A single crystal silicon sample etching system and etching process thereof

Abstract

The present invention relates to the technical field of single crystal silicon corrosion treatment, and in particular to a single crystal silicon sample corrosion system and its corrosion process, wherein the corrosion system comprises a corrosion tank, a material loading box and a cover plate, wherein the corrosion tank contains corrosion liquid, and the corrosion tank is divided into an inner tank and an outer tank. The present invention is provided with an inner tank, an outer tank and a material loading box, and during the corrosion operation, the corrosion liquid in the outer tank is directed to flow into the inner tank, and the corrosion liquid in the inner tank flows from bottom to top, so that the corrosion liquid after reacting with the single crystal silicon sample and the reaction product flow from bottom to top, ensuring that the corrosion liquid around the single crystal silicon sample is always the corrosion liquid that has not reacted with the single crystal silicon sample, thereby ensuring that the concentration of the corrosion liquid around the single crystal silicon sample remains as constant as possible, and further ensuring that the corrosion rate of the corrosion liquid can be accurately predicted, so that by controlling the immersion time of the single crystal silicon sample in the corrosion liquid, the corrosion depth and surface morphology of the surface of the single crystal silicon sample can be accurately controlled.

Description

Technical Field

[0001] The present invention relates to the technical field of single crystal silicon corrosion treatment, in particular to a single crystal silicon sample corrosion system and a corrosion process thereof. Background Art

[0002] Single-crystal silicon wafers are thin slices made from a single crystal of silicon. Single-crystal silicon has a highly ordered atomic structure, which gives it excellent electronic properties and makes it widely used in the manufacture of various semiconductor devices, such as integrated circuits. During the cutting and grinding process, a damaged layer inevitably forms on the wafer surface. This damage can seriously affect the wafer's electrical performance and may cause subsequent process failures. Etching can effectively remove this damaged layer and restore the high-quality crystal structure of the wafer surface.

[0003] The most common existing silicon wafer etching technology is wet etching. During this process, a silicon wafer is placed in an etching solution, where a chemical reaction occurs between the solution and the wafer to remove surface defects. However, this etching process presents several challenges: Substances removed from the wafer (such as hexafluorosilicic acid and silicates) dissolve in the etching solution. These substances can cause persistent interference with the etching process, leading to the consumption of active ingredients in the etching solution (such as HNO3, HF, and KOH), a decrease in solution concentration, and difficulty in precisely controlling the etching depth and surface morphology of the wafer. Summary of the Invention

[0004] Based on this, it is necessary to provide a single crystal silicon sample etching system and its etching process to address the problems existing in the current silicon wafer etching equipment, so as to solve the problem of difficulty in accurately controlling the etching depth and surface morphology of the silicon wafer surface.

[0005] The above purpose is achieved through the following technical solutions:

[0006] A single crystal silicon sample etching system comprises:

[0007] The corrosion tank contains the corrosion liquid. The corrosion tank is divided into an inner tank and an outer tank. The tops of the inner tank and the outer tank are both open. The upper part of the inner tank is provided with a drain port, and the lower part of the inner tank is provided with a communication hole.

[0008] A material loading box, which can move in a vertical direction and is used to place single crystal silicon samples. The material loading box is located inside the inner tank, and the outer wall of the material loading box is slidably sealed with the inner tank;

[0009] The cover plate is movable in a vertical direction and is located inside the outer trough and is slidably sealed with the outer trough;

[0010] During the corrosion operation, the loading box moves vertically downward, so that the corrosive liquid inside the inner tank flows into the outer tank through the connecting hole. When the loading box moves vertically until its interior is connected with the connecting hole, the loading box stops moving downward. At this time, the cover plate moves vertically downward, so that the corrosive liquid inside the outer tank flows into the loading box through the connecting hole. At the same time, the corrosive liquid flowing into the loading box is sucked from the drain port so as to flow from bottom to top.

[0011] Preferably, a first driving assembly is provided outside the corrosion tank, and the first driving assembly is used to drive the cover plate to move in a vertical direction;

[0012] The first drive assembly includes a first linear drive element, a connecting frame and a first connecting plate. The first linear drive element is arranged on the outside of the corrosion groove. The connecting frame is fixedly connected to the power end of the first linear drive element. The upper end of the first connecting plate is fixedly connected to the connecting frame. The lower end of the first connecting plate is fixedly connected to the upper surface of the cover plate.

