A tin terminal semiconductor material and a method of making the same

Abstract

The application discloses a tin terminal semiconductor material and a preparation method thereof. The preparation method first carries out hydrogenation treatment, so that a hydrogen terminal is formed on the surface of the semiconductor material, at this time, carbon-hydrogen bonds are formed between the semiconductor material and hydrogen atoms, and the semiconductor surface is mainly composed of hydrogen atoms; then, the semiconductor surface is subjected to tinization treatment by high-pressure electrolysis of a tin-containing aqueous solution, in the tinization treatment process, enough tin atoms replace a large number of hydrogen atoms, so that carbon-tin bonds can be formed on the semiconductor surface, and then the semiconductor material is tin terminal; the preparation method of the application uses hydrogen atoms as an intermediate medium, so that tin atoms can be combined on the surface of the semiconductor material. The method first realizes the preparation of the tin terminal surface of the semiconductor, and is a high-efficiency, clean and safe surface tinization method, the tin terminal semiconductor surface obtained by the method has high tinization degree and good stability.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of microelectronic information technology, and relates to a tin terminal semiconductor material and a preparation method thereof. BACKGROUND

[0002] The semiconductor industry is an important support for the rapid development of modern electronic information society and is one of the important cornerstones of a new round of technological and industrial revolution. The world today is in a great change that has not been seen in a century, and the competition in the field of high technology is increasingly intense. The global semiconductor industry is becoming more and more complex in the situation of "neck". The surface treatment of semiconductor materials plays a fundamental and important role in the semiconductor industry. In particular, the surface of a semiconductor is combined with other atoms or groups to form a specific terminal structure, which changes the properties of the surface such as conductivity, affinity potential, work function, and thus significantly affects the performance of electronic devices.

[0003] The tin terminal surface has great potential for application in the field of microelectronic technology. The terminal of the surface of a semiconductor is usually composed of non-metallic atoms or groups such as oxygen terminal, hydrogen terminal, fluorine terminal, chlorine terminal, nitrogen terminal, sulfur terminal and hydroxyl terminal. Tin, as a metal material, has a unique surface affinity potential and work function after being combined with the surface of a semiconductor to form a tin terminal. The tin terminal semiconductor surface has important application prospects in the preparation of high-performance Schottky diodes. Traditional chemical treatment methods are difficult to combine tin atoms with the surface of a semiconductor, and plasma methods are difficult to find suitable gas sources, making it extremely difficult to prepare a tin terminal semiconductor surface. SUMMARY

[0004] The purpose of the present application is to overcome the shortcomings of the prior art and provide a tin terminal semiconductor material and a preparation method thereof to solve the bottleneck of being unable to prepare a tin terminal semiconductor surface at present.

[0005] To achieve the above-mentioned purpose, the following technical solutions are adopted in the present application:

[0006] One aspect of the present application discloses a preparation method of a tin terminal semiconductor material, comprising the following steps:

[0007] Step 1: performing plasma hydrogenation treatment on the surface of a semiconductor material to obtain a hydrogen terminal semiconductor material;

[0008] Step 2: fixing the hydrogen terminal semiconductor material on a metal electrode and placing it in an electrolyte containing tin ions, and performing tinization treatment by electrolysis to obtain a tin terminal semiconductor material.

[0009] Preferably, in step 1, the method of plasma hydrogenation treatment is radio frequency and microwave plasma hydrogenation, jet plasma hydrogenation, high-voltage pulse plasma hydrogenation or glow discharge plasma hydrogenation.

[0010] Preferably, in step 2, the electrolyte is a soluble ionic compound of tin.

[0011] Preferably, the soluble ionic compound of tin is tin chloride, stannous chloride, tin bromide, stannous bromide, tin hydroxide, stannous nitrate or stannous sulfate.

[0012] Preferably, in step 2, the electrolyte is a solution of the soluble ionic compound of tin added to water, wherein the concentration of tin ions in the soluble ionic compound of tin is 1 mg / mL and the water content is 100 mL.

[0013] Preferably, in step 2, the electrolysis process applies direct current.

[0014] Preferably, in step 2, the voltage is 100-1000 V and the current is 10-50 mA.

[0015] Preferably, after step 2, the process further comprises a cleaning process.

[0016] Preferably, in step 2, the cleaning process is to sequentially clean the tin-terminated semiconductor material with deionized water, an organic solvent, an acid solution and a base solution.

[0017] Another aspect of the present application discloses a tin-terminated semiconductor material prepared by any of the above preparation methods.

