A wafer position error detection method and device

Abstract

The present invention belongs to the technical field of semiconductor equipment calibration, and specifically relates to a wafer position error detection method and device, wherein a single position detection sensor is arranged on the side of a wafer transmission path to realize recording and scanning of a non-center chord length and an end point position on a wafer, and the position of a standard wafer is used as a reference standard system, thereby restoring the position coordinates of the end points of the standard wafer and the wafer to be tested scanned by the position detection sensor in the reference coordinate system, thereby obtaining a deviation value between the center of a wafer to be tested in a second chamber and the center of a standard wafer, and performing position calibration on the wafer to be tested according to the deviation value, which is beneficial to improving the process quality of wafer manufacturing; compared with a multi-sensor detection solution, the embodiment of the present invention only uses a single position detection sensor to realize wafer position calibration, has a lower calibration cost, and is easy to replace and maintain.

Description

Technical Field

[0001] The present invention belongs to the technical field of semiconductor equipment calibration, and in particular relates to a wafer position error detection method and device. Background Art

[0002] Most modern PECVD equipment is equipped with automatic alignment function, which automatically detects the alignment marks on the wafer surface and accurately aligns the wafer to the reference position of the equipment by using optical or laser systems. Correction completed: Once the automatic alignment is completed, the equipment will record the position offset of the wafer and use it to correct the position of the wafer. Repeated correction: Multiple alignment marks are usually corrected to improve the accuracy and stability of the measurement. The equipment automatically calculates the average position of the wafer and uses this correction value to align the wafer in subsequent processes. Check and adjust: The operator may need to check the correction results and make fine adjustments to ensure that the position alignment of the wafer meets the required accuracy requirements.

[0003] The working principle of some common automatic alignment systems: Optical alignment systems use optical cameras or microscopes to observe alignment marks on the surface of the wafer. These alignment marks are usually special patterns or structures, such as crosses, T-shaped or other easily recognizable shapes. The camera or microscope captures the image of the alignment mark and transmits it to the computer system for image processing. The computer system performs image processing and analysis on the captured alignment mark image. This includes algorithms such as edge detection, shape recognition and image matching. Through these processing steps, the system is able to accurately identify the position and shape of the alignment mark. Once the position of the alignment mark is accurately calculated, the automatic alignment system will calculate the offset of the wafer, that is, the offset of the current position of the wafer relative to the reference position of the equipment. The automatic alignment system transmits the calculated offset to the equipment control system, which adjusts the position of the wafer accordingly so that it is accurately aligned to the reference position of the equipment. This adjustment process can be completed in a very short time, usually within a few seconds. In the process, alignment may need to be performed in multiple steps, so the automatic alignment system repeats the same process in each step to ensure that the wafer is always in the correct position. The optical alignment system can achieve high-speed and high-precision alignment, providing a reliable automation solution for the semiconductor manufacturing process. Through automatic alignment, the accuracy and consistency of the process can be greatly improved, resulting in high-quality semiconductor devices.

[0004] The above wafer position correction method is relatively cumbersome and costly. For some methods that use a small number of sensors for detection and correction, although the structure is simple, it is only applicable to round wafers or wafers with small gaps. For wafers with large flat edges, the different deflection directions of the flat edges will inevitably affect the data measured by the detection mechanism, thereby affecting the accuracy of wafer correction.

[0005] It should be noted that this part of the present invention only provides background technology related to the present invention and does not necessarily constitute prior art or known technology. Summary of the invention

[0006] The object of the present invention is to provide a wafer position error detection method and device to overcome the problem of low wafer position calibration accuracy of existing semiconductor equipment.