[0013] Preferably, a second driving assembly is further provided outside the corrosion tank, and the second driving assembly is used to drive the loading box to move in a vertical direction;

[0014] The second drive assembly includes a second linear drive element, an intermediate plate and a second connecting plate. The second linear drive element is arranged on the outside of the corrosion groove. The intermediate plate is fixedly connected to the power end of the second linear drive element. The upper end of the second connecting plate is fixedly connected to the intermediate plate. The lower end of the second connecting plate is fixedly connected to the outer side surface of the loading box.

[0015] Preferably, a rotating disk is rotatably provided inside the loading box, the axis of the rotating disk is horizontal, and a plurality of loading clamps are provided at equal intervals in the circumferential direction of the rotating disk, and the loading clamps are used to clamp the single crystal silicon sample.

[0016] Preferably, a third driving assembly is provided between the rotating disk and the intermediate plate, and the third driving assembly is used to drive the rotating disk to rotate around its own axis at a low speed.

[0017] Preferably, the third drive assembly includes a motor, a long shaft, a central shaft and a conical transmission disk. The motor is arranged on the middle plate, the output shaft of the motor is coaxially fixedly connected to the long shaft, a conical transmission surface is provided at the end of the long shaft away from the motor, the central shaft is coaxially arranged at one end of the rotating disk, and the central shaft rotates out from the side of the loading box, and the conical transmission disk cooperates with the conical transmission surface for transmission.

[0018] Preferably, the loading clamp comprises a connecting rod, an outer clamping plate, an inner clamping plate and a right clamping block, one end of the connecting rod is arranged on the side wall of the loading box, the inner clamping plate is fixedly connected to the end of the connecting rod away from the loading box, the outer clamping plate is elastically slidably connected to the outer side of the inner clamping plate, and the outer clamping plate can move relative to the inner clamping plate along the corresponding axis of the connecting rod, there are multiple right clamping blocks, the multiple right clamping blocks are equidistantly arranged on the upper surface and lower surface of the inner side of the outer clamping plate along the corresponding axis of the connecting rod, and the inner upper surface and lower surface of the inner clamping plate are equidistantly provided with left clamping blocks along the corresponding axis of the connecting rod;

[0019] When the outer clamping plate moves relative to the inner clamping plate along the corresponding connecting rod axis, the left clamping block and the right clamping block move away from each other.

[0020] Preferably, a fourth driving assembly is provided between the connecting rod and the loading box, and the fourth driving assembly is used to drive the connecting rod to rotate around its axis.

[0021] Preferably, the fourth drive assembly includes planetary gears and an outer gear ring. There are multiple planetary gears, and the multiple planetary gears correspond one-to-one to the multiple center shafts. The planetary gears are coaxially fixedly connected to the center shafts. The outer gear ring is arranged on the inner side wall of the loading box, and the outer gear ring is engaged with the planetary gears.

[0022] A single crystal silicon sample etching process uses any of the single crystal silicon sample etching systems described above.

[0023] The beneficial effects of the present invention are:

[0024] The present invention is provided with an inner tank, an outer tank and a loading box. During the etching operation, the etching liquid in the outer tank is directed to flow into the inner tank, and the etching liquid in the inner tank flows from bottom to top, so that the etching liquid after reacting with the single crystal silicon sample and the reaction product flow from bottom to top, ensuring that the etching liquid around the single crystal silicon sample is always the etching liquid that has not reacted with the single crystal silicon sample, thereby ensuring that the concentration of the etching liquid around the single crystal silicon sample remains as constant as possible, and further ensuring that the etching rate of the etching liquid can be accurately predicted. In this way, by controlling the immersion time of the single crystal silicon sample in the etching liquid, the etching depth and surface morphology of the surface of the single crystal silicon sample can be accurately controlled. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is an overall schematic diagram of a single crystal silicon sample etching system of the present invention;

[0026] Figure 2 This is a structural schematic diagram of a first driving component in a single crystal silicon sample etching system of the present invention;

[0027] Figure 3 This is a structural schematic diagram of a liquid replenishing port in a single crystal silicon sample etching system of the present invention;

[0028] Figure 4 This is a schematic structural diagram of an inner tank and an outer tank in a single crystal silicon sample etching system of the present invention;

[0029] Figure 5 This is a structural schematic diagram of a material loading fixture in a single crystal silicon sample etching system of the present invention;

[0030] Figure 6 This is a schematic structural diagram of a third drive assembly and a fourth drive assembly in a single crystal silicon sample etching system of the present invention;

[0031] Figure 7 This is a structural schematic diagram of a material loading box in a single crystal silicon sample etching system of the present invention;

[0032] Figure 8 This is an exploded view of a third driving component in a single crystal silicon sample etching system of the present invention;

[0033] Figure 9 for Figure 8 Schematic diagram of the enlarged structure at A in the middle;

[0034] Figure 10 This is an exploded view of a material loading fixture in a single crystal silicon sample etching system of the present invention.

