A method for quickly determining the orientation of the positioning surface of indium phosphide cutting sheets and their crystal rods

Abstract

The present application relates to a method for quickly determining the orientation of the positioning surface of an indium phosphide cutting blade and its crystal rod. The method comprises the following steps: S1, manually polishing a (100) face cutting blade cut from the end face of an indium phosphide crystal rod using a manual polishing liquid; S2, contacting the polished indium phosphide cutting blade with a first etching liquid and performing a first etching; S3, cleaning the indium phosphide cutting blade after the first etching and contacting it with a second etching liquid for a second etching; S4, cleaning and drying the indium phosphide cutting blade after the second etching, observing the shape of the dislocation etching pit on the indium phosphide cutting blade after the second etching with an optical microscope, thereby determining the orientation of the positioning surface of the indium phosphide cutting blade and its crystal rod; wherein the second etching liquid contains a hydrobromic acid solution with a mass fraction of hydrobromic acid of 39-41%. The method allows a certain number of scratches to exist on the polished surface, and the entire process can be completed within 1 hour, thereby improving production efficiency.

Description

Technical Field

[0001] The present application relates to the field of semiconductor material technology, and in particular to a method for rapidly determining the orientation of a positioning surface of an indium phosphide cutting sheet and a crystal rod thereof. Background Art

[0002] Indium phosphide (InP) single crystals are III-V binary semiconductor materials composed of phosphorus and indium. They have a bandgap of 1.35 eV and possess superior properties, including high electron mobility, excellent radiation resistance, high thermal conductivity, and a high breakdown electric field. This makes them a key substrate for a wide range of applications, including fiber-optic communications, microwave and millimeter-wave devices, and radiation-hardened solar cells. Satellite signal receivers and amplifiers fabricated using InP chips can operate at extremely high frequencies, are minimally affected by external influences, and exhibit high stability. Light-emitting diodes and PIN detectors fabricated using InP as substrates exhibit near-zero dispersion and low transmission loss, making them widely used in data centers and 5G optical communications.

[0003] In the semiconductor materials industry, indium phosphide wafers are oriented in the (100) crystal plane. To produce qualified indium phosphide wafers, the indium phosphide ingot must be pre-processed with a positioning surface (for diameters under 6 inches) or a positioning notch (for diameters 6 inches and above) in a specific crystallographic direction before slicing. Due to the characteristics of the indium phosphide crystal structure, this positioning surface or positioning notch cannot be determined solely by X-ray diffraction orientation identification.

[0004] At present, the method for determining the positioning surface or positioning cut of indium phosphide cutting disc and its crystal rod (hereinafter referred to as positioning surface) is a chemical mechanical polishing sheet etching method: first, a (100) cutting disc is cut from the end face of the crystal rod, and a series of processing steps such as edge chamfering, grinding, waxing, patching, CMP rough polishing, CMP medium polishing and CMP fine polishing are carried out to obtain a mirror polished surface. Then, the polishing disc is etched with a dislocation etching liquid, and the morphology of the dislocation etching pit is observed with an optical microscope to determine the direction of the positioning surface, and the orientation of the corresponding positioning surface on the wafer and its crystal rod is determined accordingly. Finally, an X-ray diffraction orientation instrument is used to further accurately determine the orientation of the positioning surface, and then the corresponding positioning surface or positioning cut is processed. This method has extremely high requirements for the polishing surface, a long cycle (more than 2 days), and requires the use of dedicated processing equipment, which is inefficient and increases the cost.

[0005] Therefore, it is necessary to provide a method that is simple to operate and can quickly determine the orientation of the positioning surface of the indium phosphide cutting sheet and its crystal rod. Summary of the Invention

[0006] In order to address the shortcomings of the existing technology, the present application provides a new method for quickly determining the orientation of the positioning surface of the indium phosphide cutting blade and its crystal rod. This method can significantly reduce the identification cycle and cost of the positioning surface orientation of the indium phosphide cutting blade and its crystal rod, improve production efficiency, and the entire process can be completed within 1 hour.

