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

Abstract

The present application provides a method, device, and equipment for generating a wafer map and testing a wafer, including: positioning the edge of the wafer within the field of view of a first image acquisition device, determining the position of the center point of the wafer based on the positional relationship between the center of the field of view of the first image acquisition device and a point on the edge arc; using the center point of the wafer as the center of the circle, preliminarily arranging the chips on the wafer based on the size of the chips and the position of a 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 map. The wafer map generated by the present application includes position information that corresponds one-to-one to the actual chip positions and is not affected by the number of chips, thereby shortening the time to generate the wafer map and greatly improving the efficiency of generating the wafer map.

Description

Technical Field

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

[0002] Wafer maps play an important role in the field of semiconductor technology. They can visualize chips and facilitate chip testing based on the locations marked on the wafer map. This helps locate problem areas, conduct fault analysis and repair, optimize production processes, and thus promote yield improvement. However, the following problems are often encountered in the traditional wafer map generation process: the generated wafer map does not include chip location information, or it is necessary to traverse the chips on the wafer one by one to collect location information, and then generate a wafer map that includes 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, apparatus, and device for generating a wafer map and testing a wafer, so as to solve the problem of extremely low efficiency in generating a wafer map including chip location information in the prior art.

[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:

[0005] 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 evenly distributed; wherein the first groove is located at the intersection of the scribe lines between the chips;

[0006] Moving the wafer so that the edge of the wafer is within the field of view of a first image acquisition device, and determining the position of the center point of the wafer based on the positional 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;

[0007] Positioning the chip on the wafer within the field of view of the first image acquisition device, determining the position of a first template on the chip based on the position of the center of the field of view of the first image acquisition device and any structure on the wafer located at the same position within the chip; and determining the size of the chip based on the position of the first template;

[0008] 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;

[0009] 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.

[0010] In conjunction with the first aspect, in one possible implementation, determining the position of the center point of the wafer based on the positional 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 includes:

[0011] Determining a first mechanical position coordinate such that the arc of the wafer edge is within the field of view of a first image acquisition device; determining, within the field of view of the first image acquisition device, 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; and determining, based on the first mechanical position coordinate and the plurality of 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; or

[0012] The wafer is moved so that a plurality of arcs on the wafer edge are sequentially located within a field of view of a first image acquisition device, and corresponding first mechanical position coordinates are sequentially determined so that the plurality of arcs on the wafer edge 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 a position of any point on the plurality of arcs and a position of a center of the field of view of the first image acquisition device is determined; and a second mechanical position coordinate is determined 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 plurality of first mechanical position coordinates and the corresponding first coordinate deviations;

[0013] Based on 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.

[0014] In conjunction with the first aspect, in a possible implementation manner, after determining the position of the first template of the chip, the method further includes:

[0015] Rotating the wafer according to the position of the first template so that the chips on the wafer are aligned to a horizontal state within the field of view of the first image acquisition device includes:

[0016] Determining a first angle of wafer rotation according to an angle between a straight line connecting preset positions in the first template corresponding to at least two chips in the same row or column and a horizontal line;

[0017] 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.

[0018] In conjunction with the first aspect, in a possible implementation manner, determining the size of the chip according to the position of the first template includes:

[0019] Determining the lateral size of the chip based on 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;

[0020] The longitudinal size 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 size 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.

[0021] In conjunction with the first aspect, in one possible implementation, the preliminarily arranging the chips on the wafer based on the center point of the wafer and the size of the chips and the position of the first template includes:

[0022] Determining 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;

[0023] 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.

[0024] In conjunction with the first aspect, in one possible implementation, the steps 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 include:

[0025] 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;

[0026] Subtracting the preset position coordinates of the first template from the fifth mechanical position coordinates, performing 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;

[0027] 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.

[0028] In a second aspect, a method for testing a wafer is provided, comprising:

[0029] Determine the location of the pads inside the chip based on the center coordinates of the chip on the wafer map;

[0030] Positioning the probe within the field of view of a second image acquisition device to determine the position of the probe tip;

[0031] 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; 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.

[0032] In conjunction with the second aspect, in one possible implementation, determining the position of the pad inside the chip based on the center position coordinates of the chip on the wafer map includes:

[0033] Aligning the center of the chip with the center of the field of view of the first image acquisition device based on the center coordinates of the chip on the wafer map, and determining a third coordinate deviation of the position of the pad inside the chip relative to the center of the field of view of the first image acquisition device;

[0034] 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:

[0035] The probe is brought into contact with the pad according to the third coordinate deviation and the position of the probe tip to test the wafer.

[0036] In conjunction with the second aspect, in one possible implementation, determining the position of the pad inside the chip based on the center position coordinates of the chip on the wafer map includes:

[0037] Aligning the center of the chip with the center of the field of view of the first image acquisition device based on the center coordinates of the chip on the wafer map, and determining a third coordinate deviation of the position of the pad inside the chip relative to the center of the field of view of the first image acquisition device;

[0038] Determine a seventh mechanical position coordinate when the position of the pad inside the chip coincides with 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 center of the field of view of the first image acquisition device from the third coordinate deviation;

[0039] 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:

[0040] The probe is brought into contact with the pad according to the seventh mechanical position coordinate and the position of the probe tip to test the wafer.