[0035] in:

[0036] 100, corrosion tank; 110, inner tank; 111, drain port; 112, connecting hole; 120, outer tank; 121, liquid filling port; 130, cover plate;

[0037] 200, material loading box; 210, rotating disk; 220, through hole;

[0038] 300, first drive assembly; 310, first linear drive element; 320, connecting frame; 330, first connecting plate;

[0039] 400, second drive assembly; 410, second linear drive element; 420, intermediate plate; 430, second connecting plate;

[0040] 500, material loading fixture; 510, connecting rod; 520, outer clamping plate; 530, inner clamping plate; 540, right clamping block; 550, left clamping block;

[0041] 600, third drive assembly; 610, motor; 620, long shaft; 621, conical transmission surface; 630, central shaft; 640, conical transmission plate;

[0042] 700, fourth drive assembly; 710, planetary gear; 720, outer gear ring;

[0043] 800. Single crystal silicon sample. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0045] The serial numbers assigned to components herein, such as "first," "second," etc., are used solely to distinguish the objects being described and do not convey any sequential or technical meaning. References to "connection" and "coupling" herein, unless otherwise specified, include both direct and indirect connections (couplings). In the description of the present invention, it should be understood that terms such as "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise" indicate positions or relationships based on those shown in the accompanying drawings. These terms are intended solely to facilitate the description of the present invention and simplify the description. They are not intended to indicate or imply that the device or component being referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0046] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0047] like Figures 1 to 10As shown, a single crystal silicon sample etching system includes an etching tank 100, a material loading box 200 and a cover plate 130. The etching tank 100 is filled with etching liquid. The etching tank 100 is divided into an inner tank 110 and an outer tank 120. The tops of the inner tank 110 and the outer tank 120 are both open. A drain port 111 is provided at the upper part of the inner tank 110, and a connecting hole 112 is provided at the lower part of the inner tank 110. The material loading box 200 can move in the vertical direction. The material loading box 200 is used to place the single crystal silicon sample 800. The material loading box 200 is located inside the inner tank 110 and the outer wall of the material loading box 200 is slidably sealed with the inner tank 110. The cover plate 130 can move in the vertical direction. Move, and the cover plate 130 is located inside the outer tank 120 and is slidably sealed with the outer tank 120. During the corrosion operation, the loading box 200 moves vertically downward, so that the corrosive liquid inside the inner tank 110 flows directionally to the outer tank 120 through the connecting hole 112. When the loading box 200 moves vertically until its interior is connected with the connecting hole 112, the loading box 200 stops moving downward. At this time, the cover plate 130 moves vertically downward, so that the corrosive liquid inside the outer tank 120 flows directionally into the loading box 200 through the connecting hole 112. At the same time, the corrosive liquid flowing into the loading box 200 is sucked from the drain port 111 to flow directionally from bottom to top.

[0048] It should also be added that, in order to enable the corrosive liquid inside the outer tank 120 to flow into the loading box 200 through the connecting hole 112 when the loading box 200 moves vertically downward to a preset position, specifically, a number of through holes 220 are evenly opened circumferentially on the lower side of the loading box 200. In this way, when the loading box 200 moves vertically downward until the through holes 220 on it and the connecting hole 112 at the lower part of the inner tank 110 are at the same height position, the through holes 220 and the connecting hole 112 are connected. At this time, the corrosive liquid inside the outer tank 120 can enter the interior of the loading box 200 in sequence through the connecting hole 112 and the through holes 220.

