Method for displaying metallographic structure of tellurium dioxide wafer

Abstract

The invention provides a metallographic structure display method of a tellurium dioxide wafer. The metallographic structure display method comprises the following steps: carrying out mechanical grinding, mechanical polishing, metallographic corrosion, ultrasonic cleaning, microscope observation and the like on a tellurium dioxide single crystal wafer metallographic sample. The metallographic sample is a tellurium dioxide single crystal wafer. The metallographic phase corrosive is a 1 # metallographic phase corrosive sodium hydroxide aqueous solution and a 2 # metallographic phase corrosive perchloric acid aqueous solution. The concentration of sodium hydroxide is 1mol / L, and the volume ratio of perchloric acid to deionized water is 1: 2. The purity of the sodium hydroxide particles is 99%. The mass percent of the used perchloric acid is 70%-72%. By adopting the metallographic structure display method disclosed by the invention, the grain boundary and defects of the tellurium dioxide single crystal can be clearly displayed.

Description

Technical Field

[0001] The present invention relates to a technique for observing a metallographic structure, and more particularly to a method for displaying the metallographic structure of a tellurium dioxide wafer. Background Art

[0002] Tellurium dioxide (TeO2), also known as tellurium oxide, is an inorganic compound obtained by burning tellurium in air or oxidizing it with hot nitric acid. Tellurium dioxide has a tetragonal crystal structure, is slightly soluble in water, and soluble in strong acids and strong bases. Tellurium dioxide can be used to prepare tellurium dioxide crystals. Tellurium dioxide crystals have birefringence and optical activity and are ideal single crystal materials for making various acousto-optic devices such as acousto-optic deflectors, acousto-optic resonators, acousto-optic modulators, and tunable acousto-optic filters. During the preparation process of tellurium dioxide single crystals, it is necessary to observe the metallographic microstructure of the crystal surface, observe the grain morphology and the size of lattice defects, and further judge its performance.

[0003] However, in the prior art, the effect of displaying the metallographic microstructure of tellurium dioxide is poor, and the methods and steps for displaying the metallographic microstructure of tellurium dioxide single crystal wafers are cumbersome.

[0004] Therefore, it is very necessary to select a suitable metallographic etchant, to make the etching effect of tellurium dioxide single crystal wafers good, to make the display effect of the grains and defect sizes of tellurium dioxide single crystal wafers good, and to simplify the metallographic structure display method. Summary of the Invention

[0005] The purpose of the present invention is to provide a metallographic etchant with good etching effect and precisely controllable etching time, an etching method for a metallographic specimen, and a method for displaying a metallographic structure.

[0006] The purpose of the present invention is achieved through the following technical solutions: A method for displaying the metallographic structure of a tellurium dioxide wafer, the display method specifically includes the following steps:

[0007] S1) Mechanically grind the metallographic specimen of the tellurium dioxide wafer, and mechanically polish the ground metallographic specimen for standby;

[0008] S2) Immerse the metallographic specimen polished in S1) into a No. 1 metallographic etchant for metallographic micro-etching first, and then perform cleaning and drying;

[0009] S3) Immerse the metallographic specimen processed in S2) into a No. 2 metallographic etchant for further etching, and after rinsing and drying, it can be observed under a metallographic microscope.

[0010] Further, the specific steps of S1) are:

[0011] S1.1) Use a 600-mesh grinding disc, with water as the abrasive, control the rotational speed at 20 - 40 rpm, and grind for 20 - 40 min;

[0012] S1.2) Use a 1200-mesh grinding disc for the metallographic specimen processed in S1.1), with W7 corundum micropowder as the abrasive, control the rotational speed at 20 - 40 rpm, and grind for 20 - 40 min;

[0013] S1.3) Use a 3000-mesh grinding disc for the metallographic specimen processed in S1.2), with W0.75 cerium oxide micropowder as the abrasive, control the rotational speed at 20 - 40 rpm, and grind for 20 - 40 min;

[0014] S1.4) Use an 8000-mesh grinding disc for the metallographic specimen processed in S1.3), with W0.5 diamond polishing liquid as the abrasive, control the rotational speed at 20 - 40 rpm, and grind for 20 - 40 min;

[0015] S1.5) Use a polyurethane polishing pad for the metallographic specimen processed in S1.4), with W0.05 silica polishing liquid as the abrasive, control the rotational speed at 20 - 40 rpm, and grind for 20 - 40 min; thus obtaining a metallographic specimen of tellurium dioxide wafer with a surface roughness at the sub-nanometer level.

