Method, device and equipment for generating wafer graph and testing wafer

Abstract

The invention provides a method, device and equipment for generating a wafer graph and testing a wafer, and the method comprises the steps: enabling the edge of the wafer to be located in the visual field range of first image collection equipment, and determining the position of a circle center point of the wafer according to the position relation between the position of the visual field center of the first image collection equipment and a point on an edge arc; taking the position of the circle center point of the wafer as the circle center, and performing preliminary arrangement on the chips on the wafer according to the sizes of the chips and the position of the first template; and correcting the positions of the chips arranged on the wafer based on the deviation between the position of the first template and the position of the first groove to generate a wafer graph. The wafer graph generated by the method comprises the position information in one-to-one correspondence with the actual chip positions and is not influenced by the number of the chips, the time for generating the wafer graph is shortened, and the efficiency for generating the wafer graph is greatly improved.

Description

Technical Field

[0001] The present disclosure relates to the field of semiconductor technology, and in particular to a method, device and equipment for generating a wafer map and testing a wafer. Background Art

[0002] Wafer Map plays an important role in the field of semiconductor technology. It can visualize chips and facilitate testing of chips according to the positions marked on the wafer map. It helps to locate problem areas, conduct fault analysis and repair, optimize production processes, and thus promote yield improvement. However, in the traditional wafer map generation process, the following problems are often encountered: the generated wafer map does not include the location information of the chip, or it is necessary to collect location information by traversing the chips on the wafer one by one, and then generate a wafer map including chip location information. The efficiency of this method is significantly affected by the number of chips, especially when the number of chips is large, the efficiency of generating wafer maps is extremely low. Summary of the invention

[0003] The embodiments of the present disclosure provide a method, device and equipment for generating a wafer map and testing a wafer, so as to solve the problem of extremely low efficiency in the existing generation of a wafer map including chip location information.

[0004] Based on the above problems, in a first aspect, an embodiment of the present disclosure provides a method for generating a wafer map, comprising: A wafer and a first image acquisition device for observing the wafer are provided; the wafer is provided with a plurality of chips of the same shape and size and a first groove which are evenly distributed; wherein the first groove is located at the intersection area of ​​the scribe lines between the chips; Move the wafer so that the edge of the wafer is within the field of view of a first image acquisition device, and determine the position of the center point of the wafer according to the position relationship between the center of the field of view of the first image acquisition device and at least three points on the arc of the edge of the wafer; The chip on the wafer is located within the field of view of the first image acquisition device, and the position of the first template on the chip is determined according to the position of the center of the field of view of the first image acquisition device and any mechanism on the wafer located at the same position in the chip; and the size of the chip is determined according to the position of the first template; Taking the center point of the wafer as the center of the circle, preliminarily arranging the chips on the wafer according to the size of the chips and the position of the first template; Based on the deviation between the position of the first template and the position of the first groove, the positions of the chips arranged on the wafer are corrected to generate a wafer map.

[0005] In combination with the first aspect, in a possible implementation manner, determining the position of the center point of the wafer according to the position relationship between the position of the center of the field of view of the first image acquisition device and at least three points on the arc of the edge of the wafer includes: Determine a first mechanical position coordinate that makes the arc of the wafer edge within the field of view of a first image acquisition device; determine first coordinate deviations between the positions of a plurality of arbitrary points on the arc of the wafer edge and the position of the center of the field of view of the first image acquisition device within the field of view of the first image acquisition device; determine a second mechanical position coordinate when the position of each arbitrary point coincides with the position of the center of the field of view of the first image acquisition device based on the first mechanical position coordinate and the plurality of first coordinate deviations; or The wafer is moved so that a plurality of circular arcs on the edge of the wafer are sequentially located within the field of view of a first image acquisition device, and the corresponding first mechanical position coordinates are sequentially determined so that the plurality of circular arcs on the edge of the wafer are respectively located within the field of view of the first image acquisition device; within the field of view of the first image acquisition device, a first coordinate deviation between the position of any point on the plurality of circular arcs and the position of the center of the field of view of the first image acquisition device is respectively determined; based on the plurality of first mechanical position coordinates and the corresponding first coordinate deviations, a second mechanical position coordinate when the position of each arbitrary point coincides with the position of the center of the field of view of the first image acquisition device is respectively determined; According to the principle that three non-collinear points can uniquely determine a circle, the center point of the wafer is fitted based on the second mechanical position coordinates corresponding to at least three arbitrary points, and the third mechanical position coordinates when the center point of the wafer coincides with the center of the field of view of the first image acquisition device are determined.

[0006] In combination with the first aspect, in a possible implementation manner, after determining the position of the first template of the chip, the method further includes: Rotating the wafer according to the position of the first template so that the chip on the wafer is aligned to a horizontal state within the field of view of the first image acquisition device includes: Determine a first angle of wafer rotation according to an angle between a straight line where a line connecting preset positions in the first template corresponding to at least two chips in the same row or column respectively is located and a horizontal line; The wafer is rotated according to the first angle so that the chips on the wafer are adjusted to a horizontal state within the field of view of the first image acquisition device.

[0007] In combination with the first aspect, in a possible implementation manner, determining the size of the chip according to the position of the first template includes: Determine the lateral size of the chip according to the distance between the preset positions in the first template corresponding to the left and right adjacent chips respectively; wherein the lateral size of the chip includes: the sum of the length of the horizontal side of the chip and the width of the scribe line between the chips; The longitudinal dimension of the chip is determined according to the distance between the preset positions in the first template corresponding to the upper and lower adjacent chips respectively; wherein the longitudinal dimension of the chip includes: the sum of the length of the vertical side of the chip and the width of the scribe line between the chips.

[0008] In combination with the first aspect, in a possible implementation, the preliminarily arranging the chips on the wafer with the center point of the wafer as the center of the circle according to the size of the chips and the position of the first template includes: Determining a fourth mechanical position coordinate that makes the preset position of the first template coincide with the position of the center of the field of view of the first image acquisition device; The preset position of the first template is used as the designated position of the corresponding chip, and the chips on the wafer are preliminarily arranged according to the center point position of the wafer, the size of the wafer, the size of the chip and the fourth mechanical position coordinates.

[0009] In combination with the first aspect, in a possible implementation manner, the position of the chips arranged on the wafer is corrected based on the deviation between the position of the first template and the position of the first groove to generate a wafer map, including: Determining a fifth mechanical position coordinate that causes the center position of the first groove to coincide with the center position of the field of view of the first image acquisition device; Subtract the preset position coordinates of the first template from the fifth mechanical position coordinates, perform a modulo operation on the obtained coordinate difference and the size of the chip, and determine a second coordinate deviation between the center position of the first groove and the preset position of the first template; The preset position coordinates of the first template of the chips arranged on the wafer are compensated by using the second coordinate deviation to generate a wafer map.

[0010] In a second aspect, a method for testing a wafer is provided, comprising: Determine the location of the pad inside the chip based on the center coordinates of the chip on the wafer map; The probe is placed within the field of view of the second image acquisition device to determine the position of the needle tip of the probe; According to the position of the pad and the position of the probe tip, the probe is made to contact the pad to test the wafer; wherein the wafer map is generated by the method for generating a wafer map as described in the first aspect or in combination with any possible implementation manner of the first aspect.

[0011] In conjunction with the second aspect, in a possible implementation manner, determining the position of the pad inside the chip according to the center position coordinates of the chip on the wafer map includes: According to the center position coordinates of the chip on the wafer map, the center position of the chip is made to coincide with the center position of the field of view of the first image acquisition device, and a third coordinate deviation of the position of the pad inside the chip relative to the center position of the field of view of the first image acquisition device is determined; The step of making the probe contact the pad according to the position of the pad and the position of the probe tip to test the wafer includes: According to the third coordinate deviation and the position of the needle tip of the probe, the probe is made to contact the pad to test the wafer.

[0012] In conjunction with the second aspect, in a possible implementation manner, determining the position of the pad inside the chip according to the center position coordinates of the chip on the wafer map includes: According to the center position coordinates of the chip on the wafer map, the center position of the chip is made to coincide with the center position of the field of view of the first image acquisition device, and a third coordinate deviation of the position of the pad inside the chip relative to the center position of the field of view of the first image acquisition device is determined; Determine the seventh mechanical position coordinate when the position of the pad inside the chip coincides with the position of the center of the field of view of the first image acquisition device by subtracting the sixth mechanical position coordinate when the center position of the chip coincides with the position of the center of the field of view of the first image acquisition device from the third coordinate deviation; The step of making the probe contact the pad according to the position of the pad and the position of the probe tip to test the wafer includes: According to the seventh mechanical position coordinate and the position of the needle tip of the probe, the probe is made to contact the pad to test the wafer.

[0013] In conjunction with the second aspect, in a possible implementation manner, determining the position of the pad inside the chip according to the center position coordinates of the chip on the wafer map includes: Determine an eighth mechanical position coordinate that makes the pad inside the chip be located within the field of view of the first image acquisition device; Determine, within the field of view of the first image acquisition device, a fourth coordinate deviation between the center position of the pad and the center position of the field of view of the first image acquisition device; and / or, Determine, according to the eighth mechanical position coordinate and the fourth coordinate deviation, a ninth mechanical position coordinate when the center position of the pad coincides with the center position of the field of view of the first image acquisition device; and / or, Determine the chip corresponding to the pad and a fifth coordinate deviation of the center position of the pad and the corresponding chip according to the center position coordinate of the chip on the wafer map and the ninth mechanical position coordinate; The step of making the probe contact the pad according to the position of the pad and the position of the probe tip to test the wafer includes: Acquire a first position of the pad; the first position of the pad includes at least one of the following: a fourth coordinate deviation, a ninth mechanical position coordinate, and a fifth coordinate deviation; According to the first position of the pad and the position of the needle tip of the probe, the probe is made to contact the pad to test the wafer.

