Wafer pressing device and test equipment

Abstract

The utility model provides a wafer pressing device and test equipment, which are applied to the technical field of wafer testing, and is characterized in that a wafer is mounted on a test board disc, a moving mechanism drives a warping part of the wafer to move below a soft contact compression column, and a gas control system controls on-off of gas to control a moving part of a cylinder system to move up and down; the moving part of the air cylinder system drives the soft contact pressing column to press the warping position of the wafer, the warping degree of the wafer can be reduced, the thinning effect is achieved, adsorption can be easily achieved, meanwhile, the corresponding parameter testing effect can be improved, the testing distortion degree is reduced, and the feedback testing performance is improved.

Description

Technical Field

[0001] The present application relates to the field of wafer testing technology, and in particular to a wafer pressing device and testing equipment. Background Art

[0002] During SIC (silicon carbide) testing, thinner wafers, such as thin wafers, can improve related test performance such as VF (forward voltage), BV (breakdown voltage), and VTH (threshold voltage). However, thinning the wafers also leads to greater warpage, which in turn results in poorer test performance.

[0003] Based on this, a new technical solution is needed. Utility Model Content

[0004] In view of this, embodiments of the present disclosure provide a wafer pressing device and a testing apparatus.

[0005] The embodiments of this specification provide the following technical solutions:

[0006] According to an embodiment of the present specification, a wafer pressing device is provided, which includes a bridge, a gas control system, a cylinder system, a soft contact pressure column, a gas pipeline, a test table and a moving mechanism;

[0007] The bridge is mounted on the machine platform, and the gas control system and the fixed part of the cylinder system are mounted on the bridge; the input end of the gas control system is filled with gas through a gas pipeline, and the output end of the gas control system is connected to the fixed part of the cylinder system; the movable part of the cylinder system is connected to a soft contact pressure column, so that the gas control system controls the on and off of the gas to control the up and down movement of the movable part of the cylinder system;

[0008] The test table is installed on the machine through a moving mechanism, and the test table is located under the bridge. The test table is used to install wafers so that the moving mechanism drives the warped part of the wafer to move below the soft contact pressure column, and the moving part of the cylinder system drives the soft contact pressure column to press toward the warped part of the wafer.

[0009] Preferably, the moving part of the cylinder system is fixedly connected to a link fastener, and the link fastener is detachably connected to the soft contact pressure column through an embedded pin.

[0010] Preferably, the soft contact pressure column is a soft rubber contact pressure column.

[0011] Preferably, the wafer pressing device further comprises a wafer scanning device; the wafer scanning device is mounted on the bridge; the wafer scanning device is used to assist in performing horizontal measurement on the wafer on the test table to determine the warping of the wafer.

[0012] Preferably, the gas control system is a solenoid valve control system, and the solenoid valve control system controls the soft contact pressure column to move up and down through a cylinder system.

[0013] Preferably, the soft contact pressure column is provided with a needle mark or a reflective image; the wafer pressing device also includes a probe camera device, which is located under the test table; the probe camera device is used to assist in measuring the needle mark or reflective image to determine the downward pressing height of the soft contact pressure column.

[0014] Preferably, the moving mechanism includes a vertical moving and rotating system and a horizontal and vertical plane moving system. The horizontal and vertical plane moving system is movably installed on the machine platform, the vertical moving and rotating system is installed on the horizontal and vertical plane moving system, and the test table is installed on the vertical moving and rotating system. The rotation direction of the vertical moving and rotating system is vertical rotation.

[0015] Preferably, the bridge is movably mounted on the machine platform, and the movement direction of the bridge along the plane where the mounting direction is located is parallel to the test platform.

[0016] Preferably, the test table is a suction cup, so that the test table can mount the wafer by adsorption.

[0017] A testing device provided according to an embodiment of the present specification includes a machine platform and any of the wafer pressing devices described above.