[0016] Furthermore, the specific steps of S2) are as follows:

[0017] S2.1) Immerse the polished metallographic specimen in S1) into the No. 1 metallographic etchant, heat it in a water bath to 40 - 60 °C, and the etching time is 10 - 20 min;

[0018] S2.2) Place the metallographic specimen etched in S2.1) in the first cleaning solution and ultrasonicate for 4 - 8 min, then use the second cleaning solution to ultrasonically clean for 4 - 8 min, and then rinse and dry with alcohol.

[0019] Furthermore, the No. 1 metallographic etchant in S2.1) is a sodium hydroxide solution with a concentration of 1 - 4 mol / L.

[0020] Furthermore, the specific steps of S3) are as follows:

[0021] S3.1) Immerse the polished metallographic specimen in S2) into the No. 2 metallographic etchant, and the etching time is 40 - 60 min;

[0022] S3.2) Place the metallographic specimen etched in S3.1) in the first cleaning solution and ultrasonicate for 4 - 8 min, then use the second cleaning solution to ultrasonically clean for 4 - 8 min, and then rinse and dry with alcohol.

[0023] Further, the No. 2 metallographic etchant in S3.1) is an aqueous perchloric acid solution.

[0024] Further, the aqueous perchloric acid solution is prepared by mixing perchloric acid with a mass percentage of 70% - 72% and deionized water in a volume ratio of 1:2.

[0025] Further, the first cleaning solution is an aqueous solution of alcohol and deionized water, and the ratio of the two is 1:1;

[0026] The second cleaning solution is an acetone solution.

[0027] The present invention has the following beneficial effects: Using the above technical solution can greatly improve the etching efficiency of tellurium dioxide single crystal wafers and the display effect of the surface metallographic microstructure.

[0028] The method of the present invention utilizes an alkali-acid combined etching method. After the sample material reacts with the alkaline etching solution to generate a wetting angle, and then reacts with the acidic etching solution, it can effectively etch out the tellurium dioxide single crystal grains. In the ordinary bright field mode, a metallographic structure with obvious grain differences and complete and clear grain boundaries can be obtained, and the distinction of the grain sizes of the single crystal can be clearly observed, and obvious single crystal growth information can be obtained according to the grain boundaries.

[0029] Compared with the conventional single etching method, this method greatly improves the discrimination rate of the microstructure, the pictures are clear, and this method is simple and easy to implement without any special equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a flowchart of a method for displaying the metallographic structure of a tellurium dioxide wafer according to the present invention.

[0031] Figure 2 It is a metallographic microscope image of the <001> crystal plane of the tellurium dioxide wafer after etching in the embodiment of the present invention.

[0032] Figure 3 It is an electron microscope image of the <001> crystal plane of the tellurium dioxide wafer after etching in the embodiment of the present invention, magnified 3000 times.

[0033] Figure 4 It is an electron microscope image of the <001> crystal plane of the tellurium dioxide wafer after etching in the embodiment of the present invention, magnified 500 times.

[0034] Figure 5 It is an electron microscope image of the <001> crystal plane of the tellurium dioxide wafer after etching in the embodiment of the present invention, magnified 1000 times. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] In order to enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be described in detail below with reference to specific examples.

[0036] As Figure 1 shown, a method for displaying the metallographic structure of a tellurium dioxide wafer according to the present invention includes the following specific steps:

[0037] S1) Mechanically grind the metallographic specimen of the tellurium dioxide wafer, and then mechanically polish the ground metallographic specimen for standby;

[0038] S2) Immerse the metallographic specimen polished in S1) into the No. 1 metallographic etchant for metallographic micro-etching first, and then perform cleaning and drying;

[0039] S3) Immerse the metallographic specimen treated in S2) into the No. 2 metallographic etchant for further etching. After rinsing and drying, it can be observed under a metallographic microscope.

[0040] Furthermore, the specific steps of S1) are:

[0041] S1.1) Use a 600-mesh grinding disc, use water as the abrasive, control the rotation speed at 20 - 40 rpm, and grind for 20 - 40 min;

[0042] S1.2) Use a 1200-mesh grinding disc for the metallographic specimen treated in S1.1), use W7 corundum micropowder as the abrasive, control the rotation speed at 20 - 40 rpm, and grind for 20 - 40 min;

[0043] S1.3) Use a 3000-mesh grinding disc for the metallographic specimen treated in S1.2), use W0.75 cerium oxide micropowder as the abrasive, control the rotation speed at 20 - 40 rpm, and grind for 20 - 40 min;

[0044] S1.4) Use an 8000-mesh grinding disc for the metallographic specimen treated in S1.3), use W0.5 diamond polishing liquid as the abrasive, control the rotation speed at 20 - 40 rpm, and grind for 20 - 40 min;

[0045] S1.5) Use a polyurethane polishing pad No. 3 for the metallographic specimen treated in S1.4), use W0.05 silica polishing liquid as the abrasive, control the rotation speed at 20 - 40 rpm, and grind for 20 - 40 min; that is, a metallographic specimen of a tellurium dioxide wafer with a surface roughness at the sub-nanometer level is obtained.