[0014] In conjunction with the second aspect, in a possible implementation, for a single probe, placing the probe within a field of view of a second image acquisition device and determining a position of a needle tip of the probe includes: Determine a tenth mechanical position coordinate that makes the position of the center of the field of view of the second image acquisition device coincide with the position of the center of the field of view of the first image acquisition device; wherein the second image acquisition device is moved in advance so that the center of the field of view of the first image acquisition device and the center of the field of view of the second image acquisition device are calibrated according to the same reference object; Determining an eleventh mechanical position coordinate that places the tip of the probe within the field of view of the second image acquisition device, and determining a sixth coordinate deviation between the position of the tip of the probe and the position of the center of the field of view of the second image acquisition device; A seventh coordinate deviation of the position of the needle tip of the probe relative to the center of the field of view of the first image acquisition device is determined based on the tenth mechanical position coordinate and the difference between the eleventh mechanical position coordinate and the coordinate deviation.

[0015] In combination with the second aspect, in a possible implementation, for a single row of probes, the step of placing the probes within a field of view of a second image acquisition device and determining the positions of the probe tips includes: Determine a twelfth mechanical position coordinate that makes the position of the center of the field of view of the second image acquisition device coincide with the position of the center of the field of view of the first image acquisition device; wherein the second image acquisition device is moved in advance so that the center of the field of view of the first image acquisition device and the center of the field of view of the second image acquisition device are calibrated according to the same reference object; Determine a thirteenth mechanical position coordinate that makes the tip of any probe in the single row of probes be located within the field of view of the second image acquisition device, and determine an eighth coordinate deviation between the position of the tip of any probe and the position of the center of the field of view of the second image acquisition device; Determine a ninth coordinate deviation of the position of the tip of any probe relative to the center of the field of view of the first image acquisition device according to the twelfth mechanical position coordinate and the difference between the thirteenth mechanical position coordinate and the eighth coordinate deviation; Determine a second angle of wafer rotation according to an angle between a straight line connecting positions of at least two internal pads of the chips in the same row or column and a straight line connecting positions of needle tips of at least two probes in the single row of probes; The wafer is rotated according to the second angle to make the straight line connecting the positions of the tips of at least two probes in a single row of probes parallel to the straight line connecting the positions of the pads inside at least two chips in the same row or column.

[0016] In conjunction with the second aspect, in a possible implementation manner, before testing the wafer, the method further includes: measuring the thickness of the wafer; According to the thickness of the wafer and the preset wafer thickness, the direction and distance of movement of the carrier carrying the wafer are determined, and the carrier moves in the direction and distance of movement.

[0017] In a third aspect, a device for generating a wafer map is provided, comprising: An image acquisition module is used to provide a wafer and a first image acquisition device for observing the wafer; the wafer is provided with a plurality of chips of the same shape and size and a first groove that are evenly distributed; wherein the first groove is located at the intersection of the scribe lines between the chips; a wafer centering module is used to move the wafer so that the edge of the wafer is located within the field of view of the first image acquisition device, and determine the position of the center point of the wafer according to the positional relationship between the position of the center of the field of view of the first image acquisition device and at least three points on the arc of the edge of the wafer; a wafer map generation module, configured to locate the chip on the wafer within the field of view of the first image acquisition device, determine the position of the first template on the chip according to the position of the center of the field of view of the first image acquisition device and any mechanism on the wafer located at the same position within the chip; and determine the size of the chip according to the position of the first template; Taking the center point of the wafer as the center of the circle, preliminarily arranging the chips on the wafer according to the size of the chips and the position of the first template; Based on the deviation between the position of the first template and the position of the first groove, the positions of the chips arranged on the wafer are corrected to generate a wafer map.

[0018] In a fourth aspect, a device for testing a wafer is provided, comprising: The pad positioning module is used to determine the position of the pad inside the chip according to the center position coordinates of the chip on the wafer map; A probe positioning module, used to locate the probe within the field of view of the second image acquisition device and determine the position of the needle tip of the probe; A wafer testing module is used to test the wafer by making the probe contact the pad according to the position of the pad and the position of the probe tip; wherein the wafer map is generated by the method for generating a wafer map as described in the first aspect, or in combination with any possible implementation of the first aspect.

[0019] In a fifth aspect, a device for testing wafers is provided, comprising: a wafer image generating device as described in the third aspect and / or a wafer testing device as described in the fourth aspect.

[0020] The beneficial effects of the embodiments of the present disclosure include: A method, device and equipment for generating a wafer map and testing a wafer provided by an embodiment of the present disclosure include: providing a wafer and a first image acquisition device for observing the wafer; a plurality of chips and a first groove of the same shape and size are evenly distributed on the wafer; wherein the first groove is located at the intersection of the scribe lines between the chips; moving the wafer so that the edge of the wafer is located within the field of view of the first image acquisition device, and determining the position of the center point of the wafer according to the position relationship between the position of the center of the field of view of the first image acquisition device and at least three points on the arc of the edge of the wafer; making the chip on the wafer located within the field of view of the first image acquisition device, and determining the position of the first template on the chip according to the position of the center of the field of view of the first image acquisition device and any mechanism on the wafer located at the same position in the chip; and determining the size of the chip according to the position of the first template; taking the position of the center point of the wafer as the center of the circle, preliminarily arranging the chips on the wafer according to the size of the chip and the position of the first template; and correcting the position of the chips arranged on the wafer based on the deviation between the position of the first template and the position of the first groove to generate a wafer map. The method for generating a wafer map provided by the embodiment of the present disclosure determines the position of the center point of the wafer, preliminarily arranges the chips on the wafer according to the size of the chips and the position of the first template, and then corrects the position of the chips arranged on the wafer according to the deviation between the position of the first template and the position of the first groove to generate a wafer map. Compared with the related art, the wafer map generated by the present disclosure includes position information that corresponds one-to-one to the actual chip position, and is not affected by the number of chips, which shortens the time for generating a wafer map and greatly improves the efficiency of generating a wafer map. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A flowchart of a method for generating a wafer map provided by an embodiment of the present disclosure; Figure 2 A schematic diagram of the structure of a device for generating a wafer image provided by an embodiment of the present disclosure; Figure 3One of the schematic diagrams of the field of view of the first image acquisition device provided in the embodiment of the present disclosure; Figure 4 A second schematic diagram of the field of view of the first image acquisition device provided in an embodiment of the present disclosure; Figure 5 A schematic diagram of a preliminary arrangement of chips on a wafer provided in an embodiment of the present disclosure; Figure 6 One of the schematic diagrams of the field of view of the second image acquisition device provided in the embodiment of the present disclosure; Figure 7 A second schematic diagram of the field of view of the second image acquisition device provided in an embodiment of the present disclosure; Figure 8 A schematic diagram of the structure of a device for generating a wafer map provided in an embodiment of the present disclosure; Fig. 9 A schematic diagram of the structure of a device for testing wafers provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0022] The embodiments of the present disclosure provide a method, device and apparatus for generating a wafer map and testing a wafer. The preferred embodiments of the present disclosure are described below in conjunction with the drawings of the specification. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present disclosure, and are not used to limit the present disclosure. In addition, the embodiments and features in the embodiments of the present application can be combined with each other if there is no conflict.

[0023] The present disclosure provides a method for generating a wafer map. Figure 1 As shown, the following steps are included: S101, providing a wafer and a first image acquisition device for observing the wafer; a plurality of chips of the same shape and size and a first groove are evenly distributed on the wafer; wherein the first groove is located at the intersection area of ​​the scribe lines between the chips; S102, moving the wafer so that the edge of the wafer is located within the field of view of the first image acquisition device, and determining the position of the center point of the wafer according to the position relationship between the center of the field of view of the first image acquisition device and at least three points on the arc of the wafer edge; S103, placing the chip on the wafer within the field of view of the first image acquisition device, determining the position of the first template of the chip according to the position of the center of the field of view of the first image acquisition device and any mechanism on the wafer located at the same position within the chip; and determining the size of the chip according to the position of the first template; S104, taking the center point of the wafer as the center of the circle, preliminarily arranging the chips on the wafer according to the size of the chips and the position of the first template; S105 . Based on the deviation between the position of the first template and the position of the first groove, correct the positions of the chips arranged on the wafer to generate a wafer map.

