A device for detecting microtubule defects under positive pressure

Abstract

The application discloses a positive pressure detection microtube defect device, and relates to the technical field of microtube defect detection.The device comprises a cavity bottom plate, a detection cavity is arranged above the cavity bottom plate, a sealing upper cover is further arranged, a pressing cylinder is arranged on the cavity bottom plate around the detection cavity, the pressing cylinder can press the sealing upper cover above the detection cavity, a detection bearing disc for bearing a to-be-detected sample is arranged at the lower part of the detection cavity, the outer periphery of the detection bearing disc is attached to the inner wall of the detection cavity, the detection bearing disc is provided with through holes penetrating therethrough and flow guide grooves arranged on the upper surface thereof, and a gas inlet and outlet is arranged on one side of the detection cavity, so that a large pressure difference can be formed between the upper and lower surfaces of the to-be-detected sample after the gas inlet and outlet is connected with positive pressure gas.The application solves the technical problems of low detection efficiency and easy to miss detection in the prior art microtube defect detection process.

Description

Technical Field

[0001] This invention relates to the field of microtube defect detection technology, and in particular to a device for positive pressure detection of microtube defects. Background Technology

[0002] With the continuous deepening of research on silicon carbide substrates and the continuous improvement of processes, the single-crystal quality of silicon carbide substrates has been greatly improved. However, high-density defects remain the most significant factor affecting the single-crystal quality of silicon carbide substrates, such as screw dislocations, edge dislocations, basal plane dislocations, and microtube defects. Microtube defects not only affect the single-crystal quality of silicon carbide substrates but also severely restrict their performance, leading to reverse bias failure of devices and even breakdown, resulting in a significant degradation in the performance of subsequent devices. Therefore, microtube detection in silicon carbide substrates is a crucial step in the production and processing of silicon carbide materials. Existing technologies for microtube detection in silicon carbide substrates include microscopic inspection, which uses a high-precision microscope for observation. This method is not only inefficient but also prone to missed detections. Another existing technology is negative pressure chuck inspection, which uses a negative pressure microtube detection device to create a pressure difference between the upper and lower surfaces of the sample under vacuum, and then detects the microtubes under this pressure difference.

[0003] The inventors have discovered that the above-mentioned prior art has at least the following defects: when the detection is performed by the negative pressure suction cup method, the detection efficiency is low because only one atmosphere of pressure difference can be formed between the upper and lower surfaces of the sample to be tested; moreover, when the microtube diameter is small (such as less than 10 micrometers), negative pressure detection is difficult to determine whether there are microtube defects, which can easily lead to missed detection. Summary of the Invention

[0004] This application provides a device for positive pressure detection of microtube defects, thereby solving the technical problems of low detection efficiency and easy missed detection in the prior art during the microtube defect detection process.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a device for positive pressure detection of microtube defects, including a cavity base plate, a detection cavity disposed above the cavity base plate, and a sealing cover. A clamping cylinder is disposed on the cavity base plate around the detection cavity, which can press the sealing cover tightly against the top of the detection cavity. A detection support plate for carrying the sample to be tested is disposed at the lower part of the detection cavity. The outer periphery of the detection support plate is fitted with the inner wall of the detection cavity. The detection support plate has a through hole running through it from top to bottom and a guide groove located on its upper surface. A gas inlet and outlet are disposed on one side of the detection cavity. When positive pressure gas is introduced into the gas inlet and outlet, a pressure difference can be formed between the upper and lower surfaces of the sample to be tested.

[0006] The lower part of the detection chamber can be sealed by the detection support plate, and the upper part of the detection chamber can be sealed by the sealing cover. Therefore, during the process of introducing positive pressure gas through the gas inlet and outlet, the detection chamber, the sealing cover, and the detection support plate can form a sealed chamber. The sealing cover can be pressed tightly against the top of the detection chamber by a pressure cylinder, so this sealed chamber can withstand high gas pressure. This creates a large pressure difference between the upper and lower sides of the sample to be tested, thereby significantly improving the efficiency of microtube detection and avoiding the problem of easily missed detection of very small microtubes on silicon carbide substrates.

