Detection assembly and detection method for high-purity germanium single crystal low-temperature hall detection

Abstract

A detection assembly and a detection method for high-purity germanium single crystal low-temperature Hall detection are provided. The detection assembly comprises a circuit board having a board surface and four electrodes. The detection assembly further comprises an elastic lever mechanism and a gallium-indium eutectic alloy. The elastic lever mechanism comprises two supports, an insulating plate, two pivot shafts and a metal coil spring. The insulating plate has an operating portion and a pressing portion, the pressing portion passes through the space between the two electrodes into the space surrounded by the four electrodes. The two pivot shafts are respectively pivotally connected to the two supports. The metal coil spring is made of a material that expands when heated and contracts when cooled. The upper end of the metal coil spring is fixed to the lower surface of the pressing portion, and the lower end is fixed to the board surface. The size of the metal coil spring in the direction perpendicular to the board surface is set such that the insulating plate is inclined relative to the board surface of the circuit board and the pressing portion is close to the board surface but spaced apart from the board surface without applying pressure to the pressing portion. The gallium-indium eutectic alloy is used to electrically connect the high-purity germanium single crystal wafer to the four electrodes.

Description

Technical Field

[0001] This disclosure relates to the field of germanium materials, and specifically to a detection component and detection method for low-temperature Hall effect detection of high-purity germanium single crystals. Background Technology

[0002] Currently, for high-purity germanium products with a purity of 12-13N, the impurity concentration of high-purity germanium is determined by using germanium thin sheets to make ohmic electrodes, forming good ohmic contact, and using a Hall effect meter for low-temperature Hall detection. The measured carrier concentration is its impurity concentration.

[0003] Chinese patent document CN116087571A, published on May 9, 2023, discloses a method for using a micro probe station to solve the problems of poor contact and poor ohmic contact at the soldering points when the four vertices of a square thin sample are soldered to a test circuit board via leads in the prior art.

[0004] In the low-temperature environment of low-temperature Hall effect detection, the shrinkage of the leads and solder can cause the connection at the solder joints to become cold or broken.

[0005] The miniature probe station of CN116087571A includes a testing stage and four probe assemblies. The upper surface of the testing stage has a rectangular sample placement area. The testing stage contains a circuit board electrically connected to a Hall effect tester. The four probe assemblies are evenly distributed around the sample placement area. Each probe assembly includes a fixing plate, a limiting rod, and a probe. The limiting rod is mounted on the testing stage and connected to the circuit board. The fixing plate is located at the upper end of the testing stage and rotatably connected to the limiting rod. The probe is connected to the other end of the fixing plate and is longitudinally adjustable. When it is necessary to move the probe upwards, the upper end of the probe is manually lifted, and the probe moves upwards while a clamping plate compresses the first spring. When it is necessary to lower the probe, the external force is removed, and the probe moves downwards under the action of the first spring, pressing against the test point (using an indium-tin alloy point) on the sample.

[0006] CN116087571A uses a first spring to keep the probe pressed firmly against the sample, preventing poor contact. While CN116087571A does not specify the material of the first spring, it is typically made of a material that expands and contracts with temperature changes. The initial test point on the sample is pressed against the probe at room temperature. However, in the subsequent low-temperature Hall effect test, the first spring in CN116087571A contracts. This contraction is equivalent to manually lifting the top of the probe, causing it to move upwards. This loosens the pressure of the probe at low temperatures, reducing the ohmic contact between the probe and the test point on the sample (i.e., reducing the stability and reliability of the ohmic contact). Summary of the Invention

[0007] In view of the problems existing in the background art, the purpose of this disclosure is to provide a detection component and detection method for low-temperature Hall detection of high-purity germanium single crystals, which can ensure the stability and reliability of ohmic contact in the low-temperature environment of low-temperature Hall detection.