[0007] In order to achieve the above-mentioned object, in a first aspect, an embodiment of the present invention provides a wafer position error detection method, based on a wafer position error detection device, including a position detection sensor, wherein the position detection sensor is located on a transmission path installed between a first chamber and a second chamber, and the detection method includes:

[0008] S100, obtaining a first standard center position of a standard wafer in a first chamber, and obtaining a second standard center position of a standard wafer moved to a second chamber, and determining a transmission path according to the first standard center position and the second standard center position, and simultaneously obtaining a first standard reference position and a second standard reference position of the standard wafer determined by a position detection sensor along the transmission path, and determining the distance between the first standard reference position and the second standard reference position as a standard chord length;

[0009] S200, obtaining a first actual center position of the wafer to be tested in the first chamber, and obtaining a second actual center position of the wafer to be tested when it is moved to the second chamber, and determining a transmission path of the robot arm according to the first actual center position and the second actual center position, and simultaneously obtaining a first actual reference position and a second actual reference position of the wafer to be tested determined by a position detection sensor along the transmission path, and determining the distance between the first actual reference position and the second actual reference position as a reference chord length;

[0010] S300, establishing a reference coordinate system with the second standard circle center position as the origin, the transmission path direction as the first coordinate direction, and the direction perpendicular to the transmission path direction as the second coordinate direction;

[0011] S400, obtaining the midpoint coordinates of the standard chord length in the reference coordinate system as the standard midpoint coordinates; and obtaining the midpoint coordinates of the reference chord length in the reference coordinate system as the actual midpoint coordinates;

[0012] S500, based on the relative position relationship between the second standard circle center position and the standard midpoint coordinates, and the relative position relationship between the second actual circle center position and the actual midpoint coordinates, determine the deviation value of the second actual circle center position relative to the second standard circle center position to perform position error calibration.

[0013] Optionally, in S500, determining a deviation value of the second actual circle center position relative to the second standard circle center position according to a relative position relationship between the second standard circle center position and the standard midpoint coordinates, and a relative position relationship between the second actual circle center position and the actual midpoint coordinates, includes:

[0014] Determine a first distance according to the second standard circle center position and the standard midpoint coordinates, and determine a second distance according to the second actual circle center position and the actual midpoint coordinates;

[0015] A first deviation value along a first coordinate direction is determined according to the standard midpoint coordinate and the actual midpoint coordinate, and a second deviation value along a second coordinate direction is determined according to a difference between the first distance and the second distance.

[0016] Optionally, after S500, the method further includes:

[0017] An adjustment amount of the wafer to be tested is determined according to a first difference between the first deviation value and a first preset offset threshold value, and a second difference between the second deviation value and a second preset offset threshold value.

[0018] Optionally, after S500, the method further includes:

[0019] If the first difference is smaller than a first preset difference, and the second difference is smaller than a second preset difference, the position of the wafer to be tested is not adjusted;

[0020] If the first difference is greater than a first preset difference and / or the second difference is greater than a second preset difference, the position of the wafer to be tested is adjusted according to the corresponding differences.

[0021] Optionally, in S100, determining the transmission path based on the first standard circle center position and the second standard circle center position includes:

[0022] The transmission path overlaps with a line connecting the first standard circle center position and the second standard circle center position.

[0023] Optionally, in S100, acquiring a first standard reference position and a second standard reference position of the standard wafer determined by a position detection sensor along the transmission path includes:

[0024] The first standard reference position is the position of the standard wafer when the rising edge of the position detection sensor is triggered when the standard wafer moves with the robot arm;

[0025] The second standard reference position is the position of the standard wafer when the falling edge of the position detection sensor is triggered when the standard wafer moves with the robot arm.

[0026] Optionally, in S200, acquiring a first actual reference position and a second actual reference position of the standard wafer along the transmission path determined by a position detection sensor includes:

[0027] The first actual reference position is the position of the wafer to be tested when the rising edge of the position detection sensor is triggered when the wafer moves with the robot arm;

[0028] The second actual reference position is the position of the wafer to be tested when the falling edge of the position detection sensor is triggered when the wafer moves with the robot arm.

[0029] Optionally, in S400, obtaining the midpoint coordinates of the standard chord length in the reference coordinate system as standard midpoint coordinates includes:

[0030] Determine that a line connecting the first standard reference position and the second standard reference position is parallel to the first coordinate direction;

[0031] Determine a first standard coordinate of a first standard reference position in a reference coordinate system and a second standard coordinate of a second standard reference position in a reference coordinate system according to a length of the standard wafer passing through the position detection sensor when the standard wafer moves along the transmission path and a size of the standard wafer;

[0032] The midpoint position between the first standard coordinates and the second standard coordinates is determined as the standard midpoint coordinates.