[0007] To this end, the present application provides a method for quickly determining the orientation of the positioning surface of an indium phosphide cutting sheet and its crystal rod, the method comprising the following steps:

[0008] S1, manually polishing a (100) faceted slice cut from the end face of an indium phosphide crystal rod using a manual polishing liquid to obtain a polished indium phosphide slice;

[0009] S2, contacting the polished indium phosphide cutting blade with a first etching solution and performing a first etching to obtain an indium phosphide cutting blade after the first etching;

[0010] S3, cleaning the indium phosphide cutting blade after the first etching and contacting it with a second etching solution to perform a second etching, thereby obtaining an indium phosphide cutting blade after the second etching;

[0011] S4, after cleaning and drying the indium phosphide cut piece after the second etching, observing the shape of the dislocation etching pits on the indium phosphide cut piece after the second etching under an optical microscope, so as to determine the orientation of the positioning surface of the indium phosphide cut piece and its crystal rod;

[0012] The second etching solution contains a hydrobromic acid solution, and the mass fraction of the hydrobromic acid in the hydrobromic acid solution is 39-41%.

[0013] In some specific embodiments, the mass fraction of hydrobromic acid in the hydrobromic acid solution can be 39%, 40% or 41%, respectively. In some preferred embodiments, the mass fraction of hydrobromic acid in the hydrobromic acid solution is 40%.

[0014] The second etching solution of the present application contains a specific concentration of hydrobromic acid solution (the mass fraction of hydrobromic acid is 39-41%), which can make the dislocation corrosion pits on the indium phosphide cutting blade have a specific morphology (rectangle). According to the morphology of the dislocation corrosion pits, the orientation of the positioning surface of the indium phosphide cutting blade and its crystal rod can be quickly and accurately determined. If the mass fraction of hydrobromic acid in the hydrobromic acid solution is too high, such as higher than 41%, the aspect ratio of the obtained dislocation corrosion pits will be too small, and even the morphology of the dislocation corrosion pits will directly become square, which is not conducive to the determination of the orientation of the positioning surface; if the mass fraction of hydrobromic acid in the hydrobromic acid solution is too low, such as lower than 39%, it is not conducive to the formation of dislocation corrosion pits. When the mass fraction of hydrobromic acid in the hydrobromic acid solution is 40%, the dislocation corrosion pits formed can have a better morphology, which is conducive to the identification of the positioning surface of the indium phosphide crystal ingot.

[0015] In some embodiments, the dislocation etch pit is rectangular, with a long side of the rectangle parallel to a (0-1-1) crystal plane and a short side parallel to a (0-11) crystal plane.

[0016] The present application discloses that the obtained dislocation etching pit is a rectangle, and the crystallographic orientation of the positioning surface of the indium phosphide ingot can be quickly and accurately revealed based on the long and short sides of the rectangle. The operation process is simple, accurate, fast, economical and efficient.

[0017] In some embodiments, the second etching solution is composed of a hydrobromic acid solution and water; the volume ratio of the hydrobromic acid solution to water is (3-4.5):(0.7-1.5). In some specific embodiments, the volume ratio of the hydrobromic acid solution to water can be, for example, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, or 4.5:1. In some preferred embodiments, the volume ratio of the hydrobromic acid solution to water can be (3-4):1. In some more preferred embodiments, the volume ratio of the hydrobromic acid solution to water is 3.5:1.

[0018] In the present application, the second etching liquid is composed only of hydrobromic acid solution and water, and the volume ratio of the hydrobromic acid solution and water is specifically limited. By adopting the above-mentioned second etching liquid, the obtained dislocation etching pits can be clear, with a high aspect ratio and extremely high recognition, which greatly improves the recognition efficiency of the positioning surface of the indium phosphide ingot and saves production costs.

[0019] In some embodiments, the second etching is performed at a temperature of 30 to 50° C. and for a time of 30 to 120 seconds.

[0020] In some preferred embodiments, the conditions for the second corrosion are: temperature 40° C., time 60 seconds.

[0021] In this application, the second etching is performed at a relatively high temperature, resulting in a shorter etching time, which is conducive to the formation of rectangular dislocation etch pits. If the etching time is too long, such as greater than 120 seconds, the aspect ratio of the obtained dislocation etch pits is too small, which is not conducive to determining the orientation of the aligning plane. If the etching time is too short, such as less than 30 seconds, the formation of dislocation etch pits is not conducive.

[0022] In some embodiments, the manual polishing liquid includes a methanol solution and a liquid bromine solution, and the volume ratio of the methanol solution to the liquid bromine solution is (3-5):1; the mass fraction of methanol in the methanol solution is 99-100%, and the mass fraction of liquid bromine in the liquid bromine solution is 99-100%.

