Wafer positioning method and semiconductor process equipment

Abstract

The invention discloses a wafer positioning method and semiconductor process equipment, and relates to the field of semiconductors. A wafer positioning method is applied to an edge etching chamber, and comprises the following steps: obtaining a current etching uniformity parameter value according to etching rates of a plurality of sampling points on a sampling circle of a wafer, and determining a direction to be corrected; according to the target value of the etching uniformity parameter and a fitting function of the variable quantity of the etching uniformity parameter value and the deviation correction quantity, the deviation correction quantity of the wafer transmission mechanism is obtained; and correcting the wafer transmission mechanism according to the to-be-corrected quantity and the to-be-corrected direction. According to the invention, the problem of large deviation rectification volatility can be solved.

Description

Technical Field

[0001] The present application belongs to the field of semiconductor technology, and specifically relates to a wafer positioning method and semiconductor process equipment. Background Art

[0002] In the integrated circuit manufacturing process, plasma etching is a very important link. As the technology nodes extend to 65nm and more advanced process nodes according to Moore's Law, the impact of the yield related to the edge and side of the wafer becomes particularly prominent. Edge etching uses plasma to remove unstable film accumulation at the edge of the wafer due to the interaction between film deposition, lithography, etching and chemical mechanical polishing, reducing its impact on subsequent processes and thereby improving the yield.

[0003] Edge etching has high requirements for etching uniformity. Since several chips are integrated on a wafer, the plasma etching state at the required etching position needs to be as consistent as possible to ensure the performance consistency and controllability of the final chip. Seeking an accurate and efficient method to adjust the uniformity can not only improve the chip yield but also reduce the number of debugging times, thereby reducing debugging costs.

[0004] In the related art, some methods of improving uniformity only perform correction based on single-chip data, which results in large fluctuations in correction; in other methods, an adjustable extended electrode structure is used to change the electrode size, thereby achieving the purpose of adjusting uniformity. However, this method results in a more complex hardware structure of the equipment, greater difficulty in implementation, and higher cost, and is unable to improve the offset between the geometric center of the wafer and the processing center, so the effect of improving uniformity with edge etching is limited. Summary of the invention

[0005] The purpose of the embodiments of the present application is to provide a wafer positioning method and semiconductor process equipment, which can solve at least one of the above problems.

[0006] In order to solve the above technical problems, this application is implemented as follows:

[0007] The embodiment of the present application provides a wafer positioning method, which is applied to an edge etching chamber, and the positioning method includes:

[0008] According to the etching rates of multiple sampling points on the sampling circle of the wafer, a current etching uniformity parameter value is obtained and a direction to be corrected is determined;

[0009] Obtaining the desired deviation correction amount of the wafer transport mechanism according to the etching uniformity parameter target value and the fitting function of the etching uniformity parameter value change and the deviation correction amount;

[0010] The wafer transport mechanism is skewed according to the desired skew amount and the desired skew direction.

[0011] The present application also provides a semiconductor process equipment, including an edge etching chamber, a wafer transfer mechanism and a controller;

[0012] The wafer transfer mechanism is used to transfer the wafer into or out of the edge etching chamber;

[0013] The controller includes a memory and a processor, and when the memory is read by the processor, the wafer positioning method is executed.

[0014] The embodiment of the present application can predict the distance that the wafer needs to move to achieve the goal of coinciding with the processing center during the edge etching process through the wafer positioning method, and use the prediction results of the method to teach the wafer transfer mechanism to perform deviation correction to achieve uniform etching results. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A flowchart of a positioning method disclosed in an embodiment of the present application;

[0016] Figure 2 A schematic diagram of the principle of wafer deflection disclosed in an embodiment of the present application;

[0017] Figure 3 A schematic diagram of taking 8 sampling points on a sampling circle in the edge area of ​​a wafer disclosed in an embodiment of the present application;

[0018] Figure 4 A schematic diagram of a fitting function disclosed in an embodiment of the present application;

[0019] Figure 5 This is a schematic diagram of selecting two sampling points at both ends of a first diameter and selecting two sampling points at both ends of a second diameter on the same sampling circle disclosed in an embodiment of the present application;

[0020] Figure 6 This is a schematic diagram of the case where the second diameter disclosed in the embodiment of the present application forms an angle α with the X-axis;

[0021] Figure 7 This is a schematic diagram of the correction along the X-axis and Y-axis directions disclosed in the embodiment of the present application. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0023] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0024] The embodiments of the present application are described in detail below through specific embodiments and their application scenarios in conjunction with the accompanying drawings.