[0007] Furthermore, it also includes a testing frame, the bottom of which has a horizontal plate for placing the cavity bottom plate. A top cover lifting mechanism is provided on one side of the testing frame. The top cover lifting mechanism includes a slide rail fixed to the testing frame and a slide block that can move vertically relative to the slide rail. The slide block can drive the sealing top cover down and close the sealing top cover with the upper end of the testing cavity. Thus, during operation, by controlling the slide block to descend along the vertical slide rail, the sealing top cover can be closed with the upper end of the testing cavity, which is convenient for operation.

[0008] Furthermore, the detection chamber is also equipped with a detection liquid baffle ring and a baffle ring support ring. The detection liquid baffle ring is nested on the outer periphery of the bottom of the baffle ring support ring, and the bottom of the detection liquid baffle ring is in contact with the upper surface of the sample to be tested. Thus, during operation, the detection liquid can be dripped into the detection liquid support ring, which makes it easy for the detection liquid to cover the upper surface of the sample to be tested.

[0009] Furthermore, the cross-section of the flow guide channel is a triangle that is wider at the top and narrower at the bottom, and the flow guide channel spirals around the center of the detection support plate; the through hole is located at the center of the detection plate and is connected to the flow guide channel; thus, even if there is little detection liquid under the sample to be tested, it can still flow along the flow guide channel to the through hole and be detected by the sensor, thereby improving the detection efficiency.

[0010] Furthermore, a sealing ring is provided between the detection chamber and the sealing cover, and a sealing ring is provided between the detection bearing plate and the detection chamber; thus, when positive pressure gas is introduced, the detection chamber can withstand higher gas pressure, maintaining a large pressure difference between the upper and lower sides of the sample to be tested.

[0011] Furthermore, the upper end face of the detection chamber is provided with an annular groove, and the sealing ring of the upper cover is located in the groove on the upper end face of the detection chamber and can be squeezed by the sealing cover.

[0012] Furthermore, the detection chamber has an annular stepped surface, which supports the lower end face of the detection support plate. The outer periphery of the detection support plate is provided with an annular groove, and the support plate sealing ring is located in the groove of the detection support plate and can be squeezed by the inner wall of the detection chamber.

[0013] Furthermore, the clamping cylinder includes a cylinder body and a telescopic rod that can move up and down relative to the cylinder body. The upper end of the telescopic rod is horizontally rotatably mounted with a clamping part. Thus, during the process of the upper cover lifting mechanism driving the sealed upper cover to move downward, the clamping cylinder will not interfere with it. When the sealed upper cover is engaged with the detection chamber, the clamping cylinder can be controlled to clamp the upper part of the sealed upper cover through the clamping part.

[0014] Furthermore, the pressure range of the positive pressure gas is 0.2 to 0.7 MPa.

[0015] Furthermore, the sample to be tested is a wafer that has been ground and flattened.

[0016] As can be seen from the above technical solutions, the present invention has at least the following technical effects or advantages: The lower part of the detection chamber can be sealed by the detection support plate, and the upper part of the detection chamber can be sealed by the sealing cover. Therefore, during the process of introducing positive pressure gas through the gas inlet and outlet, the detection chamber, the sealing cover, and the detection support plate can form a sealed chamber. The sealing cover can be pressed tightly against the top of the detection chamber by a pressure cylinder, so this sealed chamber can withstand high gas pressure. This creates a large pressure difference between the upper and lower sides of the sample to be tested, thereby significantly improving the efficiency of microtube detection and avoiding the problem of easily missed detection of very small microtubes on silicon carbide substrates. Attached Figure Description

[0017] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Figure 1 This is a partial structural schematic diagram of the present invention; Figure 2 for Figure 1 A schematic diagram of the cross section along AB-AB; Figure 3 for Figure 2 A magnified view of a portion of point A in the middle; Figure 4 for Figure 2 A magnified view of a portion of point B in the middle; Figure 5 for Figure 2 A magnified view of a portion of point C in the middle; Figure 6 for Figure 1 Top view; Figure 7 This is a schematic diagram of the overall structure of the present invention; Figure 8 for Figure 7A schematic diagram of the cross-section along the middle DD.