[0049] In the initial state, the etching tank 100 is filled with etching liquid. Since the lower parts of the inner tank 110 and the outer tank 120 are connected through the connecting hole 112, the liquid level in the inner tank 110 is the same as the liquid level in the outer tank 120. At this time, the material loading box 200 is located above the liquid surface of the etching liquid. The material loading box 200 contains the single crystal silicon sample 800 to be etched. The surface of the single crystal silicon sample 800 to be etched is exposed, and the surface of the single crystal silicon sample 800 that does not need to be treated is wrapped with a protective film. During the etching operation, the staff moves the material loading box 200 vertically downward. When the material loading box 200 moves downward, the material loading box 200 is placed in the etching liquid. After moving to its lower bottom surface in contact with the liquid surface of the corrosive liquid, the loading box 200 pushes the corrosive liquid in the inner tank 110, causing the corrosive liquid level in the inner tank 110 to drop. At this time, the corrosive liquid in the inner tank 110 enters the outer tank 120 through the connecting hole 112, causing the corrosive liquid level in the outer tank 120 to rise. When the loading box 200 moves vertically downward until the connecting hole 112 and the through hole 220 on the side of the loading box 200 are at the same height position, the connecting hole 112 and the through hole 220 are in a connected state. At this time, under the action of the liquid level difference, the corrosive liquid in the outer tank 120 enters the outer tank 120 through the connecting hole 112 in turn. The through hole 112 and the through hole 220 flow into the interior of the material loading box 200 in a directional manner, and the single crystal silicon sample 800 in the material loading box 200 is immersed in corrosion. In order to speed up the directional flow speed of the etching liquid, the staff moves the cover plate 130 downward in the vertical direction, thereby pushing the etching liquid level in the outer tank 120 to drop rapidly, increasing the directional flow speed of the etching liquid. At the same time, the staff connects the drain port 111 to the pump to suck the etching liquid in the inner tank 110, so that the etching liquid in the inner tank 110 maintains a directional flow from bottom to top. Specifically, the drain port 111 can be connected to the input of the pump. The ends are connected, so that the etching liquid in the inner tank 110 can flow from bottom to top, and the etching liquid after reacting with the single crystal silicon sample 800 and the reaction products flow from bottom to top, ensuring that the etching liquid around the single crystal silicon sample 800 is always the etching liquid that has not reacted with the single crystal silicon sample 800, thereby ensuring that the concentration of the etching liquid around the single crystal silicon sample 800 remains as constant as possible, and further ensuring that the corrosion rate of the etching liquid can be accurately predicted. In this way, by controlling the immersion time of the single crystal silicon sample 800 in the etching liquid, the corrosion depth and surface morphology of the surface of the single crystal silicon sample 800 can be accurately controlled.

[0050] It should also be noted that before the loading box 200 is immersed in the corrosive liquid, the corrosive liquid in the inner tank 110 is squeezed by the bottom surface of the loading box 200 and enters the outer tank 120, so that the liquid level in the outer tank 120 is higher than the liquid level in the inner tank 110. At this time, the corrosive liquid in the outer tank 120 surrounds the loading box 200. In addition, the corrosive liquid in the inner tank 110 is located at the bottom of the loading box 200. Therefore, it can form a temperature package for the single crystal silicon sample 800 in the loading box 200, preheat the single crystal silicon sample in the loading box 200, and reduce the temperature difference between the single crystal silicon sample 800 and the corrosive liquid.

[0051] It should also be noted that the existing etching tank 100 for containing the etchant is usually open at the top. The etching liquid near the liquid surface of the etching liquid is very easy to undergo oxidation reaction with the air. This will cause the single crystal silicon sample 800 to inevitably come into contact with this part of the etching liquid when the single crystal silicon sample 800 is placed down. The concentration of this part of the etching liquid becomes unpredictable due to the oxidation reaction, which will cause the corrosion depth and surface morphology of the surface of the single crystal silicon sample 800 to become uncontrollable. To solve this problem, the present invention provides a cover plate 130 to seal the opening of the outer tank 120, and makes the lower surface of the material loading box 200 and the peripheral wall of the inner tank 110 slide and seal. In this way, before the etching liquid enters the interior of the material loading box 200, the etching liquid inside the etching tank 100 will not come into contact with the outside air, thereby reducing the possibility of the etching liquid being oxidized.

[0052] It should also be noted that when the corrosive liquid inside the outer tank 120 enters the loading box 200 and the liquid level height inside the inner tank 110 is lower than the height of the drain port 111, the corrosive liquid inside the inner tank 110 cannot move stably from bottom to top. To solve this problem, a flexible tube can be inserted into the drain port 111, and a lightweight plastic float is set at the end of the flexible tube away from the drain port 111. In this way, the plastic float always floats at the liquid surface position inside the inner tank 110. In this way, when the liquid level height inside the inner tank 110 is lower than the height of the drain port 111, it can also ensure that the corrosive liquid in the inner tank 110 flows from bottom to top.

[0053] In this embodiment, if Figure 2 As shown, a first driving assembly 300 is provided on the outside of the corrosion trough 100. The first driving assembly 300 is used to drive the cover plate 130 to move in the vertical direction. The first driving assembly 300 includes a first linear driving element 310, a connecting frame 320 and a first connecting plate 330. The first linear driving element 310 is arranged on the outside of the corrosion trough 100. The connecting frame 320 is fixedly connected to the power end of the first linear driving element 310. The upper end of the first connecting plate 330 is fixedly connected to the connecting frame 320, and the lower end of the first connecting plate 330 is fixedly connected to the upper surface of the cover plate 130.