[0023] In some specific embodiments, the manual polishing liquid comprises a methanol solution and a liquid bromine solution, wherein the volume ratio of the methanol solution to the liquid bromine solution is 5:1; the methanol solution has a methanol mass fraction of 99.5%, and the liquid bromine solution has a liquid bromine mass fraction of 99.5%. The present application discloses that the manual polishing liquid with the above composition can effectively remove micro-defects and damaged layers left on the cutting blade from the previous process.

[0024] In the present application, the (100) faceted cutting blade cut from the end face of the indium phosphide crystal rod is first manually polished with a manual polishing liquid before the dislocation is corroded. In the prior art, chemical mechanical polishing is used for the cutting blade, which must be polished on a dedicated polishing machine for a long time and in multiple steps, otherwise it is impossible to achieve a scratch-free and mirror-like effect. However, the manual polishing with a manual polishing liquid used in the present application is a process that combines chemical and manual friction. During the polishing process, the surface of the cutting blade reacts with the oxidant in the manual polishing liquid to generate a soluble salt. The manual polishing liquid and the polishing pad generate mechanical friction with the rapidly sliding surface of the cutting blade, wiping off the surface reactants. The newly exposed surface continues to react with the manual polishing liquid. The chemical and mechanical effects are alternately circulated to remove the micro defects and damage layers left on the surface by the previous process to obtain a relatively flat surface.

[0025] In some embodiments, the first etching solution includes an acid solution, a hydrogen peroxide solution, and water; the volume ratio of the acid solution, the hydrogen peroxide solution, and the water is (0.8-1.2):(3-6):(10-15).

[0026] In the present application, the first etching liquid has a relatively fast etching rate, and after etching is completed, defects such as pits and scratches can be revealed.

[0027] In some preferred embodiments, the acid solution consists of a sulfuric acid solution and a citric acid solution, and the volume ratio of the sulfuric acid solution to the citric acid solution is (5-8):1.

[0028] In the present application, when the acid solution in the first etching solution includes both a sulfuric acid solution and a citric acid solution, a synergistic effect can be achieved, further enhancing the etching effect of the first etching solution. Even if a certain number of scratches and pits are present on the polished surface, subsequent etching can still produce dislocation pits of ideal shape. In some more preferred embodiments, the volume ratio of the sulfuric acid solution to the citric acid solution is 6:1. When the volume ratio of the sulfuric acid solution to the citric acid solution is controlled to 6:1, the effect of the first etching solution can be maximized, and the resulting dislocation etching pits have a better morphology and are clear.

[0029] In some embodiments, the mass fraction of sulfuric acid in the sulfuric acid solution is 98-99.5%; the mass fraction of citric acid in the citric acid solution is 40-45%; and the mass fraction of hydrogen peroxide in the hydrogen peroxide solution is 30-32%.

[0030] In some preferred embodiments, the mass fraction of sulfuric acid in the sulfuric acid solution is 98%, the mass fraction of citric acid in the citric acid solution is 45%, and the mass fraction of hydrogen peroxide in the hydrogen peroxide solution is 30%.

[0031] By controlling the concentration of each component in the first etching solution within the above range, the present application can effectively corrode the cutting blade, revealing defects such as pits and scratches on the cutting blade, and making the dislocation etching pits finally obtained have a better morphology and clear dislocation etching pits.

[0032] In the present application, the water in the first etching solution and the second etching solution is pure water.

[0033] In some embodiments, the conditions for the first corrosion are: temperature of 20-40° C., and time of 1-3 minutes.

[0034] In some specific embodiments, the conditions for the first corrosion are: temperature is room temperature (about 25° C.) and time is 2 minutes.

[0035] In some embodiments, the (100) faceted cut piece cut from the end face of the indium phosphide crystal rod is pre-polished with a grinding fluid to remove saw marks on the surface of the cut piece before manual polishing.

[0036] The grinding liquid used in this application is a conventional grinding liquid in the art, and those skilled in the art can make a conventional selection.

