Surface processing methods for irregularly shaped large-size zinc-cadmium telluride substrates

Abstract

A surface processing method for an irregularly shaped, large-sized cadmium zinc telluride (CZD) substrate includes the following steps: S1, cleaning the irregularly shaped, large-sized CZD wafer with its A and B sides clearly defined; S2, using a sapphire wafer as the substrate; S3, applying wax to bond the CZD wafer to the sapphire wafer and fixing them together; S4, thinning one side using a thinning machine, including the sub-step: S41, placing the bonded and fixed CZD wafer and sapphire wafer onto the worktable of the thinning machine. On the upper part, the angle between the end face of the grinding wheel and the worktable is 0.0057°. S42, multi-step grinding wheel processing; S5, single-polish CMP polishing; S6, wax removal: remove the cadmium zinc telluride wafer and sapphire wafer from the single polishing machine, and clean the white wax between the A side of the cadmium zinc telluride wafer and the sapphire wafer; S7, repeat steps S1 to S6 to perform surface processing on the A side of the cadmium zinc telluride wafer, and finally obtain a cadmium zinc telluride wafer with TTV≤2μm and Ra≤1nm.

Description

Technical Field

[0001] This disclosure relates to the field of cadmium zinc telluride materials, and more specifically to a surface processing method for irregularly shaped large-sized cadmium zinc telluride substrates. Background Technology

[0002] The zinc-cadmium telluride substrate is made of zinc-cadmium telluride (Cd). 1-x Zn x The substrate is made of Te (x = 0.04, CZT) crystal. Its excellent photoelectric properties allow it to be used at room temperature, and its applications are mainly concentrated in infrared detectors and high-energy detectors. As a substrate material, its surface quality requirements are very high, generally requiring a surface roughness of less than 1 nm, a surface flatness (TTV) of less than 3 μm, and Ra ≤ 1 nm.

[0003] Cadmium zinc telluride (CZZ) materials are brittle and have low hardness. Furthermore, CZZ single crystal materials exhibit significant randomness in grain growth control, resulting in mostly irregular wafers. Therefore, surface polishing is necessary during substrate fabrication. To achieve high-quality substrates, multiple polishing processes are typically performed.

[0004] In traditional processing, crystals are sliced, then the wafers are ground, followed by a first polishing to remove the damaged layer from the ground surface, and a second polishing to smooth the surface roughness. Double-sided polishing cannot solve the polishing problem of irregular wafers. In single-sided polishing, due to the rotation of the polishing disc and the polishing head, the linear velocity of the wafer surface gradually decreases from the edge to the center, and the material removal rate is similarly reduced. Under these conditions, the wafer surface forms a convex state with lower edges and a higher center, resulting in the common edge collapse condition. Furthermore, during prolonged polishing, the edges are prone to chipping.

[0005] Current processing technologies offer solutions for polishing edge chipping, poor TTV (Total Transformation Value), and edge collapse during the polishing of large-sized irregular zinc-cadmium telluride substrates, but there is no effective processing solution that can simultaneously address all three issues.

[0006] With the development of cadmium zinc telluride (CZN) crystal growth technology, the demand for CZN substrate arrays is increasing. However, the surface protrusion and edge collapse caused by traditional polishing processes severely affect the utilization rate of the substrate, leading to increased costs. Therefore, it is necessary to improve the processing technology for irregular, large-sized substrates. Summary of the Invention

[0007] In view of the problems existing in the background art, one object of this disclosure is to provide a surface processing method for irregular large-size cadmium zinc telluride substrates, which can simultaneously solve the problems of edge chipping, TTV and edge collapse.