[0033] Optionally, in S400, obtaining the midpoint coordinates of the reference chord length in the reference coordinate system as actual midpoint coordinates includes:

[0034] Determine that a line connecting the first actual reference position and the second actual reference position is parallel to the first coordinate direction;

[0035] Determine a first actual coordinate of a first actual reference position in a reference coordinate system and a second actual coordinate of a second actual reference position in a reference coordinate system according to a length of the wafer to be measured that passes through the position detection sensor when the wafer to be measured moves along the transmission path and a size of the wafer to be measured;

[0036] The midpoint position between the first actual coordinate and the second actual coordinate is determined as the actual midpoint coordinate.

[0037] In a second aspect, an embodiment of the present invention further provides a wafer position error detection device, comprising: a first chamber, a second chamber, a robot arm, a position detection sensor, and a control unit;

[0038] The position detection sensor is arranged at a position deviating from the transmission path, and is used to obtain a reference position of the wafer at the edge during the movement of the wafer along the transmission path;

[0039] The control unit is electrically connected to the position detection sensor and the robotic arm, respectively, and is used to obtain the coordinates corresponding to the first actual center position and the second actual center position, and to obtain the rising edge and falling edge signals of the position detection sensor, so as to execute the wafer position error detection method as described in the first aspect.

[0040] The embodiments of the present invention have at least the following technical effects:

[0041] The wafer position error detection method and device provided by the embodiment of the present invention set a single position detection sensor on the side of the wafer transmission path to realize the recording and scanning of the non-center chord length and the end point position on the wafer, and use the position of the standard wafer as the reference standard system to restore the position coordinates of the end point positions of the standard wafer and the wafer to be tested scanned by the position detection sensor in the reference coordinate system, so as to obtain the deviation value between the center of the standard wafer and the center of the wafer to be tested in the second chamber, and perform position calibration on the wafer to be tested according to the deviation value, which is beneficial to improve the calibration accuracy of the wafer, and then improve the process quality of the wafer; compared with the multi-sensor detection solution, the embodiment of the present invention only uses a single position detection sensor to realize the calibration of the wafer position, the calibration cost is lower, and it is easy to replace and maintain. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0043] Figure 1 A schematic structural diagram of a wafer position error detection device provided by an embodiment of the present invention;

[0044] Figure 2 A schematic diagram of position comparison between a standard wafer and a wafer to be tested of a wafer position error detection device provided by an embodiment of the present invention (including a schematic diagram of the position of the wafer before the robotic arm moves it);

[0045] Figure 3 A schematic diagram of position comparison between a standard wafer and a wafer to be tested of another wafer position error detection device provided by an embodiment of the present invention;

[0046] Figure 4 A flowchart of a wafer position error detection method provided by an embodiment of the present invention.

[0047] Reference numerals:

[0048] 100 - first chamber; 101 - robotic arm; 200 - second chamber; 300 - position detection sensor; 400 - standard wafer; 500 - wafer to be tested. DETAILED DESCRIPTION

[0049] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] Those skilled in the art will understand that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those generally understood by those skilled in the art in the field to which the present invention belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless specifically defined as here.

[0051] Those skilled in the art will appreciate that, unless otherwise stated, the singular forms "a", "an", "said" and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present invention refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. The term "and / or" used herein includes all or any unit and all combinations of one or more associated listed items.

[0052] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0053] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0054] Combination Figure 1 As shown, an embodiment of the present invention provides a wafer position error detection device, including: a first chamber, a second chamber, a robotic arm, a position detection sensor and a control unit (not shown in the figure). Among them, the first chamber, the second chamber and the robotic arm are all structures of the semiconductor equipment itself, the first chamber is a process chamber, the second chamber is a transfer chamber, and the robotic arm is used to put the wafer to be reacted on the first wafer support platform in the first chamber for reaction (for example: thin film deposition), and then take the wafer out to the second chamber after the reaction is completed, and then prepare for the next process.

[0055] When the robotic arm is located at the standard position in the first chamber (no offset), the center of the standard wafer is located at the first standard center position. When the robotic arm is located at the standard position in the second chamber (no offset), the center of the standard wafer is located at the second standard center position. The first standard center position and the second standard center position can be calibrated in advance to serve as reference positions for subsequent calibration.

