A kind of etching device and etching method of germanium sheet or germanium ingot

Abstract

The present invention provides an etching device and method for germanium sheets or germanium ingots, wherein the etching device comprises an etching cylinder; a pad is provided inside the etching cylinder, and a preset distance is provided between the pad and the bottom of the etching cylinder, and the preset distance is greater than 0; the pad comprises a pad body and conical protrusions and holes distributed on the pad body; a heater is provided below the etching cylinder. The device is provided with a conical protrusion to reduce the contact area between the germanium raw material and the etching device, so that the etching is thorough and the etching effect is good. The germanium material is away from the heater below the etching cylinder, and is heated evenly, thereby reducing the generation of cracks.

Description

Technical Field

[0001] The invention belongs to the field of material surface corrosion, and in particular relates to a device and method for corroding a germanium sheet or a germanium ingot. Background Art

[0002] The preparation of infrared-grade germanium single crystals or detector-grade high-purity germanium requires very high purity of the germanium raw material. Before purification, the germanium raw material must be subjected to surface etching to remove the oxide layer and some sticky impurities on the raw material surface. A commonly used etching solution is a NaOH and H2O2 ratio. When germanium is corroded in this etching solution, the main chemical reaction equation is as follows:

[0003] (1)Ge+H2O2=GeO+H2O

[0004] (2)GeO+H2O2=GeO2+H2O

[0005] (3)GeO2+H2O=H2GeO3

[0006] (4) H2GeO3+NaOH=Na2GeO3+H2O

[0007] (5) 2H2O2=2H2O+O2

[0008] The dissolution of GeO2 in water is a relatively slow process. When the concentration of H2O2 is low, the reaction is slow and the corrosion efficiency is low. When the concentration of H2O2 is high, reactions (1) and (2) are simultaneously intensified. When GeO2 is generated, it covers the surface of GeO, hindering further contact between germanium and the oxidant. At the same time, as the concentration of H2O2 increases and the corrosion time prolongs, the generated GeO2 becomes thicker and thicker, and a layer of insoluble white precipitate will form on the surface of germanium. During the corrosion and cleaning process, if the temperature and heat uniformity are not well controlled, the germanium material is very likely to crack under the action of stress.

[0009] Germanium is relatively stable chemically, but when exposed to air, especially at high temperatures, it slowly oxidizes with oxygen and water vapor, forming oxides that adhere to the surface. Germanium is a brittle and hard substance. Improperly configured etching equipment can easily collide with the raw germanium during placement or during the etching process, damaging the equipment or even breaking the raw germanium. Summary of the Invention

[0010] In view of this, an object of the present invention is to provide an etching device and an etching method for germanium sheets or germanium ingots, which have a good etching effect on germanium raw materials.

[0011] The present invention provides an etching device for germanium sheets or ingots, comprising an etching cylinder;

[0012] A pad is provided inside the corrosion cylinder, and a preset distance is set between the pad and the bottom of the corrosion cylinder, and the preset distance is greater than 0;

[0013] The pad includes a pad body and conical protrusions and holes distributed on the pad body;

[0014] A heater is provided below the corrosion cylinder.

[0015] Preferably, the conical protrusions and the holes are arranged in rows, and two adjacent rows of the conical protrusions are separated by a row of the holes.

[0016] Preferably, the conical protrusion is a pyramid or a cone.

[0017] Preferably, the spacing between adjacent conical protrusions is 20 to 30 mm, and the vertical height of each conical protrusion is 3 to 5 mm;

[0018] The distance between adjacent holes is 20-30 mm, and the diameter of each hole is 4.5-5.5 mm.

[0019] Preferably, the corrosion cylinder further comprises a support rod for supporting the backing plate;

[0020] The support rod is installed at the bottom of the inner cavity of the corrosion cylinder.

[0021] Preferably, the pad is provided with multiple layers, and two adjacent layers are separated by support rods.

[0022] Preferably, an overflow port is provided on the upper portion of the side wall of the corrosion cylinder;

[0023] A water outlet is arranged on the side wall of the corrosion cylinder between the pad and the bottom of the corrosion cylinder, and a water outlet pipe is connected to the water outlet; a water outlet flow meter is provided on the water outlet pipe.