[0025] refer to Figures 1 to 7 The embodiment of the present application discloses a wafer positioning method, which is applied to an edge etching chamber. The disclosed positioning method includes:

[0026] According to the etching rates of multiple sampling points on the sampling circle of the wafer, the current etching uniformity parameter value is obtained, and the direction to be corrected is determined;

[0027] Obtaining the desired deviation correction amount of the wafer transport mechanism according to the etching uniformity parameter target value and the fitting function of the etching uniformity parameter value change and the deviation correction amount;

[0028] The wafer transport mechanism is skewed according to the desired skew amount and direction.

[0029] The embodiment of the present application can predict the distance that the wafer needs to move to achieve the goal of coinciding with the processing center during the edge etching process through the wafer positioning method, and use the prediction results of the method to teach the wafer transfer mechanism to perform deviation correction to achieve uniform etching results.

[0030] In an embodiment of the present application, at least one sampling circle can be selected in the edge area of ​​the wafer. Taking a wafer with a radius of 150 mm as an example, a sampling circle in the range of 147.80 mm to 149.6 mm can be selected in the edge area, and multiple sampling points can be selected on each sampling circle, and then the etching rate of each sampling point can be calculated.

[0031] It should be noted that the diameter of the selected sampling circle can be the inner circle or the outer circle, or some other radius of focus, according to the needs.

[0032] Exemplarily, the initial film thickness measured by using a silicon oxide wafer is used as the previous value, and the sampling points and coordinates thereof are shown in Table 1.

[0033] Table 1 Sampling points and coordinates before etching

[0034]

[0035] Wherein, R represents the distance from the center of the wafer, and X and Y represent the rectangular coordinate positions under R, respectively.

[0036] Optionally, obtain the current etching uniformity parameter values, including:

[0037] Selecting the maximum etching rate and the minimum etching rate from the etching rates of the plurality of sampling points, and calculating the average etching rate of the plurality of sampling points;

[0038] The difference between the maximum etching rate and the minimum etching rate is compared with twice the average etching rate to obtain the etching uniformity parameter value of the sampling circle.

[0039] For example, 8 sampling points are selected from each sampling circle, and the distribution of the 8 sampling points is as follows: Figure 3 shown.

[0040] The wafer is placed in the edge etching chamber for etching process, and then the post-etching value is collected at the same coordinate position, and the etching rate (ER) of each sampling point is calculated, where the etching rate is calculated as follows:

[0041]

[0042] During the adjustment process, uniformity (U value) is used to characterize the etching uniformity parameter value, wherein the calculation formula of the etching uniformity parameter value is:

[0043]

[0044] The U value collected before the wafer transmission mechanism is corrected is recorded as U1, the U value collected after the wafer transmission mechanism is corrected is recorded as U2, and the change in the etching uniformity parameter value after the correction is recorded as ΔU, where the calculation formula for the change in the etching uniformity parameter value is:

[0045] ΔU=U1-U2

[0046] According to the above calculation formula, the etching rates at the eight sampling points on each sampling circle can be obtained, as shown in Table 2.

[0047] Table 2 shows the etching rates at the sampling points

[0048] R ER1 ER2 ER3 ER4 ER5 ER6 ER7 ER8 Homogeneity (%) 149.60 10105 7487 10445 3928 6006 3323 4653 3816 57.2 149.55 7656 5750 7761 2761 4549 2443 3509 2849 57.1 149.50 5917 4114 6979 1988 3284 1809 2615 2122 59.9 149.45 4349 2911 4627 1516 2357 1402 1960 1642 62.1 149.40 3074 2126 3382 1208 1754 1122 1508 1294 58.5 149.35 2191 1583 2403 979 1347 914 1186 1043 51.1 149.30 1612 1239 1763 810 1068 762 963 860 44.1 149.20 955 807 1037 567 707 546 658 611 33.4 149.10 624 558 668 417 491 405 477 449 25.7 149.00 429 397 452 312 351 308 355 339 19.6 148.80 221 214 231 180 192 181 206 209 12.4 148.50 84 87 92 82 82 85 98 110 15.6 148.20 27 29 34 33 31 36 44 60 45.8 148.00 11 11 15 18 14 19 24 42 82.1 147.80 3 0 5 7 4 9 15 33 171.3

