Wafer probe test calibration method, device, equipment, medium and product

Abstract

The present application relates to a wafer probe test calibration method, device, equipment, medium and product, and relates to the field of semiconductor equipment. The method comprises: obtaining an initial OD value and a length value of the probe of a wafer test machine when the probe on a probe card and a contact point on a wafer are in a zero-pressure contact state; obtaining a first height difference between a first reference measurement point above the wafer and a second reference measurement point below the wafer; obtaining a second height difference between the first reference measurement point and the top surface of the wafer; obtaining a third height difference between the bottom surface of the probe card and the second reference measurement point; calculating a measurement spacing value between the bottom surface of the probe and the contact point according to the first height difference, the second height difference, the third height difference and the length value; calibrating the initial OD value according to the measurement spacing value. The method can eliminate the influence of WAT machine error and product film thickness on OD value setting, and monitor product film layer changes and equipment status according to the target displacement value obtained by calibration.

Description

Technical Field

[0001] The present application relates to the field of semiconductor equipment, and in particular to a wafer probe test calibration method, device, equipment, medium and product. Background Art

[0002] Wafer Acceptance Test (WAT) is also called electrical test. WAT test can screen out chips with functional defects in wafers in advance through wafer testing machines. It is a key test link to ensure the quality and reliability of finished wafers in the integrated circuit manufacturing process.

[0003] In the WAT test, a test pad is set on the wafer surface to be tested, forming contact points on the wafer surface to be tested. The position of the probe card remains unchanged, and the carrier carries the wafer and moves in the vertical direction, so that the contact point gradually approaches the probe. When it moves to a certain position, the probe and the contact point on the wafer surface to be tested are electrically connected, thereby realizing electrical testing of the wafer. This moving distance is called the needle pressing distance (Over Drive, OD). Therefore, how to accurately set the OD value in the WAT test to ensure good contact between the probe and the contact point on the wafer surface to be tested has become one of the important issues that researchers are concerned about. Summary of the invention

[0004] Based on this, it is necessary to provide a wafer probe test calibration method, device, equipment, medium and product to address the technical problems in the prior art, which can at least avoid the influence of machine errors and product film thickness on the set OD value in WAT testing, and ensure good contact between the probe and the contact points on the surface of the wafer to be tested.

[0005] In a first aspect, the present application provides a wafer probe test calibration method, including: obtaining an initial OD value and a length value of the probe when a wafer testing machine is in a zero pressure contact state between a probe on a probe card and a contact point on a wafer; obtaining a first height difference between a first reference measurement point above the wafer and a second reference measurement point below the wafer; obtaining a second height difference between the first reference measurement point and the top surface of the wafer; obtaining a third height difference between the bottom surface of the probe card and the second reference measurement point; calculating a measured spacing value between the bottom surface of the probe and the contact point based on the first height difference, the second height difference, the third height difference and the length value; and calibrating the initial OD value based on the measured spacing value.

[0006] In the wafer probe test calibration method in the above embodiment, a high-precision first sensor and a second sensor can be used to measure the first height difference between the sensors, the second height difference from the sensor to the wafer contact point, and the third height difference from the bottom surface of the probe card. The distance between the bottom surface of the probe and the wafer contact point is calculated by combining the first height difference, the second height difference and the third height difference, that is, the measured spacing value. The initial OD value is calibrated according to the measured spacing value to obtain the target displacement value required for the carrier to move toward the probe. When the carrier controls the wafer to be tested to move toward the probe by the corresponding target displacement value, the probe is in contact with the contact point of the wafer to be tested, which can effectively avoid unnecessary losses caused by false or excessive piercing of the probe and extend the service life of the probe.

[0007] In the aforementioned calibration method, the distance measurement technology is introduced for the machine error and product film layer in the WAT test. The designed algorithm can calibrate the initial OD value while ignoring the differences that may occur in different devices, and omits the step of repeated measurement of film thickness in the traditional calibration method. The purpose of reducing the difficulty and workload of calibration is achieved, and the influence of the machine error caused by the installation of sensors / probe cards of different devices and the film thickness of the product on the set OD value in the WAT test is eliminated. In addition, since the initial OD value can be customized according to different products, and the calibration method does not restrict the product model or form, it has good versatility.