[0037] The existing chemical mechanical polishing method requires a nearly scratch-free polished surface to produce highly recognizable dislocation etch pits, which results in a long cycle (over 2 days) and high costs. However, the method described in this application uses a manual polishing solution for polishing before dislocation etching, alternating chemical and mechanical action cycles. The polished cutting blade has a high surface flatness. Although there are many surface scratches, the dislocation etching pits obtained by using a first etching solution and a second etching solution in conjunction with each other to perform dislocation etching on the indium phosphide cutting blade are clear, have a high aspect ratio, and are highly recognizable. This allows for the rapid and accurate determination of the crystallographic orientation of the positioning surface of the indium phosphide cutting blade and its crystal rod. The operation process is simple, accurate, fast, and economical.

[0038] The principle of the present application using the first etching liquid and the second etching liquid to cooperate with each other to perform dislocation etching of the indium phosphide cutting blade is as follows: the acid etching (sulfuric acid etching and citric acid etching) in the first etching liquid is isotropic etching with a relatively fast rate. During the chemical etching process of the indium phosphide cutting blade, the chemical reaction process is controlled by the complex dissolution rate or the oxidation rate. When the complex dissolution rate controls the chemical reaction process, the reaction products on the surface of the indium phosphide cannot be dissolved in the etching liquid in time, and a barrier layer is formed on the surface of the cutting blade. The presence of the barrier layer inhibits the further progress of the chemical reaction, causing the corrosion rate to decrease; when the oxidation rate controls the chemical reaction process, the reaction products on the surface of the indium phosphide cutting blade can be dissolved in the etching liquid in time, and the chemical reaction can proceed continuously. Therefore, controlling the ratio of the first etching liquid can only display defects such as pits and scratches, but cannot display defects of smaller scales. The hydrobromic acid etching in the second etching liquid is anisotropic etching, which can display micro defects such as dislocations. Defects in a crystal can cause lattice distortion. Compared to intact regions, the potential energy around the defects is higher and the chemical activity is also stronger, resulting in preferential corrosion in a hydrobromic acid etchant, forming dislocation etch pits. Therefore, the present application uses a first etchant and a second etchant to perform dislocation etching on an indium phosphide cutting blade, thereby obtaining dislocation etch pits of a specific morphology. Based on the morphology of the dislocation etch pits, the crystallographic orientation of the positioning plane of the indium phosphide cutting blade and its crystal rod can be determined.

[0039] The beneficial technical effects of the present application are as follows: the method described in the present application first uses a manual polishing liquid to polish the indium phosphide cutting blade before performing dislocation etching, and the polishing is carried out through alternating cycles of chemical and mechanical effects. The surface flatness of the polished cutting blade is relatively high, and by using a specific first etching liquid and a second etching liquid to cooperate with each other to perform dislocation etching on the indium phosphide cutting blade, even when there are many scratches on the cutting blade surface, clear dislocation etching pits can still be obtained. This method can not only quickly and accurately reveal the orientation of the corresponding positioning surface of the indium phosphide single crystal cutting blade and its crystal rod, but also has a simple operation process, and the etching dislocation etching pits have a large aspect ratio, which greatly improves the recognition efficiency and accuracy of the positioning surface of the indium phosphide cutting blade. The entire process can be completed within 1 hour, significantly reducing the processing cycle and cost of the indium phosphide wafer, and has a high application prospect. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is an optical microscope morphology image of the surface of the indium phosphide cutting sheet after manual polishing in Example 1.

[0041] Figure 2 This is an optical microscope morphology image of the surface of the indium phosphide cutting sheet after the first etching by the first etching solution in Example 1.

[0042] Figure 3This is an optical microscope morphology image of the surface of the indium phosphide cut piece after the second etching with the second etching solution in Example 1 and a schematic diagram of the crystallographic orientation of the positioning plane revealed. DETAILED DESCRIPTION

[0043] To make this application easier to understand, the following examples will be used to further illustrate this application. These examples are for illustrative purposes only and are not intended to limit the scope of application of this application. Unless otherwise specified, the raw materials or components used in this application can be obtained through commercial channels or conventional methods.

[0044] Example 1: Determination of the Orientation of the Positioning Surface of the Indium Phosphide Cutting Sheet and its Crystal Ingot

[0045] Preparation of hand polishing liquid: Pour methanol solution into a beaker, then add liquid bromine solution to prepare hand polishing liquid. The mass fraction of methanol in the methanol solution is 99.5%, the mass fraction of bromine in the liquid bromine solution is 99.5%, and the volume ratio of methanol solution to liquid bromine solution is 5:1.