[0024] Preferably, it further comprises a water inlet pipe, wherein the water inlet pipe is provided with a water inlet flow meter;

[0025] The water inlet pipe provides water for the corrosion cylinder.

[0026] The present invention provides a method for etching a germanium sheet or a germanium ingot using the etching device described in the above technical solution, comprising the following steps:

[0027] The germanium raw material to be corroded is placed on the pad inside the corrosion cylinder;

[0028] Fill the corrosion cylinder with water through the water inlet pipe, stop filling water to 3 / 4 of the corrosion cylinder, start heating, wait until the water temperature reaches 80-100°C, add alkaline substances, react for 4-8 minutes, stop heating, and simultaneously open the water inlet and outlet, rinse for 3-5 minutes, and then close the water inlet and outlet;

[0029] Turn on the heating, wait until the water temperature reaches 80-100℃, add alkaline substances to dissolve, add H2O2 in batches, stop heating, and simultaneously add and discharge water, rinse for 3-5 minutes, and then close the water inlet and outlet;

[0030] Turn on the heating again, wait until the water temperature reaches 80-100℃, add alkaline substances, react for 4-8 minutes, stop heating, and simultaneously inlet and outlet water, rinse for 3-5 minutes, and then close the water inlet and outlet;

[0031] Continue to turn on the heating, wait until the water temperature reaches 80-100℃, stop heating, and simultaneously add and discharge water for the first time, the water inlet temperature is 50-60℃, rinse for the first time, and close the water inlet and outlet at the same time; add and discharge water for the second time, the water inlet temperature is 30-40℃, rinse for the second time, and close the water inlet and outlet at the same time; add and discharge water for the third time, the water inlet temperature is 10-20℃, rinse for the third time, and close the water inlet and outlet at the same time, take out the germanium raw material, dry it, and complete the corrosion process.

[0032] In the present invention, the alkaline substance is selected from KOH and / or NaOH.

[0033] The stepwise addition of H2O2 specifically includes: based on 5 to 10 kg of the germanium raw material to be corroded;

[0034] When the water temperature reaches 80-100℃, add 5-8g of alkaline substance. After the alkaline substance is completely dissolved, add 30-40mL of H2O2 and react for 2-3min. Add 30-40mL of H2O2 for the second time and react for 2-3min. Add 30-40mL of H2O2 for the third time and react for 2-3min.

[0035] The present invention provides an etching device for germanium sheets or ingots, comprising an etching cylinder; a backing plate disposed within the etching cylinder, with a predetermined distance between the backing plate and the bottom of the etching cylinder being greater than zero; the backing plate comprising a backing plate body and conical protrusions and holes distributed thereon; and a heater disposed beneath the etching cylinder. The conical protrusions reduce the contact area between the germanium material and the etching device, ensuring thorough etching and achieving effective results. The germanium material is kept away from the heater beneath the etching cylinder, receiving uniform heating and reducing the risk of cracks. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1This is a schematic structural diagram of the etching device for germanium sheets or ingots provided by the present invention, wherein 1 is an etching cylinder, 2 is a water inlet, 21 is a water inlet flow meter, 3 is a pad, 31 is a hole, 32 is a conical protrusion, 33 is a support rod, 4 is a water outlet, 41 is a water outlet flow meter, 5 is a heater, and 6 is an overflow port. DETAILED DESCRIPTION

[0037] The present invention provides an etching device for germanium sheets or ingots, comprising an etching cylinder;

[0038] A pad is provided inside the corrosion cylinder, and a preset distance is set between the pad and the bottom of the corrosion cylinder, and the preset distance is greater than 0;

[0039] The pad includes a pad body and conical protrusions and holes distributed on the pad body;

[0040] A heater is provided below the corrosion cylinder.

[0041] In the present invention, the etching device includes an etching cylinder, and a pad is provided inside the etching cylinder; the germanium sheet or germanium ingot is placed on the pad as the germanium raw material for etching, and the pad is made of PTFE.

