is worth noting that the central angle The size of is directly related to the angle between the positioning edge 11 of the wafer 1 and the reference line Specifically, the central angle The larger the angle, the greater the angle between the positioning edge 11 and the reference line. At this time, in order to achieve accurate positioning of the wafer 1, the positioning edge 11 of the wafer 1 needs to be accurately adjusted along the direction of the first detection hole 21 to reduce the central angle , until the positioning edge 11 of the wafer 1 is parallel to the reference line.

[0142] In the embodiment of the present application, the chord-center distance of the first detection hole 21 is set to , set the chord-center distance of the second detection hole 22 to . Then use radians as follows and radians Calculate the chord-center distance as The chord distance is :

[0143] ,

[0144] ,

[0145] like Figure 4 and Figure 5 As shown, in one embodiment, the secant formed by the positioning edge 11 of the wafer 1 and the first detection hole 21 and the second detection hole 22 is set to be located at a distance from the center of the circle on the same side of the line segment AB and line segment CD (i.e., line segment AB and line segment CD are on the same side of the line segment On the same side), in this embodiment, the positioning edge 11 of the wafer 1 and the line segment There is no intersection, but the extension line of the positioning edge 11 and the line segment The extension line of the positioning edge 11 intersects with the line segment. The distance from the intersection point of the extended lines to the center of the first detection hole 21 is less than the distance from the intersection point to the center of the second detection hole 22 (e.g. Figure 4 ); Another situation is that the extension line of the positioning edge 11 and the line segment The distance from the intersection point of the extended lines to the center of the second detection hole 22 is less than the distance from the intersection point to the center of the first detection hole 21 (e.g. Figure 5 The following is a detailed analysis of the two situations.

[0146] Scenario 3

[0147] like Figure 4 As shown, the extension line of the positioning edge 11 and the line segment The distance between the intersection point of the extended lines and the center of the first detection hole 21 is less than the distance between the intersection point and the center of the second detection hole 22. The intersection point is recorded as point , intersection To the center The distance between . The distance is calculated as follows and angle :

[0148] ,

[0149] or .

[0150] Scenario 4

[0151] like Figure 5 As shown, the extension line of the positioning edge 11 and the line segment The distance from the intersection point of the extended lines to the center of the second detection hole 22 is less than the distance from the intersection point to the center of the first detection hole 21, and the intersection point is recorded as point , intersection To the center The distance between . The distance is calculated as follows and angle :

[0152] ,

[0153] or .

[0154] like Figure 6 As shown, in another embodiment, the secant formed by the positioning edge 11 of the wafer 1 and the first detection hole 21 and the second detection hole 22 is set to be located at a distance from the center of the circle on the opposite side of the line segment AB (i.e., line segment AB and line segment CD are on the line segment In this embodiment, the positioning edge 11 of the wafer 1 and the line segment There is an intersection point, which is located between the first detection hole 21 and the second detection hole 22. This intersection point is recorded as point , intersection To the center The distance between , intersection To the center Then The distance is calculated as follows and angle :

[0155] ,

[0156] .

[0157] In seeking You can then determine the angle by looking up a trigonometric table or using an inverse trigonometric calculator. Then, the positioning edge 11 of the wafer 1 is rotated toward the reference line by an angle The positioning edge 11 of the wafer 1 can be made parallel to the reference line, thereby achieving positioning of the positioning edge 11 of the wafer 1 .

[0158] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the embodiments of the present invention. This application is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not covered by this application. The specification and embodiments are intended to be exemplary only, and the true scope and spirit of the present invention are indicated by the appended claims.

Claims

1. A method for edge deviation positioning, characterized in that: The method is applied to an edge-finding mechanism, the edge-finding mechanism comprising a positioning base (2) and a detection mechanism; a wafer (1) is placed on the positioning base (2), and a first detection hole (21) and a second detection hole (22) are provided on the positioning base (2); the first detection hole (21) and the second detection hole (22) have the same size and are both connected to the detection mechanism, and a line connecting the center of the first detection hole (21) and the center of the second detection hole (22) is a positioning reference line; the detection mechanism is used to detect a detection value of a set detection substance passing through the first detection hole (21) and the second detection hole (22), and the detection value is proportional to the area of ​​the first detection hole (21) and the second detection hole (22) blocked by the wafer (1); The method comprises the following steps: The wafer (1) is placed on the positioning base (2) and the first detection hole (21) and the second detection hole (22) are completely covered, and the detection values ​​in the first detection hole (21) and the second detection hole (22) under the above condition are obtained. ; The wafer (1) is moved so that the positioning edge (11) of the wafer (1) is tangent to or intersected with the first detection hole (21) and intersected with the second detection hole (22), and the detection value of the first detection hole (21) under the above condition is obtained. , and the detection value of the second detection hole (22) ; According to the detection value The detection value of the first detection hole (21) , and the detection value of the second detection hole (22) , the radius of the first detection hole (21) , and the center distance between the first detection hole (21) and the second detection hole (22) , calculate the angle between the positioning edge (11) of the wafer (1) and the positioning reference line ; The first point of the positioning edge (11) is selected as a fixed point, and the wafer (1) is driven to rotate around the first point by an angle of , so that the positioning edge (11) of the wafer (1) is parallel to the positioning reference line.