[0046] Furthermore, the specific steps of S2) are:

[0047] S2.1) Immerse the metallographic specimen polished in S1) into the No. 1 metallographic etchant, heat it in a water bath to 40 - 60 °C, and the etching time is 10 - 20 min;

[0048] S2.2) Immerse the metallographic specimen after being etched in S2.1) into the first cleaning solution and ultrasonically clean for 4 - 8 minutes, then use the second cleaning solution for ultrasonic cleaning for 4 - 8 minutes, and then rinse with alcohol and dry.

[0049] Furthermore, the No. 1 metallographic etchant in S2.1) is a sodium hydroxide solution with a concentration of 1 - 4 mol / L.

[0050] Furthermore, the specific steps of S3) are as follows:

[0051] S3.1) Immerse the metallographic specimen polished in S2) into the No. 2 metallographic etchant for 40 - 60 minutes for etching;

[0052] S3.2) Immerse the metallographic specimen after being etched in S3.1) into the first cleaning solution and ultrasonically clean for 4 - 8 minutes, then use the second cleaning solution for ultrasonic cleaning for 4 - 8 minutes, and then rinse with alcohol and dry.

[0053] Furthermore, the No. 2 metallographic etchant in S3.1) is an aqueous perchloric acid solution.

[0054] Furthermore, the aqueous perchloric acid solution is prepared by mixing perchloric acid with a mass percentage of 70% - 72% and deionized water in a volume ratio of 1:2.

[0055] Furthermore, the first cleaning solution is an alcohol - deionized water solution with a ratio of 1:1;

[0056] The second cleaning solution is an acetone solution.

[0057] Example:

[0058] The metallographic specimen of a tellurium dioxide single - crystal wafer to be processed is as shown in Figure 2 , and then the metallographic specimen is first mechanically ground and polished, and the mechanically polished metallographic specimen is immersed in the No. 1 metallographic etchant for 10 - 20 minutes. After etching, ultrasonically clean with a 1:1 alcohol - water solution for 5 - 8 minutes, then use an acetone solution to clean for 5 - 8 minutes to wash away the remaining etching solution and etching impurities. Then immerse the metallographic specimen in the No. 2 metallographic etchant for 40 - 60 minutes. After etching, ultrasonically clean with a 1:1 alcohol - water solution for 5 - 8 minutes, then use an acetone solution to clean for 5 - 8 minutes to wash away the remaining etching solution and etching impurities. Then rinse with alcohol and dry, and then the etched metallographic specimen of the tellurium dioxide single - crystal wafer is obtained. By using the technical solution of the present invention, the grains and lattice defects of the tellurium dioxide single - crystal wafer can be clearly shown, which is beneficial for metallographic observation. The metallographic microscope image of the <001> crystal plane of the processed tellurium dioxide wafer after etching is as shown in Figures 2 - 4 .

[0059] The 1# metallographic etchant in this embodiment is an aqueous sodium hydroxide solution, and the concentration of sodium hydroxide is 1 - 4 mol / L. The 2# metallographic etchant is an aqueous perchloric acid solution, which is prepared by mixing perchloric acid with a mass percentage of 70% - 72% and deionized water in a volume ratio of 1:2. These metallographic etchants are used in sequence and have a synergistic effect. Applying the metallographic etchant to the tellurium dioxide single crystal wafer can greatly improve the etching efficiency of the tellurium dioxide single crystal wafer and the display effect of the metallographic microstructure. Mixing the required reagents evenly according to the required ratio gives the metallographic etchant. The preparation method is simple, and the reagents used are all conventional reagents, which can make the promotion and use of the present invention more convenient.

[0060] In addition, the etching rate of the metallographic etchant of the present invention shows a uniform and stable trend, enabling the etching degree to be more effectively controlled.

[0061] The above has introduced in detail a method for displaying the metallographic structure of a tellurium dioxide wafer provided by the embodiments of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those of ordinary skill in the art, according to the idea of the present application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.