[0018] Compared with the prior art, the at least one technical solution adopted in the embodiments of this specification can achieve the following beneficial effects:

[0019] The wafer pressing device of the present application installs the wafer on the test table, and the moving mechanism drives the warped part of the wafer to move to the bottom of the soft contact pressure column. The gas control system controls the on and off of the gas to control the up and down movement of the moving part of the cylinder system; the moving part of the cylinder system drives the soft contact pressure column to press toward the warped part of the wafer, which can reduce the warping of the wafer and achieve a thinning effect, making it easier to adsorb. At the same time, it can also improve the corresponding parameter test effect, reduce the test distortion, and improve the feedback test performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments. 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 any creative work.

[0021] Figure 1 This is a comparison chart of ultra-thin slices and normal slices in related technology;

[0022] Figure 2 This is a comparison chart of the VF@20A JBS platform for ultra-thin and normal slice tests in related technologies;

[0023] Figure 3 This is a schematic diagram of an ultra-thin wafer test reverse bias VTH MOS platform in the related art;

[0024] Figure 4 It is a schematic diagram of the overall structure of this application;

[0025] Figure 5 It is a partial structural diagram in this application;

[0026] Figure 6 This is the flowchart before and after the update in this application.

[0027] Figure numerals: 1. Low-magnification wafer scanning camera; 2. High-magnification wafer scanning camera; 3. Solenoid valve control system; 4. Cylinder system; 5. Link fastener; 6. Embedded pin; 7. Retractable soft rubber contact pressure column; 8. Test table; 9. Probe low-magnification camera; 10. Probe high-magnification camera; 11. Gas pipeline; 12. Horizontal control box; 13. Horizontal scanning bridge; 14. Vertical movement and rotation system; 15. Horizontal and vertical plane movement system. DETAILED DESCRIPTION

[0028] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0029] The following describes the embodiments of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the features in the following embodiments and embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of this application.

[0030] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on this application, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspect described herein can be used to implement an apparatus and / or practice a method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this apparatus and / or practice this method.

[0031] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application. The illustrations only show components related to the present application and are not drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complicated.

[0032] Additionally, in the following description, specific details are provided to provide a thorough understanding of the examples, however, one skilled in the art will appreciate that the examples can be practiced without these specific details.

[0033] In view of this, the applicant conducted in-depth research and improvement exploration on the wafer and the pressing device, and found that: since other problems will arise after the wafer is thinned, such as large warping, fragility, difficulty in adsorption, etc., it will also affect the corresponding parameter test results, test distortion, inability to feedback test performance, and failure to achieve the thinning effect.

[0034] The relevant data are as follows: 150um & 110um test comparison: Figure 1 and Figure 2 shown. Figure 1 Medium: Ultra-thin wafer test: SiC test ultra-thin wafer specification (specifications), Thinner thickness (thin layer thickness) 75 ~ 110um, 1 ~ 2mm warpage on a horizontal table, back metal Ti (titanium) / Ni (nickel) / Ag (silver), test voltage 650V / 1200V / 1700V (<3000V), test current 5A ~ 100A, ultra-thin wafer test VF range (forward voltage range) is large, the difference from the actual value is about 0.15V, the deviation is about 12%, Figure 1 Value represents value, and Color represents color. Figure 2In the VF@20AJBS platform for ultra-thin wafer testing, the junction barrier Schottky diode forward voltage test item at a test current of 20A is compared with the BSL (110um baseline, 110um test related data) of 175um and 150um. In the comparison of CP (Chip Probing, wafer probe test) and FT (Final Test, final test) results, the ultra-thin wafer CP and FT differences are greater, exceeding 10%. The CPBox chart and FT chart of normal wafer testing are shown in the figure below. Figure 2 As shown in the left box, the CP Box chart & FT chart of the ultra-thin sheet is as follows Figure 2 As shown in the box on the right. Box chart means box plot, and chart means chart.

[0035] The test results of the automatic wafer transfer and slight pressure test: the ultra-thin wafer test VF JBS platform is manually pressed, and the SiC ultra-thin wafer test VF@20A is automatically placed and pressed, and the test is normal.