[0041] In conjunction with the second aspect, in one possible implementation, determining the position of the pad inside the chip based on the center position coordinates of the chip on the wafer map includes:

[0042] Determining an eighth mechanical position coordinate so that the pad inside the chip is located within the field of view of the first image acquisition device;

[0043] 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

[0044] determining, based on the deviation between the eighth mechanical position coordinate and the fourth coordinate, 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

[0045] Determining the chip corresponding to the pad and a fifth coordinate deviation between the pad and the center position of the corresponding chip according to the center position coordinates of the chip on the wafer map and the ninth mechanical position coordinates;

[0046] 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:

[0047] 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;

[0048] According to the first position of the pad and the position of the probe tip, the probe is brought into contact with the pad to test the wafer.

[0049] In conjunction with the second aspect, in one possible implementation, for a single probe, placing the probe within a field of view of a second image acquisition device and determining the position of the probe tip includes:

[0050] determining a tenth mechanical position coordinate at which a center of a field of view of the second image acquisition device coincides with a center of a field of view of the first image acquisition device; wherein the second image acquisition device is preliminarily moved 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 with respect to a common reference object;

[0051] 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;

[0052] A 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 is determined based on the tenth mechanical position coordinate and the difference between the eleventh mechanical position coordinate and the coordinate deviation.

[0053] In conjunction with the second aspect, in one possible implementation, for a single-row probe, positioning the probe within a field of view of a second image acquisition device and determining the position of the probe tip includes:

[0054] Determining a twelfth mechanical position coordinate that causes the center of the field of view of the second image acquisition device to coincide with the center of the field of view of the first image acquisition device; wherein the second image acquisition device is preliminarily moved 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 based on a common reference object;

[0055] determining a thirteenth mechanical position coordinate at which the tip of any probe in the single row of probes is 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;

[0056] determining a ninth coordinate deviation of the position of the tip of the probe relative to the center of the field of view of the first image acquisition device based on the twelfth mechanical position coordinate and a difference between the thirteenth mechanical position coordinate and the eighth coordinate deviation;

[0057] Determining a second angle of wafer rotation based on 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;

[0058] The wafer is rotated according to the second angle to make the line connecting the positions of the tips of at least two probes in a single row parallel to the line connecting the positions of the pads inside at least two chips in the same row or column.

[0059] In conjunction with the second aspect, in a possible implementation manner, before testing the wafer, the method further includes:

[0060] measuring the thickness of the wafer;

[0061] 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.

[0062] In a third aspect, a device for generating a wafer map is provided, comprising:

[0063] An image acquisition module is configured to provide a wafer and a first image acquisition device for observing the wafer; the wafer is provided with a plurality of chips of identical shape and size and a first groove evenly distributed thereon; wherein the first groove is located at the intersection of scribe lines between the chips; a wafer centering module is configured to move the wafer so that the edge of the wafer is within the field of view of the first image acquisition device, and determine the center point of the wafer based on the positional 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;

[0064] 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 a first template on the chip based on the position of the center of the field of view of the first image acquisition device and any structure on the wafer located at the same position within the chip, and determine the size of the chip based on the position of the first template;

[0065] 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;

[0066] 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.

[0067] In a fourth aspect, a device for testing a wafer is provided, comprising:

[0068] 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;

[0069] a probe positioning module, configured to locate the probe within the field of view of the second image acquisition device and determine the position of the probe tip;

[0070] 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 method of the first aspect.

[0071] 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.

[0072] The beneficial effects of the embodiments of the present disclosure include:

[0073] The embodiments of the present disclosure provide a method, apparatus, and device for generating a wafer map and testing a wafer, comprising: providing a wafer and a first image acquisition device for observing the wafer; providing a plurality of chips of the same shape and size and a first groove evenly distributed on the wafer; wherein the first groove is located at the intersection of 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 based on 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 wafer edge; positioning the chip on the wafer within the field of view of the first image acquisition device, and determining the position of a first template on the chip based on 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 based on the position of the first template; preliminarily arranging the chips on the wafer based on the size of the chip and the position of the first template with the position of the center point of the wafer as the center of the circle; 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 map. The method for generating a wafer map provided by an 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 chip size and the position of the first template, and then corrects 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. Compared with related technologies, the wafer map generated by the present disclosure includes position information that corresponds one-to-one with the actual chip position and is not affected by the number of chips, which shortens the time to generate the wafer map and greatly improves the efficiency of generating the wafer map. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] Figure 1 A flowchart of a method for generating a wafer map according to an embodiment of the present disclosure;

[0075] Figure 2 A schematic diagram of the structure of a device for generating a wafer image according to an embodiment of the present disclosure;

[0076] Figure 3 One of the schematic diagrams of the field of view of the first image acquisition device provided in an embodiment of the present disclosure;

[0077] 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;

[0078] Figure 5 A schematic diagram of a preliminary arrangement of chips on a wafer according to an embodiment of the present disclosure;

[0079] Figure 6 One of the schematic diagrams of the field of view of the second image acquisition device provided in an embodiment of the present disclosure;

[0080] Figure 7A second schematic diagram of the field of view of the second image acquisition device provided in an embodiment of the present disclosure;

[0081] Figure 8 A schematic structural diagram of a device for generating a wafer image according to an embodiment of the present disclosure;

[0082] Figure 9 A schematic structural diagram of a wafer testing apparatus provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0083] The embodiments of the present disclosure provide a method, apparatus, and device for generating a wafer map and testing wafers. Preferred embodiments of the present disclosure are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are intended only to illustrate and explain the present disclosure and are not intended to limit the present disclosure. Furthermore, the embodiments and features within the embodiments of the present disclosure may be combined with one another unless there is a conflict.

