Positioning method of wafer conveying device on heating machine table

Abstract

The invention provides a positioning method of a wafer conveying device on a heating machine table, and the method comprises the steps: adjusting the heating temperature of a bearing surface of a wafer bearing table to be set in a manner of increasing or decreasing along the radial direction based on the linear relation between the temperature of thermal oxygen annealing treatment and the thickness of a grown oxide layer; when the position of the wafer on the wafer bearing table deviates, the thickness of the growing oxide layer also deviates on the wafer as a whole, at the moment, multi-point linear measurement is carried out on the thickness of the oxide layer in the first direction passing through the circle center of the wafer, the extreme point is determined, linear fitting is carried out on all point positions on the two sides of the extreme point, and the maximum point position and the minimum point position are obtained. And an abscissa value of an intersection point of the two linear curves is used as a compensation value for adjustment of the wafer conveying device. According to the positioning method, machine parts do not need to be disassembled, meanwhile, the compensation value of the wafer conveying device can be accurately calculated, operation is easy, the positioning adjustment frequency of the wafer conveying device is reduced, and the positioning result is accurate.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor equipment, and in particular to a positioning method for a wafer conveying device on a heating machine. Background Art

[0002] There are many processes involved in semiconductor processing, and each process requires different equipment. Wafer transfer devices (such as robotic arms) play a vital role in semiconductor processing, used to transport wafers between different processes and ensure that wafers move smoothly from one process to the next.

[0003] In some processes that require heating of the wafer, the stability of the wafer heating is very high. At this time, the tolerance of the position deviation of the wafer in the heating machine chamber is very low, so the positioning accuracy of the wafer conveyor on the heating machine is very high. For example, the RTP machine, the main functions of the RTP machine are to promote the diffusion and activation of implanted ions, grow high-quality silicon dioxide, and anneal after the formation of metal silicide. When the wafer is processed in the heating machine, in order to further improve the uniformity of the wafer heating, while heating the wafer, the wafer will be supported by a lift pin or an edge ring and then rotated horizontally. However, if the wafer conveyor does not place the wafer in the center of the chamber, it will cause uneven heating of the wafer, resulting in the risk of wafer acceptance test data drift (WAT data shift) or even the risk of the wafer rotating out of the base and breaking, which will reduce the product yield.

[0004] At present, the method for detecting whether the wafer is in the center of the chamber in the heating machine process chamber is mainly through visual method, that is, observing the edge of the rotating wafer after opening the chamber. This method has certain limitations. It requires disassembly of machine components, which is complicated to operate. In addition, the positioning of the wafer conveyor device is adjusted visually, which requires multiple adjustments and the positioning results are rough. Summary of the invention

[0005] In view of the shortcomings of the prior art mentioned above, an object of the present invention is to provide a positioning method for a wafer conveying device on a heating machine, which is used to solve the problem that in the prior art, the process chamber of the heating machine detects whether the wafer is in the center of the chamber by visual method, resulting in low positioning accuracy of the wafer conveying device, requiring multiple adjustments and complicated operation.

[0006] To achieve the above-mentioned purpose and other related purposes, the present invention provides a positioning method for a wafer conveyor on a heating machine, wherein the heating machine comprises a wafer carrier, and the wafer carrier is at least used to heat the wafer carried thereon; wherein the carrying surface of the wafer carrier comprises at least three heat zones which are concentrically nested in sequence; and the positioning method comprises the following steps:

[0007] S1, a wafer conveying device conveys the wafer to the wafer carrying platform;

[0008] S2, the wafer is subjected to annealing treatment to grow an oxide layer on the surface of the wafer; wherein, during the annealing treatment, the annealing temperatures of all the hot zones are set in an increasing or decreasing manner along the radial direction of the wafer carrier;