[0046] Preparation of the first etching solution: Pure water and citric acid solution are added to a beaker, and then sulfuric acid solution is slowly added and stirred to obtain a mixed solution containing the acid solution; hydrogen peroxide solution is added to another beaker, and then the mixed solution containing the acid solution is poured into the beaker containing the hydrogen peroxide solution to prepare the first etching solution. In the first etching solution, the volume ratio of the acid solution (citric acid solution and sulfuric acid solution), hydrogen peroxide solution, and water is 1:5:10, the volume ratio of the sulfuric acid solution to the citric acid solution in the acid solution is 6:1, the mass fraction of sulfuric acid in the sulfuric acid solution is 98%, the mass fraction of citric acid in the citric acid solution is 45%, and the mass fraction of hydrogen peroxide in the hydrogen peroxide solution is 30%.

[0047] Preparation of the second etching solution: Add pure water to a beaker, then add hydrobromic acid solution to prepare the second etching solution. The volume ratio of hydrobromic acid solution to water in the second etching solution is 3.5:1, and the mass fraction of hydrobromic acid in the hydrobromic acid solution is 40%.

[0048] Cut a (100) faceted cut piece from the end face of the indium phosphide crystal rod, and use abrasive fluid to grind off the saw marks on the surface of the indium phosphide cut piece. Pour the prepared manual polishing liquid on the polishing pad, then adhere the indium phosphide cut piece to a flat iron block with water and press it on the polishing pad for manual reciprocating polishing. After polishing, rinse it with ultrapure water to obtain the polished indium phosphide cut piece. The optical microscope morphology of its surface is shown in the figure below. Figure 1 As shown. Figure 1It can be seen that the polished indium phosphide cutting sheet has a relatively flat surface. The polished and cleaned indium phosphide cutting sheet is placed in the first etching solution and etched at room temperature for 2 minutes to obtain the indium phosphide cutting sheet after the first etching. The optical microscope morphology of its surface is as follows Figure 2 As shown. Figure 2 It can be seen that the surface of the indium phosphide cutting sheet after the first etching shows defects such as pits and scratches. The indium phosphide cutting sheet after the first etching was washed with pure water and then placed in the second etching solution. It was etched at 40°C for 60 seconds to obtain the indium phosphide cutting sheet after the second etching. After washing with pure water and drying, the morphology of the dislocation etching pits on the indium phosphide cutting sheet after the second etching was observed under an optical microscope. The results are as follows Figure 3 As shown. Figure 3 The dislocation pits are clearly etched and rectangular (with an aspect ratio of 1.74). The orientation of the indium phosphide slices and their ingots is such that the long sides of the dislocation pits are parallel to the (0-1-1) crystal plane, and the short sides are parallel to the (0-11) crystal plane.

[0049] Example 2: Determination of the Orientation of the Positioning Surface of the Indium Phosphide Cutting Sheet and its Crystal Ingot

[0050] The determination process is basically the same as that of Example 1, except that the volume ratio of the sulfuric acid solution to the citric acid solution in the prepared first etching solution is 4:1.

[0051] The final dislocation etching pit is rectangular in shape with an aspect ratio of 1.21, which is relatively low. In addition, the dislocation etching pit is not clear enough, which is not conducive to the identification and determination of the orientation of the positioning plane of the indium phosphide cutting piece and its crystal rod.

[0052] Example 3: Determination of the Orientation of the Positioning Surface of the Indium Phosphide Cutting Sheet and its Crystal Ingot

[0053] The determination process is basically the same as that of Example 1, except that the volume ratio of the citric acid solution to the sulfuric acid solution in the prepared first etching solution is 10:1.

[0054] The final dislocation etching pit is rectangular in shape with an aspect ratio of 1.19, which is relatively low. In addition, the dislocation etching pit is not clear enough, which is not conducive to the identification and determination of the orientation of the positioning plane of the indium phosphide cutting piece and its crystal rod.

[0055] Example 4: Determination of the Orientation of the Positioning Surface of the Indium Phosphide Cutting Sheet and its Crystal Ingot

[0056] The determination process is basically the same as that of Example 1, except that the mass fraction of citric acid in the citric acid solution in the prepared first etching solution is 40%.