[0084] The present disclosure provides a method for generating a wafer map. Figure 1 As shown, the following steps are included:

[0085] 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 first grooves are evenly distributed on the wafer; wherein the first grooves are located at the intersection of scribe lines between the chips;

[0086] S102, moving the wafer so that the edge of the wafer is within the field of view of the first image acquisition device, and determining the position of the center point of the wafer based on the positional 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;

[0087] S103, positioning the chip on the wafer within the field of view of a first image acquisition device, and determining the position of a first template of the chip based on the position of the center of the field of view of the first image acquisition device and any structure on the wafer located at the same position within the chip; and determining the size of the chip based on the position of the first template;

[0088] 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;

[0089] 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.

[0090] In the disclosed embodiments, a wafer may refer to the silicon wafer used to fabricate silicon semiconductor circuits (chips), which is the fundamental raw material for chip manufacturing. A die is a microelectronic device fabricated on a wafer, forming an extremely small circuit structure through a series of complex semiconductor manufacturing processes. A pad (PAD) refers to the connection point or pin on a chip that contacts a probe to test the chip's electrical characteristics. A scribe line, also known as a saw street, may refer to the space reserved between chips on a wafer for dicing, used to separate the chips on the wafer into individual units. A wafer map is a critical tool in the semiconductor industry. A wafer map provides a visual representation of the chips, enabling engineers to more intuitively identify and analyze defective chips. A wafer map also provides chip location information, facilitating precise connection of probes to the pads within the chip for chip testing. Probe pins are precision connection tools that 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 position, which consumes a lot of manpower. 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.

[0091] In the embodiment of the present disclosure, the following example is an 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 capture device 202 is mounted on a table 201 in a fixed position and is used to observe a wafer 203 positioned on a carrier 204. The carrier 204 is used to secure the wafer 203 and is equipped with a precision moving device. A spatial rectangular coordinate system is established with the preset position of the carrier 204 as the coordinate origin. The carrier can move along the moving device in the x-, y-, and z-axis directions. The moving device equipped with the carrier 204 can move the wafer 203 to a specified mechanical position coordinate. The preset position is fixed relative to the center of the field of view of the first image capture device 202. In one possible embodiment, the preset position of the carrier 204 coincides with the center of the field of view of the first image capture device 202. The first image capture device 202 may include a high-magnification camera and a low-magnification camera. The low-magnification camera is used for coarse adjustment of the field of view, while the high-magnification camera is used for fine adjustment of the field of view. By calibrating the fields of view of the high-magnification and low-magnification cameras, objects observed within the field of view can be clearly visible. For a wafer 203, the chips inside it are all of the same size. Multiple chips are evenly distributed on the wafer 203. Scribe lines of equal width are reserved between the chips. The first grooves are located in the area where the scribe lines intersect. The first grooves are of the same size and evenly distributed on the wafer 203. 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. 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. Based on the positional 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 point on the edge arc is determined. Based on the principle that three non-collinear points can uniquely define a circle, the position of the center point of the wafer 203 is determined. To determine the size of the chip, as shown in FIG. 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. Within any chip 401 on the wafer 203, any mechanism is selected as the first template 402 of the chip 401. For multiple chips 401, the position of any selected mechanism is the same, that is, the same position within multiple chips 401 includes the same first template 402. The first template 402 can have uniqueness and high contrast, which is conducive to image matching and feature recognition. In one possible embodiment, 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 based on the distance between adjacent first templates 402.

[0092] Further, if Figure 5As shown, the center of the wafer 203 is used as the center of the circle, and the position of the first template 402 is used as the position of the chip 401. Based on this, the chips 401 are preliminarily arranged according to the size of the chip 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 chip 401, in order to correct the position of the chip 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.

[0093] In this embodiment of the present application, by matching and identifying a highly identifiable first template within the chips on the wafer, and determining key features such as the wafer center position and chip size, the chips on the wafer are preliminarily arranged based on the position of the first template. The positions of the arranged chips on the wafer are then corrected using the determined positions of the first grooves. The resulting wafer map includes position information that corresponds one-to-one with the actual chip positions. Furthermore, this is not affected by the number of chips, shortening the time required to generate the wafer map and significantly improving its efficiency.

[0094] In another embodiment of the present disclosure, in the above step S102, the wafer is moved so that the edge of the wafer is within the field of view of the first image acquisition device, and the position of the center point of the wafer is determined based on 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 wafer edge, including the following steps:

[0095] Step 1: determining a first mechanical position coordinate that causes the arc of the wafer edge to be within the field of view of a first image acquisition device; determining 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; and determining, based on the first mechanical position coordinate and the plurality of 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; or

[0096] Step 2: Moving the wafer so that multiple arcs on the wafer edge are sequentially located within the field of view of a first image acquisition device, sequentially determining corresponding first mechanical position coordinates for each of the multiple arcs on the wafer edge that are located within the field of view of the first image acquisition device; determining first coordinate deviations between the positions of any point on the multiple arcs 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; and determining second mechanical position coordinates when the position of each 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.

[0097] Step 3: Based on 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.