[0008] Therefore, a surface processing method for an irregularly shaped, large-sized cadmium zinc telluride (CZN) substrate includes the following steps: S1, wafer cleaning: cleaning the irregularly shaped, large-sized CZN wafer with clearly defined A and B sides; S2, providing a substrate: using a sapphire wafer as the substrate, the size of the sapphire wafer being such that its surface contour covers the CZN wafer, and the surface TTV of the sapphire wafer being ≤1μm; S3, waxing and mounting, including the sub-step: S31, applying white paraffin wax to the surface of the sapphire wafer using a waxing machine. S32, aligning and bonding the A-side of the cadmium zinc telluride (CZD) wafer with the sapphire wafer; S33, applying pressure and cooling to bond and fix the CZD wafer and sapphire wafer together; S4, single-sided thinning using a thinning machine, including the sub-steps: S41, placing the bonded and fixed CZD wafer and sapphire wafer onto the worktable of the thinning machine, with the end face of the grinding wheel tilted at an angle of 0.0057° relative to the worktable, and the projection of the end face of the grinding wheel in the direction opposite to the worktable. The process involves several steps: S42, grinding the B-side of the cadmium zinc telluride (CZD) wafer using a grinding wheel (multi-step grinding process); S5, single-sided CMP polishing, including the following sub-steps: S51, mounting the single-sided thinned CZD wafer and sapphire wafer onto the pressure head; S52, mounting the pressure head onto the single-sided polishing machine, and polishing the wafer through the polishing pad on the polishing disc. Polishing is performed by spraying polishing fluid between the light pad and the pressure head. S53: The surface roughness Ra of the B side of the polished cadmium zinc telluride wafer is <1nm, and the TTV is 0-1μm. S6: Waxing: Remove the cadmium zinc telluride wafer and the sapphire wafer from the single polishing machine, and clean the white wax between the A side of the cadmium zinc telluride wafer and the sapphire wafer. S7: Repeat steps S1 to S6 to perform surface processing on the A side of the cadmium zinc telluride wafer, and finally obtain a cadmium zinc telluride wafer with TTV≤2μm and Ra≤1nm.

[0009] The beneficial effects of this disclosure are as follows: In the surface processing method of irregular large-size cadmium zinc telluride substrate wafers according to this disclosure, in the single-sided thinning of the thinning machine in step S4, the end face of the grinding wheel in sub-step S4 is tilted at an angle of 0.0057° relative to the worktable, and the projection of the end face of the grinding wheel in the direction opposite to the worktable covers the rotation center of the worktable. After the multi-step processing of the grinding wheel in sub-step S42, the B-side of the processed cadmium zinc telluride wafer is concave from the edge to the center point, thus avoiding the convex (collapsed edge) state of low edge and high center in the background art, and thus avoiding edge chipping; based on step S4, the single-polishing machine CMP polishing in step S5 is further performed to achieve a surface roughness Ra < 1nm and TTV of 0-1μm on the B-side; by repeating steps S1 to S6 in step S7, the final cadmium zinc telluride wafer is TTV ≤ 2μm, Ra ≤ 1nm, and has no edge chipping or collapse. In other words, the surface processing method for irregular large-size cadmium zinc telluride substrates disclosed herein can simultaneously solve the problems of edge chipping, TTV (transient current volume), and edge collapse. Attached Figure Description

[0010] Figure 1 This is a schematic flowchart of a surface processing method for irregularly shaped large-size cadmium zinc telluride substrates according to this disclosure.

[0011] Figure 2 This is a diagram illustrating the application of waxed patches.

[0012] Figure 3 This is a schematic diagram of a thinning machine performing single-sided thinning.

[0013] Figure 4 It is the projection of the grinding wheel and the worktable in the vertical direction.

[0014] Figure 5 This is a schematic diagram of CMP polishing with a single-shot polishing machine.

[0015] The reference numerals in the attached figures are explained below.

[0016] 100 tellurium zinc cadmium wafers 22 grinding wheels

[0017] 200 sapphire wafer 221 end face

[0018] 300 White Paraffin 23 Thinning Machine Suction Cup

[0019] 1 waxing machine 3 single polishing machines

[0020] 11 heating platform, 31 pressure head

[0021] 12 pressure plates, 32 polishing discs

[0022] 2 Thinning machine 33 Polishing pad

[0023] 21 Workbench, 34 Single Throwing Machine Suction Cup

[0024] 211 Rotary Center 35 Polishing Fluid Injection Pipe Detailed Implementation

[0025] The accompanying drawings illustrate embodiments of this disclosure, and it will be understood that the disclosed embodiments are merely examples of this disclosure, which can be implemented in various forms. Therefore, the specific details disclosed herein should not be construed as limiting, but are intended only as the basis for the claims and as an illustrative basis to teach those skilled in the art how to implement this disclosure in various ways.