[0008] In some embodiments, the wafer probe test calibration method calculates the measurement distance value H between the bottom surface of the probe and the top surface of the wafer according to the following formula:

[0009] H = Hbase–Hpin;

[0010] Hbase=h2+h3-h1;

[0011] Among them, Hbase is the spacing value between the bottom surface of the probe card and the top surface of the wafer, Hpin is the length value of the probe, h1 is the first height difference, h2 is the second height difference, and h3 is the third height difference.

[0012] In some embodiments, the wafer probe test calibration method also includes: obtaining the spacing values ​​between multiple different contact points on the top surface of the wafer and the bottom surface of the probe; calculating the average of the spacing values ​​between the multiple different contact points and the bottom surface of the probe; and determining the measured spacing value based on the average.

[0013] In some embodiments, the wafer probe test calibration method further includes: periodically calibrating an initial OD value of the wafer test machine according to a preset period value.

[0014] In the second aspect, the present application also provides a wafer probe test and calibration device, including: a first sensor, arranged above the wafer, for measuring a first height difference between a first reference measurement point above the wafer and a second reference measurement point below the wafer, and a second height difference between the first reference measurement point and the top surface of the wafer; a second sensor, arranged below the wafer, for measuring a third height difference between the bottom surface of the probe card and the second reference measurement point; a controller, connected to the first sensor and the second sensor, and configured to: obtain an initial OD value and a length value of the probe of the wafer testing machine when the probe on the probe card and the contact point on the wafer are in a zero pressure contact state; obtain the first height difference, the second height difference, and the third height difference between the bottom surface of the probe card and the second reference measurement point; calculate the measured spacing value between the bottom surface of the probe and the contact point according to the first height difference, the second height difference, the third height difference and the length value; and calibrate the initial OD value according to the measured spacing value.

[0015] In the wafer probe test and calibration device in the above embodiment, the first sensor and the second sensor, two high-precision distance measuring sensors, are respectively arranged above the probe card of the original wafer test machine and below the carrier. The controller is electrically connected to the first sensor and the second sensor. The structure of the wafer probe test and calibration device is relatively simple, consisting only of a controller, a first sensor and a second sensor, and is easy to operate. Therefore, it is possible to reduce the maintenance and repair costs of the device, reduce downtime, and thus improve its availability and efficiency.

[0016] In addition, the wafer probe test calibration device accurately measures the first height difference, the second height difference and the third height difference, including the position offset value caused by machine installation, sensor installation, thermal deformation and vibration, as well as the film thickness on the wafer surface. Therefore, under the condition of ignoring the film thickness and machine error, combined with the calculation formula provided by the wafer probe test calibration, the initial OD value can be calibrated directly to obtain the target displacement value.

[0017] In a third aspect, the present application also provides a wafer probe test and calibration device, including a memory and a processor, wherein the memory stores a computer program, and the processor implements the wafer probe calibration method in any of the above embodiments when executing the computer program.

[0018] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the wafer probe calibration method in any of the above embodiments is implemented.

[0019] In a fifth aspect, the present application also provides a computer program product, including a computer program, which implements the wafer probe calibration method in any of the above embodiments when the computer program is executed by a processor.

[0020] The wafer probe test calibration equipment, computer-readable storage medium, and computer program product in the above embodiments are all associated with the above wafer probe test calibration method and device. Among them, the wafer probe test calibration equipment is used to execute the computer program code storing the wafer probe test calibration method, and operate the wafer probe test calibration device to realize automatic calibration of the OD value; the computer-readable storage medium is used to store the computer program code and data for executing the wafer probe test calibration method, and the storage medium can be various types of media such as hard disk, optical disk, USB flash drive, etc.; the computer program product includes a computer program code for calculating the measurement spacing value in the wafer probe test calibration method. The program can be installed on a computer or other electronic device to run and instruct the device to perform the calibration task.

[0021] The unexpected technical effects that can be produced by the above-mentioned embodiments include: using a high-precision first sensor and a second sensor to measure the first height difference between the sensors, the second height difference from the sensor to the wafer contact point, and the third height difference from the bottom surface of the probe card, and combining the first height difference, the second height difference and the third height difference to calculate the distance between the bottom surface of the probe and the wafer contact point, that is, the measured spacing value. The initial OD value is calibrated according to the measured spacing value to obtain the target displacement value required for the carrier to move in the direction toward the probe. When the carrier controls the wafer to be tested to move toward the probe by the corresponding target displacement value, the probe just contacts the contact point of the wafer to be tested, which can effectively avoid unnecessary losses caused by false or excessive piercing of the probe and extend the service life of the probe.