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

[0010] S4 determines the maximum point of the oxide layer thickness from the coordinate relationship, then linearly fits the points on both sides of the maximum point to obtain two linear curves, and finally calculates the abscissa value of the intersection of the two linear curves, where the abscissa value is the compensation value of the wafer conveying device adjusted along the first direction;

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

[0012] Optionally, step S3 also includes performing multi-point linear measurement 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 point position in the corresponding second direction and the oxide layer thickness; step S4 also includes determining the maximum point of the corresponding oxide layer thickness from the coordinate relationship in the corresponding second direction, and then linearly fitting the points on both sides of the corresponding maximum point to obtain two linear curves, and finally calculating the horizontal coordinate value of the intersection of the two linear curves obtained by linear fitting of the points on both sides of the corresponding maximum point, and the horizontal coordinate value is the compensation value for adjusting the wafer conveying device along the corresponding second direction, wherein the first direction intersects with the second direction, and all the second directions are different; step S5 also includes adjusting the wafer conveying device based on the corresponding compensation value.

[0013] Furthermore, one of the first direction and the second direction is selected, and 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.

[0014] Furthermore, it also includes step S6: repeating steps S1 to S4 to obtain the horizontal coordinate value of the intersection of the two corresponding linear curves, and judging whether the horizontal coordinate value of the intersection of the two corresponding linear curves is within the allowable range; if it is within the allowable range, the adjustment of the wafer conveying device is completed; if it exceeds the allowable range, continue with step S5 and then repeat step S6 until the adjustment of the wafer conveying device is completed.

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

[0016] Optionally, the carrying surface of the wafer carrying platform includes four heat zones which are concentrically nested in sequence, and each of the heat zones is provided with a circumferentially distributed heating structure, and the heating structure heats the heat zone in which it is located.

[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 set in each of the hot zones in step S2 is set in an arithmetic progression within a tolerance range below 10°C.

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

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

[0020] Optionally, the heating machine is a rapid thermal processing machine.

[0021] As described above, the positioning method of the wafer conveyor on the heating machine of the present invention is based on the linear relationship between the temperature of the thermal oxygen annealing treatment 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 carrying surface of the wafer carrier to be set in an arithmetic progression along the radial direction, theoretically, when the wafer is not offset on the wafer carrier, the thickness of the grown oxide layer in all hot areas arranged along the radial direction should be distributed in an arithmetic progression, and the maximum value of the oxide layer thickness should be located at the center of the wafer, but When the position of the wafer on the wafer carrier is offset, the thickness of the grown oxide layer will also be offset as a whole on the wafer, and the maximum value of the oxide layer thickness will also deviate from the center of the wafer. At this time, the thickness of the oxide layer is linearly measured at multiple points in the first direction through the center of the wafer, and the maximum value point is determined, and all points on both sides of the maximum value point are linearly fitted. The horizontal coordinate value of the intersection of the two linear curves is the offset value of the wafer in the first direction. The wafer conveying device uses this offset value as the compensation value for adjustment along the first direction, and the positioning of the wafer conveying device in the first direction can be achieved. The positioning method of the present invention does not require the disassembly of the machine components, and can also more accurately calculate the compensation value of the wafer conveying device. The operation is simple, the number of positioning adjustments of the wafer conveying device is reduced, and the positioning result is accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The diagram shows a top view of a structure in which a wafer carrier in an exemplary heating machine is provided with four heat zones.

[0023] Figure 2 The diagram shows a top view of a heating machine in which a wafer carrier is provided with heating structures in four annular areas.

[0024] Figures 3 to 5 It is a schematic diagram of a top view of the structure of forming an oxide layer on a wafer in the positioning method of a wafer conveying device on a heating machine of the present invention.