[0026] [Surface processing methods for irregularly shaped large-size cadmium zinc telluride substrates]

[0027] Reference Figures 1 to 5 The surface processing method for irregularly shaped large-size cadmium zinc telluride substrates according to this disclosure includes the following steps:

[0028] S1, chip cleaning: Clean the irregular, large-sized cadmium zinc telluride chips 100 with the A and B sides clearly distinguished.

[0029] S2, Substrate provided: Sapphire wafer 200 is used as substrate, the size of sapphire wafer 200 is such that the surface profile of sapphire wafer 200 covers cadmium zinc telluride wafer 100, and the surface TTV of sapphire wafer 200 is ≤1μm;

[0030] S3, applying waxed patches, including sub-steps:

[0031] S31, apply white paraffin wax 300 to the surface of sapphire wafer 200 on waxing machine 1;

[0032] S32, which aligns the A-side of the cadmium zinc telluride wafer 100 with the sapphire wafer 200.

[0033] S33, pressurized cooling, pressurized cooling causes the cadmium zinc telluride wafer 100 to be bonded and fixed together with the sapphire wafer 200;

[0034] S4, single-sided thinning by a thinning machine, including sub-steps:

[0035] S41, the cadmium zinc telluride wafer 100 and sapphire wafer 200, which are bonded and fixed together, are placed on the worktable 21 of the thinning machine 2. The angle of inclination of the end face 221 of the grinding wheel 22 relative to the worktable 21 is 0.0057°. In the direction opposite to the worktable 21, the projection of the end face 221 of the grinding wheel 22 covers the rotation center 211 of the worktable 21.

[0036] S42, the B-side of the zinc zinc cadmium wafer 100 is ground using a grinding wheel 22. The grinding wheel 22 is used for multi-step processing. The B-side TTV of the processed zinc zinc cadmium wafer 100 is 1-3μm, concave from the edge to the center point, and the surface roughness is ≤10nm.

[0037] S5, single-stage CMP polishing, including sub-steps:

[0038] S51, the single-sided thinned cadmium zinc telluride wafer 100 and sapphire wafer 200 are mounted onto the pressure head 31;

[0039] S52, the pressure head 31 is installed on the single polishing machine 3, and polishing liquid is sprayed between the polishing pad 33 on the polishing disc 32 and the pressure head 31 for polishing;

[0040] S53, the surface roughness Ra of the B side of the polished cadmium zinc telluride wafer 100 is <1nm, and the TTV is 0-1μm;

[0041] S6, Waxing: Remove the cadmium zinc telluride wafer 100 and sapphire wafer 200 from the single polishing machine 3, and clean the white paraffin wax 300 between the A side of the cadmium zinc telluride wafer 100 and the sapphire wafer 200.

[0042] S7. Repeat steps S1 to S6 to perform surface processing on surface A of the cadmium zinc telluride wafer 100, and finally obtain the cadmium zinc telluride wafer 100 with TTV≤2μm and Ra≤1nm.

[0043] In the surface processing method for irregular large-size cadmium zinc telluride substrates according to this disclosure, in the single-sided thinning process of the thinning machine in step S4, the end face 221 of the grinding wheel 22 in sub-step S4 is tilted at an angle of 0.0057° relative to the worktable 21, and the projection of the end face 221 of the grinding wheel 22 in the direction opposite to the worktable 21 covers the rotation center 211 of the worktable 21. After multiple steps of processing by the grinding wheel 22 in sub-step S42, the processed cadmium zinc telluride wafer 100 The B-side is concave from the edge to the center, thus avoiding the convex (collapsed edge) state with a low edge and high center as seen in the prior art, thereby preventing edge chipping. Based on step S4, step S5 further involves single-shot CMP polishing to achieve a surface roughness Ra < 1 nm and a TTV of 0-1 μm for the B-side. By repeating steps S1 to S6 in step S7, the final obtained cadmium zinc telluride wafer 100 has a TTV ≤ 2 μm, Ra ≤ 1 nm, and is free from edge chipping and collapse. In other words, the surface processing method for irregular large-size cadmium zinc telluride substrates disclosed herein can simultaneously solve the problems of edge chipping, TTV, and edge collapse.

[0044] In step S1, for example, cleaning is performed by wiping with alcohol.

[0045] In step S2, for example, the sapphire wafer 200 has a diameter of 5 inches and a thickness of 2 mm.