[0024] In the disclosed embodiments, a wafer may refer to a silicon wafer used to make a silicon semiconductor circuit (chip), which is the basic raw material for chip manufacturing. A die is a microelectronic device manufactured on a wafer, which forms an extremely small circuit structure through a series of complex semiconductor manufacturing processes. A pad (PAD) refers to a connection point or pin on a chip, which is used to contact a probe to test the electrical characteristics of the chip. A scribe line, also known as a saw street, may refer to the space reserved for cutting between chips on a wafer, which is used to separate the chips on the wafer into independent individuals. Wafer Map is an important tool in the semiconductor industry. Wafer Map can provide a visual representation of the chip, allowing engineers to more intuitively find and analyze bad chips. Wafer Map can also provide chip location information, which helps the probe to accurately connect to the pad inside the chip, so as to test the chip. Probe Pins is a precision connection tool that can establish an electrical connection between the chip and the test system. The main function of the probe is to ensure that the test signal can be accurately transmitted from the tester to the pads of each chip on the wafer, and to collect feedback signals for analysis. However, in the traditional wafer map generation process, the following problems are often encountered: the generated wafer map does not include the chip location information or the generated chip location information is inaccurate, and engineers are often required to manually locate the chip. This method consumes a lot of manpower costs. Other wafer map generation methods require traversing the chips on the wafer one by one to collect their location information, and then generate a wafer map including chip location information. The efficiency of this method is significantly affected by the number of chips, especially when the number of chips is large, the efficiency of generating wafer maps is extremely low.

[0025] In the embodiments of the present disclosure, the following examples are based on the example of generating a wafer map by moving a wafer. The method concept of generating a wafer map by moving the first image acquisition device is consistent with that of generating a wafer map by moving a wafer. Figure 2As shown, a first image acquisition device 202 is arranged on the table 201, and its position is fixed, and it is used to observe the wafer 203 located on the stage 204. The stage 204 is used to fix the wafer 203 and is equipped with a precise moving device. With the preset position of the stage 204 as the coordinate origin, a spatial rectangular coordinate system is established. The stage can move along the moving device in the x-axis, y-axis, and z-axis directions. The moving device equipped with the stage 204 can move the wafer 203 to a specified mechanical position coordinate. The relative position of the preset position and the center of the field of view of the first image acquisition device 202 is fixed. In a possible implementation, the preset position of the stage 204 coincides with the center of the field of view of the first image acquisition device 202. The first image acquisition device 202 may include a high-magnification camera and a low-magnification camera. The low-magnification camera is used to roughly adjust the field of view, and the high-magnification camera is used to finely adjust the field of view. By calibrating the field of view of the high-magnification camera and the low-magnification camera, it can be ensured that the object observed within the field of view is clearly visible. For a wafer 203, the chips inside it are of the same size, and multiple chips are evenly distributed on the wafer 203. Scribing lines of equal width are reserved between the chips. The first grooves are located in the intersection area of ​​the scribe lines. The first grooves have the same size and are evenly distributed on the wafer 203. In order to determine the position of the center point of the wafer, the wafer 203 is moved so that the edge of the wafer 203 is within the field of view of the first image acquisition device 202, such as Figure 3 As shown, the edge of the wafer 203 is observed in the field of view 301 of the first image acquisition device 202. The position of the point on the edge arc is determined based on the position relationship between the center of the field of view of the first image acquisition device 202 and the point on the arc of the edge of the wafer 203. The position of the center point of the wafer 203 is determined based on the principle that three non-collinear points can uniquely determine a circle. To determine the size of the chip, Figure 4 As shown, the wafer 203 is moved so that the chip 401 on the wafer 203 is within the field of view of the first image acquisition device 202, and any mechanism is selected as the first template 402 of the chip 401 in any chip 401 on the wafer 203. For multiple chips 401, the position of any selected mechanism is the same, that is, the same position in multiple chips 401 includes the same first template 402. The first template 402 can have the characteristics of uniqueness and high contrast, which is conducive to image matching and feature recognition. In a possible implementation, the chip 401 can be determined as the first template 402. After determining the first template 402, the size of the chip 401 is determined according to the distance between adjacent first templates 402.

[0026] Furthermore, if Figure 5As shown, the position of the center point of the wafer 203 is taken as the center of the circle, and the position of the first template 402 is taken as the position of the chip 401. Based on this, the chips 401 are preliminarily arranged according to the size of the chips 401. Since the position of the chips 401 preliminarily arranged based on the position of the first template 402 has a certain deviation from the actual position of the chips 401, in order to correct the position of the chips 401, as shown in FIG. Figure 4 As shown, the intersection area of ​​the scribe lines between the chips 401 can be used as the position of the first groove 403, and the position of the first template of the chips arranged on the wafer can be compensated according to the deviation between the position of the first template 402 and the position of the first groove 403, thereby generating a wafer map including the position of the chip 401.

[0027] In the embodiment of the present application, by matching and identifying the highly identifiable first template in the chip on the wafer, and determining the key features such as the center position of the wafer and the size of the chip, the chips on the wafer are preliminarily arranged based on the position of the first template, and the position of the chips arranged on the wafer is corrected by determining the position of the first groove, and the generated wafer map includes position information corresponding to the actual chip position. It is not affected by the number of chips, shortens the time to generate the wafer map, and greatly improves the efficiency of generating the wafer map.

[0028] In another embodiment of the present disclosure, in the above step S102, the wafer is moved so that the edge of the wafer is located within the field of view of the first image acquisition device, and the position of the center point of the wafer is determined according to the position relationship between the position of the center of the field of view of the first image acquisition device and at least three points on the arc of the edge of the wafer, including the following steps: Step 1, determining the first mechanical position coordinates that make the arc of the wafer edge within the field of view of the first image acquisition device; within the field of view of the first image acquisition device, determining the first coordinate deviations between the positions of multiple arbitrary points on the arc of the wafer edge and the position of the center of the field of view of the first image acquisition device; based on the first mechanical position coordinates and the multiple first coordinate deviations, determining the second mechanical position coordinates when the position of each arbitrary point coincides with the position of the center of the field of view of the first image acquisition device; or Step 2: Move the wafer so that multiple arcs on the edge of the wafer are located in the field of view of the first image acquisition device in sequence, and sequentially determine the corresponding first mechanical position coordinates that make the multiple arcs on the edge of the wafer located in the field of view of the first image acquisition device; within the field of view of the first image acquisition device, respectively determine the first coordinate deviation between the position of any point on the multiple arcs and the position of the center of the field of view of the first image acquisition device; and respectively determine the second mechanical position coordinates when the position of each arbitrary point coincides with the position of the center of the field of view of the first image acquisition device based on the multiple first mechanical position coordinates and the corresponding first coordinate deviations; Step three: based on the principle that a circle can be uniquely determined by three non-collinear points, the center point of the wafer is fitted based on the second mechanical position coordinates corresponding to at least three arbitrary points, and the third mechanical position coordinates are determined when the center point of the wafer coincides with the center of the field of view of the first image acquisition device.

[0029] In the embodiment of the present disclosure, based on the principle that a circle can be uniquely determined by three non-collinear points, the edge arc of the wafer is identified by machine vision for fitting, the arc contour is extracted, and the positions of at least three non-collinear points on the arc are determined to fit the center of the circle, thereby determining the position of the center point of the wafer. For the above step one, a circle is determined by determining the coordinates of at least three non-collinear points in an arc. For the above step two, a circle is determined by determining the coordinates of points on the arc in at least three different arcs. By determining the position of the center point of the wafer, it can help reduce the positioning error of the chip position and improve the positioning accuracy, thereby ensuring the accuracy and stability of subsequent process steps. For example, Figure 2 As shown, the initial position of the stage 204 coincides with the center of the field of view of the first image acquisition device, and a spatial rectangular coordinate system is established with the initial position as the origin of the coordinate system, as shown in FIG. Figure 3 As shown, the moving stage 204 moves the wafer 203 so that the arc of the edge of the wafer 203 is located within the field of view 301 of the first image acquisition device 202, and the center of the field of view of the first image acquisition device 202 is located at point A, that is, the mechanical position coordinate (X) of the stage 204 corresponding to point A. A , Y A , Z A ) is the first mechanical position coordinate, the edge arc of the wafer 203 is identified by machine vision for fitting, the arc contour is extracted, and the position of any point B on the arc line of the wafer 203 is determined. The coordinate deviation (△X AB , △Y AB ) is the first coordinate deviation. According to the first mechanical position coordinate (X A , Y A , Z A ) and the first coordinate deviation (△X AB , △Y AB ) to determine the second mechanical position coordinate when the position B of any point on the arc coincides with the position of the center of the field of view of the first image acquisition device 202, that is, the mechanical position coordinate of point B is (X A -△X AB , Y A -△Y AB , Z A). In a possible implementation, the wafer 203 can be moved so that the center of the field of view of the first image acquisition device 202 coincides with any point on the edge arc of the wafer 203, then the first coordinate deviation is (0, 0), and the second mechanical position coordinate is equal to the first mechanical position coordinate. The second mechanical position coordinates corresponding to multiple arbitrary points are determined on an arc or multiple arcs on the edge of the wafer 203.

[0030] Furthermore, the center point of the wafer is fitted based on the second mechanical position coordinates corresponding to at least three arbitrary points. Fitting the center point may refer to the process of determining the center position of a circle based on a set of data points by mathematical methods. There may be many methods for fitting the center point, such as the least squares method, geometric method, iterative method, etc. Then, the third mechanical position coordinates when the center point of the wafer 203 coincides with the center of the field of view of the first image acquisition device 202 are determined. Figure 2 As shown, due to the gap between the edge of the carrier 204 and the wafer 203, there may be some offset in the position of the wafer 203 placed on the carrier 204. By determining the mechanical position coordinates of at least three points on the arc of the edge of the wafer 203, the mechanical position coordinates of the center point of the wafer 203 can be determined quickly, flexibly and accurately.