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

[0026] Component number description

[0027] 10 Wafer carrier

[0028] 100 hot zones

[0029] 101 Heating structure

[0030] 11 Wafer

[0031] 110 Positioning notch

[0032] 12 Oxide layer DETAILED DESCRIPTION

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

[0034] See also Figures 1 to 6 It should be noted that the illustrations provided in this embodiment are only used to illustrate the basic concept of the present invention in a schematic manner, and the illustrations only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0035] like Figures 1 to 3As shown, this embodiment provides a positioning method for a wafer conveyor on a heating machine, wherein the heating machine includes a wafer carrier 10, and the wafer carrier 10 is at least used to heat the wafer carried thereon; wherein the carrying surface of the wafer carrier 10 includes at least three heat zones 100 which are concentrically nested in sequence, that is, the heat zone 100 located in the center is a circular heat zone, and the other heat zones 100 are annular heat zones; the positioning method includes the following steps:

[0036] S1, a wafer conveying device conveys the wafer 11 to the wafer carrying platform 10;

[0037] S2, annealing the wafer 11 to grow an oxide layer 12 on the surface of the wafer 11; wherein, during the annealing process, the annealing temperatures of all the hot areas 100 are set in an increasing or decreasing manner along the radial direction of the wafer carrier 10;

[0038] S3, along a first direction passing through the center of the wafer 11 (eg 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, determining the maximum point of the oxide layer thickness from the coordinate relationship, then performing linear fitting on the points on both sides of the maximum point to obtain two linear curves L1=ax+b and L2=cx+d, and finally calculating the abscissa value x=(db) / (ac) of the intersection of the two linear curves, which is the compensation value of the wafer conveying device adjusted along the first direction;

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

[0041] It should be noted here that the annealing temperature of all the hot areas 100 in the annealing process in step S2 is set in an increasing or decreasing manner along the radial direction of the wafer carrier, that is, the annealing temperature can be sequentially increased by a specific tolerance temperature along the radial direction of the wafer carrier, or can be sequentially decreased by a specific tolerance temperature. When the annealing temperature is sequentially increased by a specific tolerance temperature along the radial direction of the wafer carrier, the thickness of the formed oxide layer is sequentially thickened along the radial direction of the wafer carrier, and at this time, the maximum 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 is sequentially decreased by a specific tolerance temperature along the radial direction of the wafer carrier, the thickness of the formed oxide layer is sequentially thinned along the radial direction, and at this time, the maximum 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 step S3 and step S4 is described by taking the annealing temperature of all the hot areas 100 in the annealing process in step S2 as an example to increase in sequence according to the specific tolerance temperature. Figure 3 In the embodiment, the first direction passing through the center of the wafer 11 is the X1 direction from left to right. A plurality of measuring points are selected in the X1 direction to measure the thickness of the oxide layer 12, and the thickness of the oxide layer 12 is obtained as follows: Figure 6 The coordinate relationship between the point position of the blue discontinuous line (X-axis) and the thickness of the oxide layer 12 (Y-axis), and the thinnest point A of the oxide layer 12 is determined from the coordinate relationship, and then all the 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, and finally the horizontal coordinate value x=(db) / (ac) of the intersection B of the two linear curves is calculated. The horizontal coordinate value is the compensation value of the wafer conveying device adjusted along the first direction X1.

[0043] The positioning method of the wafer conveyor on the heating platform of the present embodiment is based on the linear relationship between the temperature of the thermal oxygen annealing treatment 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 carrying 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 deviate on the wafer carrier, the thickness of the grown oxide layer in all hot areas arranged along the radial direction of the wafer carrier should be distributed in an increasing or decreasing manner in sequence, and the maximum value of the oxide layer thickness should be located at the wafer. However, when the position of the wafer on the wafer carrier is offset, the thickness of the grown oxide layer will also produce an overall offset on the wafer, and the maximum value of the oxide layer thickness will also deviate from the center of the wafer. At this time, the thickness of the oxide layer is measured linearly at multiple points in the first direction through the center of the wafer, and the maximum value point is determined, and all points on both sides of the maximum value point are linearly fitted. The horizontal coordinate value of the intersection of the two linear curves is the offset value of the wafer in the first direction. The wafer conveying device uses this offset value as the compensation value for adjusting it along the first direction, and the positioning of the wafer conveying device in the first direction can be achieved. The positioning method of this embodiment does not require the disassembly of the machine components, and can also more accurately calculate the compensation value of the wafer conveying device. The operation is simple, the number of positioning adjustments of the wafer conveying device is reduced, and the positioning result is accurate.