[0042] The pad includes a pad body and conical protrusions and holes distributed on the pad body; the conical protrusions are preferably pyramids or cones; the conical protrusions can minimize the contact area between the germanium raw material and the corrosion device, and the corrosion is thorough and the corrosion effect is good. The conical protrusions and the holes are arranged in rows, and two adjacent rows of the conical protrusions are separated by a row of the holes. In the present invention, the spacing between adjacent conical protrusions is 20 to 30 mm, and the vertical height of each conical protrusion is 3 to 5 mm; the spacing between adjacent holes is 20 to 30 mm, and the diameter of each hole is 4.5 to 5.5 mm. In a specific embodiment, the area of ​​the pad is 300 to 350 cm 2 The backing plate has one layer, and the distance from the bottom of the corrosion cylinder is 45 mm. The backing plate is provided with triangular pyramids and holes. Two adjacent rows of triangular pyramids are separated by a row of holes. The vertical height of the triangular pyramids is 4 mm, and the spacing between two adjacent triangular pyramids is 25 mm. The diameter of each hole is 5 mm, and the distance between two adjacent holes is 25 mm.

[0043] In this application, a preset distance is preferably provided between the backing plate and the bottom of the corrosion cylinder, wherein the preset distance is greater than 0. The backing plate preferably achieves the desired preset distance via a support rod, the support rod being used to form the backing plate and being mounted on the bottom of the inner cavity of the corrosion cylinder. In a specific embodiment, the preset distance is preferably 40 to 50 mm.

[0044] In the present invention, the number of layers of the backing plate can be one or more. If the backing plate is provided in multiple layers, adjacent layers are separated by support rods. By providing multiple layers of backing plates, more germanium raw materials can be etched at one time, thereby improving etching efficiency.

[0045] In the present invention, an overflow port is provided on the upper portion of the side wall of the corrosion cylinder. In a specific embodiment, the overflow port is provided 20 to 30 mm below the upper edge of the corrosion cylinder to prevent boiling liquid from flowing out of the corrosion cylinder during the corrosion process. In a specific embodiment, the overflow port is provided 25 mm below the upper edge of the corrosion cylinder.

[0046] A water outlet is provided on the side wall of the corrosion cylinder between the backing plate and the bottom of the corrosion cylinder, and a water outlet pipe is connected to the water outlet; the water outlet pipe is provided with a water outlet flow meter and a water outlet switch; the water outlet flow meter and water outlet switch control the flow rate of the water outlet. If the backing plates are provided in multiple layers, the water outlet is located on the side wall of the corrosion cylinder between the bottom backing plate and the bottom of the corrosion cylinder.

[0047] In the present invention, the corrosion device further comprises a water inlet pipe, on which a water flow meter is provided; the water inlet pipe provides water for the corrosion cylinder; the water inlet is preferably 18 megohm high-purity water.

[0048] In the present invention, a heater is provided below the corrosion cylinder, and the heater is used to heat the corrosion liquid and the cleaning liquid.

[0049] In the present invention, the method for etching a germanium sheet or a germanium ingot using the above-mentioned etching device comprises the following steps:

[0050] The germanium raw material to be corroded is placed on the pad inside the corrosion cylinder;

[0051] Fill the corrosion cylinder with water through the water inlet pipe, stop filling water to 3 / 4 of the corrosion cylinder, start heating, wait until the water temperature reaches 80-100°C, add alkaline substances, react for 4-8 minutes, stop heating, and simultaneously open the water inlet and outlet, rinse for 3-5 minutes, and then close the water inlet and outlet;

[0052] Turn on the heating, wait until the water temperature reaches 80-100℃, add alkaline substances to dissolve, add H2O2 in batches, stop heating, and simultaneously add and discharge water, rinse for 3-5 minutes, and then close the water inlet and outlet;

[0053] Turn on the heating again, wait until the water temperature reaches 80-100℃, add alkaline substances, react for 4-8 minutes, stop heating, and simultaneously inlet and outlet water, rinse for 3-5 minutes, and then close the water inlet and outlet;

[0054] Continue to turn on the heating, wait until the water temperature reaches 80-100℃, stop heating, and simultaneously add and discharge water for the first time, the water inlet temperature is 50-60℃, rinse for the first time, and close the water inlet and outlet at the same time; add and discharge water for the second time, the water inlet temperature is 30-40℃, rinse for the second time, and close the water inlet and outlet at the same time; add and discharge water for the third time, the water inlet temperature is 10-20℃, rinse for the third time, and close the water inlet and outlet at the same time, take out the germanium raw material, dry it, and complete the corrosion process.