[0022] In summary, the wafer probe test calibration method, apparatus, equipment, media and products together constitute a complete wafer probe test calibration system, which provides important support for the wafer probe test calibration method and apparatus. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 A flowchart of a wafer probe test calibration method provided in an embodiment;

[0025] Figure 2 Schematic diagram corresponding to steps S202 - S212 in a wafer probe test calibration method provided in an embodiment.

[0026] Figure 3A schematic diagram showing the correspondence of multiple different contact points on the top surface of a wafer in a wafer probe test calibration method provided in another embodiment.

[0027] Description of reference numerals:

[0028] 10. First sensor; 20. Second sensor; 30. Probe card; 31. Probe; 40. Wafer; 50. Carrying platform. DETAILED DESCRIPTION

[0029] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present application are given in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present disclosure belongs. The terms used herein in the specification of the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0031] It should be understood that when an element or layer is referred to as "on ...", "connected to" or "coupled to" other elements or layers, it can be directly on, connected to or coupled to other elements or layers, or there can be intervening elements or layers. On the contrary, when an element is referred to as "directly on ...", "directly connected to" or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc. can be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present disclosure, the first element, component, region, layer or part discussed below can be represented as a second element, component, region, layer or part.

[0032] Spatial relationship terms such as "under", "below", "lower", "beneath", "above", "upper", etc. can be used herein to describe the relationship of one element or feature shown in the figure with other elements or features. It should be understood that, in addition to the orientations shown in the figure, spatial relationship terms also include different orientations of the device in use and operation. For example, if the device in the attached drawing is flipped, an element or feature described as "under other elements" or "beneath it" or "under it" will be oriented "above" the other elements or features. Thus, the exemplary terms "under" and "beneath" can include both upper and lower orientations. In addition, the device may also have other orientations (such as, rotated 90 degrees or other orientations), and the spatial descriptors used herein are to be interpreted accordingly.

[0033] As used herein, the singular forms of "a", "an" and "the" may also include the plural forms unless the context clearly dictates otherwise. It should also be understood that when the terms "comprise" and / or "include" are used in this specification, the presence of the stated features, integers, steps, operations, elements and / or components can be determined, but one or more other features, integers, steps, operations, elements, components and / or groups thereof are not excluded from existence or addition. Also, as used herein, the term "and / or" includes any and all combinations of the related listed items.

[0034] Traditional WAT testing relies on calculating the film thickness and manually setting the OD value according to the film thickness rule. In this method of setting the OD value, the corresponding OD value is set in stages according to the size of the film thickness formed on the wafer. For example, when the film thickness is not less than thickness A, the initial OD value is 55 microns; when the film thickness is less than thickness A and greater than thickness B (B < A), the initial OD value is 60 microns; when the film thickness is not greater than thickness B, the initial OD value is 65 microns.

[0035] However, the device film layer topography of the wafer is not the same. In the same stage, when using the same OD, products with a larger film thickness may be over-punched, resulting in probe bending and / or damage to the contact points on the surface of the wafer to be tested; while products with a smaller film thickness may be under-punched, causing the failure of the WAT test. In addition, when the same product uses the same initial OD value on different devices, due to the existence of machine differences, there may be a certain deviation in the set OD value, which also results in the situation that some devices may be over-punched while some devices may be under-punched.

[0036] Therefore, if the classification is not fine enough, it will affect the accuracy of the film thickness calculation, and if it is too complicated, it will increase the calibration workload. It will bring certain errors to the OD value, resulting in problems such as poor contact quality between the probe and the contact point of the wafer to be tested, causing deviations in the evaluation of the quality and reliability of the finished wafer, affecting the accuracy, stability and reliability of the WAT test. The current mainstream calibration method for the WAT test system usually starts with the film thickness of the device layer, ignoring the machine error introduced by the installation of the calibration device, increasing the risk of false detection and missed detection in the WAT test. Therefore. It is necessary to comprehensively consider the influence of film thickness differences and machine errors, and improve the OD setting method to ensure that the probe contacts the wafer just right and reduce the defect rate and false detection rate.