[0057] The resulting dislocation etch pits are clear and rectangular in shape, with a high aspect ratio of 1.37. The orientation of the indium phosphide cut wafer and its ingot positioning surface is such that the long side of the dislocation etch pit is parallel to the (0-1-1) crystal plane, and the short side is parallel to the (0-11) crystal plane.

[0058] Example 5: Determination of the Orientation of the Positioning Surface of the Indium Phosphide Cutting Sheet and its Crystal Ingot

[0059] The determination process is basically the same as that of Example 1, except that the mass fraction of citric acid in the citric acid solution in the prepared first etching solution is 50%.

[0060] The final dislocation etching pit is rectangular in shape with an aspect ratio of 1.22, which is relatively low. In addition, the dislocation etching pit is not clear enough, which is not conducive to the identification and determination of the orientation of the positioning plane of the indium phosphide cutting piece and its crystal rod.

[0061] Example 6: Determination of the Orientation of the Positioning Surface of the Indium Phosphide Cutting Sheet and its Crystal Ingot

[0062] The determination process is basically the same as that of Example 1, except that the volume ratio of the hydrobromic acid solution to water in the prepared second etching solution is 1.5:1.

[0063] The shape of the dislocation corrosion pit finally formed is approximately square, with an aspect ratio of 1.06, low recognition, and the dislocation corrosion pit formed is not clear enough, which is not conducive to the identification and determination of the orientation of the positioning surface of the indium phosphide cutting piece and its crystal rod.

[0064] Example 7: Determination of the Orientation of the Positioning Surface of the Indium Phosphide Cutting Sheet and its Crystal Ingot

[0065] The determination process is basically the same as that of Example 1, except that the volume ratio of the hydrobromic acid solution to water in the prepared second etching solution is 2.5:1.

[0066] The resulting dislocation etch pits are slightly less clear and rectangular in shape with an aspect ratio of 1.31. The orientation of the indium phosphide cut wafer and its ingot positioning surface is such that the long side of the dislocation etch pits is parallel to the (0-1-1) crystal plane, and the short side is parallel to the (0-11) crystal plane.

[0067] Example 8: Determination of the Orientation of the Positioning Surface of the Indium Phosphide Cutting Sheet and its Crystal Ingot

[0068] The determination process is basically the same as that of Example 1, except that the volume ratio of the hydrobromic acid solution to water in the prepared second etching solution is 4.5:1.

[0069] The resulting dislocation etch pits are clear and rectangular in shape, with a high aspect ratio of 1.65. The orientation of the indium phosphide saw blades and their ingot positioning surfaces is such that the long side of the dislocation etch pits is parallel to the (0-1-1) crystal plane, and the short side is parallel to the (0-11) crystal plane.

[0070] Example 9: Determination of the Orientation of the Positioning Surface of the Indium Phosphide Cutting Sheet and its Crystal Ingot

[0071] The determination process is basically the same as that of Example 1, except that the mass fraction of hydrobromic acid in the hydrobromic acid solution in the prepared second etching solution is 39%.

[0072] The resulting dislocation etch pits are clear and rectangular in shape, with a high aspect ratio of 1.52. The orientation of the indium phosphide cut wafer and its ingot positioning surface is such that the long side of the dislocation etch pit is parallel to the (0-1-1) crystal plane, and the short side is parallel to the (0-11) crystal plane.

[0073] Example 10: Determination of the Orientation of the Positioning Surface of the Indium Phosphide Cutting Sheet and its Crystal Ingot

[0074] The determination process is basically the same as that of Example 1, except that the mass fraction of hydrobromic acid in the hydrobromic acid solution in the prepared second etching solution is 48%.

[0075] The shape of the dislocation etching pit finally formed is square, and the dislocation etching pit formed is not clear enough, which is not conducive to the identification and determination of the orientation of the positioning surface of the indium phosphide cutting piece and its crystal rod.

[0076] Example 11: Determination of the Orientation of the Positioning Surface of the Indium Phosphide Cutting Sheet and its Crystal Ingot

[0077] The determination process is basically the same as that of Example 1, except that the second etching is performed at room temperature (25° C.) for 60 seconds.

[0078] Ultimately, no corrosion pits were formed.