[0046] In one example, sub-step S31 involves placing the sapphire wafer 200 onto the heating stage 11 of the waxing machine 1. The heating stage 11 is heated to 55-60°C. White paraffin wax 300 is applied to the surface of the sapphire wafer 200. After the white paraffin wax 300 melts, the prepared cadmium zinc telluride wafer 100 is placed onto the sapphire wafer 200. In another example, the alignment in sub-step S32 is achieved by aligning the crosshairs laser-marked on the center of the surface of the sapphire wafer 200 in step S2 with the coordinates drawn on the A and B surfaces using a marker after cleaning in step S1. In one example, the operation in sub-step S33 is as follows: The pressure plate 12 of the waxing machine 1 is activated to squeeze out excess paraffin wax 300 between the sapphire wafer 200 and the cadmium zinc telluride wafer 100. The pressure applied by the pressure plate 12 is 20N, and the pressure application time is 3-5 minutes. After pressure application, the heating stage 11 of the waxing machine 1 cools naturally. Further, after cooling, the sapphire wafer 200 and cadmium zinc telluride wafer 100, which are bonded and fixed together, are removed, and the overall TTV of both is measured to be ≤2μm.

[0047] In one example, in sub-step S41, the bonded and adhered cadmium zinc telluride wafer 100 and sapphire wafer 200 are placed on the thinning machine suction cup 23 of the worktable 21 of the thinning machine 2. The thinning machine suction cup 23 has the same diameter as the sapphire wafer 200, and the thinning machine suction cup 23 adsorbs and fixes the sapphire wafer 200. For example, the grinding wheel 22 is a 4000-mesh silicon carbide grinding wheel. Figure 2 As shown, in one example, in sub-step S41, the projected contour of the end face 221 of the grinding wheel 22 extends beyond the rotation center 211 of the worktable 21 by 1-2 μm. In another example, in sub-step S42, the grinding wheel 22 rotates at 2000 r / min, the worktable 21 rotates at 100 r / min, and the grinding wheel 22 is processed in three steps: first, a machining amount of 20 μm and a machining speed of 0.5 μm / s are used to remove the surface protrusions; second, a machining amount of 50 μm and a machining speed of 0.5 μm / s are used to remove the damaged layer; third, a machining amount of 10 μm and a machining speed of 0.3 μm / s are used to finish the surface roughness.

[0048] In one example, in sub-step S51, the pressure of the pressure head 31 is 45-65 N. For example, in sub-step S52, the polishing pad 33 is a damping cloth, and the polishing solution is prepared by mixing sodium dichloroisocyanurate, sodium bicarbonate, sodium benzenesulfonate, anhydrous sodium sulfate, nano-silica with a particle size of 60-80 nm, and water in a mass ratio of 10:2:1:10:0.08:1000. In one example, in sub-step S52, the rotation speed of the pressure head 31 is 50 r / min, the rotation speed of the polishing disc 32 is 150 r / min, the flow rate of the polishing solution is 300-500 mL / min, the polishing time is 3-5 min, and the removal amount is 3-4 μm.

[0049] In one example, step S6 is as follows: Remove the cadmium zinc telluride wafer 100 and the sapphire wafer 200 from the single-shot polisher 3; melt the white paraffin wax 300 between the cadmium zinc telluride wafer 100 and the sapphire wafer 200 using a heating furnace (not shown); remove the cadmium zinc telluride wafer 100 from the sapphire wafer 200; place the cadmium zinc telluride wafer 100 into a container (not shown) containing a dewaxing agent; and clean the white paraffin wax 300. For example, the dewaxing agent is orange juice.

[0050] [test]

[0051] Example 1

[0052] The surface processing method for irregular large-size cadmium zinc telluride substrates in Example 1 employs the following steps (see also...). Figures 2 to 5 ):

[0053] S1, chip cleaning: Clean the irregularly shaped, large-sized cadmium zinc telluride chip 100 with the A and B sides clearly distinguished. After cleaning, use a marker to draw coordinates on the A and B sides at the midpoint of a cross. The cleaning is done by wiping with alcohol.

[0054] S2, providing a substrate: using a 5-inch diameter, 2mm thick sapphire wafer 200 as the substrate, the size of the sapphire wafer 200 is such that the surface outline of the sapphire wafer 200 covers the cadmium zinc telluride wafer 100, the surface TTV of the sapphire wafer 200 is 1μm, and the center of the surface of the sapphire wafer 200 is marked with cross coordinates by a laser marking machine.