[0044] As an example, the wafer conveying device is provided with an adjustable robotic arm, which is used to clamp and transfer wafers. Therefore, the positioning method in this embodiment mainly realizes the process of accurately positioning and adjusting the path of the robotic arm for transferring wafers.

[0045] like Figure 1 As shown, the temperature and temperature uniformity that can be provided by the hot area 100 on the carrying surface of the wafer carrying platform 10 are determined by the heating structure set in the area and the distribution of the heating structure, so the radial size of the hot area 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 area 100 is provided by a circumferentially distributed heating structure 101 arranged in the corresponding hot area 100, and the heating structure can be, for example, a circumferentially arranged heating wire, or a plurality of circumferentially arranged heating lamps, or other commonly used heating structures. Figure 1 and Figure 2As shown, in this embodiment, the carrying surface of the wafer carrier 10 is selected to include four heat zones 100 concentrically nested in sequence, and each of the heat zones 100 is provided with a circumferentially distributed heating structure 101, which is a circumferentially arranged heating lamp; further, in this embodiment, preferably along the radial direction from inside to outside, the number of heating lamps distributed circumferentially in the innermost circular heat zone is 16, the number of heating lamps distributed circumferentially in the second and third annular heat zones is 12, and the number of heating lamps distributed circumferentially in the fourth annular heat zone is 16.

[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 To ensure measurement accuracy.

[0047] In step S3, the number of points selected when performing multi-point linear measurement on the thickness of the oxide layer 12 is, in theory, more accurate the linear curve obtained by subsequent linear fitting is. Generally, no less than 31 points are selected for measurement. In addition, the total number of points selected is as close as possible to the total number of points on both sides of the maximum point, that is, the total number is an odd number of points. For example, when 49 points are selected, the total number of points on both sides of the maximum point is 24.

[0048] As an example, the material of the wafer 11 is preferably all materials that can be oxidized at room temperature or higher temperature, such as semiconductor materials such as silicon, germanium, gallium nitride, etc. 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 provided in each of the hot zones 100 in step S2 is set in an arithmetic progression within a tolerance range of less than 10°C. For example, the temperature of a general thermal oxygen growth silicon oxide process is about 1050°C. In this embodiment, the temperatures of the four hot zones 100 can be increased radially outward with a tolerance of 5°C, specifically 1045°C, 1050°C, 1055°C, 1060°C, or decreased with a tolerance of 5°C, specifically 1060°C, 1055°C, 1050°C, 1045°C; in addition, the oxygen-containing precursor introduced in step S2 is oxygen, the annealing treatment time is not less than 60s, and after the process is completed, the multi-point linear measurement process of the oxide layer thickness in step S3 is performed within 30min.

[0049] The positioning method of the wafer conveyor on the heating machine of this embodiment can realize compensation adjustment of the wafer conveyor along one direction, for example, the first direction, through steps S3 to S5. In order to further improve the accuracy of the compensation adjustment of the wafer conveyor, the wafer conveyor can be compensated and adjusted in two or more different directions, such as Figure 4As shown, in step S3, at least one second direction X2 intersecting with the first direction X1 and passing through the center of the wafer 11 can also be selected to implement compensation adjustment of the wafer conveying device along the second direction. Figure 4 A second direction X2 is selected in the embodiment. In practice, two or more second directions X2 may be selected as needed, as long as the more second directions X2 are different and intersect with the first direction X1. 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 position and the thickness of the oxide layer 12; in step S4, the maximum point of the thickness of the oxide layer 12 is determined from the coordinate relationship, and then the points on both sides of the maximum point are linearly fitted to obtain two linear curves L3=mx+e and L4=nx+f, and finally the horizontal coordinate value x=(fe) / (mn) of the intersection of the two linear curves is calculated, and the horizontal coordinate value is the compensation value of the wafer conveying device adjusted along the second direction X2; finally, in step S5, the horizontal coordinate value x=(fe) / (mn) is used as the compensation value of the wafer conveying device adjusted along the second direction X2 to adjust the wafer conveying device. In this way, the adjustment of the wafer conveying device on the entire plane can be achieved.