[0008] Therefore, a detection component for low-temperature Hall effect detection of high-purity germanium single crystals is provided. The detection component includes a circuit board with a surface and four electrodes protruding from the surface. The four electrodes are electrically connected to a circuit within the circuit board for electrical connection with a Hall effect detector. The relative arrangement of the four electrodes corresponds to the four corners of the high-purity germanium single crystal wafer to be detected. The detection component also includes an elastic lever mechanism and a gallium-indium eutectic alloy. The elastic lever mechanism includes two supports, an insulating plate, two pivot shafts, and a metal helical spring. The two supports are located outside the square area enclosed by four electrodes. The insulating plate has an operating part and a pressure-applying part. The operating part is used by the operator to apply downward pressure and release the pressure. The pressure-applying part passes through the space enclosed by the four electrodes between the two electrodes on the same side of the square. The two pivot shafts are located between the operating part and the pressure-applying part, extending horizontally outward from both sides of the insulating plate in the width direction and pivotally connected to the two supports respectively, so that the operating part and the pressure-applying part form a lever movement around the two pivot shafts. The metal helical spring is made of a material that expands and contracts with temperature. The metal helical spring is located between the two pivot shafts and the two electrodes through which the pressure-applying part passes. The upper end of the metal helical spring is fixed to the lower surface of the pressure-applying part, and the lower end of the metal helical spring is fixed to the surface of the circuit board. The metal helical spring is sized in a direction perpendicular to the surface of the circuit board such that, when no pressure is applied by the pressure-applying part, the insulating plate is inclined relative to the surface of the circuit board, and the pressure-applying part is close to the surface of the circuit board relative to the operating part but spaced apart from the surface of the circuit board. Gallium-indium eutectic alloy is used to drop onto four electrodes before placing a high-purity germanium single crystal wafer onto the four electrodes, and then place the high-purity germanium single crystal wafer onto the four electrodes so that the high-purity germanium single crystal wafer is electrically connected to the four electrodes via the gallium-indium eutectic alloy.

[0009] A detection method for low-temperature Hall effect detection of high-purity germanium single crystals employs the aforementioned detection components. The detection method includes the following steps: Step 1, an operator applies downward pressure to the operating part, causing the insulating plate to pivot so that the pressure-applying part moves away from the surface of the circuit board, thereby ensuring that the gap between the lower surface of the pressure-applying part and the four electrodes meets the requirements for placing the high-purity germanium single crystal wafer on the four electrodes. Simultaneously, a metal helical spring is stretched. Step 2, a gallium-indium eutectic alloy is dropped onto the four electrodes. Step 3, the high-purity germanium single crystal wafer is placed on the four electrodes so that the high-purity germanium single crystal wafer is positioned close to the four electrodes. The electrodes are electrically connected via a gallium-indium eutectic alloy; Step four, the operator releases the downward pressure applied to the operating part, the metal helical spring elastically recovers and contracts, the insulating plate pivots, causing the pressure part to move close to the board surface and press against the high-purity germanium single crystal square placed on the four electrodes; Step five, after step five is completed, a waiting time begins; Step six, after the waiting time ends, the detection component and the high-purity germanium single crystal square are placed in a cryogenic liquid nitrogen environment to cool to the low temperature of Hall detection; Step seven, the circuit board is electrically connected to the Hall detector; Step eight, the Hall detector is started for detection.

[0010] The beneficial effects of this disclosure are as follows.

[0011] In the detection component and method for low-temperature Hall effect detection of high-purity germanium single crystals disclosed herein, at room temperature, the high-purity germanium single crystal wafer is pressed onto four electrodes by the movement of an elastic lever mechanism. In the low-temperature environment of subsequent low-temperature Hall effect detection, the metal helical spring of the elastic lever mechanism, being a material that expands and contracts with temperature, contracts. The contraction of the metal helical spring causes the pressure part to move closer to the surface of the circuit board and further press tightly against the high-purity germanium single crystal wafer placed on the four electrodes. This ensures the stability and reliability of the ohmic contact between the four electrodes and the high-purity germanium single crystal wafer in the low-temperature environment of low-temperature Hall effect detection.

