Positioning method for wafer transfer device on heating machine

Abstract

The present application provides a positioning method for a wafer conveying device on a heating machine, based on the linear relationship between the temperature of thermal oxygen annealing treatment and the thickness of the grown oxide layer, the heating temperature of the bearing surface of the wafer bearing table is adjusted in an incremental or decremental manner along the radial direction, when the wafer position on the wafer bearing table deviates, the thickness of the grown oxide layer on the wafer will also produce overall deviation, at this time, the thickness of the oxide layer is measured by multiple point linear measurement in the first direction through the center of the wafer, the maximum point is determined, and the linear fitting of all points on both sides of the maximum point is carried out, the abscissa value of the intersection point of the two linear curves is obtained as the compensation value of the wafer conveying device adjustment. The positioning method does not need to disassemble the machine parts, and can also accurately calculate the compensation value of the wafer conveying device, the operation is simple, the positioning adjustment frequency of the wafer conveying device is reduced, and the positioning result is accurate.

Description

Technical Field

[0001] This invention relates to the field of semiconductor equipment technology, and in particular to a positioning method for a wafer transfer device on a heating machine platform. Background Technology

[0002] Semiconductor manufacturing involves multiple processes, each requiring different equipment. Wafer transfer devices (such as robotic arms) play a crucial role in semiconductor manufacturing, handling wafers between different processes to ensure their smooth movement from one process to the next.

[0003] In some processes requiring wafer heating, the stability of wafer heating is critical. The tolerance for wafer positional deviation within the heating chamber is extremely low, necessitating highly precise positioning of the wafer transport device. For example, in RTP (Remote Timing Processing) machines, the primary functions include promoting ion diffusion and activation, growing high-quality silicon dioxide, and annealing after metal silicide formation. During wafer processing within the heating chamber, to further improve heating uniformity, the wafer is simultaneously heated and rotated horizontally using lift pins or edge rings. However, if the wafer transport device fails to center the wafer within the chamber, uneven heating can occur, leading to wafer data shift (WAT) and even wafer breakage due to rotation off the mounting base, ultimately reducing product yield.

[0004] Currently, the main method for detecting whether a wafer is centered in the process chamber of a heating machine is visual inspection, which involves opening the chamber and observing the edge of the rotating wafer. This method has certain limitations: it requires disassembling machine components, making the operation complex. Furthermore, adjusting the positioning of the wafer transfer device visually requires multiple adjustments, and the positioning results are often rough. Summary of the Invention

[0005] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a positioning method for a wafer transfer device on a heating machine, which solves the problem that in the prior art, the positioning accuracy of the wafer transfer device is low, requiring multiple adjustments and complex operation, because the wafer is visually inspected to determine whether it is centered in the process chamber of the heating machine.

[0006] To achieve the above and other related objectives, the present invention provides a positioning method for a wafer transfer device on a heating machine platform, the heating machine platform including a wafer carrier stage, the wafer carrier stage being used at least for heating the wafers carried thereon; wherein, the bearing surface of the wafer carrier stage includes at least three hot zones arranged concentrically in sequence; the positioning method includes the following steps:

[0007] S1. The wafer transfer device transfers the wafer to the wafer carrier stage;

[0008] S2. The wafer is annealed to grow an oxide layer on the wafer surface; wherein, during the annealing process, the annealing temperature of all the hot areas is set in an increasing or decreasing manner along the radial direction of the wafer support stage;

[0009] S3. Perform multi-point linear measurement of the thickness of the oxide layer along the first direction passing through the center of the wafer to obtain the coordinate relationship between the point position and the thickness of the oxide layer.

[0010] S4 determines the extreme point of the oxide layer thickness from the coordinate relationship, then performs linear fitting on the points on both sides of the extreme point to obtain two linear curves, and finally calculates the abscissa value of the intersection of the two linear curves. The abscissa value is the compensation value for the wafer transfer device to be adjusted along the first direction.

[0011] S5. Adjust the wafer transfer device based on the compensation value.