[0031] In another embodiment of the present disclosure, after determining the position of the first template of the chip, the method further includes: The wafer is rotated according to the position of the first template so that the chip on the wafer is aligned to a horizontal state within the field of view of the first image acquisition device, including: Step 1: determining a first angle of wafer rotation according to an angle between a straight line connecting preset positions in a first template corresponding to at least two chips in the same row or column and a horizontal line; Step 2: Rotate the wafer according to the first angle so that the chips on the wafer are adjusted to a horizontal state within the field of view of the first image acquisition device.

[0032] In the embodiment of the present disclosure, after determining the position of the first template of the chip, an accurate image matching and feature recognition algorithm can be used to achieve accurate alignment of the wafer. For the above step 1, for example, Figure 4As shown, by fitting a straight line at a preset position in at least two first templates 402 images along the same row or column, the fitted straight line may refer to finding a straight line through a set of data points so that the straight line is as close to these data points as possible. The method of fitting a straight line may include the least squares method, the matrix method, etc. According to the angle between the fitted straight line and the horizontal line, the first angle of rotation of the wafer 203 is determined. For the above step two, the wafer 203 is rotated according to the first angle, and the rotation angle of the wafer 203 is gradually adjusted until the desired preset alignment accuracy is reached, so that the chip 401 on the wafer 203 is centered in the field of view 301 of the first image acquisition device 202. Therefore, by identifying and matching the first template 402 with high recognition in the chip 401, the chip 401 can be more accurately centered in the horizontal state.

[0033] In another embodiment of the present disclosure, in the above step S103, determining the size of the chip according to the position of the first template includes: Step 1: Determine the lateral size of the chip according to the distance between the preset positions in the first template corresponding to the left and right adjacent chips; wherein the lateral size of the chip includes: the sum of the length of the horizontal side of the chip and the width of the scribe line between the chips; Step 2: Determine the longitudinal dimension of the chip according to the distance between the preset positions in the first template corresponding to the upper and lower adjacent chips; wherein the longitudinal dimension of the chip includes: the sum of the length of the vertical side of the chip and the width of the scribe line between the chips.

[0034] In the embodiment of the present disclosure, the size of the chip is determined according to the distance between the positions of adjacent first templates. The size of the chip can be used to locate the specific position of the chip on the wafer. The wafer map can show the specific position and size of the chip on the wafer, which is beneficial to subsequent testing, cutting and packaging steps. For the above step 1, for example, Figure 4 As shown, in the left and right adjacent chips 401, for each first template 402, the preset position inside is the same, and the distance between the preset positions in the two first templates 402 is equal to the lateral size of the chip 401. The lateral size of the chip 401 includes: the sum of the length of the horizontal side of the chip 401 and the width of the scribe line between the chips 401. For the above step 2, in the upper and lower adjacent chips 401, for each first template 402, the preset position inside is the same, and the distance between the preset positions in the two first templates 402 is equal to the longitudinal size of the chip 401. The longitudinal size of the chip 401 includes: the sum of the length of the vertical side of the chip 401 and the width of the scribe line between the chips 401. Therefore, the size of the chip can be determined according to the distance between the positions of adjacent first templates.

[0035] In another embodiment of the present disclosure, in the above step S104, the chips on the wafer are preliminarily arranged with the center point of the wafer as the center of the circle according to the size of the chips and the position of the first template, including: Step 1, determining a fourth mechanical position coordinate that makes the preset position of the first template coincide with the position of the center of the field of view of the first image acquisition device; Step 2: Using the preset position of the first template as the designated position of the corresponding chip, preliminarily arrange the chips on the wafer according to the center point position of the wafer, the size of the wafer, the size of the chip and the fourth mechanical position coordinate.

[0036] In the embodiment of the present disclosure, the center of the circle of the wafer is taken as the center of the circle, and the chips are arranged according to the size of the chips and the position of the first template, so that the time for generating the wafer map is not affected by the number of chips, which greatly improves the efficiency of generating the wafer map. Figure 4 As shown, the wafer 203 is moved so that the preset position C of the first template 402 coincides with the center of the field of view of the first image acquisition device 202. The mechanical position coordinates (X c , Y c , Z c ) is the fourth mechanical position coordinate. For the above step 2, if Figure 5 As shown, the preset position C of the first template is used as the designated position of the corresponding chip 401, and the designated position can be the position of the upper left corner of the corresponding chip 401, or can be any position of the corresponding chip 401. The chips are arranged according to the center point position of the wafer, the size of the chip, and the mechanical position coordinates of the preset position of the first template 402, and the part exceeding the size of the wafer is cut.

[0037] In another embodiment of the present disclosure, in the above step S105, based on the deviation between the position of the first template and the position of the first groove, the position of the chips arranged on the wafer is corrected to generate a wafer map, including: Step 1, determining a fifth mechanical position coordinate that makes the center position of the first groove coincide with the center position of the field of view of the first image acquisition device; Step 2: Subtract the preset position coordinates of the first template from the fifth mechanical position coordinates, perform a modulo operation on the obtained coordinate difference and the size of the chip to determine a second coordinate deviation between the center position of the first groove and the preset position of the first template; Step three: using the second coordinate deviation to compensate for the preset position coordinates of the first template of the chips arranged on the wafer to generate a wafer map.

[0038] In the embodiment of the present disclosure, by correcting the positions of the chips initially arranged on the wafer, a wafer map including positions corresponding to the actual chips is generated. For the above step 1, for example, Figure 4 As shown, the first groove 403 is located at the intersection of the scribe lines between the chips 401. The wafer 203 is moved so that the center position D of the first groove 403 coincides with the center of the field of view of the first image acquisition device 202. The mechanical position coordinates of point D are (X d , Y d , Z d ) is the fifth mechanical position coordinate. For the above step 2, the mechanical position coordinate of the preset position of the first template is subtracted from the fifth mechanical position coordinate, for example Figure 4 The mechanical position coordinates of point C (X c , Y c , Z c ) and the mechanical position coordinates of point D (X d , Y d , Z d ) and subtract to get (X cd , Y cd , Z cd ). The obtained coordinate deviation is modulo-calculated with the chip size to obtain the second coordinate deviation. For example, the horizontal and vertical dimensions of the chip are X die size and Y die size , then the second coordinate deviation is (X cd mod X die size , Y cd modY die size ), if the second coordinate deviation value is a negative number, the second coordinate deviation chip size can be added to obtain the coordinate deviation of the first template 402 and the first groove 403 adjacent thereto. For step three, the preset position coordinates of the first template on the wafer are compensated by the second coordinate deviation, so as to correct the position of the chip and determine a wafer map including a one-to-one correspondence with the position of the actual chip. By compensating the position of the chips preliminarily arranged on the wafer by determining the position of the first groove, the waste of manpower costs caused by the complex and cumbersome operation of manually correcting the chip position is avoided, and the accuracy of the chip position information can also be guaranteed.

[0039] Based on the wafer map provided in the above embodiment, the embodiment of the present disclosure further provides a method for testing a wafer, comprising the following steps: Step 1: Determine the position of the pad inside the chip according to the center position coordinates of the chip on the wafer map; Step 2: The probe is placed within the field of view of the second image acquisition device to determine the position of the probe tip; Step 3: According to the position of the pad and the position of the probe tip, the probe is brought into contact with the pad to test the wafer; The wafer map may be generated by using the method for generating a wafer map provided in any of the above embodiments.

[0040] In the embodiment of the present disclosure, the electrical characteristics of the chip are tested using the center position coordinates of the chip on the generated wafer map. For the scenario where the probe tip position is determined using the first image acquisition device 202, the wafer 203 can be moved within the field of view 301 so that the pad and the probe tip contact the wafer for testing. Figure 2 As shown, for the scenario where the second image acquisition device 205 is used to determine the position of the probe tip, the position of the probe and the position of the chip cannot be observed simultaneously within the field of view of the first image acquisition device, and the position of the probe can be determined with the help of the second image acquisition device. The second image acquisition device 205 may include a high-magnification camera and a low-magnification camera. The low-magnification camera is used to roughly adjust the field of view, and the high-magnification camera is used to finely adjust the field of view. By calibrating the field of view of the high-magnification camera and the low-magnification camera, it can be ensured that the object being observed within the field of view is clearly visible. For example, for step 1 above, Figure 4 As shown, first, within the field of view of the first image acquisition device 202, the position of the pad 404 inside the chip 401 is determined according to the center position coordinates of the chip 401 on the wafer map. Figure 2 As shown, the second image acquisition device 205 and the wafer 203 are both moved using the same device of the stage 204, so the relative position of the second image acquisition device 205 and the wafer 203 remains unchanged. The second image acquisition device 205 is moved so that the probe 206 is located within the field of view of the second image acquisition device 205, and the position of the needle tip of the probe 206 is determined. With respect to the above step 3, according to the position of the pad 404 and the position of the needle tip of the probe 206, the probe 206 is brought into contact with the pad 404, thereby testing the wafer 203.