[0049] in addition, Figure 7 It is the etching rate MAP diagram, according to Figure 7Etching, the etching rate ER along the positive direction of the X axis is too fast, and the etching rate ER along the positive direction of the Y axis is too fast, so it is determined that the wafer transfer mechanism should move in the negative direction of the X axis and the negative direction of the Y axis. Therefore, the direction to be corrected is determined.

[0050] Optionally, the steps of obtaining the fitting function of the variation of the etching uniformity parameter value and the deviation correction amount are as follows:

[0051] A historical database of component changes and corrections regarding etching uniformity parameter values;

[0052] The preset function is used to fit the change amount and the correction amount of the etching uniformity parameter value to obtain a fitting function.

[0053] Specifically, the process data under the preset fixed accessory configuration in the past are collected, and the change in the etching uniformity parameter value ΔU and the correction amount ΔR of the wafer transfer mechanism are recorded respectively. Based on the previous process data, a historical database of the change in the etching uniformity parameter value ΔU and the correction amount ΔR can be constructed.

[0054] Based on the above historical database, the change amount ΔU and the deviation correction amount ΔR are fitted using a preset function model to obtain a fitting function, wherein the preset function may be determined according to a specific degree of fitting.

[0055] Exemplarily, the types of preset functions may include: power function, polynomial function, exponential function, logarithmic function, etc. Of course, other types of function models may also be used, which are not specifically limited here. In the example application, a function with better fitting degree can be selected for fitting according to the quality of the mean square error of the fitting function. Among them, if the mean square error of the fitting function is greater than 0.5, it can be considered that the fitting degree is good, and the closer it is to 1, the more accurate the fitting is.

[0056] Optionally, a linear function may be used to fit the variation ΔU of the etching uniformity parameter value and the deviation correction amount ΔR, and the obtained fitting function is in the form of:

[0057] ΔU=kΔR+b

[0058] Among them, ΔU is the change in the etching uniformity parameter value, ΔR is the correction amount of the mechanical transmission mechanism, k is the coefficient, and b is a constant.

[0059] Exemplarily, a linear function is selected to fit the change ΔU and the correction amount ΔR at a radius of 149.4 mm to obtain the above fitting function form, and the fitting function is differentiated to obtain (ΔU)'=k, which mathematically means that for every 1 μm change in ΔR, ΔU changes by k.

[0060] In addition, according to the difference between the current etching uniformity parameter value and the etching uniformity parameter target value, and the fitting function, the deviation correction amount ΔR can be obtained.adjust , and its calculation formula is:

[0061]

[0062] Among them, ΔU adjust Indicates the desired change in etching uniformity parameter, the desired change ΔU adjust The calculation formula is:

[0063] ΔU adjust =U now -U target

[0064] Among them, U now Indicates the current etching uniformity parameter value, U target Indicates the target value of the etching uniformity parameter (ie, the U value to be adjusted).

[0065] Figure 4 To fit the function curve, according to Figure 4 It can be seen that the mean square error (R 2 ) is 0.8, so the linear function model can be used to predict the amount of correction. In addition, according to the fitting function, under the hardware configuration conditions, for a sampling circle with a radius of 149.4 mm, the etching uniformity parameter value U changes by 10.8% for every 100 μm movement in a certain direction.

[0066] According to Table 2, at a radius of 149.4 mm, the etching uniformity parameter value U is 58.5%, and the desired adjustment value U is 10%, so that the desired change △U adjust =48.5%, that is, it should be moved 450μm in a certain direction.

[0067] Based on the above process, the desired deviation correction amount △R can be obtained.

[0068] refer to Figure 2 , considering that in the process of adjusting the wafer transmission mechanism, the distance in the X-axis direction and the distance in the Y-axis direction are adjusted, and the X-axis direction adjustment value and the Y-axis direction adjustment value can be superimposed by vectors to obtain the distance that the wafer moves along a certain radial direction, and this distance is the above-mentioned desired adjustment amount △R.