[0018] Explanation of reference numerals in the attached drawings: 1. Testing frame; 2. Upper cover lifting mechanism; 3. Testing chamber; 4. Testing support plate; 5. Sealed upper cover; 6. Chamber bottom plate; 7. Pressing cylinder; 8. Upper cover sealing ring; 9. Pressure gauge; 10. Testing liquid baffle ring; 11. Baffle ring support ring; 12. Sample to be tested; 13. Support plate sealing ring. Detailed Implementation To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this patent, other embodiments obtained by those skilled in the art without creative effort are all within the scope of protection of this patent.

[0019] This invention discloses a device for positive pressure detection of microtube defects, comprising a cavity base plate 6, a detection cavity 3 disposed above the cavity base plate 6, and a sealing cover 5. A clamping cylinder 7 is disposed on the cavity base plate 6 surrounding the detection cavity 3, and the clamping cylinder 7 can press the sealing cover 5 tightly against the detection cavity 3. A detection support plate 4 for supporting the sample 12 to be tested is disposed at the lower part of the detection cavity 3. The outer periphery of the detection support plate 4 is fitted against the inner wall of the detection cavity 3. The detection support plate 4 has a through hole extending from top to bottom and a guide groove located on its upper surface. A gas inlet and outlet are disposed on one side of the detection cavity 3. In one example, the sample 12 to be tested is placed on the detection support plate 4, and then a detection liquid is dripped above the sample 12. The sealing cover 5 is then pressed tightly against the detection cavity 3 by the clamping cylinder 7. When positive pressure gas is introduced through the gas inlet and outlet, the gas pressure above the test sample 12 is greater than the gas pressure below it. If the test sample 12 contains a microtube, the test liquid will flow through the microtube into the guide groove below the test sample 12 under the action of the pressure difference. The pressure range of the positive pressure gas is 0.2 to 0.7 MPa. It should be understood that the test sample 12 is a polished wafer, which can be a silicon carbide substrate, silicon wafer, or epitaxial wafer, or other hard sheet material.

[0020] The lower part of the detection chamber 3 can be sealed by the detection support plate 4, and the upper part of the detection chamber 3 can be sealed by the sealing cover 5. Therefore, during the process of introducing positive pressure gas through the gas inlet and outlet, the detection chamber 3, the sealing cover 5, and the detection support plate 4 can form a sealed chamber. The sealing cover 5 can be pressed tightly against the top of the detection chamber 3 by the pressing cylinder 7, so the sealed chamber can withstand high gas pressure. This creates a large pressure difference between the upper and lower sides of the sample 12 to be tested, thereby significantly improving the efficiency of microtube detection.

[0021] Preferably, the positive pressure detection device for microtube defects further includes a detection frame 1. The bottom of the detection frame 1 has a horizontal plate for placing the cavity bottom plate 6. A top cover lifting mechanism 2 is provided on one side of the detection frame 1. The top cover lifting mechanism 2 includes a slide rail fixed to the detection frame 1 and a slide block that can move vertically relative to the slide rail. Thus, during operation, by controlling the slide block to descend along the vertical slide rail, the sealing top cover 5 can be closed to the upper end of the detection cavity 3, facilitating operation.

[0022] After the sealing cover 5 is closed to the upper end of the detection chamber 3, positive pressure gas needs to be introduced into the sealed chamber through the gas inlet and outlet to create a pressure difference between the upper and lower sides of the sample 12 to be tested. Therefore, in order to facilitate the detection liquid to cover the upper surface of the sample 12 to be tested, such as... Figure 4 As shown, the detection chamber 3 is also equipped with a detection liquid baffle ring 10. During detection, the detection liquid baffle ring 10 can be placed on the upper surface of the sample 12 to be tested, so that the detection liquid can be distributed within the detection liquid baffle ring 10. In addition, the detection liquid baffle ring 10 is also equipped with a baffle ring support ring 11. That is, the detection liquid baffle ring 10 is nested on the outer periphery of the baffle ring support ring 11. Specifically, the detection liquid baffle ring 10 is located at the bottom of the baffle ring support ring 11, and the bottom of the detection liquid baffle ring 10 is in contact with the upper surface of the sample 12 to be tested.