[0012] In the detection component disclosed herein, a gallium-indium eutectic alloy is dropped onto four electrodes to electrically connect the four corners of the high-purity germanium single-crystal wafer to the four electrodes via the gallium-indium eutectic alloy. The gallium-indium eutectic alloy is liquid at room temperature, and its fluidity and adhesion make the electrical connection between the four corners of the high-purity germanium single-crystal wafer and the four electrodes very simple. The gallium-indium eutectic alloy directly replaces the solder or indium-tin alloy points in the prior art, thus making the test point setting of the high-purity germanium single-crystal wafer very free and flexible. In addition, the gallium-indium eutectic alloy has a small coefficient of thermal expansion, which is suitable for maintaining the electrical connection between the four corners of the high-purity germanium single-crystal wafer and the four electrodes in the low-temperature environment of subsequent low-temperature Hall detection. Combined with the aforementioned metal helical spring under compression during cold contraction, the stability and reliability of the ohmic contact between the four electrodes and the high-purity germanium single-crystal wafer are ensured. Attached Figure Description

[0013] Figure 1It is a state diagram of the detection component according to this disclosure before the droplet gallium indium eutectic alloy.

[0014] Figure 2 This is a state diagram of the detection component according to this disclosure after the gallium indium eutectic alloy is dropped.

[0015] Figure 3 This is a state diagram of the detection component according to the present disclosure moving in an elastic lever mechanism to place a high-purity germanium single crystal wafer on an electrode.

[0016] Figure 4 This is a state diagram of the detection component according to the present disclosure moving in an elastic lever mechanism to press down a high-purity germanium single crystal wafer placed on an electrode.

[0017] The reference numerals in the attached figures are explained as follows:

[0018] 100 Detection Components 221 Operation Section

[0019] 1 Circuit board 222 Pressure application section

[0020] 11 Plate 23 Pivot Axis

[0021] 12-electrode 24-metal helical spring

[0022] 2. Elastic lever mechanism; 3. Gallium indium eutectic alloy

[0023] 21 supports and 4 card sleeves

[0024] 22 Insulating Board 200 High-Purity Germanium Single Crystal Square Sheet 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] [Detection components for low-temperature Hall effect detection of high-purity germanium single crystals]

[0027] Reference Figures 1 to 4 The detection component 100 for low-temperature Hall detection of high-purity germanium single crystals includes a circuit board 1, an elastic lever mechanism 2, and a gallium-indium eutectic alloy 3.

[0028] The circuit board 1 has a board surface 11 and four electrodes 12 protruding from the board surface 11. The four electrodes 12 are electrically connected to a circuit (not shown) provided in the circuit board 1 for electrical connection with a Hall detector. The relative arrangement of the four electrodes 12 corresponds to the four corners of the high-purity germanium single crystal square 200 to be tested.

[0029] The elastic lever mechanism 2 includes two supports 21, an insulating plate 22, two pivot shafts 23, and a metal coil spring 24. The two supports 21 are located outside the square area enclosed by the four electrodes 12. The insulating plate 22 has an operating part 221 and a pressure-applying part 222. The operating part 221 is used by an operator to apply downward pressure and release the pressure. The pressure-applying part 222 passes between the two electrodes 12 on the same side of the square and enters the space enclosed by the four electrodes 12. The two pivot shafts 23 are located between the operating part 221 and the pressure-applying part 222, extending horizontally outward from both sides of the insulating plate 22 in the width direction and pivotally connected to the two supports 21 respectively, so that the operating part 221 and the pressure-applying part 222 form a lever motion around the two pivot shafts 23. The metal coil spring 24 is made of a material that expands and contracts with temperature changes. The metal helical spring 24 is located between the two pivot shafts 23 and the two electrodes 12 through which the pressure part 222 passes. The upper end of the metal helical spring 24 is fixed to the lower surface of the pressure part 222, and the lower end of the metal helical spring 24 is fixed to the board surface 11 of the circuit board 1. The metal helical spring 24 is sized in a direction perpendicular to the board surface 11 such that when the pressure part 222 does not apply pressure, the insulating plate 22 is inclined relative to the board surface 11 of the circuit board 1, and the pressure part 222 is close to the board surface 11 of the circuit board 1 relative to the operating part 221 but spaced apart from the board surface 11 of the circuit board 1.