[0012] Optionally, step S3 further includes performing multi-point linear measurements of the thickness of the oxide layer along at least one second direction passing through the center of the wafer to obtain the coordinate relationship between the position of the point in the corresponding second direction and the thickness of the oxide layer; step S4 further includes determining the extreme point of the thickness of the corresponding oxide layer from the coordinate relationship of the corresponding second direction, then performing linear fitting on the points on both sides of the extreme point to obtain two linear curves, and finally calculating the abscissa value of the intersection point of the two linear curves obtained by linear fitting on both sides of the extreme point, the abscissa value being the compensation value for adjusting the wafer transfer device along the corresponding second direction, wherein the first direction intersects the second direction, and all second directions are different; step S5 further includes adjusting the wafer transfer device based on the corresponding compensation value.

[0013] Furthermore, a second direction is selected, and one of the first direction and the second direction is parallel to the positioning notch on the wafer, while the other direction is perpendicular to the positioning notch on the wafer.

[0014] Furthermore, it also includes step S6: repeating steps S1 to S4 to obtain the abscissa value of the intersection point of the corresponding two linear curves, and determining whether the abscissa value of the intersection point of the corresponding two linear curves is within the acceptable range; if it is within the acceptable range, the adjustment of the wafer transfer device is completed; if it exceeds the acceptable range, then continue to step S5 and repeat step S6 until the adjustment of the wafer transfer device is completed.

[0015] Furthermore, the permissible range is no greater than 0.03 mm.

[0016] Optionally, the bearing surface of the wafer carrier stage includes four concentrically nested hot zones arranged in sequence, and each hot zone is provided with a circumferentially distributed heating structure, which heats the hot zone it is located in.

[0017] Furthermore, the wafer is a silicon wafer, and the oxide layer is a silicon oxide layer; the annealing temperature provided by the heating structure in each of the hot regions in step S2 is set in an arithmetic sequence with a tolerance of less than 10°C.

[0018] Optionally, the thickness gradient difference of the oxide layer grown on the wafer surface in step S2 is not less than

[0019] Optionally, in step S3, when performing multi-point linear measurement of the thickness of the oxide layer, no less than 31 points are selected for measurement.

[0020] Optionally, the heating machine is a rapid heat treatment machine.

[0021] As described above, the positioning method of the wafer transfer device on the heating platform of the present invention is based on the linear relationship between the temperature of the thermo-oxidative annealing process and the thickness of the grown oxide layer, i.e., the higher the temperature, the thicker the grown oxide layer, and the lower the temperature, the thinner the grown oxide layer. By adjusting the heating temperature of the bearing surface of the wafer carrier to be set in an arithmetic progression along the radial direction, theoretically, when the wafer does not shift on the wafer carrier, the thickness of the grown oxide layer should be distributed in an arithmetic progression across all the radially arranged hot regions, and the maximum value of the oxide layer thickness should be located at the center of the wafer. When the wafer shifts position on the wafer carrier, the thickness of the grown oxide layer on the wafer also shifts overall, and the maximum or minimum value of the oxide layer thickness deviates from the wafer center. At this point, by performing multi-point linear measurements of the oxide layer thickness along a first direction passing through the wafer center, the maximum or minimum value point is determined. Linear fitting is then performed on all points on both sides of this maximum or minimum value point, and the x-coordinate of the intersection point of the two linear curves is the wafer's shift value in that first direction. The wafer transport device uses this shift value as a compensation value for adjustments along the first direction, thus achieving positioning of the wafer transport device in that direction. This positioning method of the present invention does not require disassembling machine components, can accurately calculate the compensation value of the wafer transport device, is simple to operate, reduces the number of positioning adjustments required for the wafer transport device, and provides accurate positioning results. Attached Figure Description

[0022] Figure 1 The diagram shown is a top view of a heating machine in which a wafer carrier stage has four hot zones.

[0023] Figure 2 The diagram shown is a top view of a heating machine in which heating structures are arranged in four annular regions on a wafer carrier stage, serving as an example.

[0024] Figures 3 to 5 The diagram shown is a top view of the structure in which an oxide layer is formed on a wafer in the positioning method of the wafer transfer device on the heating machine platform according to the present invention.

[0025] Figure 6 The diagram shows a comparison of two linear curves obtained by linear fitting based on the relationship between the position of a point and the thickness of the oxide layer in the positioning method of the wafer transfer device on the heating machine platform of the present invention.