[0069] In the actual correction process, the X-axis direction and the Y-axis direction can be adjusted respectively to achieve the desired correction amount ΔR. Therefore, it is necessary to calculate the distances moved in the X-axis direction and the Y-axis direction respectively.

[0070] Based on the above settings, the embodiment of the present application can obtain the desired deviation correction amount in the X-axis direction and the desired deviation correction amount in the Y-axis direction according to the desired deviation correction amount, wherein the Y-axis or the X-axis passes through a preset reference point of the edge etching chamber.

[0071] It should be noted here that the valve of the edge etching chamber is used as a reference, and when the wafer is transferred to the edge etching chamber, the position where the edge of the wafer faces the valve is the preset reference point.

[0072] Further, the amount of deviation correction to be made in the X-axis direction and the amount of deviation correction to be made in the Y-axis direction are obtained according to the deviation correction amount, including:

[0073] Obtaining the etching rates of two sampling points located at two ends of the first diameter on the sampling circle, and calculating the absolute value of the etching rate difference between the two sampling points, which is ΔER1;

[0074] Obtain the etching rates of two sampling points located at both ends of the second diameter perpendicular to the first diameter on the sampling circle, and calculate the absolute value of the etching rate difference between the two sampling points, which is ΔER2; wherein,

[0075]

[0076] ΔR1 adjust is the moving distance along the first diameter direction, ΔR2 adjust is the moving distance along the second diameter direction;

[0077] According to the Pythagorean theorem:

[0078]

[0079] Combining the two equations, the moving distance ΔR1 along the first diameter direction can be calculated: adjust and the moving distance ΔR2 along the second diameter direction adjust .

[0080] refer to Figure 5 and Figure 6 The sampling point corresponding to ER4 and the sampling point corresponding to ER5 are respectively located at two ends of the first diameter, while the sampling point corresponding to ER1 and the sampling point corresponding to ER8 are respectively located at two ends of the second diameter.

[0081] The difference between ER4 and ER5 is:

[0082] △ER1=|ER4-ER5|

[0083] The difference between ER1 and ER8 is:

[0084] △ER2=|ER1-ER8|

[0085] For easy understanding, three conditions are given below:

[0086] 1. For a certain sampling point on the wafer, the etching rate within a radius close enough to the sampling point is linear;

[0087] 2. Under the same hardware configuration conditions, for the same process recipe, different wafers are in the same plasma environment, including plasma density distribution, etc.;

[0088] 3. Ideally, the distribution of plasma is radially uniform, that is, the etching rate is the same for sampling points with the same radius from the plasma processing center.

[0089] Based on this, under the condition that "the etching rate of the sampling points with the same radius of the plasma processing center is the same", the moving distance ΔR1 along the first diameter direction is adjust and the moving distance ΔR2 along the second diameter direction adjust The calculation formula is:

[0090]

[0091] Combining the Pythagorean theorem, the moving distance ΔR1 along the first diameter direction can be calculated. adjust and the moving distance ΔR2 along the second diameter direction adjust .

[0092] When the first diameter is parallel to the X-axis and the second diameter is parallel to the Y-axis, Figure 6 In this case, the adjustment amount ΔX in the X-axis direction is 90°. adjust With ΔR1 adjust Equal, Y axis direction adjustment amount ΔY adjust With ΔR2 adjust Of course, when the angle between the first diameter and the X-axis is less than or equal to the preset angle, it can be regarded as being within the range, and the desired adjustment amount ΔX in the X-axis direction will not be changed. adjust The Y-axis direction adjustment amount ΔY adjust For example, the preset angle may be 15°, and of course, may be other degrees, which are not specifically limited here.

[0093] For the embodiment of the present application, the desired adjustment amount ΔX in the X-axis direction within the error range can be obtained by calculation: adjust =130μm, Y-axis direction adjustment amount ΔY adjust =430μm.

[0094] At this point, by adopting the positioning method in the embodiment of the present application, the correction amount and correction direction of the wafer conveying mechanism are obtained, so that the wafer conveying mechanism can be corrected according to the correction amount and correction direction.

[0095] When the angle between the first diameter and the X-axis is outside the error range, corresponding adjustments need to be made to reduce error interference.