[0098] 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 coordinate origin, 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. 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 and fitted, 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 ) is subtracted 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 one possible implementation, wafer 203 can be moved so that the center of the field of view of first image acquisition device 202 coincides with any point on the edge arc of wafer 203. In this case, the first coordinate deviation is (0, 0), and the second mechanical position coordinate is equal to the first mechanical position coordinate. Second mechanical position coordinates corresponding to multiple points on one or more arcs of the edge of wafer 203 are determined.

[0099] 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 of a circle can refer to the process of determining the center position of a circle based on a set of data points using mathematical methods. There are many methods for fitting the center point of a circle, such as the least squares method, geometric method, iterative method, etc. Then, the third mechanical position coordinates are determined when the center point of the wafer 203 coincides with the center of the field of view of the first image acquisition device 202. 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.

[0100] In another embodiment of the present disclosure, after determining the position of the first template of the chip, the method further includes:

[0101] Rotating the wafer according to the position of the first template so that the chips on the wafer are aligned to a horizontal state within the field of view of the first image acquisition device includes:

[0102] Step 1: determining a first angle of wafer rotation based on an angle between a straight line connecting preset positions corresponding to at least two chips in the same row or column in the first template and a horizontal line;

[0103] 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.

[0104] In the embodiment of the present disclosure, after determining the position of the first template of the chip, accurate image matching and feature recognition algorithms can be used to achieve accurate alignment of the wafer. Figure 4As shown, by fitting a straight line along the preset position in the image of at least two first templates 402 in the same row or column, the fitted straight line can 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 required preset alignment accuracy is reached, so that the chip 401 on the wafer 203 is aligned to a horizontal state within 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 aligned to a horizontal state more accurately.

[0105] 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:

[0106] Step 1: Determine the lateral size of the chip based on 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;

[0107] Step 2: Determine the longitudinal size of the chip based on the distance between the preset positions in the first template corresponding to the upper and lower adjacent chips; the longitudinal size 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.

[0108] In the embodiment of the present disclosure, the size of the chip is determined based on 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 example, in step 1 above, 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 horizontal dimension of the chip 401. The horizontal dimension of the chip 401 includes: the sum of the length of the horizontal side of the chip 401 and the width of the scribing 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 dimension of the chip 401. The longitudinal dimension of the chip 401 includes: the sum of the length of the vertical side of the chip 401 and the width of the scribing line between the chips 401. Therefore, the size of the chip can be determined based on the distance between the positions of adjacent first templates.

[0109] In another embodiment of the present disclosure, in the above step S104, the chips on the wafer are preliminarily arranged based on the center point of the wafer and the size of the chips and the position of the first template, including:

[0110] 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;

[0111] 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.

[0112] In the embodiment of the present disclosure, the center point of the wafer is used as the center of the circle, and the chips are arranged according to the chip size and the position of the first template. This can make the time for generating the wafer map unaffected by the number of chips, greatly improving the efficiency of generating the wafer map. For example, in step 1 above, 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 corresponding to chip 401. The designated position can be the upper left corner of the corresponding chip 401, or any position corresponding to chip 401. The chips are arranged according to the center point position of the wafer, the size of the chips, and the mechanical position coordinates of the preset position of the first template 402. The portion exceeding the wafer size is cropped.

[0113] In another embodiment of the present disclosure, in the above step S105, the positions of the chips arranged on the wafer are 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:

[0114] 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;

[0115] 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 chip size to determine a second coordinate deviation between the center position of the first groove and the preset position of the first template;

[0116] Step 3: Use the second coordinate deviation to compensate the preset position coordinates of the first template of the chips arranged on the wafer to generate a wafer map.

[0117] In the embodiment of the present disclosure, by correcting the positions of the chips initially arranged on the wafer, a wafer map is generated that corresponds to the positions of the actual chips. 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 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 operation with the chip size to obtain the second coordinate deviation. For example, the horizontal size and vertical size 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 second coordinate deviation is used to compensate for the preset position coordinates of the first template on the wafer, thereby correcting the position of the chip and determining a wafer map that corresponds one-to-one 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 tedious operation of manually correcting the chip position is avoided, and the accuracy of the chip position information can also be guaranteed.

[0118] Based on the wafer map provided in the above embodiment, the present disclosure further provides a method for testing a wafer, comprising the following steps:

[0119] Step 1: Determine the location of the pad inside the chip based on the center coordinates of the chip on the wafer map.

[0120] Step 2: Place the probe within the field of view of the second image acquisition device and determine the position of the probe tip;

[0121] 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;

[0122] The wafer map may be generated by using the method for generating a wafer map provided in any of the above embodiments.

[0123] 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. In 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. 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, in 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, second image acquisition device 205 and wafer 203 are both moved using the same mechanism on stage 204, so the relative positions of second image acquisition device 205 and wafer 203 remain unchanged. Second image acquisition device 205 is moved so that probe 206 is within its field of view, and the position of the probe tip is determined. Regarding step 3 above, based on the position of pad 404 and the position of the probe tip, probe 206 is brought into contact with pad 404, thereby testing wafer 203.