[0055] In this application, the germanium materials to be corroded should be placed horizontally or vertically, and the germanium materials should not touch each other. In the embodiment, the weight of the germanium material is 5 to 10 kg.

[0056] In this application, water is injected into the corrosion cylinder through a water inlet pipe. Water injection is stopped when the corrosion cylinder is 3 / 4 of the way up, and heating is started. When the water temperature reaches 80-100°C, an alkaline substance is added. After reacting for 4-8 minutes, heating is stopped, and the water inlet and outlet are opened simultaneously. Rinse for 3-5 minutes, and then the water inlet and outlet are closed. This process is a pretreatment of the corroded germanium material. In this application, water is preferably injected to 3 / 4 of the corrosion cylinder. In the embodiment, about 5-7 L of water is injected. In the present invention, based on 5-10 kg of the germanium raw material to be processed, the pretreatment preferably includes 2-3 g of NaOH or 3-4 g of KOH. In a specific embodiment, 2.5 g of NaOH or 3.5 g of KOH are added. Water is simultaneously introduced and discharged at a water flow rate of 2-3 L / min, with the inlet flow rate preferably equal to the outlet flow rate. The inlet water temperature is preferably 50-60°C. The present invention uses alkaline substances to pre-treat the germanium material, remove dirt and oxides on the surface, and discharge them without contaminating the subsequent etching solution.

[0057] After pretreatment, the present application turns on the heating, waits for the water temperature to reach 80-100°C, adds the alkaline substance to dissolve, then adds H2O2 in batches, stops heating, and simultaneously introduces and discharges water, rinses for 3-5 minutes, and then closes the water inlet and outlet. This process is the corrosion process of the germanium material. After pretreatment, the amount of liquid inside the corrosion cylinder still maintains 3 / 4 of the volume of the corrosion cylinder. The present application is based on 5-10 kg of germanium raw material to be processed. Preferably, when the water temperature reaches 80-100°C, the alkaline substance is added, and after the alkaline substance is completely dissolved, 30-40 mL of H2O2 is added, and the reaction is carried out for 2-3 minutes. 30-40 mL of H2O2 is added for the second time, and the reaction is carried out for 2-3 minutes. 30-40 mL of H2O2 is added for the third time, and the reaction is carried out for 2-3 minutes. After stopping heating, water is introduced and discharged simultaneously, the temperature of the inlet water is 50-60°C, the water flow rate is 2-3 L / min, and the inlet flow rate is equal to the outlet flow rate.

[0058] The H2O2 is added in batches during the etching process, avoiding excessively high concentrations when added all at once. Adding all at once would cause the H2O2 to quickly decompose, reducing the etching efficiency and effectiveness. In the present invention, the amount of alkaline material added during the etching process is 5 to 8 g. In a specific embodiment, the amount of NaOH added is 5.5 g, or the amount of KOH added is 7.7 g.

[0059] After the corrosion is completed, the present application turns on the heating again, waits for the water temperature to reach 80-100°C, adds alkaline substances, and stops heating after reacting for 4-8 minutes, while water is introduced and discharged, rinses for 3-5 minutes, and then closes the water inlet and outlet. This process is the final treatment process of the germanium material, and NaOH is used for final treatment to further remove residual oxides and newly generated oxides to ensure that the surface of the germanium material is thoroughly corroded; in a specific embodiment, the amount of NaOH added is (2-3) g; the amount of KOH added is (3-4) g. The flow rates of the inlet and outlet water are both 2-3 L / min, and the inlet and outlet flow rates are equal. The temperature of the inlet water is preferably 50-60°C. In a specific embodiment, the flow rates of the inlet and outlet water are 2.5 L / min; the amount of NaOH added is 2.5 g, or the amount of KOH added is 3.5 g.