[0056] The position detection sensor is arranged at a position deviating from the transmission path, and is used to obtain the reference position of the wafer at the edge during the movement of the wafer along the transmission path. The control unit is electrically connected to the position detection sensor and the robotic arm, respectively, and is used to obtain the coordinates corresponding to the first actual center position and the second actual center position, and to obtain the rising edge and falling edge signals of the position detection sensor, and is used to execute the following wafer position error detection method. It should be noted that the position of the position detection sensor relative to the wafer is different, and the corresponding error calibration direction will be different.

[0057] The wafer position error detection method provided by the embodiment of the present invention is specifically described below. Figure 1 , Figure 2 as well as Figure 4 As shown, the detection method comprises the following steps:

[0058] S100, obtaining the first standard center position of the standard wafer 400 in the first chamber 100, and obtaining the second standard center position of the standard wafer 400 when it is moved to the second chamber 200, and determining the transmission path by the first standard center position and the second standard center position, and at the same time obtaining the first standard reference position and the second standard reference position of the standard wafer 400 determined by the position detection sensor 300 along the transmission path, and determining the distance between the first standard reference position and the second standard reference position as the standard chord length.

[0059] Alternatively, if Figure 3As shown, the first standard center position is point O1 in the figure, the second standard center position is point O2 in the figure, the first standard reference position is point B in the figure, and the second standard reference position is point A in the figure. As the standard wafer 400 moves from the first chamber 100 to the second chamber 200 with the robot arm 101, the position detection sensor 300 scans from point B of the standard wafer 400 to point A, thereby obtaining a reference chord length (i.e., the distance between point A and point B). The scanning process is triggered by the standard wafer 400 blocking the position detection sensor 300, and the direction of the standard chord length is parallel to the direction of the transmission path.

[0060] Optionally, in S100, determining the transmission path according to the first standard circle center position and the second standard circle center position includes:

[0061] The transmission path overlaps with a line connecting the first standard circle center position and the second standard circle center position.

[0062] Optionally, in S100, obtaining a first standard reference position and a second standard reference position of the standard wafer 400 determined by the position detection sensor 300 along the transmission path includes:

[0063] The first standard reference position is the position of the standard wafer 400 when the rising edge of the position detection sensor 300 is triggered when the robot arm 101 moves.

[0064] Specifically, the first standard reference position B is an initial position of the standard wafer 400 detected by the position detection sensor 300 .

[0065] The second standard reference position is the position of the standard wafer 400 when the falling edge of the position detection sensor 300 is triggered when the standard wafer 400 moves with the robot arm 101 .

[0066] Specifically, the second standard reference position A is the end position of the standard wafer 400 detected by the position detection sensor 300 .

[0067] S200, obtaining the first actual center position of the wafer 500 to be tested in the first chamber 100, and obtaining the second actual center position of the wafer 500 to be tested when it is moved to the second chamber 200, and determining the transmission path of the robot arm 101 according to the first actual center position and the second actual center position, and simultaneously obtaining the first actual reference position and the second actual reference position of the wafer 500 to be tested determined along the transmission path by the position detection sensor 300, and determining the distance between the first actual reference position and the second standard reference position as the reference chord length.

[0068] Alternatively, if Figure 3As shown, the first actual center position of the circle is the point o1 position in the figure, the second actual center position of the circle is the point o2 position in the figure, the first actual reference position is the point b position in the figure, and the second actual reference position is the point a position in the figure. During the process of the wafer 500 to be tested moving from the first chamber 100 to the second chamber 200 with the robot arm 101, the position detection sensor 300 scans from point b to point a of the wafer 500 to be tested, thereby obtaining a reference chord length (i.e., the distance between point a and point b). The scanning process is triggered by the wafer 500 to be tested blocking the position detection sensor 300, and the direction of the reference chord length is parallel to the direction of the transmission path.

[0069] Optionally, in S200, obtaining a first actual reference position and a second actual reference position of the standard wafer 400 determined by the position detection sensor 300 along the transmission path includes:

[0070] The first actual reference position is the position of the wafer 500 to be tested when it moves with the robot arm 101 and triggers the rising edge of the position detection sensor 300 .

[0071] Specifically, the first actual reference position b is the initial position of the wafer 500 to be tested detected by the position detection sensor 300 .