[0124] In another embodiment of the present disclosure, in step 1 above, determining the position of the pad inside the chip according to the center position coordinates of the chip on the wafer map includes:

[0125] Aligning the center of the chip with the center of the field of view of the first image acquisition device based on the center coordinates of the chip on the wafer map, and determining a third coordinate deviation of the position of the bonding pad inside the chip relative to the center of the field of view of the first image acquisition device;

[0126] In step 3 above, the wafer is tested by contacting the probe with the pad according to the position of the pad and the position of the probe tip, including:

[0127] 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.

[0128] In the embodiment of the present disclosure, based on the center position coordinates of the chip on the generated wafer map, the coordinate deviation of the position of the pad inside the chip relative to the center of the first image acquisition device is determined, and the coordinate deviation and the position of the probe tip are used to make the probe contact the pad, thereby testing the wafer. Figure 4 As shown, wafer 203 is moved to the mechanical coordinates of the center of chip 401 on the wafer map, so that point E, the center of chip 401, coincides with the center of the field of view of first image capture device 202. Within the field of view of first image capture device 202, the third coordinate deviation of the position of pad 404 within chip 401 relative to point E, the center of the field of view of first image capture device 202, is determined. Based on the relative position of pad 404 to the center of the field of view of first image capture device 202 and the relative position of the probe tip to the center of the field of view of first image capture device 202, wafer 203 is moved so that probe 206 contacts pad 404, and wafer 203 is tested. By determining the coordinate deviation of the position of pad 404 within chip 401 relative to the center of the field of view of first image capture device 202, calculation steps can be simplified and measurement errors can be reduced. This coordinate deviation and the position of the probe tip are used to ensure that the probe contacts the pad.

[0129] In another embodiment of the present disclosure, in step 1 above, determining the position of the pad inside the chip according to the center position coordinates of the chip on the wafer map includes:

[0130] Step 1: Based on the center coordinates of the chip on the wafer map, the center of the chip is aligned with the center of the field of view of the first image acquisition device, and a third coordinate deviation of the position of the bonding pad inside the chip relative to the center of the field of view of the first image acquisition device is determined;

[0131] Step 2: Determine the seventh mechanical position coordinate when the position of the pad inside the chip coincides with 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 center of the field of view of the first image acquisition device from the third coordinate deviation;

[0132] In step 3 above, the wafer is tested by contacting the probe with the pad according to the position of the pad and the position of the probe tip, including:

[0133] According to the seventh mechanical position coordinate and the position of the probe tip, the probe is brought into contact with the pad to test the wafer.

[0134] In the embodiment of the present disclosure, the mechanical position coordinates of the pads inside the chip are determined based on the center position coordinates of the chip on the generated wafer map, and the mechanical position coordinates and the needle tip position of the probe are used to make the probe contact the pads, thereby testing the wafer. Figure 4 As shown, wafer 203 is moved to the mechanical coordinates of the center of chip 401 on the wafer map, so that point E, the center of chip 401, coincides with the center of the field of view of first image acquisition device 202. Within the field of view of first image acquisition device 202, a third coordinate deviation of the position of pad 404 within chip 401 relative to point E, the center of the field of view of first image acquisition device 202, is determined. For step 2 above, the sixth mechanical coordinate of the center of chip 401 is subtracted from the third coordinate deviation to determine the seventh mechanical coordinate of pad 404 within chip 401 when it coincides with the center of the field of view of first image acquisition device 202. Based on the seventh mechanical coordinate and the position of the probe tip of probe 206, wafer 203 is moved so that probe 206 contacts pad 404, and wafer 203 is tested. The mechanical position coordinates 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 coordinates and the tip position of the probe to make the probe contact the pad 404.

[0135] In another embodiment of the present disclosure, in step 1 above, determining the position of the pad inside the chip according to the center position coordinates of the chip on the wafer map includes:

[0136] Step 1: determining an eighth mechanical position coordinate so that the pad inside the chip is within the field of view of the first image acquisition device;

[0137] 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,

[0138] Step 3: Determine, based on the deviation between the eighth mechanical position coordinate and the fourth coordinate, 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; and / or

[0139] Step 4: Determine the chip corresponding to the pad and the fifth coordinate deviation between the pad and the center position of the corresponding chip based on the center position coordinates of the chip on the wafer map and the ninth mechanical position coordinates;

[0140] In step 3 above, the wafer is tested by contacting the probe with the pad according to the position of the pad and the position of the probe tip, including:

[0141] 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;

[0142] According to the first position of the pad and the position of the needle tip of the probe, the probe is brought into contact with the pad to test the wafer.

[0143] 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 based on the position information of the chip in the wafer map. For example, in step 1 above, Figure 4 As shown, wafer 203 is moved so that pad 404 is within the field of view of first image capture device 202. The corresponding mechanical position coordinate is the eighth mechanical position coordinate. Regarding step 2 above, the fourth coordinate deviation between the center position of pad 404 and the center position of first image capture device 202 is visually identified within the field of view of first image capture device 202. Regarding step 3 above, the eighth mechanical position coordinate is subtracted from the fourth coordinate deviation to obtain the ninth mechanical position coordinate when the center position of pad 404 coincides with the center of the field of view of first image capture device 202. Regarding step 4 above, the chip 401 corresponding to pad 404 is determined by comparing the center position coordinate information of the chip on the wafer map with the ninth mechanical position coordinate. The ninth mechanical position coordinate is then subtracted from the mechanical position coordinate of the center position of chip 401 to obtain the fifth coordinate deviation of the center position of pad 404 relative to the center position of chip 401. This fifth coordinate deviation represents the offset between pad 404 and the center position of chip 401 within chip 401. The fourth coordinate deviation, the ninth mechanical position coordinate, or the fifth coordinate deviation described above can all be used to determine the position of pad 404. Based on the position of pad 404 and the position of the probe tip of probe 206, probe 206 is brought into contact with pad 404 to test wafer 203. By using 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 can be quickly located, as well as the coordinate deviation of the pad relative to the center of the chip, thereby determining the position of the pad within each chip on the wafer.