[0079] Example 12: Determination of the Orientation of the Positioning Surface of the Indium Phosphide Cutting Sheet and its Crystal Ingot

[0080] The determination process is basically the same as that of Example 1, except that the second etching is performed at room temperature (25° C.) for 120 seconds.

[0081] The final dislocation etching pit is rectangular in shape with an aspect ratio of 1.40. The dislocation etching pit is not clear enough, which is not conducive to the identification and determination of the orientation of the positioning plane of the indium phosphide cutting piece and its crystal rod.

[0082] Example 13: Determination of the Orientation of the Positioning Surface of the Indium Phosphide Cutting Sheet and its Crystal Ingot

[0083] The determination process is basically the same as that of Example 1, except that the second etching is performed at 40° C. for 120 seconds.

[0084] The resulting dislocation etch pits are slightly less clear and rectangular in shape with an aspect ratio of 1.43. The orientation of the indium phosphide cut wafer and its ingot positioning surface is such that the long side of the dislocation etch pits is parallel to the (0-1-1) crystal plane, and the short side is parallel to the (0-11) crystal plane.

[0085] It should be noted that the embodiments described above are only used to explain the present application and do not constitute any limitation to the present application. The present application has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present application may be modified as specified within the scope of the claims of the present application, and the invention may be revised without departing from the scope and spirit of the present application. Although the present application described therein relates to specific methods, materials and embodiments, it does not mean that the present application is limited to the specific examples disclosed therein. On the contrary, the present application can be extended to all other methods and applications with the same function.

Claims

1. A method for quickly determining the orientation of the positioning surface of an indium phosphide cutting sheet and its crystal rod, characterized in that: The method comprises the following steps: S1, manually polishing the (100) face slice cut from the end face of the indium phosphide crystal rod using a manual polishing liquid to obtain a polished indium phosphide slice; S2, contacting the polished indium phosphide cutting blade with a first etching solution and performing a first etching to obtain an indium phosphide cutting blade after the first etching; S3, cleaning the indium phosphide cutting blade after the first etching and contacting it with a second etching solution to perform a second etching, thereby obtaining an indium phosphide cutting blade after the second etching; S4, after cleaning and drying the indium phosphide cut piece after the second etching, observing the shape of the dislocation etching pits on the indium phosphide cut piece after the second etching under an optical microscope, so as to determine the orientation of the positioning surface of the indium phosphide cut piece and its crystal rod; The second etching solution is composed of a hydrobromic acid solution and water, the volume ratio of the hydrobromic acid solution to water is 3.5:1, and the mass fraction of hydrobromic acid in the hydrobromic acid solution is 40%; The first etching solution includes an acid solution, a hydrogen peroxide solution, and water; the acid solution is composed of a sulfuric acid solution and a citric acid solution, and the volume ratio of the sulfuric acid solution to the citric acid solution is 6:1; the mass fraction of sulfuric acid in the sulfuric acid solution is 98%; the mass fraction of citric acid in the citric acid solution is 45%; in the first etching solution, the volume ratio of the acid solution, the hydrogen peroxide solution, and water is (0.8-1.2):(3-6):(10-15); The dislocation corrosion pit is in the shape of a rectangle, wherein the long side of the rectangle is parallel to the (0-1-1) crystal plane, and the short side of the rectangle is parallel to the (0-11) crystal plane.

2. The method according to claim 1, characterized in that The conditions of the second corrosion are: temperature 30-50° C., time 30-120 seconds.

3. The method according to claim 1 or 2, characterized in that The manual polishing liquid includes a methanol solution and a liquid bromine solution, wherein the volume ratio of the methanol solution to the liquid bromine solution is (3-5):1; the mass fraction of methanol in the methanol solution is 99-100%, and the mass fraction of liquid bromine in the liquid bromine solution is 99-100%.

4. The method according to claim 1, wherein The mass fraction of hydrogen peroxide in the hydrogen peroxide solution is 30-32%.

5. The method according to claim 4, characterized in that The mass fraction of hydrogen peroxide in the hydrogen peroxide solution is 30%.

6. The method according to claim 1 or 2, characterized in that The conditions for the first corrosion are: temperature 20-40° C., and time 1-3 minutes.

7. The method according to claim 1 or 2, characterized in that The (100) face cutting piece cut from the end face of the indium phosphide crystal rod is pre-polished with a grinding fluid to remove the saw marks on the surface of the cutting piece before manual polishing.

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