[0036] like Figure 3 As shown, the ultra-thin wafer test reverse bias VTH MOS platform, that is, the reverse bias threshold voltage test item of the metal-oxide semiconductor field-effect transistor: the VTH high area is different in the first manual and automatic tests. After manually pressing the wafer edge in the second manual test, the abnormal heap is significantly improved.

[0037] Chinese invention patent document CN110610877A discloses a device and method for reducing wafer warpage, which uses a heating unit and a temperature control unit to adjust the temperature of the wafer to soften the wafer, and uses a hollow pressure ring to press the wafer to ultimately achieve the purpose of reducing the wafer warpage.

[0038] Based on this, the technical solutions provided by the various embodiments of the present application are described below in conjunction with the accompanying drawings.

[0039] The embodiment of this specification provides a new type of bridge (bridge frame) intelligent wafer pressing system device to improve the large warpage wafer adsorption in the chuck (suction cup), such as Figure 4 and Figure 5 As shown, it includes a bridge, a gas control system, a cylinder system 4, a soft contact pressure column, a gas pipeline 11, a test table 8 and a moving mechanism. The bridge is, for example, a horizontal scanning bridge 13 on the machine platform.

[0040] The bridge is installed on the machine platform, and the fixed parts of the gas control system and the cylinder system 4 are installed on the bridge; the input end of the gas control system is filled with gas through the gas pipeline 11, and the output end of the gas control system is connected to the fixed part of the cylinder system 4; the moving part of the cylinder system 4 is connected to the soft contact pressure column, so that the gas control system controls the on and off of the gas to control the up and down movement of the moving part of the cylinder system 4.

[0041] The test platen 8 is mounted on the machine platform via a movable mechanism, located beneath the bridge. Wafers are mounted on the test platen 8 so that the movable mechanism moves the warped area of the wafer below the soft contact pressure pins. The movable portion of the cylinder system 4 then drives the soft contact pressure pins toward the warped area of the wafer. The fixed portion of the gas control system and cylinder system 4 is mounted on the bridge's horizontal control box 12, also known as the bridge alignment control box. This box is rectangular. The test platen 8 is located beneath the bridge's horizontal control box 12. The movable portion of the cylinder system 4 moves vertically perpendicular to the surface of the test platen 8.

[0042] In one embodiment, Figure 5 As shown, the movable portion of the cylinder system 4 is fixedly connected to the link fastener 5, which is detachably connected to the soft contact pressure column via an embedded latch 6. The movable portion of the cylinder system 4 is connected to the soft contact pressure column via the link fastener 5, which can maintain the shape of the soft contact pressure column as much as possible.

[0043] In one embodiment, Figure 5 As shown, the soft contact pressure column is a soft rubber contact pressure column, which serves as a retractable soft rubber contact pressure column 7. The contact surface of the retractable soft rubber contact pressure column can contact the wafer without causing any appearance problems. The soft rubber material is used, and it is cleanable, replaceable, and easy to operate.

[0044] In one embodiment, if Figure 4 and Figure 5 As shown, the wafer pressing device also includes a wafer scanning device; the wafer scanning device is mounted on a bridge, such as a level control box 12. The wafer scanning device is used to assist in leveling the wafer on the test table 8 to determine the location of wafer warpage. Two wafer scanning devices are provided, and the two wafer scanning devices include a high-magnification wafer scanning camera 2 (wafer high camera) and a low-magnification wafer scanning camera 1 (wafer lower camera), respectively, for precise positioning at high and low magnification, and calculating level, height difference, etc.

[0045] In one embodiment, if Figure 4 and Figure 5 As shown, the gas control system is a solenoid valve control system 3, which controls the soft contact pressure column to move up and down through the cylinder system 4.

[0046] In one embodiment, if Figure 4 and Figure 5 As shown, the soft contact pressure pin is provided with a needle mark or reflective image. The wafer pressing device also includes a probe camera device, located below the test table plate 8. The probe camera device is used to assist in measuring the needle mark or reflective image to determine the downward pressing height of the soft contact pressure pin. Two probe cameras are provided, and the two probe cameras include a probe high-magnification camera 10 and a probe low-magnification camera 9. These cameras are used to locate the probe card height camera on the machine and record the probe card tip position, height, level, etc.