[0060] After the final treatment, the present application continues to turn on the heating, and when the water temperature reaches 80-100°C, stops heating, and simultaneously inputs and outputs water for the first time, the inlet water temperature is 50-60°C, and rinses for the first time, and simultaneously closes the inlet and outlet water; simultaneously inputs and outputs water for the second time, the inlet water temperature is 30-40°C, and rinses for the second time, and simultaneously closes the inlet and outlet water; simultaneously inputs and outputs water for the third time, the inlet water temperature is 10-20°C, and rinses for the third time, and simultaneously closes the inlet and outlet water, takes out the germanium raw material, and dries it to complete the corrosion process.

[0061] During the cleaning process, the flow rate of each flushing is preferably 2 to 3 L / min; in a specific embodiment, the flushing flow rate is 2.5 L / min. After each closing of the water inlet and outlet, the water inlet and outlet are preferably opened again after 2 minutes. During the flushing process, the volume of the liquid in the corrosion cylinder is preferably maintained at 3 / 4 of the corrosion cylinder. A temperature gradient is set for the inlet water temperature during the cleaning process, which reduces the stress generated during the corrosion and cleaning of the germanium material and avoids the occurrence of cracks. The water inlet flow rate is not less than the water outlet flow rate, ensuring that the germanium material will not be exposed to the corrosive liquid or the cleaning liquid; the germanium material will not be exposed to the liquid surface during the corrosion and cleaning process, otherwise the germanium will be exposed to the air at a high temperature and will oxidize.

[0062] The present invention preferably takes out the germanium raw material after the cleaning liquid completely flows out of the corrosion cylinder. In the present invention, the drying method is nitrogen blowing or drying.

[0063] To further illustrate the present invention, an etching device and an etching method for a germanium sheet or ingot provided by the present invention are described in detail below in conjunction with embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0064] Example 1

[0065] S1: The germanium raw material to be corroded is weighed and placed on the PTFE pad in the corrosion cylinder. The germanium materials are required to be uniformly placed flat or vertically, and there should be no contact between the germanium materials. The weight of the germanium materials reaches 6kg; the pad has one layer, and the distance from the bottom of the corrosion cylinder is 45mm. The pad is provided with triangular pyramids and holes. Two adjacent rows of triangular pyramids are separated by a row of holes. The vertical height of the triangular pyramids is 4mm, and the spacing between two adjacent triangular pyramids is 25mm. The diameter of each hole is 5mm, and the distance between two adjacent holes is 25mm.

[0066] An overflow port is provided 25 mm below the upper edge of the corrosion cylinder, and a water outlet is provided on the side wall of the corrosion cylinder between the pad and the bottom of the corrosion cylinder. The water outlet is connected to a water outlet pipe, and the water outlet pipe is provided with a water outlet switch and a water outlet flow meter. A heater is provided directly below the corrosion cylinder for heating the corrosion liquid and the cleaning liquid.

[0067] S2: Turn on the water inlet switch, add room temperature pure water, and the water volume should reach three-quarters of the beaker volume. Turn off the water inlet switch, turn on the heating, wait until the water in the corrosion beaker is slightly boiling (95℃), add 2.5g of NaOH, react for 6 minutes, turn off the heating, and turn on the water inlet switch and the water outlet switch at the same time. The water flow rate is 2.5L / min, and the water inlet flow rate is required to be equal to the water outlet flow rate. The water inlet temperature is 55℃. Rinse for 5 minutes, and then turn off the water inlet switch and the water outlet switch at the same time.