[0096] Specifically, when the angle between the first diameter and the X-axis is greater than the preset angle, the deviation correction amount ΔX in the X-axis direction is adjust And the Y-axis direction deviation correction amount ΔY adjust The calculation formulas are:

[0097] ΔX adjust =ΔR1 adjust ×sinα+ΔR2 adjust ×cisα

[0098] ΔY adjust =ΔR1 adjust ×cosα+ΔR2 adjust ×sinα

[0099] Wherein, α is the complementary angle between the first diameter and the X-axis.

[0100] Based on this, outside the error range, the desired adjustment amount ΔX in the X-axis direction can also be obtained by conversion: adjust The Y-axis direction adjustment amount ΔY adjust .

[0101] In order to verify the effectiveness of the positioning method, the embodiment of the present application collects the etching data after correction, and specifically refers to Table 3.

[0102] Table 3 Etching data after correction

[0103] R ER1 ER2 ER3 ER4 ER5 ER6 ER7 ER8 Uniformity (%) 149.60 5878 6209 5689 4989 5306 4584 5618 4976 15.0 149.55 4127 4528 4118 3612 3828 3358 4253 3716 14.8 149.50 2835 3159 2866 2554 2678 2437 3143 2726 12.9 149.45 2048 2286 2053 1899 1957 1832 2311 2034 11.7 149.40 1560 1727 1550 1457 1492 1411 1737 1556 10.4 149.35 1214 1335 1202 1165 1174 1119 1341 1235 9.0 149.30 968 1077 963 953 947 927 1081 1002 7.8 149.20 662 733 652 664 644 652 733 702 6.5 149.10 475 527 462 479 457 477 522 514 7.2 149.00 350 389 335 358 334 357 389 385 7.6 148.80 198 220 191 210 190 213 230 229 9.5 148.50 92 103 85 100 88 102 116 121 17.5 148.20 41 46 38 48 40 48 59 67 30.4 148.00 22 26 20 30 22 28 40 48 47.5 147.80 13 16 13 18 13 16 29 35 56.6

[0104] Comparing the uniformity parameter values ​​of the two sets of data before and after correction at a radius of 149.4 mm, they are 58.5% and 10.4% respectively. It can be seen that the positioning method in the embodiment of the present application can correct the deviation between the geometric center of the wafer and the processing center, thereby improving the radial uniformity of the wafer.

[0105] Of course, after the current correction, the correction requirements may not be met. In this case, correction is required to improve the correction effect. Based on this situation, in the embodiment of the present application, after the wafer reaches the desired correction amount, if the etching uniformity parameter value does not meet the requirements, the process data involved in the current correction process is stored in the historical database to update the historical database;

[0106] The preset function is used to refit the change amount and the correction amount of the etching uniformity parameter value in the updated historical database to obtain an updated fitting function. Exemplarily, the preset function can be a linear function or the like.

[0107] Based on this, the updated deviation correction amount can be obtained according to the difference between the next etching uniformity parameter value and the etching uniformity parameter target value, as well as the updated fitting function.

[0108] According to the updated amount to be corrected, an updated amount to be corrected in the X-axis direction and an updated amount to be corrected in the Y-axis direction are obtained respectively.

[0109] Therefore, the wafer transport mechanism can perform deviation correction according to the updated deviation correction amount in the X-axis direction and the updated deviation correction amount in the Y-axis direction to ensure the position accuracy of the wafer.

[0110] It should be noted here that the embodiment of the present application does not limit the number of times the wafer is corrected, until the wafer reaches the desired correction amount and the etching uniformity parameter value meets the requirements.

[0111] Based on the above-mentioned wafer positioning method, an embodiment of the present application also discloses a semiconductor process equipment, wherein the disclosed semiconductor process equipment includes an edge etching chamber, a wafer transfer mechanism and a controller, wherein the wafer transfer mechanism is used to transfer the wafer into or out of the edge etching chamber, and the controller includes a memory and a processor, and when the memory is read by the processor, the above-mentioned wafer positioning method is executed.