[0072] The second actual reference position is the position of the wafer 500 to be tested when it moves with the robot arm 101 and triggers the falling edge of the position detection sensor 300 .

[0073] Specifically, the second actual reference position a is the end position of the wafer 500 to be tested detected by the position detection sensor 300 .

[0074] S300, establishing a reference coordinate system with the second standard circle center position as the origin, the transmission path direction as the first coordinate direction, and the direction perpendicular to the transmission path direction as the second coordinate direction.

[0075] Specifically, the control unit connects the positions of O1 and O2 obtained in steps S100 and S200 and establishes a reference coordinate system at the standard position to facilitate obtaining the deviation position of the actual wafer.

[0076] Optionally, the first coordinate direction is the Y-axis direction, that is, the movement direction of the robot arm 101; the second coordinate direction is the X-axis direction, and the coordinate corresponding to the second standard circle center position O2 is (0, 0).

[0077] S400, obtaining the midpoint coordinates of the standard chord length in the reference coordinate system as the standard midpoint coordinates; and obtaining the midpoint coordinates of the reference chord length in the reference coordinate system as the actual midpoint coordinates.

[0078] Specifically, the standard midpoint coordinates are the coordinates corresponding to the midpoint between point A and point B, and the standard midpoint coordinates correspond to the position of H in the figure; the actual midpoint coordinates of the standard midpoint coordinates are the coordinates of the midpoint between point a and point b, corresponding to the position of h in the figure.

[0079] Optionally, in S400, obtaining first standard coordinates of the first standard reference position in the reference coordinate system and second standard coordinates of the second standard reference position in the reference coordinate system, and determining standard midpoint coordinates of the first standard coordinates and the second standard coordinates includes:

[0080] Determine that a line connecting the first standard reference position and the second standard reference position is parallel to the first coordinate direction.

[0081] The first standard coordinates of the first standard reference position in the reference coordinate system and the second standard coordinates of the second standard reference position in the reference coordinate system are determined according to the length of the standard wafer passing through the position detection sensor when moving along the transmission path and the size of the standard wafer 400.

[0082] The midpoint position between the first standard coordinate and the second standard coordinate is determined as the standard midpoint coordinate.

[0083] Optionally, in S400, obtaining a first actual coordinate of the first actual reference position in the reference coordinate system and a second actual coordinate of the second actual reference position in the reference coordinate system, and determining an actual midpoint coordinate of the first actual coordinate and the second actual coordinate includes:

[0084] It is determined that a line connecting the first actual reference position and the second actual reference position is parallel to the first coordinate direction.

[0085] The first actual coordinates of the first actual reference position in the reference coordinate system and the second actual coordinates of the second actual reference position in the reference coordinate system are determined according to the length of the wafer 500 to be tested that passes through the position detection sensor when moving along the transmission path and the size of the wafer 500 to be tested.

[0086] The midpoint position between the first actual coordinate and the second actual coordinate is determined according to the first actual coordinate and the second actual coordinate, that is, the actual midpoint coordinate.

[0087] S500, according to the relative position relationship between the second standard circle center position and the standard midpoint coordinates, and the relative position relationship between the second actual circle center position and the actual midpoint coordinates, determine the deviation value of the second actual circle center position relative to the second standard circle center position to perform position error calibration.

[0088] Specifically, the relative position relationship between o2 and O2 is determined according to the relative position relationship between O2 and H, the relative position relationship between o2 and h, and the relative position relationship between H and h, so as to respectively determine the deviation values ​​along the first coordinate direction and the second coordinate direction, thereby realizing the position calibration and adjustment of the wafer 500 to be tested.

[0089] Optionally, in S500, determining a deviation value of the second actual circle center position relative to the second standard circle center position according to the relative position relationship between the second standard circle center position and the standard midpoint coordinates, and the relative position relationship between the second actual circle center position and the actual midpoint coordinates, includes:

[0090] The first distance is determined according to the second standard circle center position and the standard midpoint coordinates, and the second distance is determined according to the second actual circle center position and the actual midpoint coordinates.