[0041] In another embodiment of the present disclosure, in the above step 1, determining the position of the pad inside the chip according to the center position coordinates of the chip on the wafer map includes: According to the center position coordinates of the chip on the wafer map, the center position of the chip is made to coincide with the center position of the field of view of the first image acquisition device, and a third coordinate deviation of the position of the pad inside the chip relative to the center position of the field of view of the first image acquisition device is determined; In the above step 3, the probe is brought into contact with the pad according to the position of the pad and the position of the probe tip to test the wafer, including: According to the third coordinate deviation and the position of the probe tip, the probe is brought into contact with the pad to test the wafer.

[0042] In the embodiment of the present disclosure, the coordinate deviation of the position of the pad inside the chip relative to the center of the first image acquisition device is determined based on the center position coordinates of the chip on the generated wafer map, and the probe is made to contact the pad using the coordinate deviation and the probe tip position, thereby testing the wafer. Figure 4 As shown, the wafer 203 is moved to the mechanical position coordinates of the center position of the chip 401 on the wafer map, so that the center position point E of the chip 401 coincides with the position of the center of the field of view of the first image acquisition device 202, and within the field of view of the first image acquisition device 202, the third coordinate deviation of the position of the pad 404 inside the chip 401 relative to the position point E of the center of the field of view of the first image acquisition device 202 is determined. According to the relative position of the pad 404 and the position of the center of the field of view of the first image acquisition device 202 and the relative position of the tip of the probe and the position of the center of the field of view of the first image acquisition device 202, the wafer 203 is moved so that the probe 206 contacts the pad 404, and the wafer 203 is tested. By determining the coordinate deviation of the position of the pad 404 inside the chip 401 relative to the center of the first image acquisition device 202, the calculation steps can be simplified and the measurement error can be reduced, and the coordinate deviation and the tip position of the probe are used to make the probe contact the pad. In another embodiment of the present disclosure, in the above step 1, determining the position of the pad inside the chip according to the center position coordinates of the chip on the wafer map includes: Step 1: According to the center position coordinates of the chip on the wafer map, the center position of the chip is made to coincide with the center position of the field of view of the first image acquisition device, and a third coordinate deviation of the position of the pad inside the chip relative to the center position of the field of view of the first image acquisition device is determined; Step 2: Determine the seventh mechanical position coordinate when the position of the pad inside the chip coincides with the position of the center of the field of view of the first image acquisition device by subtracting the sixth mechanical position coordinate when the center position of the chip coincides with the position of the center of the field of view of the first image acquisition device from the third coordinate deviation; In the above step 3, the probe is brought into contact with the pad according to the position of the pad and the position of the probe tip to test the wafer, including: According to the seventh mechanical position coordinate and the position of the needle tip of the probe, the probe is brought into contact with the pad to test the wafer.

[0043] In the embodiment of the present disclosure, the mechanical position coordinates of the pads inside the chip are determined according to the center position coordinates of the chip on the generated wafer map, and the probe is made to contact the pads using the mechanical position coordinates and the probe tip position, thereby testing the wafer. Figure 4As shown, the wafer 203 is moved to the mechanical position coordinates of the center position of the chip 401 on the wafer map, so that the center position point E of the chip 401 coincides with the position of the center of the field of view of the first image acquisition device 202, and within the field of view of the first image acquisition device 202, the third coordinate deviation of the position of the pad 404 inside the chip 401 relative to the position point E of the center of the field of view of the first image acquisition device 202 is determined. For the above step 2, the seventh mechanical position coordinates when the position of the pad 404 inside the chip 401 coincides with the position of the center of the field of view of the first image acquisition device 202 are determined by subtracting the sixth mechanical position coordinates of the center position of the chip 401 from the third coordinate deviation. According to the seventh mechanical position coordinates and the position of the needle tip of the probe 206, the wafer 203 is moved so that the probe 206 contacts the pad 404, and the wafer 203 is tested. The mechanical position coordinate of the pad 404 determined by the seventh mechanical position coordinate when the position of the pad 404 inside the chip 401 coincides with the position of the center of the field of view of the first image acquisition device 202 can accurately move the position of the pad 404, and use the mechanical position coordinate and the tip position of the probe to make the probe contact the pad 404.

[0044] In another embodiment of the present disclosure, in the above step 1, determining the position of the pad inside the chip according to the center position coordinates of the chip on the wafer map includes: Step 1, determining an eighth mechanical position coordinate that makes the pad inside the chip be located within the field of view of the first image acquisition device; Step 2: determining a fourth coordinate deviation between the center position of the pad and the center position of the field of view of the first image acquisition device within the field of view of the first image acquisition device; and / or, Step 3: determining the ninth mechanical position coordinate when the center position of the pad coincides with the center position of the field of view of the first image acquisition device according to the eighth mechanical position coordinate and the fourth coordinate deviation; and / or, Step 4: Determine the chip corresponding to the pad and the fifth coordinate deviation of the center position of the pad and the corresponding chip according to the center position coordinate of the chip on the wafer map and the ninth mechanical position coordinate; In the above step 3, the probe is brought into contact with the pad according to the position of the pad and the position of the probe tip to test the wafer, including: Acquire a first position of the pad; the first position of the pad includes at least one of the following: a fourth coordinate deviation, a ninth mechanical position coordinate, and a fifth coordinate deviation; According to the first position of the pad and the position of the needle tip of the probe, the probe is made to contact the pad to test the wafer.

[0045] In the embodiment of the present disclosure, the position of the pad within the field of view of the first image acquisition device is used to determine the mechanical position coordinates when the pad coincides with the center position of the field of view of the first image acquisition device, and then the chip corresponding to the pad and the coordinate deviation from the center position of the chip are determined according to the position information of the chip in the wafer map. For the above step one, for example, Figure 4 As shown, the wafer 203 is moved so that the pad 404 is located within the field of view of the first image acquisition device 202, and the corresponding mechanical position coordinate is the eighth mechanical position coordinate. For the above step 2, within the field of view of the first image acquisition device 202, the fourth coordinate deviation between the center position of the pad 404 and the center position of the first image acquisition device 202 is visually identified. For the above step 3, the eighth mechanical position coordinate is subtracted from the fourth coordinate deviation to obtain the ninth mechanical position coordinate when the center position of the pad 404 coincides with the center position of the field of view of the first image acquisition device 202. For the above step 4, the chip 401 corresponding to the pad 404 is determined based on the comparison of the center position coordinate information of the chip on the wafer map with the ninth mechanical position coordinate, and the ninth mechanical position coordinate is subtracted from the mechanical position coordinate of the center position of the chip 401 to obtain the fifth coordinate deviation of the center position of the pad 404 relative to the center position of the chip 401. The fifth coordinate deviation represents the offset between the pad 404 and the center position of the chip 401 in the chip 401. The fourth coordinate deviation, the ninth mechanical position coordinate or the fifth coordinate deviation can all determine the position of the pad 404. According to the position of the pad 404 and the position of the needle tip of the probe 206, the probe 206 is made to contact the pad 404 to test the wafer 203. Through the mechanical position coordinates of the chip on the wafer map and the mechanical position coordinates of the pad, the chip to which the pad belongs and the coordinate deviation of the pad relative to the center position of the chip can be quickly located, and then the position of the pad in each chip on the wafer can be determined.

[0046] In another embodiment of the present disclosure, for a single probe, in the above step 2, the probe is placed within the field of view of the second image acquisition device, and the position of the tip of the probe is determined, including: Step 1, determining a tenth mechanical position coordinate that makes the position of the center of the field of view of the second image acquisition device coincide with the position of the center of the field of view of the first image acquisition device; wherein the second image acquisition device is moved in advance so that the center of the field of view of the first image acquisition device and the center of the field of view of the second image acquisition device are calibrated according to the same reference object; Step 2, determining an eleventh mechanical position coordinate that makes the tip of the probe be located within the field of view of the second image acquisition device, and determining a sixth coordinate deviation between the position of the tip of the probe and the position of the center of the field of view of the second image acquisition device; Step three: determine the seventh coordinate deviation of the position of the probe tip relative to the center of the field of view of the first image acquisition device based on the tenth mechanical position coordinate and the difference between the eleventh mechanical position coordinate and the coordinate deviation.

[0047] In the embodiment of the present disclosure, the types of probes include single probes and single-row probes. For a single probe, the position of the probe tip is determined using a second image acquisition device. For the above step 1, for example, Figure 2 As shown, the positions of the visual field centers of the first image acquisition device 202 and the second image acquisition device 205 are calibrated in advance, and the same reference object is observed as a calibration object. The second image acquisition device 205 is moved so that the positions of the visual field centers of the first image acquisition device 202 and the second image acquisition device 205 coincide with each other, and the mechanical position coordinates at this time are determined to be the tenth mechanical position coordinates (X1, Y1, Z1). For the above step 2, as Figure 6 As shown, the second image acquisition device 205 is moved so that the tip of the probe 206 is located within the field of view of the second image acquisition device 205, and the mechanical position coordinates at this time are determined, that is, point G is the eleventh mechanical position coordinate (X2, Y2, Z2), and the sixth coordinate deviation (△X1, △Y1) between the position point F of the tip of the probe 206 and the position point G of the field of view center of the second image acquisition device 205 is determined. For the above step three, the seventh coordinate deviation of the position of the tip of the probe 206 relative to the position of the field of view center of the first image acquisition device 202 is (△X 针 , △Y 针 , △Z 针 ),in △X 针 = X2-X1+△X1; △Y 针 = Y2-Y1+△Y1; △Z 针 = Z2- Z1; △Z 针 According to the seventh coordinate deviation of the position of the pad 404 and the position of the tip of the probe 206 relative to the center of the field of view of the first image acquisition device 202, the probe 206 is made to contact the pad 404 to test the wafer 203.