[0055] S3, applying waxed patches, using the following sub-steps:

[0056] S31, place the sapphire wafer 200 onto the heating stage 11 of the waxing machine 1.

[0057] 11. Heat to 55°C and place the white paraffin wax 300 on the surface of the sapphire wafer 200;

[0058] S32, after the white paraffin 300 melts, the prepared cadmium zinc telluride wafer 100 is placed on the sapphire wafer 200, so that the A side of the cadmium zinc telluride wafer 100 is aligned and bonded to the sapphire wafer 200. The alignment is achieved by aligning the cross coordinates laser-marked on the center of the surface of the sapphire wafer 200 in step S2 with the coordinates drawn on the A side and B side with a marker after cleaning in step S1.

[0059] S33, pressurize and cool, start the pressure plate 12 of waxing machine 1 to extrude excess paraffin wax 300 between sapphire wafer 200 and cadmium zinc telluride wafer 100. The pressure of pressure plate 12 is 20N and the pressurization time is 4min. After pressurization, the heating table of waxing machine 1...

[0060] 11. Natural cooling: The cadmium zinc telluride wafer 100 and the sapphire wafer 200 are bonded and fixed together by pressure cooling. After cooling, the bonded and fixed sapphire wafer 200 and cadmium zinc telluride wafer 100 are taken out and the overall TTV of the two is measured to be 2μm.

[0061] S4, single-sided thinning using a thinning machine, employs the following sub-steps:

[0062] S41, the cadmium zinc telluride wafer 100 and sapphire wafer 200, which are bonded and fixed together, are placed on the thinning machine suction cup 23 of the worktable 21 of the thinning machine 2. The thinning machine suction cup 23 has the same diameter as the sapphire wafer 200 and adheres to and fixes the sapphire wafer 200. The end face 221 of the grinding wheel 22 is tilted at an angle of 0.0057° relative to the worktable 21. The grinding wheel 22 is a 4000-grit silicon carbide grinding wheel. In the direction opposite to the worktable 21 (i.e., the vertical direction), the projection of the end face 221 of the grinding wheel 22 covers the rotation center 211 of the worktable 21, and the outline of the projection of the end face 221 of the grinding wheel 22 extends beyond the worktable 21.

[0063] The rotation center 211 is 1.5 μm;

[0064] S42, the B-side of the cadmium zinc telluride wafer 100 is ground using a grinding wheel 22. The grinding wheel 22 rotates at 2000 r / min, and the table 21 rotates at 100 r / min. The grinding wheel 22 is used in three steps: First, the machining depth is 20 μm and the machining speed is 0.5 μm / s to remove the surface protrusions; second, the machining depth is 50 μm and the machining speed is 0.5 μm / s to remove the damaged layer; third, the machining depth is 10 μm and the machining speed is 0.3 μm / s to finish the surface roughness. After processing, the B-side TTV of the cadmium zinc telluride wafer 100 is 1.5 μm, concave from the edge to the center point, and the surface roughness is 10 nm.

[0065] S5, single-stage CMP polishing, uses the following sub-steps:

[0066] S51, the single-sided thinned cadmium zinc telluride wafer 100 and sapphire wafer 200 are mounted onto the single-shot suction cup 34 of the pressure head 31, and the single-shot suction cup 34 adsorbs and fixes the cadmium zinc telluride wafer 100 and sapphire wafer 200.

[0067] S52, the pressure head 31 is installed on the single polishing machine 3. The pressure of the pressure head 31 is 55N. Polishing is performed by spraying polishing liquid through the polishing pad 33 on the polishing disc 32 and between the polishing pad 33 and the pressure head 31. The polishing pad 33 is a damping cloth. The polishing liquid is prepared by mixing sodium dichloroisocyanurate, sodium bicarbonate, sodium benzenesulfonate, anhydrous sodium sulfate, 70nm nano-silica, and water in a mass ratio of 10:2:1:10:0.08:1000. The rotation speed of the pressure head 31 is 50r / min, the rotation speed of the polishing disc 32 is 150r / min, the flow rate of the polishing liquid in the polishing liquid spray pipe 35 is 400mL / min, the polishing time is 4min, and the removal amount is 3.5μm.