[0054] When the staff needs to move the cover plate 130 in the vertical direction, the power end of the first linear drive element 310 drives the connecting frame 320 to move synchronously, the connecting frame 320 drives the first connecting plate 330 to move synchronously, and the first connecting plate 330 drives the cover plate 130 to move synchronously.

[0055] It should also be noted that the first linear drive element 310 is specifically an electric telescopic rod, a cylinder or a screw slider mechanism. Taking the first linear drive element 310 as an example of a screw slider mechanism, there are two screw slider mechanisms, which are located on the left and right sides of the corrosion groove 100. The screw is vertically arranged outside the corrosion groove 100, the axis of the screw is vertical, and the screw is threadedly connected to the connecting frame 320. One end of the screw is fixedly connected to a servo motor. In order to install the servo motor, a support frame is also required to be provided on the outside of the corrosion groove 100, and the servo motor is set on the support frame.

[0056] In this embodiment, if Figure 1 As shown, a second drive assembly 400 is also provided on the outside of the corrosion trough 100. The second drive assembly 400 is used to drive the loading box 200 to move in the vertical direction. The second drive assembly 400 includes a second linear drive element 410, an intermediate plate 420 and a second connecting plate 430. The second linear drive element 410 is arranged on the outside of the corrosion trough 100, the intermediate plate 420 is fixedly connected to the power end of the second linear drive element 410, the upper end of the second connecting plate 430 is fixedly connected to the intermediate plate 420, and the lower end of the second connecting plate 430 is fixedly connected to the outer side surface of the loading box 200.

[0057] When the staff needs to move the material box 200 in the vertical direction, the power end of the second linear drive element 410 drives the middle plate 420 to move synchronously, the middle plate 420 drives the second connecting plate 430 to move synchronously, and the second connecting plate 430 drives the material box 200 to move synchronously.

[0058] It should also be noted that the second linear drive element 410 is specifically any one of an electric telescopic rod, a cylinder or a screw slider mechanism. Taking the second linear drive element 410 as a screw slider mechanism as an example, there are two screw slider mechanisms, and the two screw slider mechanisms are located on the front and rear sides of the corrosion groove 100. The screw is vertically arranged outside the corrosion groove 100, the axis of the screw is vertical, and the screw is threadedly connected to the middle plate 420. One end of the screw is fixedly connected to a servo motor. In order to install the servo motor, a support frame is also required to be provided on the outside of the corrosion groove 100, and the servo motor is set on the support frame.

[0059] In this embodiment, if Figure 5 and Figure 6As shown, a rotating disk 210 is rotatably provided inside the material loading box 200 , the axis of the rotating disk 210 is horizontal, and a plurality of material loading clamps 500 are provided at equal intervals around the rotating disk 210 , and the material loading clamps 500 are used to clamp the single crystal silicon sample 800 .

[0060] When the loading box 200 is immersed in the etching liquid, the loading fixture 500 and the single crystal silicon sample 800 clamped by it enter the etching liquid together. At this time, the staff rotates the rotating disk 210 around its own axis. Since multiple loading fixtures 500 are arranged on the rotating disk 210 at equal circumferential intervals, as the rotating disk 210 rotates circumferentially, the loading fixture 500 that enters the etching liquid first and the single crystal silicon sample 800 clamped by it are removed from the etching liquid first, and the loading fixture 500 that enters the etching liquid later and the single crystal silicon sample 800 clamped by it are removed from the etching liquid later, thereby ensuring that the single crystal silicon sample 800 clamped on each loading fixture 500 is immersed in the etching liquid for basically the same length of time, thereby ensuring that the surface corrosion depth and surface morphology of each single crystal silicon sample 800 are basically consistent.

[0061] In this embodiment, if Figure 6 and Figure 8 As shown, a third drive assembly 600 is provided between the rotating disk 210 and the middle plate 420. The third drive assembly 600 is used to drive the rotating disk 210 to rotate at a low speed around its own axis. The third drive assembly 600 includes a motor 610, a long shaft 620, a central shaft 630 and a conical transmission disk 640. The motor 610 is arranged on the middle plate 420. The output shaft of the motor 610 is coaxially fixedly connected to the long shaft 620. A conical transmission surface 621 is provided at one end of the long shaft 620 away from the motor 610. The central shaft 630 is coaxially arranged at one end of the rotating disk 210, and the central shaft 630 rotates out from the side of the loading box 200. The conical transmission disk 640 is matched with the conical transmission surface 621 for transmission.