[0023] Under conditions where there is a certain pressure difference between the upper and lower sides of the sample 12 to be tested, if the sample 12 contains microtubes, the detection liquid above it will flow into the lower part through the microtubes. After the detection liquid flows into the lower part of the sample 12, it will eventually flow towards the sensor along the guide channel. Therefore, in order to facilitate the sensor to detect the liquid outflow, in this embodiment, the cross-section of the guide channel is a triangle with a wider top and a narrower bottom, and the guide channel spirals around the center of the detection support plate 4. The through hole is located at the center of the guide channel and communicates with the guide channel. Thus, even if there is a small amount of detection liquid below the sample 12, it can still flow along the guide channel to the through hole and be detected by the sensor. This improves the efficiency of microtube detection.

[0024] Preferably, to improve the airtightness of the device, a top cover sealing ring 8 is provided between the detection chamber 3 and the sealing top cover 5, and a support plate sealing ring 13 is provided between the detection support plate 4 and the detection chamber 3. Specifically, an annular groove is provided on the upper end face of the detection chamber 3, and the top cover sealing ring 8 is located in the groove on the upper end face of the detection chamber 3 and can be squeezed by the sealing top cover 5. The lower part of the detection chamber 3 has an annular stepped surface, which can support the lower end face of the detection support plate 4. An annular groove is provided on the outer periphery of the detection support plate 4, and the support plate sealing ring 13 is located in the groove of the detection support plate 4 and can be squeezed by the inner wall of the detection chamber 3. Thus, when positive pressure gas is introduced, the detection chamber 3 can withstand higher gas pressure, maintaining a large pressure difference between the upper and lower sides of the sample 12 to be tested.

[0025] On the other hand, the clamping cylinder 7 includes a cylinder body and a telescopic rod that can move up and down relative to the cylinder body. A clamping part is horizontally rotatably mounted on the upper end of the telescopic rod. Therefore, during the downward movement of the sealed upper cover driven by the upper cover lifting mechanism 2, the clamping cylinder 7 will not interfere. Once the sealed upper cover 5 is engaged with the detection chamber 3, the clamping cylinder 7 can be controlled to press the upper part of the sealed upper cover 5 against the pressure of the clamping part. Preferably, four or more clamping cylinders 7 are evenly spaced on the outer periphery of the detection chamber 3, thereby ensuring that the sealed upper cover 5 is subjected to more even force during the clamping process by the clamping cylinder 7.

[0026] In addition, a pressure gauge 9 is installed on one side of the detection chamber 3. Thus, during the detection process, the air pressure inside the detection chamber 3 can be read through the pressure gauge 9.

[0027] When using this invention for wafer microtube inspection, the operation steps are as follows: Step 1: Place the sample 12 to be tested on the test support plate 4; Step 2: Place the test liquid baffle 10 and baffle support ring 11 on the sample 12 to be tested, and drip the test liquid into the baffle support ring 11 so that the test liquid just covers the upper surface of the sample 12 to be tested. Step 3: Start the device. The sealing cover 5 will be closed with the detection chamber 3 under the action of the upper cover lifting mechanism 2. At the same time, the surrounding pressing cylinders 7 press the sealing cover 5 tightly. Step 4: Begin filling the detection chamber 3 with air, so that the air pressure inside the detection chamber 3 reaches 0.1 to 1 MPa and is maintained for a period of time. When the sensor detects that the detection liquid is flowing out, the red light will light up. When the sensor does not detect that the detection liquid is flowing out, the green light will light up.