[0062] As used in the specification and claims, certain terms are used to refer to specific components. Those skilled in the art should understand that hardware manufacturers may use different terms to refer to the same component. The specification and claims do not use the difference in name as a way to distinguish components, but use the difference in function of components as the criterion for distinction. As mentioned throughout the specification and claims, "comprising" and "including" are open-ended terms, so they should be interpreted as "comprising / including but not limited to". "Roughly" means within an acceptable error range. Those skilled in the art can solve the technical problem within a certain error range and basically achieve the technical effect. The subsequent description in the specification is a preferred implementation manner for implementing the present application, but the description is for the purpose of explaining the general principle of the present application and is not used to limit the scope of the present application. The protection scope of the present application shall be determined by what is defined in the appended claims.

[0063] It should also be noted that the term "including", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a commodity or system including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such a commodity or system. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of another identical element in the commodity or system including the said element.

[0064] It should be understood that the term "and / or" used herein is merely a description of the associated relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0065] The above description shows and describes several preferred embodiments of the present application. However, as mentioned above, it should be understood that the present application is not limited to the form disclosed herein, should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be changed within the scope of the application concept described herein through the above teachings or the technology or knowledge in the relevant field. And the changes and variations made by those skilled in the art that do not depart from the spirit and scope of the present application shall all be within the protection scope of the appended claims of the present application.

Claims

1. A method for displaying the metallographic structure of a tellurium dioxide wafer, characterized in that: The display method specifically comprises the following steps: S1) mechanically grinding the metallographic sample of the tellurium dioxide wafer, and mechanically polishing the ground metallographic sample for standby use; S2) immersing the metallographic sample polished by S1) into a 1# metallographic etchant for metallographic micro-etching, and then cleaning and drying; S3) immersing the metallographic sample treated by S2) into 2# metallographic etchant for further etching, and after rinsing and drying, it can be observed under a metallographic microscope.

2. The display method according to claim 1, characterized in that: The specific steps of S1) are: S1.1) Use a 600 mesh grinding disc, water as abrasive, control the speed to 20-40 rpm, and grind for 20-40 minutes; S1.2) Grind the metallographic sample treated in S1.1) with a 1200-mesh grinding disc and W7 corundum powder at a speed of 20 to 40 rpm for 20 to 40 minutes; S1.3) grinding the metallographic sample treated in S1.2) with a 3000 mesh grinding disc and W0.75 cerium oxide powder as abrasive, controlling the speed to 20-40 rpm, for 20-40 min; S1.4) grinding the metallographic sample treated in S1.3) with a 8000 mesh grinding disc and W0.5 diamond polishing liquid at a speed of 20-40 rpm for 20-40 min; S1.5) The metallographic sample treated in S1.4) is polished with a 3 polyurethane polishing pad and W0.05 silicon dioxide polishing liquid as abrasive, with a rotation speed of 20 to 40 rpm for 20 to 40 minutes; thus, a metallographic sample of a tellurium dioxide wafer with a surface roughness at the sub-nanometer level is obtained.

3. The display method according to claim 1, characterized in that: The specific steps of S2) are: S2.1) Immerse the polished metallographic sample in S1) into 1# metallographic etchant, heat it to 40-60°C in a water bath, and etch for 10-20 minutes; S2.2) The metallographic sample after being corroded by S2.1) is placed in the first cleaning solution for ultrasonic cleaning for 4-8 minutes, then ultrasonically cleaned with the second cleaning solution for 4-8 minutes, and then rinsed and dried with alcohol.

4. The display method according to claim 3, characterized in that: The 1# metallographic etching agent in S2.1) is a sodium hydroxide solution with a concentration of 1 to 4 mol / L.

5. The display method according to claim 1, characterized in that: The specific steps of S3) are: S3.1) Immerse the polished metallographic sample in S2) into 2# metallographic etchant for 40 to 60 minutes; S3.2) The metallographic sample after being corroded by S3.1) is placed in the first cleaning solution for ultrasonic cleaning for 4-8 minutes, then ultrasonically cleaned with the second cleaning solution for 4-8 minutes, and then rinsed and dried with alcohol.

6. The display method according to claim 5, characterized in that: The 2# metallographic etching agent in S3.1) is a perchloric acid aqueous solution.

7. The display method according to claim 6, characterized in that: The perchloric acid aqueous solution is prepared by mixing perchloric acid with a mass percentage of 70% to 72% and deionized water in a volume ratio of 1:

2.

8. The display method according to claim 3 or 5, characterized in that: The first cleaning solution is an alcohol deionized water solution, and the ratio of the two is 1:1; The second cleaning liquid is an acetone solution.

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