[0062] When the rotating disk 210 needs to rotate about its own axis, the motor 610 is started, and the output shaft of the motor 610 drives the long shaft 620 to rotate. The long shaft 620 drives the conical transmission disk 640 to rotate through its conical transmission surface 621. The conical transmission disk 640 drives the central shaft 630 to rotate, and the central shaft 630 drives the rotating disk 210 to rotate, thereby achieving the rotation of the rotating disk 210 about its own axis. It is understood that the transmission between the conical transmission disk 640 and the conical transmission surface 621 can be a friction surface transmission or a gear transmission. In other embodiments, to drive the rotating disk 210 to rotate about its own axis, specifically, the third drive assembly 600 includes a motor 610, a first transmission gear, a second transmission gear, and a central shaft 630. The motor 610 is disposed on the second connecting plate 430, with the axis of the motor 610 horizontal. The first transmission gear is fixedly connected to the output shaft of the motor 610. The central shaft 630 is coaxially fixedly connected to one end of the rotating disk 210. The second transmission gear is coaxially fixedly connected to the central shaft 630. The first transmission gear and the second transmission gear are in transmission connection. When it is necessary to drive the rotating disk 210 to rotate about its own axis, the motor 610 is started, the output shaft of the motor 610 drives the first transmission gear to rotate, the first transmission gear drives the second transmission gear to rotate via a transmission belt, the second transmission gear drives the central shaft 630 to rotate, and the central shaft 630 drives the rotating disk 210 to rotate, thereby achieving low-speed rotation of the rotating disk 210 about its own axis.

[0063] In this embodiment, if Figure 9 and Figure 10 As shown, the loading clamp 500 includes a connecting rod 510, an outer clamping plate 520, an inner clamping plate 530 and a right clamping block 540. One end of the connecting rod 510 is arranged on the side wall of the loading box 200, and the inner clamping plate 530 is fixedly connected to the end of the connecting rod 510 away from the loading box 200. The outer clamping plate 520 is elastically slidably connected to the outer side of the inner clamping plate 530. Specifically, in order to make the outer clamping plate 520 elastically slidably connected to the outer side of the inner clamping plate 530, a compression spring is provided on the outer periphery of the connecting rod 510, one end of the compression spring is connected to the inner clamping plate 530, and the other end of the compression spring is connected to the outer On the clamping plate 520, the outer clamping plate 520 can move relative to the inner clamping plate 530 along the axis of the corresponding connecting rod 510. There are multiple right clamping blocks 540, and the multiple right clamping blocks 540 are evenly spaced along the axis of the corresponding connecting rod 510 on the upper surface and lower surface of the inner side of the outer clamping plate 520. The inner upper surface and lower surface of the inner side of the inner clamping plate 530 are evenly spaced along the axis of the corresponding connecting rod 510. Left clamping blocks 550 are provided on the upper surface and lower surface of the inner side of the inner clamping plate 530. When the outer clamping plate 520 moves relative to the inner clamping plate 530 along the axis of the corresponding connecting rod 510, the left clamping block 550 and the right clamping block 540 move away from each other.

[0064] When clamping the single crystal silicon sample 800, the staff pulls the outer clamping plate 520 so that the outer clamping plate 520 moves relative to the inner clamping plate 530 along the axis of the corresponding connecting rod 510. At this time, the left clamping block 550 and the right clamping block 540 move away from each other, and the distance between the left clamping block 550 and the right clamping block 540 becomes larger. At this time, the staff puts the single crystal silicon sample 800 into the gap between the left clamping block 550 and the right clamping block 540, and then releases the outer clamping plate 520. At this time, the outer clamping plate 520 moves in the opposite direction under the action of the spring force, so that the left clamping block 550 and the right clamping block 540 are close to each other, thereby completing the clamping of the single crystal silicon sample 800 by the left clamping block 550 and the right clamping block 540.

[0065] It should also be added that, in order to allow the inner clamping plate 530 and the outer clamping plate 520 to move relative to each other only along the axis of the connecting rod 510, specifically, slots are provided on both sides of the outer clamping plate 520 along the width direction of the outer clamping plate 520. In addition, the inner clamping plate 530 is designed to be two separable parts. During installation, the inner clamping plate 530 is slid through the slot and the side surface of the inner clamping plate 530 is brought into sliding contact with the bottom of the slot. Then, the two parts of the inner clamping plate 530 are fixedly connected together. In this way, the inner clamping plate 530 and the outer clamping plate 520 can only move relative to each other along the axis of the connecting rod 510.

[0066] In this embodiment, a fourth drive assembly 700 is provided between the connecting rod 510 and the loading box 200. The fourth drive assembly 700 is used to drive the connecting rod 510 to rotate around its axis. The fourth drive assembly 700 includes a planetary gear 710 and an outer gear ring 720. There are multiple planetary gears 710, and the multiple planetary gears 710 correspond one-to-one to the multiple center shafts 630. The planetary gears 710 are coaxially fixedly connected to the center shaft 630. The outer gear ring 720 is arranged on the inner side wall of the loading box 200, and the outer gear ring 720 is engaged with the planetary gears 710.