[0026] Component designation explanation

[0027] 10 Wafer Support Stage

[0028] 100 hot zones

[0029] 101 Heating Structure

[0030] 11 wafers

[0031] 110 Positioning Gap

[0032] 12 Oxide Layer Detailed Implementation

[0033] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0034] Please see Figures 1 to 6 It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the illustrations only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0035] like Figures 1 to 3As shown, this embodiment provides a positioning method for a wafer transfer device on a heating machine platform. The heating machine platform includes a wafer carrier stage 10, which is used at least to heat the wafers carried on it. The carrier surface of the wafer carrier stage 10 includes at least three concentrically nested hot zones 100, i.e., the central hot zone 100 is a circular hot zone, and the other hot zones 100 are annular hot zones. The positioning method includes the following steps:

[0036] S1. The wafer transfer device transfers the wafer 11 to the wafer carrier stage 10;

[0037] S2. Anneal the wafer 11 to grow an oxide layer 12 on the surface of the wafer 11; wherein, during the annealing process, the annealing temperature of all the hot regions 100 is set in an increasing or decreasing manner along the radial direction of the wafer support stage 10.

[0038] S3, along the first direction passing through the center of the wafer 11 (e.g.) Figure 3 The thickness of the oxide layer 12 is measured linearly at multiple points in the X1 direction to obtain the coordinate relationship between the point position and the thickness of the oxide layer.

[0039] S4. Determine the extreme point of the oxide layer thickness from the coordinate relationship. Then, perform linear fitting on the points on both sides of the extreme point to obtain two linear curves L1=ax+b and L2=cx+d. Finally, calculate the abscissa value x=(db) / (ac) of the intersection of the two linear curves. The abscissa value is the compensation value for the wafer transfer device to be adjusted along the first direction.

[0040] S5. Adjust the wafer transfer device using the horizontal coordinate value x = (db) / (ac) as the compensation value for adjusting the wafer transfer device along the first direction.

[0041] It should be noted that during the annealing process in step S2, the annealing temperature of all the hot regions 100 is set in an increasing or decreasing manner along the radial direction of the wafer carrier. That is, the annealing temperature can increase or decrease sequentially along the radial direction of the wafer carrier with a specific tolerance. When the annealing temperature increases sequentially along the radial direction of the wafer carrier with a specific tolerance, the thickness of the formed oxide layer increases sequentially along the radial direction of the wafer carrier. In this case, the extreme value point of the oxide layer thickness determined from the coordinate relationship in step S4 refers to the point where the oxide layer thickness is the thinnest. When the annealing temperature decreases sequentially along the radial direction of the wafer carrier with a specific tolerance, the thickness of the formed oxide layer decreases sequentially along the radial direction. In this case, the extreme value point of the oxide layer thickness determined from the coordinate relationship in step S4 refers to the point where the oxide layer thickness is the thickest.

[0042] like Figure 3 and Figure 6 As shown, the implementation process of steps S3 and S4 is explained by taking the example of the annealing temperature of all the hot zones 100 in step S2 increasing sequentially with a specific tolerance temperature. Figure 3 In the process, the first direction passing through the center of the wafer 11 is the X1 direction from left to right. Multiple measurement points are selected along this X1 direction to measure the thickness of the oxide layer 12, as shown below. Figure 6 The coordinate relationship between the position of the discontinuous blue line (X-axis) and the thickness of oxide layer 12 (Y-axis) is determined, and the thinnest point A of oxide layer 12 is determined from this coordinate relationship. Then, all points on the left and right sides of point A are linearly fitted to obtain two linear curves La=ax+b and Lb=cx+d. Finally, the x-coordinate value x=(db) / (ac) of the intersection point B of the two linear curves is calculated. This x-coordinate value is the compensation value for the wafer transfer device to be adjusted along the first direction X1.

[0043] The positioning method of the wafer transfer device on the heating platform in this embodiment is based on the linear relationship between the temperature of the thermo-oxidative annealing process and the thickness of the grown oxide layer. That is, the higher the temperature, the thicker the grown oxide layer, and the lower the temperature, the thinner the grown oxide layer. By adjusting the heating temperature of the bearing surface of the wafer carrier to be set in an increasing or decreasing manner along the radial direction of the wafer carrier, theoretically, when the wafer does not shift on the wafer carrier, the thickness of the grown oxide layer should be distributed in an increasing or decreasing manner in all the hot areas arranged radially along the wafer carrier, and the maximum value of the oxide layer thickness should be located at the wafer... At the center, however, when the wafer's position on the wafer carrier shifts, the thickness of the grown oxide layer on the wafer will also shift overall, and the maximum and minimum values ​​of the oxide layer thickness will deviate from the wafer center. In this case, by performing multi-point linear measurements of the oxide layer thickness along a first direction passing through the wafer center, the maximum and minimum value points are determined. Linear fitting is then performed on all points on both sides of the maximum and minimum value point, and the abscissa value of the intersection point of the two linear curves is the wafer's offset value in that first direction. The wafer transport device uses this offset value as its compensation value for adjustment along the first direction, thus achieving the wafer transport device's positioning in that direction. The positioning method in this embodiment does not require disassembling the machine components and can also calculate the compensation value of the wafer transport device relatively accurately. It is simple to operate, reduces the number of positioning adjustments required for the wafer transport device, and provides accurate positioning results.