[0037] Based on this, the present application provides a wafer probe test calibration method, including: step S202-step S212. Figure 1 It should be understood that although Figure 1 The steps in the flowchart are shown in sequence as indicated by the arrows, but the steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of the steps, and the steps can be executed in other orders. Moreover, Figure 1 At least part of the steps may include multiple steps or multiple stages. These steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least part of the steps or stages in other steps.

[0038] In order to facilitate understanding of this application, Figure 2 Provided are schematic diagrams corresponding to steps S202-S212 in the wafer probe test calibration method of the present application. It should be noted that the diagrams provided in this embodiment only illustrate the basic concept of the present disclosure in a schematic manner. Although the diagrams only show components related to the present disclosure rather than being drawn according to the number, shape and size of components in actual implementation, the type, quantity and proportion of each component in actual implementation may be changed arbitrarily, and the component layout type may also be more complex.

[0039] The technical solution of the present application is described in detail below with reference to the embodiments and drawings.

[0040] Step S202 : obtaining the initial OD value and the length value of the probe 31 of the wafer testing machine when the probe 31 on the probe card 30 and the contact point on the wafer 40 are in a zero pressure contact state.

[0041] For example, see Figure 2The wafer testing machine includes: a probe card 30, which is configured to be fixed directly above the carrier 50, opposite to the wafer 40, and used to fix the probe 31; the probe 31 is configured to be electrically connected to the probe card on the top surface, and the bottom surface is a free end, vertically suspended, and used to apply a test signal to the contact point on the surface to be tested of the wafer 40. A plurality of probes 31 with the same length value are evenly distributed on the probe card 30; the carrier 50 is configured to be below the probe card 30, and is arranged opposite to the probe card 30. It is used to carry and move the wafer 40, and to perform lifting and lowering movements along a predetermined direction - toward the direction of the probe 31 - to adjust the position of the wafer 40, so that the wafer 40 is in contact with the probe 31 to generate an electrical connection. Figure 2 In addition to the structure shown, the wafer tester also includes a clamping device supporting and connecting the probe card 30 and a lower end bracket supporting the carrier 50. The clamping device and the lower end bracket are electrically connected to the main structure of the wafer tester.

[0042] For example, the initial OD value can be set differently according to different products. It is only necessary to ensure that after the wafer 40 moves toward the probe 31 according to the initial OD value, the contact point on the surface to be tested of the wafer 40 does not contact the probe tip 31, that is, the two are in a zero-pressure contact state. The length value of the probe 31 is a pre-set fixed value, and it hardly changes during the test process except for damage, so it will not be described in detail here.

[0043] Step S204 : obtaining a first height difference between a first reference measurement point above the wafer 40 and a second reference measurement point below the wafer 40 .

[0044] For example, the wafer probe test calibration device provided in the present application is used to measure the first height difference. In this embodiment, the first height difference is h1.

[0045] For example, please continue to see Figure 2 The wafer probe test calibration device includes a first sensor 10, which is configured to be disposed above the wafer 40 and used to measure a first height difference h1 between a first reference measurement point above the wafer 40 and a second reference measurement point below the wafer 40; and a second sensor 20, which is configured to be disposed below the wafer 40.

[0046] In this embodiment, the horizontal line where the first reference measurement point is located is flush with the horizontal line where the transmitting end of the first sensor 10 is located, and the horizontal line where the second reference measurement point is located is flush with the horizontal line where the transmitting end of the second sensor 20 is located. The first height difference h1 represents the distance between the first sensor 10 and the second sensor 20 which are arranged relatively in a direction perpendicular to the moving path of the wafer 40.

[0047] Step S206 : obtaining a second height difference between the first reference measurement point and the top surface of the wafer 40 .

[0048] For example, in this embodiment, the second height difference is h2.

[0049] For example, please continue to see Figure 2 In some embodiments, the wafer probe test calibration device further includes a horizontal slide rail (not shown), the extension direction of the two slide rails is perpendicular to the direction toward the surface of the wafer 40, and the first sensor 10 and the second sensor 20 can move horizontally along the slide rails to ensure that the first height difference h1 remains unchanged during the movement. Of course, other moving devices can also be used to drive the first sensor 10 and the second sensor 20 to move horizontally while ensuring that the spacing remains unchanged.