[0068] S3: After S2 is completed, ensure that the water volume is still three-quarters of the beaker volume, turn on the heating, wait until the water in the corrosion beaker is slightly boiling, add 5.5g of NaOH, and after the NaOH is completely dissolved, add 35mL of H2O2 (UP level, 30%), react for 2.5min, add 35mL of H2O2 a second time, react for 2.5min, and add 35mL of H2O2 a third time, react for 2.5min; turn off the heating, and turn on the water inlet and outlet switches at the same time, with a water flow rate of 2.5L / min, requiring the inlet flow rate to be equal to the outlet flow rate, and the inlet water temperature to be 55℃. Rinse for 5min, and then turn off the water inlet and outlet switches at the same time;

[0069] S4: After S3, ensure that the water volume is still three-quarters of the beaker volume, turn on the heating, wait until the water in the corrosion beaker is slightly boiling, add 2.5g of NaOH, react for 6 minutes, turn off the heating, and turn on the water inlet and outlet switches at the same time. The water flow rate is 2.5L / min, and the inlet flow rate is required to be equal to the outlet flow rate. The inlet water temperature is 55℃. Rinse for 5 minutes, and then turn off the water inlet and outlet switches at the same time.

[0070] S5: After S4 is completed, ensure that the water volume is still three-quarters of the beaker volume, turn on the heating, wait until the water in the corrosion beaker boils slightly, turn off the heating, and open the water inlet and outlet switches at the same time. The water flow rate is 2.5L / min, and the water inlet flow rate is required to be equal to the water outlet flow rate. The water inlet temperature is 55℃. Rinse for 5 minutes, and then close the water inlet and outlet switches at the same time; 2 minutes later, open the water inlet and outlet switches at the same time, the water flow rate is 2.5L / min, and the water inlet flow rate is required to be equal to the water outlet flow rate. The water inlet temperature is 35℃. Rinse for 5 minutes, and then close the water inlet and outlet switches at the same time; 2 minutes later, open the water inlet and outlet switches at the same time, the water flow rate is 2.5L / min, and the water inlet flow rate is required to be equal to the water outlet flow rate. The water inlet temperature is room temperature. Rinse for 10 minutes, turn off the water inlet switch, and after the cleaning liquid has completely flowed out, take out the germanium material, blow it dry with high-purity nitrogen, weigh it, and complete the corrosion process.

[0071] Example 2

[0072] Based on Example 1, NaOH was replaced by KOH. The amount of KOH added in the pretreatment and final treatment was 3.5 g respectively, and the amount of KOH added in the corrosion treatment was 7.7 g.

[0073] Comparative Example 1:

[0074] Compared with Example 1, other operations remain unchanged, no pyramid is provided on the pad, and the germanium material is directly placed on the pad for etching.

[0075] Comparative Example 2:

[0076] Compared with Example 1, other operations remain unchanged, and the small pyramid provided on the pad is changed into a small cylinder, and the germanium material is supported on the small cylinder for etching.

[0077] Comparative Example 3:

[0078] Compared with Example 1, other operations remain unchanged, and 105 ml of H2O2 is added at one time in step S3.

[0079] Comparative Example 4:

[0080] Compared with Example 1, other operations remain unchanged, and the final processing of S4 is cancelled.

[0081] Comparative Example 5:

[0082] Compared with Example 1, other operations remain unchanged, no temperature gradient is set for the inlet water, and pure water at room temperature is used.

[0083] If the present application adopts the visual inspection method to evaluate the corrosion effect of the above-mentioned corroded germanium material, the corrosion standard is that the germanium surface is bright, without white or black oxides, and without cracks.

[0084] Table 1 Corrosion effects of the embodiments and comparative examples

[0085]

[0086]

[0087] In a certain wavelength band, the transmittance will decrease due to the inclusion of trace oxygen elements. If the present application adopts the method of measuring the infrared transmittance of the optical element on the surface of the corroded germanium sheet or germanium ingot, the corrosion effect of the above-mentioned corroded germanium material will be evaluated. The lower the transmittance, the worse the corrosion effect; conversely, the better the corrosion effect.

[0088] Table 2 Corrosion effects of the embodiments and comparative examples

[0089] Transmittance (wavelength 6μm) Transmittance (wavelength 10μm) Example 1 0.485 0.491 Example 2 0.486 0.490 Comparative Example 1 0.473 0.425 Comparative Example 2 0.479 0.446 Comparative Example 3 0.482 0.479 Comparative Example 4 0.484 0.488 Comparative Example 5 0.485 0.490

[0090] As can be seen from the above embodiments, the present invention provides an etching device for germanium wafers or ingots, comprising an etching cylinder; a pad disposed within the etching cylinder, with a predetermined distance between the pad and the bottom of the etching cylinder being greater than zero; the pad comprising a pad body and conical protrusions and holes distributed thereon; and a heater disposed beneath the etching cylinder. The conical protrusions reduce the contact area between the germanium raw material and the etching device, ensuring thorough etching and achieving effective results. The germanium material is kept away from the heater beneath the etching cylinder, receiving uniform heating and reducing the risk of cracks.