[0091] Specifically, the first distance (i.e., the absolute value of the O2H coordinate difference) is determined according to the distance between the second standard circle center position O2 and the standard midpoint coordinate H, and the second distance (i.e., the absolute value of the o2h coordinate difference) is determined according to the distance between the second actual circle center position O2 and the actual midpoint coordinate h.

[0092] A first deviation value along a first coordinate direction is determined according to the standard midpoint coordinate and the actual midpoint coordinate, and a second deviation value along a second coordinate direction is determined according to the difference between the first distance and the second distance.

[0093] Optionally, after determining the first deviation value and the second deviation value, the method further includes:

[0094] The adjustment amount of the wafer 500 to be tested is determined according to a first difference between the first deviation value and the first preset offset threshold value, and a second difference between the second deviation value and the second preset offset threshold value.

[0095] Optionally, after S500, the method further includes:

[0096] If the first difference is smaller than the first preset difference, and the second difference is smaller than the second preset difference, the position of the wafer 500 to be tested is not adjusted.

[0097] If the first difference is greater than the first preset difference and / or the second difference is greater than the second preset difference, the position of the wafer 500 to be tested is adjusted according to the corresponding differences.

[0098] Specifically, by comparing the first difference and the second difference with the corresponding preset difference, it is determined whether the wafer 500 to be tested needs to be adjusted and how to adjust it specifically.

[0099] The wafer position error detection method provided by the embodiment of the present invention sets a single position detection sensor 300 on the side of the wafer transmission path to realize the recording and scanning of the non-center chord length and the end point position on the wafer, and uses the position of the standard wafer 400 as the reference standard system, so as to restore the position coordinates of the end point positions of the standard wafer 400 and the wafer to be tested 500 scanned by the position detection sensor 300 in the reference coordinate system, thereby obtaining the deviation value between the center of the standard wafer 400 and the center of the wafer to be tested 500 in the second chamber 200, and calibrating the position of the wafer to be tested 500 according to the deviation value, which is beneficial to improving the calibration accuracy of the wafer, and further improving the process quality of the wafer; compared with the multi-sensor detection solution, the embodiment of the present invention only uses a single position detection sensor 300 to realize the calibration of the wafer position, the calibration cost is lower, and it is easy to replace and maintain.

[0100] The wafer position detection method of the present invention is specifically described below with specific embodiments:

[0101] (1) Standard wafer 400 calibration process:

[0102] The detection is more accurate at the places where the left or right circular slope of the standard wafer 400 changes greatly.

[0103] Move the accurately placed standard wafer 400 from the first chamber 100 to the second chamber 200. At this time, the center of the standard wafer 400 moves from O1 to O2, and the distance between O1 and O2 is recorded as L0. The direction of L0 is the transmission path direction of the robot arm 101. During this calibration process, the position detection sensor 300 will trigger the rising edge signal and the falling edge signal in sequence when scanning the standard wafer 400, and the positions of the robot arm 101 at that time are recorded as P1 and P2 respectively.

[0104] With the movement direction of the robot arm 101 as the Y axis, the movement direction of the vertical robot arm 101 as the X axis, O2 as the origin, the coordinates of point A (XA, YA), and the coordinates of point B (XB, YB), it can be known that the standard chord length AB=|P2-P1|,

[0105] AH=BH= ,

[0106] It is known that AB is perpendicular to the X-axis, and AO2 is equal to the radius R of the standard wafer 400.

[0107] |O2H|=|XA|=|XB|= ,

[0108] Thus, the offset of the standard wafer 400 relative to the position detection sensor 300 is obtained, so as to facilitate position calibration of the wafer 500 to be tested.

[0109] (2) Calibration process of wafer 500 to be tested:

[0110] During normal operation detection, when the position detection sensor 300 scans the wafer 500 to be tested, it will trigger the rising edge signal and the falling edge signal in sequence, and record the arm position at that time as p1 and p2. The reference chord length obtained by scanning is ab, and the coordinates of a and b are respectively shown as: (Xa, Ya), and (Xb, Yb). It can be seen that the reference chord length ab=|p2-p1|,

[0111] |X a |=|X b |=|X A | = ,

[0112] |o2h|= ,

[0113] like Figure 2 As shown, when the position detection sensor 300 is installed in the negative direction of the center of the wafer 500 to be tested (the left side of the Y axis),

[0114] =( ,0)

[0115] =( ,0)

[0116] The horizontal coordinate of o2 is: + =( - ,0)

[0117] = - = + -( + )=(0,p1-P1);

[0118] = - = + -( + ) = (0, p2-P2);

[0119] = + =(0, +p2-P2);

[0120] =(0,- );

[0121] = + =(0, +p2-P2);

[0122] From this we can see that the coordinates of o2 are ( - , +p2-P2, continue to calculate and simplify to get the coordinates of o2 as ( - , - ).