[0050] In some embodiments, the wafer probe test and calibration device may further include a vertical slide rail extending in a direction parallel to the moving direction of the wafer 40, and cooperate with different types of wafer test machines to control the first sensor 10 and the second sensor 20 to move a corresponding compensation distance, so that the position positioning standards are consistent during subsequent calibration, thereby improving the flexibility and adaptability of the wafer probe test and calibration device. In actual use, other components may be added to the wafer probe test and calibration device, as long as the rationality of the structure is ensured, which is not limited in this embodiment.

[0051] For example, please continue to see Figure 2 , use the wafer probe to test the first sensor 10 in the calibration device to obtain the distance between the transmitting end of the first sensor 10 and the top surface of the wafer 40 , and the second height difference h2 is used to represent the distance, wherein the second height difference h2 should not be less than the length value of the probe 31 .

[0052] Step S208: obtaining a third height difference between the bottom surface of the probe card 30 and the second reference measurement point.

[0053] For example, in this embodiment, the third height difference is h3.

[0054] For example, please continue to see Figure 2 , the second sensor 20 in the wafer probe test calibration device is used to obtain the distance between the transmitting end of the second sensor 20 and the bottom surface of the probe card 30, and the third height difference h3 is used to represent the distance. During the measurement process, the first sensor 10, the second sensor 20, and the carrier 50 need to remain stationary to ensure the consistency of the first height difference, the second height difference, and the third height difference before and after the measurement.

[0055] Step S210: Calculate the measurement distance value between the bottom surface of the probe 31 and the contact point according to the first height difference, the second height difference, the third height difference and the length value.

[0056] For example, please continue to see Figure 2 In this embodiment, the measurement spacing value is H. The measurement spacing value H between the bottom surface of the probe 31 and the top surface of the wafer 40 is calculated according to the following formula:

[0057] H = Hbase–Hpin;

[0058] Hbase=h2+h3-h1;

[0059] Among them, Hbase is the spacing value between the bottom surface of the probe card 30 and the top surface of the wafer 40, Hpin is the length value of the probe 31, h1 is the first height difference, h2 is the second height difference, h3 is the third height difference, and the measured spacing value H represents the spacing between the bottom surface of the probe 31 and the contact point of the wafer 40, that is, the OD value that needs to be compensated for the initial OD value. Since the first height difference, the second height difference and the third height difference include the deviation value introduced by the machine error between the first sensor 10, the second sensor 20 and / or the probe card 30 of different devices, and the film thickness corresponding to the device layer on the wafer 40, the measured spacing value H calculated according to the formula can eliminate the influence of the machine error introduced during the installation of the WAT on the basis of omitting the measurement of the film thickness.

[0060] Step S212: calibrating the initial OD value according to the measured spacing value.

[0061] For example, the measured spacing value H determines the amount of sinking or protrusion of the carrier 50 carrying the wafer 40, and the calibrated target displacement value is obtained by calculating the sum of the initial OD value and the measured spacing value H. At this time, the wafer tester controls the wafer 40 to move a corresponding distance toward the probe 31 according to the feedback target displacement value, so as to accurately set the OD value in the WAT test. The calibrated target displacement value can effectively avoid problems such as bending and deformation of the probe 31 or damage to the contact point of the surface to be tested of the wafer 40 caused by the probe 31 being inserted into the wafer 40 in a false or excessive manner, thereby ensuring the reliability of the WAT test, reducing its defect rate and false detection rate, and extending the service life of the probe 31.

[0062] See also Figure 3 In some embodiments, the spacing values ​​between multiple different contact points on the top surface of the wafer 40 and the bottom surface of the probe 31 are obtained; the average value of the spacing values ​​between the multiple different contact points and the bottom surface of the probe 31 is calculated; and the measured spacing value H is determined based on the average value.

[0063] For example, multiple contact points on the top surface of the wafer 40 are selected, and steps S206 to S212 are repeated, and the spacing value between the above contact points and the bottom surface of the probe 31 is equivalent to the spacing value H measured in step S210. Calculating the average value of the spacing value H of multiple different contact points can effectively eliminate the deviation caused by the measurement of a single contact point, offset the influence of external factors such as vibration of the wafer test calibration equipment during the calibration process, ensure that the calibration process is more stable and reliable, and improve the accuracy of the wafer probe calibration method.