[0044] As an example, the wafer transfer device is equipped with an adjustable robotic arm, which is used to grip and transfer wafers. Therefore, the positioning method in this embodiment mainly achieves the process of precisely positioning and adjusting the path of the robotic arm to transfer wafers.

[0045] like Figure 1 As shown, the temperature and temperature uniformity provided by the hot region 100 on the wafer carrier stage 10 are determined by the heating structures disposed in this region and their distribution. Therefore, the radial dimension of the hot region 100 is designed according to actual needs and can be the same or different. Figure 2 As shown, as an example, the temperature of the hot zone 100 is provided by heating structures 101 arranged in a circumferential pattern within the corresponding hot zone 100. These heating structures can be, for example, circumferentially arranged heating wires, multiple heating lamps arranged circumferentially, or other commonly used heating structures. Figure 1 and Figure 2As shown, in this embodiment, the bearing surface of the wafer carrier stage 10 includes four concentrically nested hot zones 100 arranged sequentially. Each hot zone 100 is provided with a circumferentially distributed heating structure 101, which is a circumferentially arranged heating lamp. Furthermore, in this embodiment, preferably along the radial direction from the inside to the outside, the innermost circular hot zone has 16 circumferentially distributed heating lamps, the second and third annular hot zones each have 12 circumferentially distributed heating lamps, and the fourth annular hot zone has 16 circumferentially distributed heating lamps.

[0046] As an example, the thickness gradient difference of the oxide layer 12 grown on the surface of the wafer 11 in step S2 is not less than [missing information]. To ensure measurement accuracy.

[0047] In step S3, when performing multi-point linear measurement of the thickness of the oxide layer 12, the more points selected, the more accurate the linear curve obtained by subsequent linear fitting will be. Generally, no fewer than 31 points are selected for measurement. In addition, the number of selected points should be approximately the same on both sides of the extreme point, i.e., the total number of points should be an odd number. For example, when 49 points are selected, the total number of points on both sides of the extreme point is 24.

[0048] As an example, the material of the wafer 11 is preferably any material that can be oxidized at room temperature or higher, such as semiconductor materials such as silicon, germanium, and gallium nitride. In this embodiment, a silicon wafer made of silicon material is selected, so the oxide layer 12 formed is a silicon oxide layer. When the wafer selected in this embodiment is a silicon wafer, the annealing temperature provided by the heating structure 101 in each of the hot regions 100 in step S2 is set in an arithmetic sequence with a tolerance of less than 10°C. For example, the temperature of a typical thermal oxygen growth silicon oxide process is about 1050°C. In this embodiment, the temperature of the four hot regions 100 can be increased sequentially in a tolerance of 5°C outwards along the radial direction, specifically 1045°C, 1050°C, 1055°C, and 1060°C, or decreased sequentially in a tolerance of 5°C, specifically 1060°C, 1055°C, 1050°C, and 1045°C. In addition, the oxygen-containing precursor introduced in step S2 is oxygen, and the annealing time is not less than 60 seconds. After the process is completed, the multi-point linear measurement process of the oxide layer thickness in step S3 is performed within 30 minutes.