[0047] In one embodiment, if Figure 4 and Figure 5 As shown, the moving mechanism includes a vertical movement and rotation system 14 and a transverse and longitudinal plane movement system 15. The transverse and longitudinal plane movement system 15 is movably mounted on the machine platform, and the vertical movement and rotation system 14 is mounted on the transverse and longitudinal plane movement system 15. The test table 8 is mounted on the vertical movement and rotation system 14, and the vertical movement and rotation system 14 rotates around the vertical direction. The moving mechanism enables the test table 8 to move in three directions and rotate in one direction. The vertical movement and rotation system 14 is a Chuck Top Zθ Stage, representing the upper and lower system and rotation system of the test table 8 system. The transverse and longitudinal plane movement system 15 is an XY Stage, representing the XY direction movement system; Z represents the vertical and upper and lower directions; X represents the horizontal direction; and Y represents the vertical direction.

[0048] In one embodiment, if Figure 4 and Figure 5 As shown, the bridge is movably mounted on the machine platform, and the moving direction of the bridge along the plane where the mounting direction is located is parallel to the test table 8, so as to serve as a horizontal scanning bridge 13 (Alignment Bridge), that is, a probe station moving bridge, which can be used as one of the machine platform structures.

[0049] In one embodiment, if Figure 4 and Figure 5 As shown, the test table 8 is a suction cup, so that the test table 8 can mount the wafer by adsorption.

[0050] like Figure 4 and Figure 5As shown, the overall structure includes: Bridge overall carrier + solenoid valve control system 3 + cylinder link module + detachable soft rubber module system + wafer high & low camera (wafer high / low camera device) + contact wafer part (contact wafer part) + probe low / high camera (probe low / high camera device) + Chuck test up / down system (suction cup test up / down system) + chuck & wafer (test table 8 and wafer).

[0051] This application can be customized to develop related software, and the process can be changed after the update as follows, such as Figure 6 As shown in the figure, Wafer loading means wafer loading, Probe alignment means probe card level measurement, Bridge Wafer Alignment means wafer level measurement and positioning, and test means wafer testing; Contact part alignment means automatic adjustment module level calculation and adjustment.

[0052] After the wafer is horizontally measured, the wafer horizontal data will be obtained, and then the solenoid valve control system 3 will be used to open the pressing device to prepare for pressing: 1. The solenoid valve control switch will protrude the pressing device and move it to the specified data; 2. Combined with the pressing module MARK (marker) coordinates, the machine automatically calculates the data after the probe camera confirms the height; 3. Combined with the wafer data & pressing device data, precise pressing is performed; 4. After pressing is completed, horizontal positioning measurement is performed again.

[0053] This application realizes automatic and precise up and down control through the linkage of the solenoid valve and the cylinder, which lowers when in use and rises when not in use; the cylinder system 4 and the link fastener 5 are linked through the fixing parts, the cylinder controls the inner cavity of the embedded pin 6 to the retractable soft rubber contact pressure column 7 to lock the contact device, which is fixed by screws on the side to achieve detachable replacement and maintenance.

[0054] A new needle alignment mark or reflective image is added to the top of the retractable soft rubber contact pressure column, enabling precise height positioning via the E1 & E2 cameras. The E1 & E2 cameras represent the probe's high and low magnification cameras. After the E1 & E2 cameras align the needle height, background calculations are performed to determine the pressing surface height. This, combined with the machine's chuck drive, allows for precise vertical positioning, similar to the positioning of probe cards and wafers. The pressing mode uses background data to obtain precise data. If the scanned document level is poor, the entire document can be pressed. If the data for a single point is poor, a single point can be pressed. This can be selected via background mode.

[0055] This application can intelligently switch between fixed-point pressing or precise height positioning pressing and contact. It can be controlled by recipe parameters, that is, the control process is controlled by program. The mode can be selected between full-area mode and fixed-area mode.