[0018] Compared with the prior art, the present application has the following beneficial effects:

[0019] The present application discloses a preparation method of a tin-terminated semiconductor material. The preparation method first performs a hydrogenation treatment to form a hydrogen termination on the surface of the semiconductor material, at this time, the semiconductor material and hydrogen atoms form a carbon-hydrogen bond, and the surface termination of the semiconductor is a hydrogen atom. Then, a high-pressure electrolysis of a tin-containing aqueous solution is performed on the surface of the semiconductor to perform a tinization treatment. In the tinization treatment process, tin atoms replace the surface hydrogen atoms, so that a carbon-tin bond can be formed on the surface of the semiconductor, and then a tin termination is formed on the semiconductor material. The preparation method of the present application enables tin atoms to be combined on the surface of the semiconductor material by means of hydrogen atoms as an intermediate medium on the basis that tin atoms are difficult to be directly combined on the surface of the semiconductor material. The method first realizes the preparation of a semiconductor tin-terminated surface, and is a high-efficiency, clean and safe surface tinization method. The obtained tin-terminated semiconductor surface has a high tinization degree and good stability.

[0020] Further, if the concentration of tin ions in the soluble ionic compound is too large, the resistance of the electrolyte is too small to apply a high voltage, resulting in insufficient energy of tin ions to replace hydrogen atoms; and if the concentration is too small, it is difficult to meet the requirement of having enough tin atoms to replace hydrogen atoms.

[0021] Further, the surface is cleaned by different types of cleaning liquid to remove the excess deposits on the surface, thereby obtaining the tin-terminated semiconductor surface. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 A schematic diagram of the high-voltage electrolysis of a tin-containing aqueous solution for treating a semiconductor.

[0023] Figure 2 An X-ray photoelectron spectrogram of the tin-terminated diamond surface after the treatment according to the present application. DETAILED DESCRIPTION

[0024] The present application provides a method for preparing a tin-terminated semiconductor material, which comprises the following steps:

[0025] Step 1: performing plasma hydrogenation treatment on the surface of the semiconductor material to obtain a hydrogen-terminated semiconductor material;

[0026] During the treatment, the plasma mode is different, and the control data of the process is different. The hydrogenation mode can be radio frequency and microwave plasma hydrogenation, jet plasma hydrogenation, high-voltage pulse plasma hydrogenation, or glow discharge plasma hydrogenation.

[0027] The binding ability of tin and semiconductor is weaker than that of oxygen, fluorine, hydroxyl, and semiconductor, and the binding ability of tin and semiconductor is stronger than that of hydrogen and semiconductor, so the semiconductor must be treated to a hydrogen-terminated surface in step 1.

[0028] Step 2: fixing the hydrogen-terminated semiconductor material on a metal electrode and placing it in an electrolyte, and performing surface tinization treatment on the hydrogen-terminated semiconductor material by applying a voltage to obtain a tin-terminated semiconductor material. During the electrolysis, a direct current is applied, the voltage is 100-1000V, the current is 10-50mA, and the metal electrode is a corrosion-resistant electrode such as platinum or palladium. In this process, tin ions interact with the semiconductor surface under the action of an electric field and are combined, and the tin atoms replace the hydrogen atoms combined with the diamond surface carbon, thereby forming a tin-terminated semiconductor surface.

[0029] Further, the hydrogen ions generated by water electrolysis under the action of an electric field also play a certain role. Too low a voltage will result in tin that cannot be combined to the semiconductor surface, and too high a voltage will result in hydrogen ions etching away the tin termination on the semiconductor surface. Therefore, the voltage applied in step 2 is 100-1000V.

[0030] The electrolyte in step 2 contains tin ions, and the electrolyte should be a soluble ionic compound of tin such as tin chloride, stannous chloride, tin bromide, stannous bromide, tin hydroxide, stannous nitrate, and stannous sulfate.

[0031] The electrolyte is an aqueous solution containing a tin compound. The preparation process involves first dissolving the soluble ionic compound in deionized water to form a tin compound solution with a tin ion concentration of 1 mg / mL. Then, the tin compound is added to a container containing deionized water to form the electrolyte.

[0032] Step 3: The tin-terminated semiconductor material is sequentially cleaned in deionized water, organic solvent, acid solution, and alkaline solution.

[0033] In step 2, in order to ensure that tin atoms can replace hydrogen atoms in large quantities, an excess of tin is added to the electrolyte. When a large number of hydrogen atoms on the semiconductor surface are replaced, the excess tin will be deposited on the semiconductor surface under the action of the electric field, mainly in the form of elemental tin. Therefore, the deposits on the surface must be removed to obtain a pure tin-terminated semiconductor surface. Therefore, the acid solution in step 3 is hydrochloric acid, sulfuric acid or nitric acid, and the alkaline solution is sodium hydroxide or potassium hydroxide.

[0034] The preparation process of this invention is mainly aimed at diamond, but the method is also applicable to other semiconductor materials, such as silicon and silicon carbide.