[0049] The positioning method of the wafer transfer device on the heating machine platform in this embodiment can achieve compensation adjustment of the wafer transfer device along one direction, such as the first direction, through steps S3 to S5. To further improve the accuracy of the compensation adjustment of the wafer transfer device, compensation adjustment can be performed on the wafer transfer device in two or more different directions, such as... Figure 4As shown, in step S3, at least one second direction X2 that intersects with the first direction X1 and passes through the center of wafer 11 can be selected to achieve compensation adjustment of the wafer transfer device along the second direction. Figure 4 In this context, a second direction X2 was selected. In practice, two or more second directions X2 can be selected as needed, as long as these multiple second directions X2 are different and intersect with the first direction X1. For example... Figure 4 As shown, taking a second direction X2 as an example, the specific process is as follows: In step S3, the thickness of the oxide layer 12 is linearly measured at multiple points along the second direction X2 passing through the center of the wafer 11 to obtain the coordinate relationship between the point positions and the thickness of the oxide layer 12. In step S4, the extreme value point of the oxide layer 12 thickness is determined from this coordinate relationship. Then, the points on both sides of the extreme value point are linearly fitted to obtain two linear curves L3 = mx + e and L4 = nx + f. Finally, the abscissa value x = (fe) / (mn) of the intersection of the two linear curves is calculated. This abscissa value is the compensation value for adjusting the wafer transport device along the second direction X2. Finally, in step S5, the wafer transport device is adjusted using the abscissa value x = (fe) / (mn) as the compensation value for adjusting the wafer transport device along the second direction X2. In this way, the wafer transport device can be adjusted on the entire plane.

[0050] Furthermore, if one adjustment of the wafer transfer device is insufficient to achieve the required acceptable accuracy, the positioning method of this embodiment can be used multiple times to adjust the wafer transfer device until the required acceptable accuracy is achieved. Specifically, step S5 is followed by step S6, which involves repeating steps S1 to S4 to obtain the abscissa value of the intersection point of the two corresponding linear curves (when one direction is selected, the abscissa value of one intersection point is obtained, so the wafer transfer device can be adjusted along one direction; when two intersecting directions are selected, the abscissa values ​​of two intersection points are obtained, so the wafer transfer device can be adjusted along two directions; when more than two intersecting directions are selected, the abscissa values ​​of more than two intersection points are obtained, so the wafer transfer device can be adjusted along more than two directions). It is then determined whether the abscissa value of the intersection point of the two corresponding linear curves is within the acceptable range, which is generally selected to be no more than 0.03 mm in accuracy. If it is within the acceptable range, the adjustment of the wafer transfer device is completed; if it exceeds the acceptable range, step S5 is continued and step S6 is repeated until the adjustment of the wafer transfer device is completed. Furthermore, after completing the positioning method of this embodiment, the temperature of all hot areas 100 on the wafer carrier stage 10 can be adjusted to be consistent, and then a thermal annealing process can be performed. Check whether the thickness map of the obtained oxide layer still has unevenness or edge deviation. If unevenness or edge deviation still exists, the positioning method of this embodiment can be used again to adjust the wafer transfer device.

[0051] like Figures 3 to 5 As shown, a positioning notch 110 is typically provided on the edge of the wafer 11. After the wafer 11 enters the cavity, the positioning notch 110 will face the cavity window. In this embodiment, it is preferred that the first direction in step S3 is parallel or perpendicular to the positioning notch 110. Furthermore, as... Figure 5 As shown, when the wafer transfer device is adjusted in both the first and second intersecting directions, in this embodiment, one direction is parallel to the positioning notch 110 and the other direction is perpendicular to the positioning notch 110.

[0052] As an example, the heating equipment of this embodiment is particularly suitable for rapid thermal processing equipment that requires thermal processes, such as a rapid thermal annealing (RTA) equipment.