2. The edge deviation positioning method according to claim 1, characterized in that: Any other point on the positioning edge (11) is selected as a driving point, the distance between the first point and the driving point is a radius, and the driving point of the positioning edge (11) is driven to rotate the positioning edge (11) around the first point by an angle , so that the positioning edge (11) of the wafer (1) is parallel to the positioning reference line.

3. The edge deviation positioning method according to claim 1, characterized in that: When the positioning edge (11) of the wafer (1) is tangent to the first detection hole (21) and intersects with the second detection hole (22), according to the detection value The detection value of the first detection hole and the detection value of the second detection hole , the radius of the first detection hole (21) , and the center distance between the first detection hole (21) and the second detection hole (22) , calculate the angle between the positioning edge (11) of the wafer (1) and the positioning reference line include: Using the detection value and detection value Calculate the arc of the blocked portion of the second detection hole (22) ; Using radians , the radius of the second detection hole (22) and the center distance between the first detection hole (21) and the second detection hole (22) Calculating the angle between the positioning edge (11) of the wafer (1) and the positioning reference line .

4. The edge deviation positioning method according to claim 3, characterized in that: The distance between the two intersection points where the positioning edge (11) and the second detection hole (22) intersect is calculated as follows: : 。 5. The edge deviation positioning method according to claim 4, characterized in that: The distance between the tangent point formed by the positioning edge (11) and the first detection hole (21) and the farther one of the two intersection points formed by the positioning edge (11) and the second detection hole (22) is calculated in the following manner: : 。 6. The edge deviation positioning method according to claim 5, characterized in that: The angle is calculated as follows : 。 7. The edge deviation positioning method according to claim 1, characterized in that: When the positioning edge (11) of the wafer (1) intersects with the first detection hole (21) and intersects with the second detection hole (22), according to the detection value The detection value of the first detection hole (21) and the detection value of the second detection hole (22) , the radius of the first detection hole (21) , and the center distance between the first detection hole (21) and the second detection hole (22) , calculate the angle between the positioning edge (11) of the wafer (1) and the positioning reference line include: Using the detection value and detection value Calculate the arc of the blocked portion of the first detection hole (21) ; Using the detection value and detection value Calculate the arc of the blocked portion of the second detection hole (22) ; Using radians ,radian , the radius of the first detection hole (21) , and the center distance between the first detection hole (21) and the second detection hole (22) , calculate the angle between the positioning edge (11) of the wafer (1) and the positioning reference line .

8. The edge deviation positioning method according to claim 7, characterized in that: The radians are calculated as follows and radians : ； 。 9. The edge deviation positioning method according to claim 8, characterized in that: The chord-center distance of the first detection hole (21) is calculated as follows: and the chord-center distance of the second detection hole (22) : ； 。 10. The edge deviation positioning method according to claim 7, characterized in that: When the secant line between the positioning edge (11) of the wafer (1) and the first detection hole (21), and the secant line between the positioning edge (11) of the wafer (1) and the second detection hole (22) are located on the same side of the connecting line between the center of the first detection hole (21) and the center of the second detection hole (22), then the extension line of the positioning edge (11) of the wafer (1) and the extension line of the line segment corresponding to the center distance L have an intersection.

11. The edge deviation positioning method according to claim 10, characterized in that: If the distance between the intersection point and the center of the first detection hole (21) is smaller than the distance between the intersection point and the center of the second detection hole (22), the distance between the intersection point and the first detection hole (21) is calculated in the following manner: and angle : ； or .

12. The edge deviation positioning method according to claim 10, characterized in that: If the distance between the intersection point and the center of the second detection hole (22) is smaller than the distance between the intersection point and the center of the first detection hole (21), the distance between the intersection point and the second detection hole (22) is calculated in the following manner: and angle : ； or .

13. The edge deviation positioning method according to claim 7, characterized in that: The secant line between the positioning edge (11) of the wafer (1) and the first detection hole (21) and the secant line between the positioning edge (11) of the wafer (1) and the second detection hole (22) are located on the opposite sides of the connecting line between the center of the first detection hole (21) and the center of the second detection hole (22). The distance between the positioning edge (11) of the wafer (1) and the center of the circle is The corresponding line segments have an intersection point, and the intersection point is located between the first detection hole (21) and the second detection hole (22).

14. The edge deviation positioning method according to claim 13, characterized in that: The distance y and the angle from the intersection point to the second detection hole (22) are calculated as follows: : ； 。 15. The edge deviation positioning method according to any one of claims 1 to 14, characterized in that: The set detection substance is gas, the first detection hole (21) is a first air blowing hole, the second detection hole (22) is a second air blowing hole, the detection value is the air pressure value of the first air blowing hole and the second air blowing hole, and the detection mechanism is configured to detect the air pressure value in the first detection hole and the second detection hole; or, The set detection material is a light beam, the first detection hole (21) is a first light-transmitting hole, the second detection hole (22) is a second light-transmitting hole, the detection value is the light-shielding rate of the first light-transmitting hole and the second light-transmitting hole, and the detection mechanism is configured to detect the light-shielding rate passing through the first light-transmitting hole and the second light-transmitting hole.

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