[0030] Gallium indium eutectic alloy 3 is used to drop onto the four electrodes 12 before placing the high-purity germanium single crystal wafer 200 onto the four electrodes 12, and then place the high-purity germanium single crystal wafer 200 onto the four electrodes 12 so that the high-purity germanium single crystal wafer 200 and the four electrodes 12 are electrically connected via gallium indium eutectic alloy 3.

[0031] During operation, when it is necessary to place the high-purity germanium single crystal wafer 200 on the four electrodes 12, the operator applies downward pressure to the operating part 221. The insulating plate 22 pivots, causing the pressure part 222 to move away from the board surface 11 of the circuit board 1, thereby ensuring that the gap between the lower surface of the pressure part 222 and the four electrodes 12 meets the requirement of placing the high-purity germanium single crystal wafer 200 on the four electrodes 12. At the same time, the metal helical spring 24 is stretched, and then the gallium indium eutectic alloy 3 is dropped onto the four electrodes 12. After that, the high-purity germanium single crystal wafer 200 is placed on the four electrodes 12, and the four corners of the high-purity germanium single crystal wafer 200 are electrically connected to the four electrodes 12. Then, the operator releases the downward pressure applied to the operating part 221, the metal helical spring 24 elastically recovers and contracts, and the insulating plate 22 pivots, causing the pressure part 222 to move closer to the board surface 11 of the circuit board 1 and press against the high-purity germanium single crystal wafer 200 placed on the four electrodes 12. Then, the high-purity germanium single crystal wafer 200 is subjected to low-temperature Hall detection in a low-temperature environment. For example, the detection component 100 (i.e., circuit board 1, elastic lever mechanism 2 and gallium indium eutectic alloy 3) together with the high-purity germanium single crystal wafer 200 pressed down is placed in a liquid nitrogen bath (not shown) for low-temperature Hall detection.

[0032] In the detection component 100 disclosed herein, at room temperature, the high-purity germanium single crystal wafer 200 is pressed onto the four electrodes 12 by the movement of the elastic lever mechanism 2. In the low-temperature environment of subsequent low-temperature Hall detection, the metal helical spring 24 of the elastic lever mechanism 2 shrinks due to its thermal expansion and contraction material. The shrinkage of the metal helical spring 24 will cause the pressure part 222 to move closer to the board surface 11 of the circuit board 1 and further press tightly against the high-purity germanium single crystal wafer 200 placed on the four electrodes 12. This ensures the stability and reliability of the ohmic contact between the four electrodes 12 and the high-purity germanium single crystal wafer 200 in the low-temperature environment of low-temperature Hall detection.

[0033] In the detection component 100 disclosed herein, a gallium indium eutectic alloy 3 is dropped onto four electrodes 12 to electrically connect the four corners of the high-purity germanium single crystal wafer 200 to the four electrodes 12 via the gallium indium eutectic alloy 3. The gallium indium eutectic alloy 3 is liquid at room temperature. The fluidity and adhesion of the liquid state make it very simple to realize the electrical connection between the four corners of the high-purity germanium single crystal wafer 200 and the four electrodes 12. The gallium indium eutectic alloy 3 directly replaces the solder or indium-tin alloy points in the prior art. In this way, the test point setting of the high-purity germanium single crystal wafer 200 becomes very free and flexible. In addition, the gallium indium eutectic alloy 3 has a small coefficient of thermal expansion and is suitable for maintaining the electrical connection between the four corners of the high-purity germanium single crystal wafer 200 and the four electrodes 12 in the low-temperature environment of subsequent low-temperature Hall detection. Combined with the aforementioned metal helical spring 24 pressing under cold contraction, the stability and reliability of the ohmic contact between the four electrodes 12 and the high-purity germanium single crystal wafer 200 are ensured.

[0034] In terms of materials, the support 21 can be made of stainless steel, the insulating plate 22 can be made of polytetrafluoroethylene (PTFE), the pivot shaft 23 can be made of stainless steel, and the metal coil spring 24 can be made of carbon steel, copper alloy, or nickel alloy. For example, carbon steel can be C67S, copper alloy can be C17300, and nickel alloy can be NiCr15Fe7TiAl.

[0035] In one example, the gallium-indium eutectic alloy 3 is composed of 80% gallium and 20% indium by mass fraction.