[0050] Furthermore, when adjusting the wafer conveying device once still cannot achieve the required accuracy within the allowable range, the positioning method of this embodiment can be used multiple times to adjust the wafer conveying device until the required accuracy is within the allowable range. Specifically: step S5 also includes step S6, which includes repeating steps S1 to S4 to obtain the horizontal coordinate value of the intersection of the two corresponding linear curves (when one direction is selected, the horizontal coordinate value of one intersection is obtained, so that the wafer conveying device can be adjusted along one direction; when two intersecting directions are selected, the horizontal coordinate values ​​of two intersections are obtained, so that the wafer conveying device can be adjusted along two directions; when more than two intersecting directions are selected, the horizontal coordinate values ​​of more than two intersections are obtained, so that the wafer conveying device can be adjusted along more than two directions), and judging whether the horizontal coordinate value of the intersection of the two corresponding linear curves is within an allowable range, and the allowable range is generally selected to be no more than 0.03mm in accuracy; if it is within the allowable range, the adjustment of the wafer conveying device is completed; if it exceeds the allowable range, continue with step S5 and then repeat step S6 until the adjustment of the wafer conveying device is completed. Furthermore, after completing the positioning method of this embodiment, the temperature of all hot areas 100 on the wafer carrier 10 can be adjusted to be consistent, and then a thermal oxygen annealing treatment can be performed to check whether the thickness map of the oxide layer obtained still has unevenness or biased edges. If unevenness or biased edges still exist, the positioning method of this embodiment can be used again to adjust the wafer conveying device.

[0051] like Figures 3 to 5 As shown, generally, a positioning notch 110 is provided on the edge of the wafer 11. After the wafer 11 enters the chamber, the positioning notch 110 is oriented toward the chamber window. In this embodiment, the first direction in step S3 is preferably parallel or perpendicular to the positioning notch 110. Figure 5 As shown, when the wafer conveying device is adjusted in both the intersecting first direction and the second direction, in this embodiment, one of the directions is selected to be parallel to the positioning notch 110 and the other direction is selected to be perpendicular to the positioning notch 110 .

[0052] As an example, the heating machine of the present embodiment is particularly suitable for a rapid thermal processing machine that needs to perform a thermal process, such as an RTA (Rapid Thermal Annealing) machine.

[0053] In summary, the present invention provides a positioning method for a wafer conveying device on a heating machine, based on the linear relationship between the temperature of a thermal oxygen annealing treatment and the thickness of a 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 carrying 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 deviate on the wafer carrier, the thickness of the grown oxide layer in all hot areas arranged along the radial direction of the wafer carrier should be distributed in an increasing or decreasing manner in sequence, and the maximum value of the oxide layer thickness should be located at The center of the wafer, but when the position of the wafer on the wafer carrier is offset, the thickness of the grown oxide layer will also produce an overall offset on the wafer, and the maximum value of the oxide layer thickness will also deviate from the center of the wafer. At this time, the thickness of the oxide layer is measured linearly at multiple points in the first direction through the center of the wafer, and the maximum value point is determined, and all points on both sides of the maximum value point are linearly fitted. The horizontal coordinate value of the intersection of the two linear curves is the offset value of the wafer in the first direction. The wafer conveying device uses this offset value as the compensation value for adjusting it along the first direction, and the positioning of the wafer conveying device in the first direction can be achieved. The positioning method of the present invention does not require the disassembly of the machine components, and can also more accurately calculate the compensation value of the wafer conveying device. The operation is simple, the number of positioning adjustments of the wafer conveying device is reduced, and the positioning result is accurate. Therefore, the present invention effectively overcomes the various shortcomings of the prior art and has a high industrial utilization value.