[0067] During the etching operation, the rotating disk 210 rotates around its own axis, and the rotating disk 210 drives multiple connecting rods 510 to rotate synchronously, that is, the connecting rods 510 follow the rotating disk 210 in revolution. At the same time, with the cooperation of the planetary gear 710 and the outer gear ring 720, the connecting rods 510 also rotate around their own axis (that is, rotate). At this time, the connecting rods 510 drive the inner clamping plate 530 to rotate synchronously, and the inner clamping plate 530 drives the outer clamping plate 520 to rotate synchronously. The outer clamping plate 520 and the inner clamping plate 530 drive the single crystal silicon sample 800 to rotate synchronously, so that the time for each part of the single crystal silicon sample 800 to be immersed in the etching solution remains basically consistent, thereby ensuring the overall corrosion uniformity of the single crystal silicon sample 800, so as to accurately control the corrosion depth and surface morphology of the surface of the single crystal silicon sample 800.

[0068] In this embodiment, a liquid replenishing port 121 is opened on the outside of the outer tank 120, and the liquid replenishing port 121 is connected to a two-way valve. One interface of the two-way valve is used to replenish the etching liquid, and the other interface is used to completely discharge the etching liquid from the etching tank 100.

[0069] A single crystal silicon sample etching process, using the above-mentioned single crystal silicon sample etching system, includes the following steps:

[0070] Cutting: Cut the single crystal silicon sample from the single crystal silicon wafer. The cut single crystal silicon wafer is about 2 cm long and about 0.5 cm wide.

[0071] Primary cleaning: Wrap the single crystal silicon sample with a blue film and place it in an ultrasonic machine for the first cleaning. The ultrasonic cleaning time is controlled within 3-5 minutes and the ultrasonic cleaning temperature is controlled within 20-50 degrees Celsius. The purpose is to remove particulate impurities on the surface of the single crystal silicon sample.

[0072] Drying: Place the cleaned single crystal silicon sample in a vacuum dryer to dry it.

[0073] Clamping: The staff pulls the outer clamping plate and clamps the dried single crystal silicon sample between the right clamping block and the left clamping block.

[0074] Preheating: Before the loading box is immersed in the etching liquid, the etching liquid in the outer tank surrounds the loading box, and the etching liquid in the inner tank is located at the bottom of the loading box, thereby forming a temperature package for the single crystal silicon sample in the loading box for preheating.

[0075] Corrosion: Before and after the material loading box enters the corrosive liquid in the inner tank, the connecting rod rotates around its own axis while also revolving around the axis of the rotating disk. The immersion time lasts for about 1 minute, and the temperature of the corrosive liquid is controlled at 20-30 degrees Celsius. After the single crystal silicon sample has been immersed in the corrosive liquid for 1 minute, the material loading box is moved vertically upward to remove the single crystal silicon sample from the corrosive liquid. At the same time, the corrosive liquid in the material loading box is drained through the drain port, and then the single crystal silicon sample is allowed to stand for 1 minute. At the same time, the corrosive liquid in the inner and outer tanks is first drained through the liquid replenishing port, and then new corrosive liquid is added to the inner and outer tanks. After the standing period is over, the material loading box is moved vertically downward again so that the immersion time of the single crystal silicon sample lasts for about 1 minute. The above operation is repeated about 10 times and the corrosion process is completed.

[0076] Rinsing: After the etching is completed, the single crystal silicon sample is placed in the cleaning agent for rinsing. The rinsing temperature is controlled at 20-35 degrees Celsius and the rinsing time is controlled at 3-15 minutes.

[0077] Secondary cleaning: Ultrasonic cleaning time is controlled within 3-5 minutes, and ultrasonic cleaning temperature is controlled within 20-50 degrees Celsius.

[0078] Secondary drying: Blow hot air along the etched surface of the single crystal silicon sample to dry the etched surface, and then put it into a vacuum dryer for drying.

[0079] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above 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.