[0064] Please continue reading Figure 3In this embodiment, five contact points on the surface of a wafer 40 to be tested are selected as shown in the figure, and measurements are performed and the average value is taken, that is, the OD average value = (OD1+OD2+OD3+OD4+OD5) / 5, and the average value of the spacing value between the surface of the wafer 40 to be tested and the bottom surface of the probe 31 is obtained, and the measurement spacing value H is determined according to the average value.

[0065] In some embodiments, after obtaining the target displacement value, it also includes inputting the target displacement value and starting the wafer testing machine, operating the carrier 50 and the wafer 40 to move the probe 31 with the preset target displacement value. The target displacement value obtained after calibration can ensure good contact between the probe 31 and the wafer 40, which helps to achieve subsequent electrical testing.

[0066] In some embodiments, the wafer probe test calibration method further includes: periodically calibrating an initial OD value of the wafer test machine according to a preset period value.

[0067] For example, the cycle value can be set according to specific needs, including but not limited to calibrating the first piece, each piece, and every few pieces of each batch of the same product; or every few batches; or every month; or the first batch within a certain time period. The calibration frequency can be freely set. Through computer program setting, the wafer probe test calibration equipment can flexibly set the calibration frequency as needed, and automatically calibrate according to the wafer probe test calibration method described in any of the above embodiments. By observing the fluctuation range of the target displacement value after calibration of the same product, monitoring and tracking the changes in the hardware spacing or the film thickness of the wafer device layer in the wafer test machine, provide a basis for replacement and preparation of spare parts. Adding automation and monitoring mechanisms can ensure the continuity of the accuracy of the wafer probe test calibration method.

[0068] See also Figure 2 The present application provides a wafer probe test and calibration device, comprising: a first sensor 10, arranged above a wafer 40, for measuring a first height difference h1 between a first reference measurement point above the wafer 40 and a second reference measurement point below the wafer 40, and a second height difference h2 between the first reference measurement point and the top surface of the wafer 40; a second sensor 20, arranged below the wafer 40, for measuring a third height difference h3 between the bottom surface of a probe card 30 and the second reference measurement point; a controller, connected to the first sensor 10 and the second sensor 20, configured to: obtain an initial OD value of a wafer test machine when a probe 31 on the probe card 30 and a contact point on the wafer 40 are in a zero pressure contact state, and a length value of the probe 31;

[0069] Obtain the first height difference h1, the second height difference h3, and the third height difference h3 between the bottom surface of the probe card 30 and the second reference measurement point; calculate the measured spacing value between the bottom surface of the probe 31 and the contact point according to the first height difference h1, the second height difference h2, the third height difference h3 and the length value; calibrate the initial OD value according to the measured spacing value.

[0070] For example, the first sensor 10 and the second sensor 20 are both high-precision distance measuring sensors, including but not limited to optical distance measuring devices such as laser distance measuring sensors or infrared distance measuring sensors. The controller is electrically connected to the sensor and is used to drive the first sensor 10 and the second sensor 20 to move.

[0071] The present application also provides a wafer probe test and calibration device, including a memory and a processor, wherein the memory stores a computer program, and the processor implements the wafer probe calibration method in any of the above embodiments when executing the computer program.

[0072] The present application also provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the wafer probe calibration method in any of the above embodiments is implemented.

[0073] The present application also provides a computer program product, including a computer program, which implements the wafer probe calibration method in any of the above embodiments when the computer program is executed by a processor.

[0074] The present application provides a wafer probe test calibration device, a computer-readable storage medium and a computer program product based on a wafer probe test calibration method and apparatus. The computer program product includes a computer code for executing the wafer probe test calibration method provided by the present application; the computer-readable storage medium stores the computer program product; and finally, the computer program product is executed by assembling the wafer probe test calibration device equipped with the computer-readable storage medium.