[0054] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may 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 a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A method for positioning a wafer conveyor device on a heating machine, characterized in that: The heating machine comprises a wafer carrier, and the wafer carrier is at least used to heat the wafer carried thereon; wherein the carrying surface of the wafer carrier comprises at least three heat zones which are concentrically nested in sequence; and the positioning method comprises the following steps: S1, a wafer conveying device conveys the wafer to the wafer carrying platform; S2, performing annealing treatment on the wafer to grow an oxide layer on the surface of the wafer; wherein, during the annealing treatment, the annealing temperatures of all the hot zones are set in an increasing or decreasing manner along the radial direction of the wafer carrier; S3, performing multi-point linear measurement on the thickness of the oxide layer along a first direction passing through the center of the wafer to obtain a coordinate relationship between the point position and the thickness of the oxide layer; S4, determining the maximum point of the oxide layer thickness from the coordinate relationship, then performing linear fitting on the points on both sides of the maximum point to obtain two linear curves, and finally calculating the abscissa value of the intersection of the two linear curves, the abscissa value being the compensation value of the wafer conveying device adjusted along the first direction; S5, adjusting the wafer conveying device based on the compensation value.

2. The method for positioning a wafer conveyor device on a heating machine according to claim 1, characterized in that: Step S3 also includes performing multi-point linear measurement 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 point position in the corresponding second direction and the oxide layer thickness; step S4 also includes determining the maximum point of the corresponding oxide layer thickness from the coordinate relationship in the corresponding second direction, then linearly fitting the points on both sides of the corresponding maximum point to obtain two linear curves, and finally calculating the horizontal coordinate value of the intersection of the two linear curves obtained by linear fitting of the points on both sides of the corresponding maximum point, and the horizontal coordinate value is the compensation value for adjusting the wafer conveying device along the corresponding second direction, wherein the first direction intersects with the second direction, and all the second directions are different; step S5 also includes adjusting the wafer conveying device based on the corresponding compensation value.

3. The method for positioning a wafer conveyor on a heating machine according to claim 2, wherein: A second direction is selected, and 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 method for positioning a wafer conveyor device on a heating machine according to any one of claims 1 to 3, characterized in that: It also includes step S6: repeating steps S1 to S4 to obtain the horizontal coordinate value of the intersection of the two corresponding linear curves, and judging whether the horizontal coordinate value of the intersection of the two corresponding linear curves is within the allowable range; if it is within the allowable range, the adjustment of the wafer conveying device is completed; if it exceeds the allowable range, continuing with step S5 and then repeating step S6 until the adjustment of the wafer conveying device is completed.

5. The method for positioning a wafer conveyor on a heating machine according to claim 4, characterized in that: The allowable range is no greater than 0.03 mm.

6. The method for positioning a wafer conveyor device on a heating machine according to claim 1, characterized in that: The carrying surface of the wafer carrying platform includes four heat zones which are concentrically nested in sequence, and each of the heat zones is provided with a circumferentially distributed heating structure, which heats the heat zone in which it is located.

7. The method for positioning a wafer conveyor device on a heating machine according to claim 6, wherein: The wafer is a silicon wafer, and the oxide layer is a silicon oxide layer; in step S2, the annealing temperature provided by the heating structure arranged in each of the thermal zones is set in an arithmetic progression within a tolerance range of less than 10°C.

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

10. The method for positioning a wafer conveyor device on a heating machine according to claim 1, wherein: The heating machine is a rapid thermal processing machine.

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