[0048] In another embodiment of the present disclosure, for a single-row probe, in the above step 2, the probe is located within the field of view of the second image acquisition device, and the position of the probe tip is determined, including: For a single-row probe, in the above step 2, the probe is placed within the field of view of the second image acquisition device, and the position of the probe tip is determined, including: Step 1, determining a twelfth mechanical position coordinate that makes the position of the center of the field of view of the second image acquisition device coincide with the position of the center of the field of view of the first image acquisition device; wherein the second image acquisition device is moved in advance so that the center of the field of view of the first image acquisition device and the center of the field of view of the second image acquisition device are calibrated according to the same reference object; Step 2, determining a thirteenth mechanical position coordinate that makes the tip of any probe in the single-row probes be located within the field of view of the second image acquisition device, and determining an eighth coordinate deviation between the position of the tip of any probe and the position of the center of the field of view of the second image acquisition device; Step 3: determining a ninth coordinate deviation of the position of the tip of any probe relative to the center of the field of view of the first image acquisition device according to the twelfth mechanical position coordinate and the difference between the thirteenth mechanical position coordinate and the eighth coordinate deviation; Step 4: determining a second angle of wafer rotation according to an angle between a straight line connecting the positions of at least two internal pads of the chips in the same row or column and a straight line connecting the positions of the needle tips of at least two probes in a single row of probes; Step 5: Rotate the wafer according to the second angle so that the line connecting the positions of the tips of at least two probes in a single row of probes is parallel to the line connecting the positions of the pads inside at least two chips in the same row or column.

[0049] In the embodiment of the present disclosure, the types of probes include single probes and single-row probes. For single-row probes, the second image acquisition device is used to determine the position of the probe tip and the angle of the tip arrangement, and then the wafer is rotated so that the position of the pad corresponds to the position of the probe. For example, in step 1 above, Figure 2 As shown, the positions of the visual field centers of the first image acquisition device 202 and the second image acquisition device 205 are calibrated in advance, and the same reference object is observed as a calibration object. The second image acquisition device 205 is moved so that the positions of the visual field centers of the first image acquisition device 202 and the second image acquisition device 205 coincide with each other, and the mechanical position coordinates at this time are determined to be the twelfth mechanical position coordinates (X1, Y1, Z1). For the above step 2, as Figure 6 As shown, the second image acquisition device 205 is moved so that the tip of any probe 206 in the single-row probe is located within the field of view of the second image acquisition device 205, and the mechanical position coordinates at this time are determined, that is, point G is the thirteenth mechanical position coordinate (X2, Y2, Z2), and the eighth coordinate deviation (△X1, △Y1) between the position point F of the tip of any probe 206 and the position point G of the field of view center of the second image acquisition device 205 is determined. For the above step three, the ninth coordinate deviation of the position of the tip of any probe 206 relative to the position of the field of view center of the first image acquisition device 202 is (△X 针 , △Y 针 , △Z针 ),in △X 针 = X2-X1+△X1; △Y 针 = Y2-Y1+△Y1; △Z 针 = Z2- Z1; △Z 针 Characterizes the distance from the needle tip to the wafer surface height. For the above step four, the angle between the straight line connecting the positions of the internal pads 404 of at least two chips 401 in the same row or column and the straight line connecting the positions of the needle tips of at least two probes in the single-row probe is the second angle. For the above step five, the wafer 203 is rotated according to the second angle, and according to the ninth coordinate deviation of the position of the pad 404 and the position of the needle tip of the probe 206 relative to the position of the center of the field of view of the first image acquisition device 202, the single-row probe is made to contact the corresponding pad, thereby testing the wafer 203.

[0050] In another embodiment of the present disclosure, before testing the wafer, the method further includes: Step 1: Measure the thickness of the wafer; Step 2: Determine the direction and distance of movement of the carrier carrying the wafer according to the thickness of the wafer and the preset wafer thickness, and move according to the direction and distance of movement.

[0051] In the disclosed embodiment, before testing the wafer, the thickness of the wafer is measured and the carrier carrying the wafer is moved so that the surface of the wafer is at a preset height. The preset thickness of the wafer is H1. For different wafers, the thickness of each wafer is slightly different. A test instrument or a visual autofocus algorithm can be used, for example: a capacitive sensor, an infrared tester, etc., to measure the thickness of the wafer as H2. The difference between the wafer thickness H2 and the preset wafer thickness H1 is used to determine the direction and distance of movement of the carrier carrying the wafer, and the wafer is moved in the direction and distance of movement so that the surface of the wafer is at a preset height. By measuring the thickness of the wafer and finely adjusting the height position of the wafer, it can be ensured that the relative position of the wafer and the probe in height remains consistent, which facilitates the use of the probe to test the wafer.

[0052] Based on the same inventive concept, the embodiments of the present disclosure also provide a device for generating a wafer image, a device for testing a wafer, and equipment for testing a wafer. Since the principles of the problems solved by these devices and equipment are similar to the aforementioned method for generating a wafer image and the method for testing a wafer, the implementation of the device and equipment can refer to the implementation of the aforementioned method, and the repeated parts will not be repeated.

[0053] The present disclosure provides a device for generating a wafer map, such as Figure 8As shown, including: The image acquisition module 801 is used to provide a wafer and a first image acquisition device for observing the wafer; a plurality of chips of the same shape and size and a first groove are evenly distributed on the wafer; wherein the first groove is located at the intersection of the scribe lines between the chips; The wafer centering module 802 is used to move the wafer so that the edge of the wafer is located within the field of view of the first image acquisition device, and determine the position of the center point of the wafer according to the position relationship between the center of the field of view of the first image acquisition device and at least three points on the arc of the wafer edge; The wafer map generation module 803 is used to make the chip on the wafer be located within the field of view of the first image acquisition device, determine the position of the first template on the chip according to the position of the center of the field of view of the first image acquisition device and any mechanism on the wafer located at the same position in the chip; and determine the size of the chip according to the position of the first template; Taking the center point of the wafer as the center of the circle, preliminarily arrange the chips on the wafer according to the size of the chips and the position of the first template; Based on the deviation between the position of the first template and the position of the first groove, the positions of the chips arranged on the wafer are corrected to generate a wafer map.

[0054] In another embodiment of the present disclosure, the wafer centering module 802 is used to determine the first mechanical position coordinates that make the arc of the wafer edge located within the field of view of the first image acquisition device; determine the first coordinate deviations between the positions of multiple arbitrary points on the arc of the wafer edge and the position of the center of the field of view of the first image acquisition device within the field of view of the first image acquisition device; determine the second mechanical position coordinates when the position of each arbitrary point coincides with the position of the center of the field of view of the first image acquisition device based on the first mechanical position coordinates and the multiple first coordinate deviations; or The wafer is moved so that a plurality of circular arcs on the edge of the wafer are sequentially located within the field of view of a first image acquisition device, and the corresponding first mechanical position coordinates are sequentially determined so that the plurality of circular arcs on the edge of the wafer are respectively located within the field of view of the first image acquisition device; within the field of view of the first image acquisition device, a first coordinate deviation between the position of any point on the plurality of circular arcs and the position of the center of the field of view of the first image acquisition device is respectively determined; based on the plurality of first mechanical position coordinates and the corresponding first coordinate deviations, a second mechanical position coordinate when the position of each arbitrary point coincides with the position of the center of the field of view of the first image acquisition device is respectively determined; According to the principle that three non-collinear points can uniquely determine a circle, the center point of the wafer is fitted based on the second mechanical position coordinates corresponding to at least three arbitrary points, and the third mechanical position coordinates when the center point of the wafer coincides with the center of the field of view of the first image acquisition device are determined.

[0055] In another embodiment of the present disclosure, after determining the position of the first template of the chip, the wafer map generation module 803 is further used to: The wafer is rotated according to the position of the first template so that the chip on the wafer is aligned to a horizontal state within the field of view of the first image acquisition device, including: Determine a first angle of wafer rotation according to an angle between a straight line where a line connecting preset positions in the first template corresponding to at least two chips in the same row or column respectively is located and a horizontal line; The wafer is rotated according to the first angle so that the chips on the wafer are adjusted to a horizontal state within the field of view of the first image acquisition device.

[0056] In another embodiment of the present disclosure, the wafer map generation module 803 is used to determine the lateral size of the chip according to the distance between the preset positions in the first template corresponding to the left and right adjacent chips respectively; wherein the lateral size of the chip includes: the sum of the length of the horizontal side of the chip and the width of the scribe line between the chips; The longitudinal dimension of the chip is determined according to the distance between the preset positions in the first template corresponding to the upper and lower adjacent chips respectively; wherein the longitudinal dimension of the chip includes: the sum of the length of the vertical side of the chip and the width of the scribe line between the chips.

[0057] In yet another embodiment of the present disclosure, the wafer map generation module 803 is used to determine a fourth mechanical position coordinate that causes the preset position of the first template to coincide with the position of the center of the field of view of the first image acquisition device; The preset position of the first template is used as the designated position of the corresponding chip, and the chips on the wafer are preliminarily arranged according to the center point position of the wafer, the size of the wafer, the size of the chip and the fourth mechanical position coordinate.