[0144] In another embodiment of the present disclosure, for a single probe, in step 2 above, the probe is positioned within the field of view of the second image acquisition device, and the position of the probe tip is determined, including:

[0145] Step 1: determining a tenth mechanical position coordinate that causes the center of the field of view of the second image acquisition device to coincide with the center of the field of view of the first image acquisition device; wherein the second image acquisition device is pre-moved 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 based on the same reference object;

[0146] Step 2: determining an eleventh mechanical position coordinate for positioning 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 center of the field of view of the second image acquisition device;

[0147] Step 3: Determine a 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.

[0148] 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 within the field of view of the second image acquisition device 205. 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 center of the field of view of the second image acquisition device 205 is determined. For the above step 3, the seventh coordinate deviation of the position of the tip of the probe 206 relative to the position of the center of the field of view of the first image acquisition device 202 is (△X 针 , △Y 针 , △Z 针 ),in

[0149] △X 针 = X2-X1+△X1;

[0150] △Y 针 = Y2-Y1+△Y1;

[0151] △Z 针 = Z2- Z1;

[0152] △Z针 Based on the seventh coordinate deviation of the position of the pad 404 and the position of the probe 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 brought into contact with the pad 404 to test the wafer 203.

[0153] In another embodiment of the present disclosure, for a single-row probe, in step 2 above, the probe is positioned within the field of view of the second image acquisition device, and the position of the probe tip is determined, including:

[0154] For a single-row probe, in step 2 above, the probe is positioned within the field of view of the second image acquisition device, and the position of the probe tip is determined, including:

[0155] Step 1: determining a twelfth mechanical position coordinate that causes the center of the field of view of the second image acquisition device to coincide with the center of the field of view of the first image acquisition device; wherein the second image acquisition device is pre-moved 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 based on the same reference object;

[0156] Step 2: determining a thirteenth mechanical position coordinate that causes the tip of any probe in the single row of probes to 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;

[0157] 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 based on the twelfth mechanical position coordinate and the difference between the thirteenth mechanical position coordinate and the eighth coordinate deviation;

[0158] Step 4: determining a second angle of wafer rotation based on an angle between a line connecting the positions of the internal bonding pads of at least two chips in the same row or column and a line connecting the positions of the needle tips of at least two probes in a single row of probes;

[0159] 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.

[0160] 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 2As 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 within the field of view of the second image acquisition device 205. 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

[0161] △X 针 = X2-X1+△X1;

[0162] △Y 针 = Y2-Y1+△Y1;

[0163] △Z 针 = Z2- Z1;

[0164] △Z 针 Characterizes the height distance from the probe tip to the wafer surface. With respect to step 4 above, 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 tips of at least two probes in the single-row probe is the second angle. With respect to step 5 above, wafer 203 is rotated according to the second angle, and based on the ninth coordinate deviation of the positions of the pads 404 and the tips of the probes 206 relative to the center of the field of view of the first image acquisition device 202, the single-row probes are brought into contact with the corresponding pads, thereby testing wafer 203.

[0165] In another embodiment of the present disclosure, before testing the wafer, the method further includes:

[0166] Step 1: Measure the thickness of the wafer;

[0167] 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.

[0168] In the embodiment of the present disclosure, 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.

[0169] 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.

[0170] The embodiment of the present disclosure provides a device for generating a wafer map, such as Figure 8 Shown, including:

[0171] Image acquisition module 801 is configured 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;

[0172] Wafer centering module 802 is used to move the wafer so that the edge of the wafer is within the field of view of the first image acquisition device, and determine the center point of the wafer based on the positional 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;

[0173] Wafer map generation module 803 is configured to locate the chip on the wafer within the field of view of a first image acquisition device, determine the position of a first template on the chip based on the position of the center of the field of view of the first image acquisition device and any structure on the wafer located at the same position within the chip, and determine the size of the chip based on the position of the first template;

[0174] 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;

[0175] 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.

[0176] In another embodiment of the present disclosure, the wafer centering module 802 is used to determine a first mechanical position coordinate so that the arc of the wafer edge is located within the field of view of the first image acquisition device; determine, within the field of view of the first image acquisition device, 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; and determine, based on the first mechanical position coordinate and the multiple 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; or

[0177] The wafer is moved so that a plurality of circular arcs on the wafer edge are sequentially located within a field of view of a first image acquisition device, and corresponding first mechanical position coordinates are sequentially determined so that the plurality of circular arcs on the wafer edge 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 a position of any point on the plurality of circular arcs and a position of a center of the field of view of the first image acquisition device is determined; and a second mechanical position coordinate is determined 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 plurality of first mechanical position coordinates and the corresponding first coordinate deviations;

[0178] Based on 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.