[0068] S53, the surface roughness Ra of the B side of the polished cadmium zinc telluride wafer 100 is 0.6 nm, and the TTV is 1.0 μm;

[0069] S6, Waxing: Remove the cadmium zinc telluride wafer 100 and sapphire wafer 200 from the single-shot polishing machine 3. Use a heating furnace to melt the white paraffin wax 300 between the cadmium zinc telluride wafer 100 and the sapphire wafer 200. Remove the cadmium zinc telluride wafer 100 from the sapphire wafer 200. Place the cadmium zinc telluride wafer 100 into a container containing a wax remover. Remove the white paraffin wax 300 between the A side of the cadmium zinc telluride wafer 100 and the sapphire wafer 200. The wax remover is orange juice.

[0070] S7. Repeat steps S1 to S6 to perform surface processing on surface A of the cadmium zinc telluride wafer 100, and finally obtain the cadmium zinc telluride wafer 100 with TTV≤2μm and Ra≤1nm.

[0071] Several exemplary embodiments have been described in detail above, but this document is not intended to limit itself to the explicitly disclosed combinations. Therefore, unless otherwise stated, the various features disclosed herein can be combined to form several other combinations, which are not shown for simplicity.

Claims

1. A surface processing method for irregularly shaped, large-sized cadmium zinc telluride substrates, characterized in that, Including the following steps: S1, chip cleaning: Clean the irregular, large-sized cadmium zinc telluride chip (100) with the A and B sides clearly distinguished; S2, Substrate provided: Sapphire wafer (200) is used as substrate, the size of sapphire wafer (200) is such that the surface profile of sapphire wafer (200) covers cadmium zinc telluride wafer (100), and the surface TTV of sapphire wafer (200) is ≤1μm; S3, applying waxed patches, including sub-steps: S31, apply white paraffin wax (300) to the surface of a sapphire wafer (200) on a waxing machine (1); S32, so that the A side of the cadmium zinc telluride wafer (100) is aligned and bonded to the sapphire wafer (200); S33, pressurized cooling, pressurized cooling causes the cadmium zinc telluride wafer (100) to be bonded and fixed together with the sapphire wafer (200); S4, single-sided thinning by a thinning machine, including sub-steps: S41, the cadmium zinc telluride wafer (100) and sapphire wafer (200) that are bonded and fixed together are placed on the worktable (21) of the thinning machine (2). The angle between the end face (221) of the grinding wheel (22) and the worktable (21) is 0.0057°. In the direction opposite to the worktable (21), the projection of the end face (221) of the grinding wheel (22) covers the rotation center (211) of the worktable (21). S42, use a grinding wheel (22) to grind the B side of the zinc zinc cadmium wafer (100). The grinding wheel (22) is used for multi-step processing. The B side of the processed zinc zinc cadmium wafer (100) has a TTV of 1-3μm, is concave from the edge to the center point, and has a surface roughness of ≤10nm. S5, single-stage CMP polishing, including sub-steps: S51, a single-sided thinned cadmium zinc telluride wafer (100) and a sapphire wafer (200) are mounted onto a pressure head (31); S52, the pressure head (31) is installed on the single polishing machine (3), and polishing liquid is sprayed through the polishing pad (33) on the polishing disc (32) and between the polishing pad (33) and the pressure head (31) for polishing; S53, the surface roughness Ra of the B side of the polished cadmium zinc telluride wafer (100) is <1nm, and the TTV is 0-1μm; S6, Waxing: Remove the cadmium zinc telluride wafer (100) and sapphire wafer (200) from the single polishing machine (3), and clean the white paraffin wax (300) between the A side of the cadmium zinc telluride wafer (100) and the sapphire wafer (200); S7. Repeat steps S1 to S6 to perform surface processing on the A side of the cadmium zinc telluride wafer (100) to finally obtain a cadmium zinc telluride wafer (100) with TTV≤2μm and Ra≤1nm.

2. The surface processing method for irregular large-size cadmium zinc telluride substrates according to claim 1, characterized in that, In step S1, the cleaning process involves wiping the surface with alcohol.

3. The surface processing method for irregularly shaped large-size cadmium zinc telluride substrates according to claim 1, characterized in that, In step S2, the sapphire wafer (200) is 5 inches in diameter and 2 mm thick.