[0080] The above-described embodiments merely illustrate several embodiments of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A single crystal silicon sample etching system, characterized in that: include: The corrosion tank contains the corrosion liquid. The corrosion tank is divided into an inner tank and an outer tank. The tops of the inner tank and the outer tank are both open. The upper part of the inner tank is provided with a drain port, and the lower part of the inner tank is provided with a communication hole. A material loading box, the lower side of which is evenly circumferentially provided with through holes, the material loading box can be moved in the vertical direction, the material loading box is used to place single crystal silicon samples, the material loading box is located inside the inner groove, and the outer wall of the material loading box is slidably sealed with the inner groove; The cover plate is movable in a vertical direction and is located inside the outer trough and is slidably sealed with the outer trough; During the corrosion operation, the loading box moves vertically downward, so that the corrosive liquid inside the inner tank flows into the outer tank through the connecting hole. When the loading box moves vertically to the point where the through hole and the connecting hole are at the same height, the loading box stops moving downward. At this time, the cover plate moves vertically downward, so that the corrosive liquid inside the outer tank flows into the loading box through the connecting hole. At the same time, the corrosive liquid flowing into the loading box is sucked from the drain port so as to flow from bottom to top.

2. A single crystal silicon sample etching system according to claim 1, characterized in that: A first driving assembly is provided outside the corrosion tank, and the first driving assembly is used to drive the cover plate to move in a vertical direction; The first drive assembly includes a first linear drive element, a connecting frame and a first connecting plate. The first linear drive element is arranged on the outside of the corrosion groove. The connecting frame is fixedly connected to the power end of the first linear drive element. The upper end of the first connecting plate is fixedly connected to the connecting frame. The lower end of the first connecting plate is fixedly connected to the upper surface of the cover plate.

3. A single crystal silicon sample etching system according to claim 2, characterized in that: A second driving assembly is further provided on the outside of the corrosion tank, and the second driving assembly is used to drive the material loading box to move in a vertical direction; The second drive assembly includes a second linear drive element, an intermediate plate and a second connecting plate. The second linear drive element is arranged on the outside of the corrosion groove. The intermediate plate is fixedly connected to the power end of the second linear drive element. The upper end of the second connecting plate is fixedly connected to the intermediate plate. The lower end of the second connecting plate is fixedly connected to the outer side surface of the loading box.

4. A single crystal silicon sample etching system according to claim 3, characterized in that: A rotating disk is rotatably provided inside the material loading box, the axis of the rotating disk is horizontal, and a plurality of material loading clamps are provided at equal intervals in the circumferential direction of the rotating disk, and the material loading clamps are used to clamp the single crystal silicon samples.

5. A single crystal silicon sample etching system according to claim 4, characterized in that: A third driving assembly is provided between the rotating disk and the middle plate, and the third driving assembly is used for driving the rotating disk to rotate around its own axis at a low speed.

6. A single crystal silicon sample etching system according to claim 5, characterized in that: The third drive assembly includes a motor, a long shaft, a center shaft and a conical transmission disk. The motor is arranged on the middle plate. The output shaft of the motor is coaxially fixedly connected to the long shaft. A conical transmission surface is provided at the end of the long shaft away from the motor. The center shaft is coaxially arranged at one end of the rotating disk, and the center shaft rotates out from the side of the loading box. The conical transmission disk and the conical transmission surface are matched for transmission.

7. A single crystal silicon sample etching system according to claim 4, characterized in that: The loading clamp comprises a connecting rod, an outer clamping plate, an inner clamping plate and a right clamping block, one end of the connecting rod is arranged on the side wall of the loading box, the inner clamping plate is fixedly connected to the end of the connecting rod away from the loading box, the outer clamping plate is elastically slidably connected to the outer side of the inner clamping plate, and the outer clamping plate can move relative to the inner clamping plate along the corresponding axis of the connecting rod, there are multiple right clamping blocks, the multiple right clamping blocks are equidistantly arranged on the upper surface and lower surface of the inner side of the outer clamping plate along the corresponding axis of the connecting rod, and the inner upper surface and lower surface of the inner clamping plate are equidistantly provided with left clamping blocks along the corresponding axis of the connecting rod; When the outer clamping plate moves relative to the inner clamping plate along the corresponding connecting rod axis, the left clamping block and the right clamping block move away from each other.

8. A single crystal silicon sample etching system according to claim 7, characterized in that: A fourth driving assembly is provided between the connecting rod and the loading box, and the fourth driving assembly is used to drive the connecting rod to rotate around its axis.

9. A single crystal silicon sample etching system according to claim 8, characterized in that: The fourth drive assembly includes planetary gears and an outer gear ring. There are multiple planetary gears, and the multiple planetary gears correspond one-to-one to the multiple center shafts. The planetary gears are coaxially fixedly connected to the center shafts. The outer gear ring is arranged on the inner side wall of the loading box, and the outer gear ring and the planetary gears are engaged with each other.

10. A single crystal silicon sample etching process, characterized in that: The single crystal silicon sample etching system according to any one of claims 1 to 9 is used.

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