[0091] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for etching a germanium sheet or a germanium ingot using an etching device, comprising the following steps: The germanium raw material to be etched is placed on the pad inside the etching cylinder; Inject water into the corrosion cylinder through the water inlet pipe, stop injecting water when the corrosion cylinder is 3 / 4, start heating, wait until the water temperature reaches 80-100°C, add alkaline substances, react for 4-8 minutes, stop heating, turn on the water inlet and outlet at the same time, rinse for 3-5 minutes, and then turn off the water inlet and outlet; Turn on the heating, wait until the water temperature reaches 80-100℃, add alkaline substances to dissolve, add H2O2 in batches, stop heating, and simultaneously inlet and outlet water, rinse for 3-5 minutes, and then close the inlet and outlet water; Turn on the heating again, wait until the water temperature reaches 80-100℃, add alkaline substances, react for 4-8 minutes, stop heating, and simultaneously inlet and outlet water, rinse for 3-5 minutes, and then close the inlet and outlet water; Continue to turn on the heating, wait until the water temperature reaches 80-100°C, stop heating, inlet and outlet water at the same time for the first time, the inlet water temperature is 50-60°C, rinse for the first time, and close the inlet and outlet water at the same time; inlet and outlet water at the same time for the second time, the inlet water temperature is 30-40°C, rinse for the second time, and close the inlet and outlet water at the same time; inlet and outlet water at the same time for the third time, the inlet water temperature is 10-20°C, rinse for the third time, close the inlet and outlet water at the same time, take out the germanium raw material, dry it, and complete the corrosion process; The device for etching the germanium sheet or ingot comprises an etching cylinder; A pad is provided inside the corrosion cylinder, and a preset distance is provided between the pad and the bottom of the corrosion cylinder, and the preset distance is greater than 0; The pad includes a pad body and conical protrusions and holes distributed on the pad body; A heater is arranged below the corrosion cylinder.

2. The method according to claim 1, characterized in that The conical protrusions and the holes are arranged in rows, and two adjacent rows of conical protrusions are separated by a row of holes.

3. The method according to claim 1, characterized in that The conical protrusion is a pyramid or a cone.

4. The method according to claim 1, characterized in that The spacing between adjacent conical protrusions is 20 to 30 mm, and the vertical height of each conical protrusion is 3 to 5 mm; The distance between adjacent holes is 20-30 mm, and the diameter of each hole is 4.5-5.5 mm.

5. The method according to claim 1, characterized in that The corrosion cylinder also includes a support rod for supporting the pad; the support rod is installed at the bottom of the inner cavity of the corrosion cylinder; It also includes a water inlet pipe, on which a water inlet flow meter is provided; the water inlet pipe provides water for the corrosion cylinder.

6. The method according to claim 1, characterized in that The pad is provided with multiple layers, and two adjacent layers are separated by support rods.

7. The method according to claim 1, characterized in that An overflow port is provided on the upper part of the side wall of the corrosion cylinder; A water outlet is arranged on the side wall of the corrosion cylinder between the pad and the bottom of the corrosion cylinder, and a water outlet pipe is connected to the water outlet; a water outlet flow meter is arranged on the water outlet pipe.

8. The method according to claim 1, characterized in that , the alkaline substance is selected from KOH and / or NaOH.

9. The method according to claim 1, characterized in that , the step of adding H2O2 in batches specifically includes: based on 5 to 10 kg of germanium raw material to be corroded; When the water temperature reaches 80-100℃, add 5-8g of alkaline substance, and after the alkaline substance is completely dissolved, add 30-40mL of H2O2 and react for 2-3min. Add 30-40mL of H2O2 for the second time and react for 2-3min. Add 30-40mL of H2O2 for the third time and react for 2-3min.

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