4. The surface processing method for irregularly shaped large-size cadmium zinc telluride substrates according to claim 1, characterized in that, Sub-step S31 is as follows: Place the sapphire wafer (200) on the heating stage (11) of the waxing machine (1), heat the heating stage (11) to 55-60°C, place white paraffin wax (300) on the surface of the sapphire wafer (200), wait for the white paraffin wax (300) to melt, and then place the prepared cadmium zinc telluride wafer (100) on the sapphire wafer (200); and / or The alignment in sub-step S32 is performed by aligning the crosshairs laser-marked on the surface of the sapphire wafer (200) in step S2 with the coordinates drawn on the A and B surfaces using a marker after cleaning in step S1; and / or The operation in sub-step S33 is as follows: start the pressure plate (12) of the waxing machine (1) to extrude the excess white paraffin wax (300) between the sapphire wafer (200) and the cadmium zinc telluride wafer (100). The pressure applied by the pressure plate (12) is 20N, and the pressure application time is 3-5 minutes. After pressure application, the heating table (11) of the waxing machine (1) is allowed to cool naturally; and / or After cooling, the sapphire wafer (200) and cadmium zinc telluride wafer (100) that were bonded and fixed together were removed, and the overall TTV of the two was measured to be ≤2μm.

5. The surface processing method for irregularly shaped large-size cadmium zinc telluride substrates according to claim 1, characterized in that, In sub-step S41, the cadmium zinc telluride wafer (100) and sapphire wafer (200) that are bonded and fixed together are placed on the thinning machine suction cup (23) of the worktable (21) of the thinning machine (2). The thinning machine suction cup (23) is the same diameter as the sapphire wafer (200), and the thinning machine suction cup (23) adsorbs and fixes the sapphire wafer (200).

6. The surface processing method for irregularly shaped large-size cadmium zinc telluride substrates according to claim 1, characterized in that, In sub-step S41, the outline of the projection of the end face (221) of the grinding wheel (22) extends 1-2 μm beyond the rotation center (211) of the worktable (21).

7. The surface processing method for irregularly shaped large-size cadmium zinc telluride substrates according to claim 6, characterized in that, In sub-step S41, the grinding wheel (22) is a 4000-mesh silicon carbide grinding wheel.

8. The surface processing method for irregularly shaped large-size cadmium zinc telluride substrates according to claim 7, characterized in that, In sub-step S42, the grinding wheel (22) rotates at a speed of 2000 r / min, and the worktable (21) rotates at a speed of 100 r / min. The grinding wheel (22) machining is divided into three steps. The first step involves removing the raised parts of the surface with a machining depth of 20μm and a machining speed of 0.5μm / s. The second step involves processing 50μm at a speed of 0.5μm / s to remove the damaged layer. The third step involves processing 10μm at a speed of 0.3µm / s to adjust the surface roughness.

9. The surface processing method for irregular large-size cadmium zinc telluride substrates according to claim 1, characterized in that, In sub-step S52, the pressure of the pressure head (31) is 45-65 N; and / or In sub-step S52, the polishing pad (33) is a damping cloth, and the polishing liquid is prepared by mixing sodium dichloroisocyanurate, sodium bicarbonate, sodium benzenesulfonate, anhydrous sodium sulfate, nano-silica with a particle size of 60-80nm, and water in a mass ratio of 10:2:1:10:0.08:1000; and / or In sub-step S52, the rotation speed of the pressure head (31) is 50 r / min, the rotation speed of the polishing disc (32) is 150 r / min, the flow rate of the polishing liquid is 300-500 mL / min, the polishing time is 3-5 min, and the removal amount is 3-4 μm.

10. The surface processing method for irregularly shaped large-size cadmium zinc telluride substrates according to claim 1, characterized in that, Step S6 is as follows: Remove the cadmium zinc telluride wafer (100) and sapphire wafer (200) from the single-shot polisher (3); melt the white paraffin wax (300) between the cadmium zinc telluride wafer (100) and sapphire wafer (200) using a heating furnace; remove the cadmium zinc telluride wafer (100) from the sapphire wafer (200); place the cadmium zinc telluride wafer (100) into a container containing a dewaxing agent; and clean the white paraffin wax (300); and / or The wax remover is orange juice.

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