[0036] Reference Figures 1 to 4 In one example, the detection assembly 100 also includes a retainer 4. The retainer 4 is U-shaped and surrounds three sides of the four electrodes 12. The height of the retainer 4 is higher than the height of the electrodes 12 but does not impede the rotational movement of the pressure portion 222 of the elastic lever mechanism 2. The space enclosed by the retainer 4 is adapted to the corresponding three sides of the high-purity germanium single-crystal wafer 200 to hold the high-purity germanium single-crystal wafer 200 placed on the four electrodes 12 from three sides. The retainer 4 helps maintain the positional stability of the high-purity germanium single-crystal wafer 200 on the four electrodes 12, further maintaining the stability and reliability of the ohmic contact between the four electrodes 12 and the high-purity germanium single-crystal wafer 200. Similarly, the retainer 4 can be a polytetrafluoroethylene (PTFE) retainer, which has corrosion resistance and scratch resistance, improving the service life and functional stability of the retainer 4.

[0037] [Detection method for low-temperature Hall effect detection of high-purity germanium single crystals]

[0038] The detection method for low-temperature Hall effect detection of high-purity germanium single crystals according to this disclosure uses the aforementioned detection component 100, and the detection method includes the following steps:

[0039] Step one: The operator applies downward pressure to the operating part 221, causing the insulating plate 22 to pivot so that the pressure-applying part 222 moves away from the board surface 11 of the circuit board 1. This ensures that the distance between the lower surface of the pressure-applying part 222 and the four electrodes 12 meets the requirement of placing the high-purity germanium single crystal wafer 200 on the four electrodes 12. At the same time, the metal helical spring 24 is stretched.

[0040] Step 2: Drop gallium-indium eutectic alloy 3 onto the four electrodes 12;

[0041] Step 3: Place the high-purity germanium single crystal wafer 200 on the four electrodes 12 so that the high-purity germanium single crystal wafer 200 and the four electrodes 12 are electrically connected via gallium indium eutectic alloy 3.

[0042] Step four: The operator releases the downward pressure applied to the operating part 221, the metal coil spring 24 elastically recovers and contracts, the insulating plate 22 pivots, causing the pressure part 222 to move close to the plate surface 11 of the circuit board 1 and press against the high-purity germanium single crystal square sheet 200 placed on the four electrodes 12.

[0043] Step 5, after completing Step 5, enter the waiting time;

[0044] Step 6: After the waiting time is over, place the detection component 100 and the high-purity germanium single crystal wafer 200 in a low-temperature liquid nitrogen environment to cool to the low temperature of Hall detection;

[0045] Step 7: Connect circuit board 1 to the Hall effect detector.

[0046] Step 8: Start the Hall effect detector for testing.

[0047] The advantages and various related features of the detection method for low-temperature Hall detection of high-purity germanium single crystals according to this disclosure can be found in the description of the detection component 100, and will not be repeated here.

[0048] In one embodiment, the waiting time in step six is ​​1-3 minutes.