[0056] This application can be extended to 8-inch and 12-inch machines, and the same type of equipment can be rolled out. It is aimed at improving the test value of ultra-thin warped large wafer carrying adsorption and optimizing the adsorption of ultra-thin large warped wafers; it is retractable and does not affect the normal use of alignment; it is linked to the test system, and the contact force is precisely controlled through the chuck linkage and OD (OVER DIRVER, test needle pressure) setting; it can achieve precise positioning, and can be calibrated after the replacement process, and can be monitored in real time to reduce the fragmentation rate; it can be set through software linkage and intelligent settings, and can accurately position based on a fixed area + alignment data; it uses a new type of rubber material, and with the help of the TEL arm nozzle material, the material has the characteristics of stability, toughness, and no damage to the wafer; it can be replaced, cleaned, and maintained regularly. Arm means machine arm, and TEL is the manufacturer of the probe station.

[0057] This application integrates the Bridge layout, adding a signal control board, pneumatic device, and lift mechanism. It also features a contact wafer mechanism and pneumatic device. This application optimizes wafer bonding, improves high-warpage wafer test values, and enhances product performance.

[0058] The present specification also discloses a test device, such as Figure 4 and Figure 5 As shown, it includes a machine platform and a wafer pressing device according to any one of the above embodiments.

[0059] In this specification, the same or similar parts between the various embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the embodiments described later, the description is relatively simple, and the relevant parts can be referred to the partial description of the previous embodiments.

[0060] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A wafer pressing device, characterized in that: Including bridge, gas control system, cylinder system, soft contact pressure column, gas pipeline, test table and moving mechanism; The bridge is mounted on the machine platform, and the gas control system and the fixed part of the cylinder system are mounted on the bridge; the input end of the gas control system is filled with gas through a gas pipeline, and the output end of the gas control system is connected to the fixed part of the cylinder system; the movable part of the cylinder system is connected to a soft contact pressure column, so that the gas control system controls the on and off of the gas to control the up and down movement of the movable part of the cylinder system; The test table is installed on the machine through a moving mechanism, and the test table is located under the bridge. The test table is used to install wafers so that the moving mechanism drives the warped part of the wafer to move below the soft contact pressure column, and the moving part of the cylinder system drives the soft contact pressure column to press toward the warped part of the wafer.

2. The wafer pressing device according to claim 1, wherein: The moving part of the cylinder system is fixedly connected to the link fastener, and the link fastener is detachably connected to the soft contact pressure column through an embedded pin.

3. The wafer pressing device according to claim 1, wherein: The soft contact pressure column is a soft rubber contact pressure column.

4. The wafer pressing device according to claim 1, wherein: The wafer pressing device also includes a wafer scanning device; the wafer scanning device is installed on the bridge; the wafer scanning device is used to assist in leveling the wafer on the test table to determine the warping of the wafer.

5. The wafer pressing device according to claim 1, wherein: The gas control system is a solenoid valve control system, which controls the soft contact pressure column to move up and down through a cylinder system.

6. The wafer pressing device according to claim 1, wherein: The soft contact pressure column is provided with a needle mark or a reflective image; the wafer pressing device also includes a probe camera device, which is located under the test table; the probe camera device is used to assist in measuring the needle mark or reflective image to determine the downward pressing height of the soft contact pressure column.

7. The wafer pressing device according to claim 1, wherein: The moving mechanism includes a vertical moving and rotating system and a horizontal and vertical plane moving system. The horizontal and vertical plane moving system is movably installed on the machine platform, the vertical moving and rotating system is installed on the horizontal and vertical plane moving system, and the test table is installed on the vertical moving and rotating system. The rotation direction of the vertical moving and rotating system is vertical rotation.

8. The wafer pressing device according to claim 1, wherein: The bridge is movably mounted on the machine platform, and the movement direction of the bridge along the plane where the mounting direction is located is parallel to the test platform.

9. The wafer pressing device according to claim 1, wherein: The test table is a suction cup, so that the test table can mount the wafer by adsorption.

10. A testing device, characterized in that: It comprises a machine and the wafer pressing device described in any one of claims 1-9.

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