[0028] In the description of this invention, the terms "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "vertical," and "horizontal," if applicable, indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used only to describe the invention and not to require the invention to be constructed or operated in a specific orientation; therefore, they should not be construed as limiting the invention. The terms "connected" and "linked" in this invention should be interpreted broadly. For example, they can refer to a connection or a detachable connection; they can refer to a direct connection or an indirect connection through intermediate components. Those skilled in the art can understand the specific meaning of these terms based on the specific circumstances.

[0029] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in its embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novelty disclosed herein.

Claims

1. A device for positive pressure detection of microtube defects, comprising a cavity base plate (6), wherein a detection cavity (3) is disposed above the cavity base plate (6), characterized in that, It also includes a sealing cover (5), and a pressing cylinder (7) is provided on the cavity bottom plate (6) around the detection cavity (3). The pressing cylinder (7) can press the sealing cover (5) on the top of the detection cavity (3); The lower part of the detection cavity (3) is provided with a detection support plate (4) for carrying the sample (12) to be tested. The outer periphery of the detection support plate (4) is in contact with the inner wall of the detection cavity (3). The detection support plate (4) has through holes running through its upper and lower parts and a guide groove located on its upper surface. The detection chamber (3) has a gas inlet and outlet on one side. When positive pressure gas is introduced into the gas inlet and outlet, a pressure difference can be formed between the upper and lower surfaces of the sample to be tested (12); and the gas pressure above the sample to be tested (12) is greater than the gas pressure below it.

2. The device for positive pressure detection of microtube defects according to claim 1, characterized in that, It also includes a testing frame (1), the bottom of which has a horizontal plate for placing the cavity bottom plate (6), and a top cover lifting mechanism (2) is provided on one side of the testing frame (1). The top cover lifting mechanism (2) includes a slide rail fixed to the testing frame (1) and a slide seat that can move vertically relative to the slide rail; the slide seat can drive the sealing top cover (5) to descend and close the sealing top cover (5) with the upper end of the testing cavity (3).

3. The device for positive pressure detection of microtube defects according to claim 2, characterized in that, The detection chamber (3) is also provided with a detection liquid baffle (10) and a baffle support ring (11). The detection liquid baffle (10) is nested on the outer periphery of the bottom of the baffle support ring (11), and the bottom of the detection liquid baffle (10) is in contact with the upper surface of the sample (12) to be tested.

4. The device for positive pressure detection of microtube defects according to claim 3, characterized in that, The cross-section of the guide channel is a triangle that is wider at the top and narrower at the bottom, and the guide channel spirals around the center of the detection bearing plate (4); the through hole is located at the center of the detection bearing plate (4) and is connected to the guide channel.

5. The apparatus for positive pressure detection of microtube defects according to any one of claims 1 to 4, characterized in that, A cover sealing ring (8) is provided between the detection chamber (3) and the sealing cover (5), and a carrier plate sealing ring (13) is provided between the detection carrier plate (4) and the detection chamber (3).

6. The device for positive pressure detection of microtube defects according to claim 5, characterized in that, The upper end face of the detection chamber (3) is provided with an annular groove, and the upper cover sealing ring (8) is located in the groove on the upper end face of the detection chamber (3) and can be squeezed by the sealing cover (5).

7. The apparatus for positive pressure detection of microtube defects according to claim 6, characterized in that, The detection chamber (3) has an annular stepped surface, which supports the lower end face of the detection support plate (4). The outer periphery of the detection support plate (4) is provided with an annular groove. The support plate sealing ring (13) is located in the groove of the detection support plate (4) and can be squeezed by the inner wall of the detection chamber (3).

8. The apparatus for positive pressure detection of microtube defects according to claim 7, characterized in that, The clamping cylinder (7) includes a cylinder body and a telescopic rod that can move up and down relative to the cylinder body. The upper end of the telescopic rod is horizontally rotatably mounted with a clamping part.

9. The device for positive pressure detection of microtube defects according to claim 1, characterized in that, The pressure range of the positive pressure gas is 0.2 to 0.7 MPa.

10. The apparatus for positive pressure detection of microtube defects according to claim 1, characterized in that, The test sample (12) is a wafer that has been ground flat.

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