[0049] 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 detection component for low-temperature Hall effect detection of high-purity germanium single crystal, the detection component (100) comprising a circuit board (1). The circuit board (1) has a board surface (11) and four electrodes (12) protruding from the board surface (11). The four electrodes (12) are electrically connected to the circuit provided in the circuit board (1) for electrical connection with the Hall detector. The relative arrangement of the four electrodes (12) corresponds to the four corners of the high-purity germanium single crystal square (200) to be tested. Its features are, The detection assembly (100) also includes a flexible lever mechanism (2) and a gallium-indium eutectic alloy (3); The elastic lever mechanism (2) includes two supports (21), an insulating plate (22), two pivot shafts (23), and a metal helical spring (24); The two supports (21) are located outside the square area enclosed by the four electrodes (12); The insulating plate (22) has an operating part (221) and a pressure application part (222). The operating part (221) is used for the operator to apply downward pressure to the operating part (221) and release the pressure. The pressure application part (222) passes through the space enclosed by the four electrodes (12) between the two electrodes (12) on the same side of the square. Two pivot shafts (23) are located between the operating part (221) and the pressure part (222), extending horizontally outward from both sides of the width direction of the insulating plate (22) and pivotally connected to the two supports (21) respectively, so that the operating part (221) and the pressure part (222) form a lever movement around the two pivot shafts (23); The metal helical spring (24) is made of a material that expands and contracts with temperature. The metal helical spring (24) is located between the two pivot shafts (23) and the square side. The square side is formed by the two electrodes (12) through which the pressure part (222) passes. The upper end of the metal helical spring (24) is fixed to the lower surface of the pressure part (222), and the lower end of the metal helical spring (24) is fixed to the plate surface (11) of the circuit board (1). The metal helical spring (24) is sized in a direction perpendicular to the plate surface (11) such that when the pressure part (222) does not apply pressure, the insulating plate (22) is inclined relative to the plate surface (11) of the circuit board (1), and the pressure part (222) is close to the plate surface (11) of the circuit board (1) relative to the operating part (221) but spaced apart from the plate surface (11) of the circuit board (1). Gallium indium eutectic alloy (3) is used to drop onto the four electrodes (12) before placing the high-purity germanium single crystal wafer (200) onto the four electrodes (12), and then place the high-purity germanium single crystal wafer (200) onto the four electrodes (12) so that the high-purity germanium single crystal wafer (200) and the four electrodes (12) are electrically connected via gallium indium eutectic alloy (3).

2. The detection component according to claim 1, characterized in that, The support (21) is made of stainless steel; The insulating board (22) is a polytetrafluoroethylene board; The pivot shaft (23) is made of stainless steel.

3. The detection component according to claim 1, characterized in that, The metal helical spring (24) is made of carbon steel, copper alloy or nickel alloy.

4. The detection component according to claim 1, characterized in that, The detection component (100) also includes a ferrule (4). The sleeve (4) is U-shaped and surrounds three sides of the four electrodes (12). The height of the sleeve (4) is higher than the height of the electrodes (12) but does not hinder the rotation of the pressure part (222) of the elastic lever mechanism (2). The space enclosed by the sleeve (4) is adapted to the corresponding three sides of the high-purity germanium single crystal square (200) to lock the high-purity germanium single crystal square (200) placed on the four electrodes (12) from the three sides of the high-purity germanium single crystal square (200).

5. The detection component according to claim 4, characterized in that, The ferrule (4) is a polytetrafluoroethylene ferrule.

6. The detection component according to claim 1, characterized in that, Gallium-indium eutectic alloy (3) consists of 80% gallium and 20% indium by mass fraction.

7. A detection method for low-temperature Hall effect detection of high-purity germanium single crystals, characterized in that, It employs the detection component (100) according to any one of claims 1-6, and the detection method includes the following steps: Step one: The operator applies downward pressure to the operating part (221), and the insulating plate (22) pivots, causing the pressure part (222) to move away from the plate surface (11) of the circuit board (1), thereby ensuring that the gap between the lower surface of the pressure part (222) and the four electrodes (12) meets the requirement of placing the high-purity germanium single crystal wafer (200) on the four electrodes (12). At the same time, the metal helical spring (24) is stretched. Step 2: Drop the gallium-indium eutectic alloy (3) onto the four electrodes (12); Step 3: Place the high-purity germanium single crystal wafer (200) on the four electrodes (12) so that the high-purity germanium single crystal wafer (200) and the four electrodes (12) are electrically connected via gallium indium eutectic alloy (3); Step four, the operator releases the downward pressure applied to the operating part (221), the metal helical spring (24) elastically recovers and contracts, the insulating plate (22) pivots so that the pressure part (222) moves close to the plate surface (11) of the circuit board (1) and presses on the high-purity germanium single crystal square (200) placed on the four electrodes (12); Step 5: After completing Step 4, you will enter a waiting period. Step 6: After the waiting time is over, place the detection component (100) and the high-purity germanium single crystal wafer (200) in a low-temperature liquid nitrogen environment to cool to the low temperature of Hall detection; Step 7: Connect the circuit board (1) to the Hall effect detector. Step 8: Start the Hall effect detector for testing.

8. The detection method for low-temperature Hall effect detection of high-purity germanium single crystals according to claim 7, characterized in that, In step six, the waiting time is 1-3 minutes.

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