[0075] In the above embodiments, the unexpected technical effects that can be produced by the present application include:

[0076] Through the first sensor and the second sensor, the first height difference, the second height difference and the third height difference are obtained; according to the set program, the measurement spacing value between the bottom surface of the probe and the contact point is calculated according to the first height difference, the second height difference, the third height difference and the length value of the probe. The spacing value from the contact point of the test wafer to the bottom surface of the probe is calculated. Compared with the traditional calibration method, the calculation process of the film thickness of the wafer device is omitted, and the purpose of eliminating the machine error caused by the installation of the first sensor, the second sensor and / or the probe card of different devices is achieved. The method can be differentiated for different products, and can provide a more specific target displacement value for different products, rather than a fixed value within a certain range, to ensure that all products are in a good measurement state, with good versatility. In addition, the wafer probe test calibration method and device in this application also include functions such as automatic calibration and monitoring of the target displacement value, which can automatically calibrate the initial OD value in a timely or quantitative manner, ensure that the probe is in proper contact with the contact point on the surface to be tested of the wafer, avoid the occurrence of situations such as collision or poor contact, and do not require manual operation and offline adjustment, reducing the workload of the calibration staff. By observing the fluctuations in the target displacement value, the changes in the hardware spacing inside the wafer testing machine are monitored, providing a basis for replacement and preparation of spare parts.

[0077] The wafer probe test device, equipment, computer-readable storage medium and computer program product together constitute a complete wafer probe test calibration system, which provides important support for implementing the wafer probe test calibration method of the present application.

[0078] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features of the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0079] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A wafer probe test calibration method, characterized in that: include: Obtaining an initial OD value of a wafer testing machine when a probe on a probe card and a contact point on a wafer are in a zero pressure contact state, and a length value of the probe; Acquire a first height difference between a first reference measurement point above the wafer and a second reference measurement point below the wafer; Acquire a second height difference between the first reference measurement point and the top surface of the wafer; The second height difference is not less than the length value of the probe; acquiring a third height difference between the bottom surface of the probe card and the second reference measurement point; The measured distance between the bottom surface of the probe and the contact point is calculated according to the first height difference, the second height difference, the third height difference and the length of the probe; the calculation formula is: H = Hbase–Hpin; Hbase=h2+h3-h1; Hbase is the distance between the bottom surface of the probe card and the top surface of the wafer, Hpin is the length of the probe, h1 is the first height difference, h2 is the second height difference, and h3 is the third height difference; The initial OD value is calibrated according to the measured spacing value.

2. The wafer probe test calibration method according to claim 1, characterized in that: The initial OD value calibration includes: The wafer carrier is controlled to move toward the probe by a target displacement value, wherein the target displacement value is associated with the measured spacing value.

3. The wafer probe test calibration method according to any one of claims 1 to 2, characterized in that: Also includes: Obtaining distance values ​​between a plurality of different contact points on the top surface of the wafer and the bottom surface of the probe; Calculating an average value of the distance values ​​between the multiple different contact points and the bottom surface of the probe; The measurement interval value is determined according to the average value.

4. The wafer probe test calibration method according to any one of claims 1 to 2, characterized in that: Also includes: The amount of sinking or protruding of the wafer carrier is determined according to the measured spacing value.

5. The wafer probe test calibration method according to any one of claims 1 to 2, characterized in that: Also includes: According to the preset period value, the initial OD value of the wafer testing machine is periodically calibrated.

6. A wafer probe test calibration device, characterized in that: include: A first sensor is disposed above the wafer and is used to measure a first height difference h1 between a first reference measurement point above the wafer and a second reference measurement point below the wafer, and a second height difference h2 between the first reference measurement point and the top surface of the wafer; A second sensor, disposed below the wafer, for measuring a third height difference h3 between the bottom surface of the probe card and the second reference measurement point; A controller is connected to the first sensor and the second sensor, and is configured to: Obtaining an initial OD value of a wafer testing machine when a probe on a probe card and a contact point on a wafer are in a zero pressure contact state, and a length value Hpin of the probe; Obtaining the first height difference h1 and the second height difference h2; Acquire a third height difference h3 between the bottom surface of the probe card and the second reference measurement point; The measurement distance H between the bottom surface of the probe and the contact point is calculated according to the first height difference h1, the second height difference h2, the third height difference h3 and the length value Hpin of the probe; the calculation formula is: H = Hbase–Hpin; Hbase=h2+h3-h1; Hbase is the distance between the bottom surface of the probe card and the top surface of the wafer; The initial OD value is calibrated according to the measured spacing value.

7. A wafer probe test calibration device, characterized in that: The method comprises a memory and a processor, wherein the memory stores a computer program, and wherein the processor implements the steps of the method according to any one of claims 1 to 5 when executing the computer program.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 5 are implemented.

9. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 5 are implemented.

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