[0112] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. A wafer positioning method, applied to an edge etching chamber, characterized in that: The positioning method comprises: According to the etching rates of multiple sampling points on the sampling circle of the wafer, a current etching uniformity parameter value is obtained, and a direction to be corrected is determined; Obtaining the desired deviation correction amount of the wafer transport mechanism according to the etching uniformity parameter target value and the fitting function of the etching uniformity parameter value change and the deviation correction amount; The wafer transport mechanism is skewed according to the desired skew amount and the desired skew direction.

2. The positioning method according to claim 1, characterized in that: The positioning method comprises: Constructing a historical database of the change in the etching uniformity parameter value and the correction amount; A preset function is used to fit the change in the etching uniformity parameter value and the deviation correction amount to obtain the fitting function.

3. The positioning method according to claim 2, characterized in that: The adopting of a preset function to fit the change amount of the etching uniformity parameter value and the deviation correction amount to obtain the fitting function comprises: A linear function is used to fit the variation of the etching uniformity parameter value and the deviation correction amount, and the fitting function obtained is: ΔU=kΔR+b Among them, ΔU is the change in the etching uniformity parameter value, ΔR is the correction amount of the wafer transmission mechanism, k is the coefficient, and b is a constant.

4. The positioning method according to claim 3, characterized in that: The desired deviation correction amount is obtained according to the difference between the current etching uniformity parameter value and the etching uniformity parameter target value, and the fitting function.

5. The positioning method according to claim 1, characterized in that: The deflection amount to be corrected in the X-axis direction and the deflection amount to be corrected in the Y-axis direction are respectively obtained according to the deflection amount to be corrected, wherein the Y-axis or the X-axis passes through a preset reference point of the edge etching chamber.

6. The positioning method according to claim 5, characterized in that: The step of obtaining the desired deviation correction amount in the X-axis direction and the desired deviation correction amount in the Y-axis direction according to the desired deviation correction amount comprises: Obtaining the etching rates of the two sampling points located at two ends of the first diameter on the sampling circle, and calculating the absolute value of the etching rate difference between the two sampling points, which is ΔER1; Obtaining the etching rates of the two sampling points on the sampling circle at both ends of the second diameter perpendicular to the first diameter, and calculating the absolute value of the etching rate difference between the two sampling points, which is recorded as ΔER2; wherein, ΔR1 adjust is the moving distance along the first diameter direction, ΔR2 adjust is the moving distance along the second diameter direction; According to the Pythagorean theorem: Combining the two equations, the moving distance ΔR1 along the first diameter direction is calculated. adjust and the moving distance ΔR2 along the second diameter direction adjust .

7. The positioning method according to claim 6, characterized in that: When the angle between the first diameter and the X-axis is less than or equal to the preset angle, the deviation correction amount ΔX in the X-axis direction is adjust With ΔR1 adjust Equal, the Y-axis direction deviation correction amount ΔY adjust With ΔR2 adjust equal; When the angle between the first diameter and the X-axis is greater than the preset angle, the deviation correction amount ΔX in the X-axis direction is adjust And the Y-axis direction deviation correction amount ΔY adjust The calculation formulas are: ΔX adjust =ΔR1 adjust ×sinα+ΔR2 adjust ×cosα ΔY adjust =ΔR1 adjust ×cosα+ΔR2 adjust ×sinα Wherein, α is the complementary angle between the first diameter and the X-axis.

8. The positioning method according to claim 1, characterized in that: The obtaining of the current etching uniformity parameter value includes: Selecting a maximum etching rate and a minimum etching rate from the etching rates of the plurality of sampling points, and calculating an average etching rate of the plurality of sampling points; The difference between the maximum etching rate and the minimum etching rate is compared with twice the average etching rate to obtain the etching uniformity parameter value of the sampling circle.

9. The positioning method according to claim 2, characterized in that: After the wafer reaches the desired deflection amount, if the etching uniformity parameter value does not meet the requirement, storing the process data involved in the current deflection correction process into the historical database to update the historical database; The preset function is used to refit the change amount of the etching uniformity parameter value and the correction amount in the updated historical database to obtain the updated fitting function.

10. A semiconductor process equipment, characterized in that: include: edge etch chamber, wafer transfer mechanism and controller; The wafer transfer mechanism is used to transfer the wafer into or out of the edge etching chamber; The controller includes a memory and a processor, and when the memory is read by the processor, the wafer positioning method described in any one of claims 1 to 9 is executed.

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