[0179] 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 configured to:

[0180] Rotating the wafer according to the position of the first template so that the chips on the wafer are aligned to a horizontal state within the field of view of the first image acquisition device includes:

[0181] Determining a first angle of wafer rotation according to an angle between a straight line connecting preset positions in the first template corresponding to at least two chips in the same row or column and a horizontal line;

[0182] 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.

[0183] In another embodiment of the present disclosure, the wafer map generation module 803 is configured to determine the lateral size of a chip based on the distance between the preset positions in the first template corresponding to the left and right adjacent chips; wherein the lateral size of a chip includes: the sum of the length of a horizontal side of the chip and the width of a scribe line between the chips;

[0184] The longitudinal size 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 size 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.

[0185] In yet another embodiment of the present disclosure, the wafer map generation module 803 is configured 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;

[0186] 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.

[0187] In another embodiment of the present disclosure, the wafer map generation module 803 is configured to determine a fifth mechanical position coordinate such that the center position of the first groove coincides with the center position of the field of view of the first image acquisition device;

[0188] Subtracting the preset position coordinates of the first template from the fifth mechanical position coordinates, performing 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;

[0189] 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.

[0190] The present disclosure provides a device for testing wafers, such as Figure 9 Shown, including:

[0191] 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;

[0192] A probe positioning module 902 is configured to position the probe within the field of view of the second image acquisition device and determine the position of the probe tip;

[0193] The wafer testing module 903 is used to test the wafer by contacting the probe with 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.

[0194] In another embodiment of the present disclosure, the pad positioning module 901 is configured to, based on the center position coordinates of the chip on the wafer map, align the center position of the chip with the center position of the field of view of the first image acquisition device, and determine 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;

[0195] 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.

[0196] In another embodiment of the present disclosure, the pad positioning module 901 is configured to, based on the center position coordinates of the chip on the wafer map, align the center position of the chip with the center position of the field of view of the first image acquisition device, and determine 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;

[0197] Determine a seventh mechanical position coordinate when the position of the pad inside the chip coincides with 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 center of the field of view of the first image acquisition device from the third coordinate deviation;

[0198] 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.

[0199] In another embodiment of the present disclosure, the pad positioning module 901 is configured to determine an eighth mechanical position coordinate such that the pad inside the chip is located within the field of view of the first image acquisition device;

[0200] 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,

[0201] determining, based on the deviation between the eighth mechanical position coordinate and the fourth coordinate, 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

[0202] Determine the chip corresponding to the pad and a fifth coordinate deviation between the pad and the center position of the corresponding chip according to the center position coordinates of the chip on the wafer map and the ninth mechanical position coordinates;

[0203] The wafer testing module 903 is configured 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;

[0204] According to the first position of the pad and the position of the needle tip of the probe, the probe is brought into contact with the pad to test the wafer.

[0205] In another embodiment of the present disclosure, for a single probe, the probe positioning module 902 is configured to determine a tenth mechanical position coordinate at which the center of the field of view of the second image acquisition device coincides with the center of the field of view of the first image acquisition device; wherein the second image acquisition device is pre-moved 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 based on the same reference object;

[0206] 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;

[0207] A 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 is determined based on the tenth mechanical position coordinate and the difference between the eleventh mechanical position coordinate and the coordinate deviation.

[0208] In another embodiment of the present disclosure, for a single-row probe, the probe positioning module 902 is configured to determine a twelfth mechanical position coordinate such that the center of the field of view of the second image acquisition device coincides with the center of the field of view of the first image acquisition device; wherein the second image acquisition device is pre-moved 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 based on the same reference object;

[0209] determining a thirteenth mechanical position coordinate at which a tip of any probe in the single row of probes is located within a 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;

[0210] determining a ninth coordinate deviation of the position of the tip of the probe relative to the center of the field of view of the first image acquisition device based on the twelfth mechanical position coordinate and a difference between the thirteenth mechanical position coordinate and the eighth coordinate deviation;

[0211] Determining a second angle of wafer rotation based on 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;

[0212] The wafer is rotated according to the second angle so that the line connecting the positions of the needle 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.

[0213] In another embodiment of the present disclosure, before testing the wafer, the wafer testing module 903 is further configured to:

[0214] Measure the thickness of wafers;

[0215] 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 according to the direction and distance of movement.

[0216] An embodiment of the present disclosure provides a device for testing wafers, including: a device for generating a wafer image as described in any of the above embodiments and / or a device for testing wafers as described in any of the above embodiments.

[0217] Those skilled in the art will understand 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.

[0218] Those skilled in the art will appreciate that the modules in the devices of the embodiments may be distributed in the devices of the embodiments as described in the embodiments, or may be located in one or more devices different from the embodiments with corresponding changes. The modules of the above embodiments may be combined into one module or further divided into multiple submodules.

[0219] The serial numbers of the above-mentioned embodiments of the present disclosure are for description only and do not represent the advantages or disadvantages of the embodiments.

[0220] Obviously, those skilled in the art may 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 intended to include such 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 evenly distributed; 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 within the field of view of a first image acquisition device, and determining the position of the center point of the wafer based on the positional 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; Positioning the chip on the wafer within the field of view of the first image acquisition device, determining the position of a first template on the chip based on the position of the center of the field of view of the first image acquisition device and any structure on the wafer located at the same position within the chip; and determining the size of the chip based on 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; Correcting the positions of the chips arranged on the wafer based on a deviation between the position of the first template and the position of the first groove to generate a wafer map; The determining the size of the chip according to the position of the first template includes: Determining the lateral size of the chip based on 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; The longitudinal size 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 size 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.