[0123] The detection range of this method is that when the sensor is installed in the negative direction of the center of the wafer 500 to be tested, the center of the wafer 500 to be tested is in the negative direction O2H in the X-axis direction, and the center of the wafer 500 to be tested is in the positive direction R-O2H.

[0124] like Figure 3 As shown, when the position detection sensor 300 is installed in the positive direction of the center of the wafer 500 to be tested (to the right of the Y axis),

[0125] =( ,0)

[0126] =( ,0)

[0127] The horizontal coordinate of o2 is: + =( + ,0)

[0128] =(0,p1-P1);

[0129] =(0,p2-P2);

[0130] = + =(0, +p2-P2);

[0131] =(0,- );

[0132] = + =(0, +p2-P2);

[0133] From this we can see that the coordinates of o2 are (- + , +p2-P2, continue to calculate and simplify to get the coordinates of o2 as (- + , - ).

[0134] The detection range of this method is that when the sensor is installed in the positive direction of the center of the wafer 500 to be tested, the center of the wafer 500 to be tested is in the negative direction R-O2H and the center of the wafer 500 to be tested is in the positive direction O2H in the X-axis direction.

[0135] It should be noted that P1 is the extension radius (or distance) of the robot arm when the rising edge of the position detection sensor is triggered when the standard position wafer moves from the first chamber to the second chamber. Since the standard wafer and the robot arm are relatively stationary, the standard wafer movement distance at this time is also called P1, which is represented as point B on the standard wafer; similarly, the falling edge is P2, which is represented as point A on the standard wafer; and during actual operation, the rising edge is represented as p1, which is represented as point b on the actual wafer, and the falling edge is represented as p2, which is represented as point a on the actual wafer. Because Bb or Aa is the difference between two points, the coordinate positions of the arm and point P can be ignored, so they are not shown in the figure.

[0136] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific conditions. In the description of this specification, specific features, structures, materials or characteristics can be combined in a suitable manner in any one or more embodiments or examples.

[0137] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wafer position error detection method, based on a wafer position error detection device, comprising a single position detection sensor, wherein the position detection sensor is located on a transmission path installed between a first chamber and a second chamber, characterized in that: The detection method comprises: S100, obtaining a first standard center position of a standard wafer in a first chamber, and obtaining a second standard center position of a standard wafer moved to a second chamber, and determining a transmission path according to the first standard center position and the second standard center position, and simultaneously obtaining a first standard reference position and a second standard reference position of the standard wafer determined by a position detection sensor along the transmission path, and determining the distance between the first standard reference position and the second standard reference position as a standard chord length; S200, obtaining a first actual center position of the wafer to be tested in the first chamber, and obtaining a second actual center position of the wafer to be tested when it is moved to the second chamber, and determining a transmission path of the robot arm according to the first actual center position and the second actual center position, and simultaneously obtaining a first actual reference position and a second actual reference position of the wafer to be tested determined by a position detection sensor along the transmission path, and determining the distance between the first actual reference position and the second actual reference position as a reference chord length; S300, establishing a reference coordinate system with the second standard circle center position as the origin, the transmission path direction as the first coordinate direction, and the direction perpendicular to the transmission path direction as the second coordinate direction; S400, obtaining the midpoint coordinates of the standard chord length in the reference coordinate system as the standard midpoint coordinates; and obtaining the midpoint coordinates of the reference chord length in the reference coordinate system as the actual midpoint coordinates; S500, determining a deviation value of the second actual circle center position relative to the second standard circle center position to perform position error calibration according to a relative position relationship between the second standard circle center position and the standard midpoint coordinates, and a relative position relationship between the second actual circle center position and the actual midpoint coordinates; In S500, determining the deviation value of the second actual circle center position relative to the second standard circle center position according to the relative position relationship between the second standard circle center position and the standard midpoint coordinates, and the relative position relationship between the second actual circle center position and the actual midpoint coordinates, includes: Determine a first distance according to the second standard circle center position and the standard midpoint coordinates, and determine a second distance according to the second actual circle center position and the actual midpoint coordinates; A first deviation value along a first coordinate direction is determined according to the standard midpoint coordinate and the actual midpoint coordinate, and a second deviation value along a second coordinate direction is determined according to a difference between the first distance and the second distance.