[0058] In yet another embodiment of the present disclosure, the wafer map generation module 803 is used to determine a fifth mechanical position coordinate that makes the center position of the first groove coincide with the center position of the field of view of the first image acquisition device; Subtract the preset position coordinates of the first template from the fifth mechanical position coordinates, perform a modulo operation on the obtained coordinate difference and the size of the chip, and determine a second coordinate deviation between the center position of the first groove and the preset position of the first template; The second coordinate deviation is used to compensate the preset position coordinates of the first template of the chips arranged on the wafer to generate a wafer map.

[0059] The present disclosure provides a device for testing a wafer, such as Fig. 9 As shown, including: The pad positioning module 901 is used to determine the position of the pad inside the chip according to the center position coordinates of the chip on the wafer map; The probe positioning module 902 is used to locate the probe within the field of view of the second image acquisition device and determine the position of the probe tip; The wafer testing module 903 is used to test the wafer by making the probe contact the pad according to the position of the pad and the position of the probe tip; wherein the wafer map can be generated by using the method for generating a wafer map provided by any of the above embodiments.

[0060] In another embodiment of the present disclosure, the pad positioning module 901 is used to make the center position of the chip coincide with the position of the center of the field of view of the first image acquisition device according to the center position coordinates of the chip on the wafer map, and determine the third coordinate deviation of the position of the pad inside the chip relative to the position of the center of the field of view of the first image acquisition device; The wafer testing module 903 is used to make the probe contact the pad according to the third coordinate deviation and the position of the probe tip to test the wafer.

[0061] In another embodiment of the present disclosure, the pad positioning module 901 is used to make the center position of the chip coincide with the position of the center of the field of view of the first image acquisition device according to the center position coordinates of the chip on the wafer map, and determine the third coordinate deviation of the position of the pad inside the chip relative to the position of the center of the field of view of the first image acquisition device; Determine the seventh mechanical position coordinate when the position of the pad inside the chip coincides with the position of the center of the field of view of the first image acquisition device by subtracting the sixth mechanical position coordinate when the center position of the chip coincides with the position of the center of the field of view of the first image acquisition device from the third coordinate deviation; The wafer testing module 903 is used to make the probe contact the pad according to the seventh mechanical position coordinate and the position of the probe tip to test the wafer.

[0062] In another embodiment of the present disclosure, the pad positioning module 901 is used to determine an eighth mechanical position coordinate that makes the pad inside the chip be located within the field of view of the first image acquisition device; Determine, within the field of view of the first image acquisition device, a fourth coordinate deviation between the center position of the pad and the center position of the field of view of the first image acquisition device; and / or, Determine, based on the eighth mechanical position coordinate and the fourth coordinate deviation, a ninth mechanical position coordinate when the center position of the pad coincides with the center position of the field of view of the first image acquisition device; and / or, Determine the chip corresponding to the pad and the fifth coordinate deviation of the center position of the pad and the corresponding chip according to the center position coordinate of the chip on the wafer map and the ninth mechanical position coordinate; The wafer testing module 903 is used to obtain a first position of the pad; the first position of the pad includes at least one of the following: a fourth coordinate deviation, a ninth mechanical position coordinate, and a fifth coordinate deviation; According to the first position of the pad and the position of the needle tip of the probe, the probe is made to contact the pad to test the wafer.

[0063] In another embodiment of the present disclosure, for a single probe, the probe positioning module 902 is used to determine a tenth mechanical position coordinate that makes the position of the center of the field of view of the second image acquisition device coincide with the position of the center of the field of view of the first image acquisition device; wherein the second image acquisition device is moved in advance so that the center of the field of view of the first image acquisition device and the center of the field of view of the second image acquisition device are calibrated according to the same reference object; Determine an eleventh mechanical position coordinate that places the tip of the probe within the field of view of the second image acquisition device, and determine a sixth coordinate deviation between the position of the tip of the probe and the position of the center of the field of view of the second image acquisition device; A seventh coordinate deviation of the position of the needle tip of the probe relative to the center of the field of view of the first image acquisition device is determined based on the tenth mechanical position coordinate and the difference between the eleventh mechanical position coordinate and the coordinate deviation.

[0064] In another embodiment of the present disclosure, for a single-row probe, the probe positioning module 902 is used to determine a twelfth mechanical position coordinate that makes the position of the center of the field of view of the second image acquisition device coincide with the position of the center of the field of view of the first image acquisition device; wherein the second image acquisition device is moved in advance so that the center of the field of view of the first image acquisition device and the center of the field of view of the second image acquisition device are calibrated according to the same reference object; Determine a thirteenth mechanical position coordinate that makes the tip of any probe in the single row of probes be located within the field of view of the second image acquisition device, and determine an eighth coordinate deviation between the position of the tip of any probe and the position of the center of the field of view of the second image acquisition device; Determine a ninth coordinate deviation of the position of the tip of any probe relative to the center of the field of view of the first image acquisition device according to the twelfth mechanical position coordinate and the difference between the thirteenth mechanical position coordinate and the eighth coordinate deviation; Determine a second angle of wafer rotation according to an angle between a straight line connecting positions of at least two internal pads of chips in the same row or column and a straight line connecting positions of needle tips of at least two probes in a single row of probes; The wafer is rotated according to the second angle to make the straight line connecting the positions of the tips of at least two probes in a single row of probes parallel to the straight line connecting the positions of the pads inside at least two chips in the same row or column.

[0065] In another embodiment of the present disclosure, before testing the wafer, the wafer testing module 903 is further used to: Measure the thickness of wafers; According to the thickness of the wafer and the preset wafer thickness, the direction and distance of movement of the carrier carrying the wafer are determined, and the carrier moves in the direction and distance of movement.

[0066] An embodiment of the present disclosure provides a device for testing a wafer, comprising: a device for generating a wafer image as described in any of the above embodiments and / or a device for testing a wafer as described in any of the above embodiments.

[0067] Those skilled in the art will appreciate that the accompanying drawings are merely schematic diagrams of a preferred embodiment, and the modules or processes in the accompanying drawings are not necessarily required for implementing the present disclosure.

[0068] Those skilled in the art can understand that the modules in the device in the embodiment can be distributed in the device in the embodiment according to the description of the embodiment, or can be changed accordingly and located in one or more devices different from the present embodiment. The modules in the above embodiment can be combined into one module, or can be further divided into multiple sub-modules.

[0069] The serial numbers of the above-mentioned embodiments of the present disclosure are only for description and do not represent the advantages or disadvantages of the embodiments.

[0070] Obviously, those skilled in the art can make various changes and modifications to the present disclosure without departing from the spirit and scope of the present disclosure. Thus, if these modifications and variations of the present disclosure fall within the scope of the claims of the present disclosure and their equivalents, the present disclosure is also intended to include these modifications and variations.

Claims

1. A method for generating a wafer map, characterized in that: include: A wafer and a first image acquisition device for observing the wafer are provided; the wafer is provided with a plurality of chips of the same shape and size and a first groove which are evenly distributed; wherein the first groove is located at the intersection area of ​​the scribe lines between the chips; Move the wafer so that the edge of the wafer is within the field of view of a first image acquisition device, and determine the position of the center point of the wafer according to the position relationship between the center of the field of view of the first image acquisition device and at least three points on the arc of the edge of the wafer; The chip on the wafer is located within the field of view of the first image acquisition device, and the position of the first template on the chip is determined according to the position of the center of the field of view of the first image acquisition device and any mechanism on the wafer located at the same position in the chip; and the size of the chip is determined according to the position of the first template; Taking the center point of the wafer as the center of the circle, preliminarily arranging the chips on the wafer according to the size of the chips and the position of the first template; Based on the deviation between the position of the first template and the position of the first groove, the positions of the chips arranged on the wafer are corrected to generate a wafer map.

2. The method according to claim 1, characterized in that Determining the position of the center point of the wafer according to the position relationship between the position of the center of the field of view of the first image acquisition device and at least three points on the arc of the edge of the wafer includes: Determine a first mechanical position coordinate that makes the arc of the wafer edge within the field of view of a first image acquisition device; determine first coordinate deviations between the positions of a plurality of arbitrary points on the arc of the wafer edge and the position of the center of the field of view of the first image acquisition device within the field of view of the first image acquisition device; determine a second mechanical position coordinate when the position of each arbitrary point coincides with the position of the center of the field of view of the first image acquisition device based on the first mechanical position coordinate and the plurality of first coordinate deviations; or The wafer is moved so that a plurality of circular arcs on the edge of the wafer are sequentially located within the field of view of a first image acquisition device, and the corresponding first mechanical position coordinates are sequentially determined so that the plurality of circular arcs on the edge of the wafer are respectively located within the field of view of the first image acquisition device; within the field of view of the first image acquisition device, a first coordinate deviation between the position of any point on the plurality of circular arcs and the position of the center of the field of view of the first image acquisition device is respectively determined; based on the plurality of first mechanical position coordinates and the corresponding first coordinate deviations, a second mechanical position coordinate when the position of each arbitrary point coincides with the position of the center of the field of view of the first image acquisition device is respectively determined; According to the principle that three non-collinear points can uniquely determine a circle, the center point of the wafer is fitted based on the second mechanical position coordinates corresponding to at least three arbitrary points, and the third mechanical position coordinates when the center point of the wafer coincides with the center of the field of view of the first image acquisition device are determined.