2. The method according to claim 1, wherein Determining 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 wafer edge includes: Determining a first mechanical position coordinate such that the arc of the wafer edge is within the field of view of a first image acquisition device; determining, within the field of view of the first image acquisition device, 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; and determining, based on the first mechanical position coordinate and the plurality of 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; or The wafer is moved so that a plurality of arcs on the wafer edge are sequentially located within a field of view of a first image acquisition device, and corresponding first mechanical position coordinates are sequentially determined so that the plurality of arcs on the wafer edge 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 a position of any point on the plurality of arcs and a position of a center of the field of view of the first image acquisition device is determined; and a second mechanical position coordinate is determined 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 plurality of first mechanical position coordinates and the corresponding first coordinate deviations; Based on 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, wherein 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 chips on the wafer are aligned to a horizontal state within the field of view of the first image acquisition device includes: Determining a first angle of wafer rotation according to an angle between a straight line connecting preset positions in the first template corresponding to at least two chips in the same row or column 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, wherein The preliminarily arranging the chips on the wafer based on the center point of the wafer and the size of the chips and the position of the first template includes: Determining 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.

5. The method according to claim 4, wherein The step 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: 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; Subtracting the preset position coordinates of the first template from the fifth mechanical position coordinates, performing 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; 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.

6. A method for testing a wafer, characterized in that: include: Determine the location of the pads inside the chip based on the center coordinates of the chip on the wafer map; Positioning the probe within the field of view of a second image acquisition device to determine the position of the probe tip; 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; wherein the wafer map is generated using the method for generating a wafer map as described in any one of claims 1 to 5.

7. The method according to claim 6, wherein 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: Aligning the center of the chip with the center of the field of view of the first image acquisition device based on the center coordinates of the chip on the wafer map, and determining a third coordinate deviation of the position of the pad inside the chip relative to the center of the field of view of the first image acquisition device; 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: The probe is brought into contact with the pad according to the third coordinate deviation and the position of the probe tip to test the wafer.

8. The method according to claim 6, wherein The method of determining the position of the pad inside the chip according to the center position coordinates of the chip on the wafer map includes: Aligning the center of the chip with the center of the field of view of the first image acquisition device based on the center coordinates of the chip on the wafer map, and determining a third coordinate deviation of the position of the pad inside the chip relative to the center of the field of view of the first image acquisition device; Determine a seventh mechanical position coordinate when the position of the pad inside the chip coincides with 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 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: The probe is brought into contact with the pad according to the seventh mechanical position coordinate and the position of the probe tip to test the wafer.

9. The method according to claim 6, wherein 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: Determining an eighth mechanical position coordinate so that the pad inside the chip is 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 determining, based on the deviation between the eighth mechanical position coordinate and the fourth coordinate, 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 between the pad and the corresponding chip's center position based on the center position coordinates of the chip on the wafer map and the ninth mechanical position coordinates; 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 probe tip, the probe is brought into contact with the pad to test the wafer.

10. The method according to claim 6, wherein 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 probe tip includes: determining a tenth mechanical position coordinate at which a center of a field of view of the second image acquisition device coincides with a center of a field of view of the first image acquisition device; wherein the second image acquisition device is preliminarily moved 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 with respect to a common 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 probe tip 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.

11. The method according to claim 6, wherein For a single-row probe, the step of positioning the probe within the field of view of the second image acquisition device and determining the position of the probe tip includes: Determining a twelfth mechanical position coordinate that causes the center of the field of view of the second image acquisition device to coincide with the center of the field of view of the first image acquisition device; wherein the second image acquisition device is preliminarily moved 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 based on a common reference object; determining a thirteenth mechanical position coordinate at which a tip of any probe in the single row of probes is 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; determining a ninth coordinate deviation of the position of the tip of the probe relative to the center of the field of view of the first image acquisition device based on the twelfth mechanical position coordinate and a difference between the thirteenth mechanical position coordinate and the eighth coordinate deviation; Determining a second angle of wafer rotation based on 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 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.

12. A device for generating a wafer map, characterized in that: include: An image acquisition module is configured 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, configured to 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 center of the wafer based on the positional 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; 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 a first template on the chip based on the position of the center of the field of view of the first image acquisition device and any structure on the wafer located at the same position within the chip, and determine the size of the chip based on 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; Correcting the positions of the chips arranged on the wafer based on a deviation between the position of the first template and the position of the first groove to generate a wafer map; The wafer map generation module is used to determine the horizontal size of the chip based on the distance between the preset positions in the first template corresponding to the left and right adjacent chips respectively; wherein the horizontal size of the chip includes: the sum of the length of the horizontal side of the chip and the width of the scribing line between the chips; and determine the vertical size of the chip based on the distance between the preset positions in the first template corresponding to the upper and lower adjacent chips respectively; wherein the vertical size of the chip includes: the sum of the length of the vertical side of the chip and the width of the scribing line between the chips.

13. A device for testing wafers, 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, configured to locate the probe within the field of view of the second image acquisition device and determine the position of the probe tip; 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 5.

14. A device for testing wafers, characterized in that: The device comprises the device for generating a wafer map as claimed in claim 12 and / or the device for testing a wafer as claimed in claim 13.

Images