[0053] In summary, this invention provides a positioning method for a wafer transfer device on a heating platform. Based on the linear relationship between the temperature of the thermo-oxidative annealing process and the thickness of the grown oxide layer—that is, the higher the temperature, the thicker the grown oxide layer, and the lower the temperature, the thinner the grown oxide layer—by adjusting the heating temperature of the wafer carrier surface to increase or decrease along the radial direction of the wafer carrier, theoretically, when the wafer does not shift on the wafer carrier, the thickness of the grown oxide layer should be distributed in a sequentially increasing or decreasing manner across all heated areas along the radial direction of the wafer carrier. Furthermore, the maximum or minimum value of the oxide layer thickness should be located at... At the center of the wafer, but when the wafer's position on the wafer carrier shifts, the thickness of the grown oxide layer on the wafer also shifts overall, and the maximum and minimum values ​​of the oxide layer thickness deviate from the wafer center. In this case, by performing multi-point linear measurements of the oxide layer thickness along a first direction passing through the wafer center, the maximum and minimum value points are determined. Linear fitting is then performed on all points on both sides of the maximum and minimum value point, and the x-coordinate of the intersection point of the two linear curves is the wafer's offset value in that first direction. The wafer transport device uses this offset value as its compensation value for adjustment along the first direction, thus achieving the wafer transport device's positioning in that direction. The positioning method of this invention does not require disassembling machine components and can accurately calculate the compensation value of the wafer transport device. It is simple to operate, reduces the number of positioning adjustments required for the wafer transport device, and provides accurate positioning results. Therefore, this invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0054] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A positioning method for a wafer transfer device on a heating machine platform, characterized in that, The heating platform includes a wafer carrier stage, which is used at least to heat the wafers it carries; wherein, the bearing surface of the wafer carrier stage includes at least three concentrically nested hot zones arranged sequentially; the positioning method includes the following steps: S1. The wafer transfer device transfers the wafer to the wafer carrier stage; S2. Anneal the wafer to grow an oxide layer on the wafer surface; wherein, during the annealing process, the annealing temperature of all the hot areas is set in an increasing or decreasing manner along the radial direction of the wafer support stage; S3. Perform multi-point linear measurement of the thickness of the oxide layer along the first direction passing through the center of the wafer to obtain the coordinate relationship between the point position and the thickness of the oxide layer. S4. Determine the extreme value point of the oxide layer thickness from the coordinate relationship, then perform linear fitting on the points on both sides of the extreme value point to obtain two linear curves, and finally calculate the abscissa value of the intersection of the two linear curves. The abscissa value is the compensation value for the wafer transfer device to be adjusted along the first direction. S5, Adjust the wafer transfer device based on the compensation value.

2. The positioning method of the wafer transfer device on the heating machine table according to claim 1, characterized in that: Step S3 further includes performing multi-point linear measurements of the oxide layer thickness along at least one second direction passing through the center of the wafer to obtain the coordinate relationship between the position of the point in the corresponding second direction and the thickness of the oxide layer; Step S4 further includes determining the extreme point of the corresponding oxide layer thickness from the coordinate relationship of the corresponding second direction, then performing linear fitting on the points on both sides of the extreme point to obtain two linear curves, and finally calculating the abscissa value of the intersection point of the two linear curves obtained by linear fitting on both sides of the extreme point. The abscissa value is the compensation value for adjusting the wafer transfer device along the corresponding second direction, wherein the first direction intersects the second direction, and all second directions are different; Step S5 further includes adjusting the wafer transfer device based on the corresponding compensation value.

3. The positioning method of the wafer transfer device on the heating machine table according to claim 2, characterized in that: Select a second direction, wherein one of the first direction and the second direction is parallel to the positioning notch on the wafer, and the other direction is perpendicular to the positioning notch on the wafer.

4. The positioning method of the wafer transfer device on the heating machine table according to any one of claims 1 to 3, characterized in that, The process also includes step S6: repeating steps S1 to S4 to obtain the abscissa value of the intersection of the two corresponding linear curves, and determining whether the abscissa value of the intersection of the two corresponding linear curves is within the acceptable range; if it is within the acceptable range, the adjustment of the wafer transfer device is completed; if it exceeds the acceptable range, then continue to step S5 and repeat step S6 until the adjustment of the wafer transfer device is completed.

5. The positioning method of the wafer transfer device on the heating machine table according to claim 4, characterized in that: The permissible range is no greater than 0.03 mm.

6. The positioning method of the wafer transfer device on the heating machine table according to claim 1, characterized in that: The wafer carrier stage has four concentrically nested hot zones on its bearing surface. Each hot zone is provided with a circumferentially distributed heating structure, which heats the hot zone it is located in.

7. The positioning method of the wafer transfer device on the heating machine table according to claim 6, characterized in that: The wafer is a silicon wafer, and the oxide layer is a silicon oxide layer; the annealing temperature provided by the heating structure in each of the hot regions in step S2 is set in an arithmetic sequence with a tolerance of less than 10°C.

8. The positioning method of the wafer transfer device on the heating machine table according to claim 1, characterized in that: In step S2, the thickness gradient difference of the oxide layer grown on the wafer surface is not less than 9. The positioning method of the wafer transfer device on the heating machine table according to claim 1, characterized in that: In step S3, when performing multi-point linear measurement of the thickness of the oxide layer, no less than 31 points are selected for measurement.

10. The positioning method of the wafer transfer device on the heating machine table according to claim 1, characterized in that: The heating machine is a rapid heat treatment machine.

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