3. The method according to claim 1, characterized in that After determining the position of the first template of the chip, the method further includes: Rotating the wafer according to the position of the first template so that the chip on the wafer is aligned to a horizontal state within the field of view of the first image acquisition device includes: Determine a first angle of wafer rotation according to an angle between a straight line where a line connecting preset positions in the first template corresponding to at least two chips in the same row or column respectively is located and a horizontal line; The wafer is rotated according to the first angle so that the chips on the wafer are adjusted to a horizontal state within the field of view of the first image acquisition device.

4. The method according to claim 1, characterized in that The step of determining the size of the chip according to the position of the first template comprises: Determine the lateral size of the chip according to the distance between the preset positions in the first template corresponding to the left and right adjacent chips respectively; wherein the lateral size of the chip includes: the sum of the length of the horizontal side of the chip and the width of the scribe line between the chips; The longitudinal dimension of the chip is determined according to the distance between the preset positions in the first template corresponding to the upper and lower adjacent chips respectively; wherein the longitudinal dimension of the chip includes: the sum of the length of the vertical side of the chip and the width of the scribe line between the chips.

5. The method according to claim 1, characterized in that The method of preliminarily arranging the chips on the wafer based on the center point of the wafer as the center of the circle and the size of the chips and the position of the first template includes: Determining a fourth mechanical position coordinate that makes the preset position of the first template coincide with the position of the center of the field of view of the first image acquisition device; The preset position of the first template is used as the designated position of the corresponding chip, and the chips on the wafer are preliminarily arranged according to the center point position of the wafer, the size of the wafer, the size of the chip and the fourth mechanical position coordinates.

6. The method according to claim 5, characterized in that The method of correcting the positions of the chips arranged on the wafer based on the deviation between the position of the first template and the position of the first groove to generate a wafer map includes: Determine a fifth mechanical position coordinate that makes the center position of the first groove coincide with the center position of the field of view of the first image acquisition device; Subtract the preset position coordinates of the first template from the fifth mechanical position coordinates, perform a modulo operation on the obtained coordinate difference and the size of the chip, and determine a second coordinate deviation between the center position of the first groove and the preset position of the first template; The second coordinate deviation is used to compensate for the preset position coordinates of the first template of the chips arranged on the wafer to generate a wafer map.

7. A method for testing a wafer, characterized in that: include: Determine the location of the pad inside the chip based on the center coordinates of the chip on the wafer map; The probe is placed within the field of view of the second image acquisition device to determine the position of the needle tip of the probe; According to the position of the pad and the position of the needle tip of the probe, the probe is made to contact the pad to test the wafer; wherein the wafer image is generated by the method for generating a wafer image as described in any one of claims 1 to 6.

8. The method according to claim 7, characterized in that The step of determining the position of the pad inside the chip according to the center position coordinates of the chip on the wafer map includes: According to the center position coordinates of the chip on the wafer map, the center position of the chip is made to coincide with the center position of the field of view of the first image acquisition device, and a third coordinate deviation of the position of the pad inside the chip relative to the center position of the field of view of the first image acquisition device is determined; The step of making the probe contact the pad according to the position of the pad and the position of the probe tip to test the wafer includes: According to the third coordinate deviation and the position of the needle tip of the probe, the probe is made to contact the pad to test the wafer.

9. The method according to claim 7, characterized in that The step of determining the position of the pad inside the chip according to the center position coordinates of the chip on the wafer map includes: According to the center position coordinates of the chip on the wafer map, the center position of the chip is made to coincide with the center position of the field of view of the first image acquisition device, and a third coordinate deviation of the position of the pad inside the chip relative to the center position of the field of view of the first image acquisition device is determined; Determine the seventh mechanical position coordinate when the position of the pad inside the chip coincides with the position of the center of the field of view of the first image acquisition device by subtracting the sixth mechanical position coordinate when the center position of the chip coincides with the position of the center of the field of view of the first image acquisition device from the third coordinate deviation; The step of making the probe contact the pad according to the position of the pad and the position of the probe tip to test the wafer includes: According to the seventh mechanical position coordinate and the position of the needle tip of the probe, the probe is made to contact the pad to test the wafer.

10. The method according to claim 7, characterized in that The step of determining the position of the pad inside the chip according to the center position coordinates of the chip on the wafer map includes: Determine an eighth mechanical position coordinate that makes the pad inside the chip be located within the field of view of the first image acquisition device; Determine, within the field of view of the first image acquisition device, a fourth coordinate deviation between the center position of the pad and the center position of the field of view of the first image acquisition device; and / or, Determine, according to the eighth mechanical position coordinate and the fourth coordinate deviation, a ninth mechanical position coordinate when the center position of the pad coincides with the center position of the field of view of the first image acquisition device; and / or, Determine the chip corresponding to the pad and a fifth coordinate deviation of the center position of the pad and the corresponding chip according to the center position coordinate of the chip on the wafer map and the ninth mechanical position coordinate; The step of making the probe contact the pad according to the position of the pad and the position of the probe tip to test the wafer includes: Acquire a first position of the pad; the first position of the pad includes at least one of the following: a fourth coordinate deviation, a ninth mechanical position coordinate, and a fifth coordinate deviation; According to the first position of the pad and the position of the needle tip of the probe, the probe is made to contact the pad to test the wafer.

11. The method according to claim 7, characterized in that For a single probe, the step of placing the probe within the field of view of the second image acquisition device and determining the position of the tip of the probe includes: Determine a tenth mechanical position coordinate that makes the position of the center of the field of view of the second image acquisition device coincide with the position of the center of the field of view of the first image acquisition device; wherein the second image acquisition device is moved in advance so that the center of the field of view of the first image acquisition device and the center of the field of view of the second image acquisition device are calibrated according to the same reference object; Determining an eleventh mechanical position coordinate that places the tip of the probe within the field of view of the second image acquisition device, and determining a sixth coordinate deviation between the position of the tip of the probe and the position of the center of the field of view of the second image acquisition device; A seventh coordinate deviation of the position of the needle tip of the probe relative to the center of the field of view of the first image acquisition device is determined based on the tenth mechanical position coordinate and the difference between the eleventh mechanical position coordinate and the coordinate deviation.

12. The method according to claim 7, characterized in that For a single-row probe, the step of placing the probe within the field of view of the second image acquisition device and determining the position of the probe tip includes: Determine a twelfth mechanical position coordinate that makes the position of the center of the field of view of the second image acquisition device coincide with the position of the center of the field of view of the first image acquisition device; wherein the second image acquisition device is moved in advance so that the center of the field of view of the first image acquisition device and the center of the field of view of the second image acquisition device are calibrated according to the same reference object; Determine a thirteenth mechanical position coordinate that makes the tip of any probe in the single row of probes be located within the field of view of the second image acquisition device, and determine an eighth coordinate deviation between the position of the tip of any probe and the position of the center of the field of view of the second image acquisition device; Determine a ninth coordinate deviation of the position of the tip of any probe relative to the center of the field of view of the first image acquisition device according to the twelfth mechanical position coordinate and the difference between the thirteenth mechanical position coordinate and the eighth coordinate deviation; Determine a second angle of wafer rotation according to an angle between a straight line connecting positions of at least two internal pads of the chips in the same row or column and a straight line connecting positions of needle tips of at least two probes in the single row of probes; The wafer is rotated according to the second angle to make the straight line connecting the positions of the tips of at least two probes in a single row of probes parallel to the straight line connecting the positions of the pads inside at least two chips in the same row or column.

13. A device for generating a wafer map, characterized in that: include: An image acquisition module is used to provide a wafer and a first image acquisition device for observing the wafer; the wafer is provided with a plurality of chips of the same shape and size and a first groove evenly distributed; wherein the first groove is located at the intersection of the scribe lines between the chips; A wafer centering module, used for moving the wafer so that the edge of the wafer is located within the field of view of a first image acquisition device, and determining the position of the center point of the wafer according to the position relationship between the center of the field of view of the first image acquisition device and at least three points on the arc of the edge of the wafer; a wafer map generation module, configured to locate the chip on the wafer within the field of view of the first image acquisition device, determine the position of the first template on the chip according to the position of the center of the field of view of the first image acquisition device and any mechanism on the wafer located at the same position within the chip; and determine the size of the chip according to the position of the first template; Taking the center point of the wafer as the center of the circle, preliminarily arranging the chips on the wafer according to the size of the chips and the position of the first template; Based on the deviation between the position of the first template and the position of the first groove, the positions of the chips arranged on the wafer are corrected to generate a wafer map.

14. A device for testing a wafer, characterized in that: include: The pad positioning module is used to determine the position of the pad inside the chip according to the center position coordinates of the chip on the wafer map; A probe positioning module, used to locate the probe within the field of view of the second image acquisition device and determine the position of the needle tip of the probe; A wafer testing module is used to test the wafer by making the probe contact the pad according to the position of the pad and the position of the probe tip; wherein the wafer map is generated using the method for generating a wafer map as described in any one of claims 1 to 6.

15. A device for testing wafers, characterized in that: The method comprises the device for generating a wafer map as claimed in claim 13 and / or the device for testing a wafer as claimed in claim 14.

Images