2. The wafer position error detection method according to claim 1, characterized in that: After S500, it also includes: An adjustment amount of the wafer to be tested is determined according to a first difference between the first deviation value and a first preset offset threshold value, and a second difference between the second deviation value and a second preset offset threshold value.

3. The wafer position error detection method according to claim 2, characterized in that: After S500, it also includes: If the first difference is smaller than a first preset difference, and the second difference is smaller than a second preset difference, the position of the wafer to be tested is not adjusted; If the first difference is greater than a first preset difference and / or the second difference is greater than a second preset difference, the position of the wafer to be tested is adjusted according to the corresponding differences.

4. The wafer position error detection method according to claim 1, characterized in that: In S100, determining the transmission path based on the first standard circle center position and the second standard circle center position includes: The transmission path overlaps with a line connecting the first standard circle center position and the second standard circle center position.

5. The wafer position error detection method according to claim 1, characterized in that: In S100, acquiring a first standard reference position and a second standard reference position of the standard wafer along the transmission path determined by a position detection sensor includes: The first standard reference position is the position of the standard wafer when the rising edge of the position detection sensor is triggered when the standard wafer moves with the robot arm; The second standard reference position is the position of the standard wafer when the falling edge of the position detection sensor is triggered when the standard wafer moves with the robot arm.

6. The wafer position error detection method according to claim 1, characterized in that: In S200, acquiring a first actual reference position and a second actual reference position of the standard wafer along the transmission path determined by a position detection sensor includes: The first actual reference position is the position of the wafer to be tested when the rising edge of the position detection sensor is triggered when the wafer moves with the robot arm; The second actual reference position is the position of the wafer to be tested when the falling edge of the position detection sensor is triggered when the wafer moves with the robot arm.

7. The wafer position error detection method according to claim 1, characterized in that: In S400, the step of obtaining the midpoint coordinates of the standard chord length in the reference coordinate system as the standard midpoint coordinates includes: Determine that a line connecting the first standard reference position and the second standard reference position is parallel to the first coordinate direction; Determine a first standard coordinate of a first standard reference position in a reference coordinate system and a second standard coordinate of a second standard reference position in a reference coordinate system according to a length of the standard wafer passing through the position detection sensor when the standard wafer moves along the transmission path and a size of the standard wafer; The midpoint position between the first standard coordinates and the second standard coordinates is determined as the standard midpoint coordinates.

8. The wafer position error detection method according to claim 1, characterized in that: In S400, the step of obtaining the midpoint coordinates of the reference chord length in the reference coordinate system as actual midpoint coordinates includes: Determine that a line connecting the first actual reference position and the second actual reference position is parallel to the first coordinate direction; Determine the first actual coordinate of the first actual reference position in the reference coordinate system and the second actual coordinate of the second actual reference position in the reference coordinate system according to the length of the wafer to be measured passing through the position detection sensor when the wafer to be measured moves along the transmission path and the size of the wafer to be measured; the size of the wafer to be measured is equal to the size of the standard wafer; The midpoint position between the first actual coordinate and the second actual coordinate is determined as the actual midpoint coordinate.

9. A wafer position error detection device, characterized in that: include: A first chamber, a second chamber, a robotic arm, a position detection sensor, and a control unit; The position detection sensor is arranged at a position deviating from the transmission path, and is used to obtain a reference position of the wafer at the edge during the movement of the wafer along the transmission path; The control unit is electrically connected to the position detection sensor and the robotic arm, respectively, and is used to obtain the coordinates corresponding to the first actual center position and the second actual center position, and to obtain the rising edge and falling edge signals of the position detection sensor, so as to execute the wafer position error detection method as described in any one of claims 1 to 8.

Images