[0035] Specific implementation example 1

[0036] (1) Hydrogen-terminated diamond surfaces were epitaxially grown using a microwave plasma chemical vapor deposition system. The growth conditions were: substrate temperature of 1150℃, hydrogen flow rate of 500 sccm, methane flow rate of 50 sccm, cavity pressure of 125 Torr, and processing time of 10 min.

[0037] (2) Weigh 100 mg of stannous chloride and dissolve it in 100 mL of deionized water to form a stannous chloride solution with a concentration of 1 mg / mL. Pour 100 mL of deionized water with a concentration of 18.25 MΩcm into the quartz electrolytic cell and add 0.1 mL of stannous chloride solution dropwise.

[0038] (3) Apply 500V DC to the electrodes and adjust the electrode spacing to make the current 20mA. Perform tinning treatment on the diamond sample for 30min, and control the water temperature during the process to prevent boiling.

[0039] (4) Tin-terminated diamond samples were ultrasonically cleaned in deionized water, acetone, concentrated hydrochloric acid (37% by mass), sodium hydroxide solution (1 mol / L), and deionized water in sequence.

[0040] Figure 2The X-ray photoelectron spectrogram of the tin-terminated diamond surface after the treatment according to the present application shows that there is a very strong tin peak on the diamond surface, and a carbon peak and an oxygen peak of the adsorbed air on the diamond itself, and no chlorine peak is found. The sample is cleaned by acid and alkali solution, so that the source of the tin can be excluded as adsorbed elemental tin or hydrolysis product of stannous chloride, and only the stable termination of carbon-tin bond is possible.

[0041] Example 2

[0042] (1) The hydrogen-terminated diamond surface is etched by inductively coupled dry etching, and the process conditions are as follows: the hydrogen flow rate is 50 sccm, the power is 100 W, and the treatment time is 5 min.

[0043] (2) 100 mg of stannous bromide is weighed and dissolved in 100 mL of deionized water. The deionized water with a resistance of 18.25 MΩcm is injected into a quartz electrolytic cell, and 0.2 mL of stannous bromide solution is added dropwise.

[0044] (3) A direct current of 100 V is applied to the electrode, and the electrode spacing is adjusted so that the current is 10 mA. The diamond sample is treated for 30 min, and the water temperature is controlled to prevent boiling during the treatment.

[0045] (4) The tin-terminated diamond sample is sequentially ultrasonically cleaned in deionized water, acetone, concentrated hydrochloric acid (mass fraction 37%), sodium hydroxide solution (1 mol / L), and deionized water.

[0046] Example 3

[0047] (1) The hydrogen-terminated diamond surface is epitaxially grown by a microwave plasma chemical vapor deposition system, and the substrate temperature is 1100℃, the hydrogen flow rate is 500 sccm, the methane flow rate is 40 sccm, the cavity pressure is 120 Torr, and the treatment time is 10 min.

[0048] (2) 100 mg of stannous nitrate is weighed and dissolved in 100 mL of deionized water. The deionized water with a resistance of 18.25 MΩcm is injected into a quartz electrolytic cell, and 0.05 mL of stannous nitrate solution is added dropwise.

[0049] (3) A direct current of 1000 V is applied to the electrode, and the electrode spacing is adjusted so that the current is 50 mA. The diamond sample is treated for 30 min, and the water temperature is controlled to prevent boiling during the treatment.

[0050] (4) The tin-terminated diamond sample is sequentially ultrasonically cleaned in deionized water, acetone, concentrated hydrochloric acid (mass fraction 37%), sodium hydroxide solution (1 mol / L), and deionized water.

[0051] Example 4

[0052] In this example, the aqueous tin-containing compound solution is an aqueous tin chloride solution, and the rest is the same as in Example 1.

[0053] Example 5

[0054] In this example, the aqueous tin-containing compound solution is an aqueous tin bromide solution, and the rest is the same as in Example 1.

[0055] Example 6

[0056] In this example, the aqueous tin-containing compound solution is an aqueous tin hydroxide solution, and the rest is the same as in Example 1.

[0057] Example 7

[0058] In this example, the aqueous tin-containing compound solution is an aqueous stannous sulfate solution, and the rest is the same as in Example 1.

[0059] The above description is merely preferred embodiments of the present application, but not to confine the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing a tin-terminated semiconductor material, characterized in that, Includes the following steps: Step 1: Perform plasma hydrogenation treatment on the surface of the semiconductor material to obtain hydrogen-terminated semiconductor material; The semiconductor material is diamond or silicon carbide; Step 2: Fix the hydrogen-terminated semiconductor material onto a metal electrode and place it in an electrolyte containing tin ions. Electrolyze the electrolyte to perform tinning treatment to obtain a tin-terminated semiconductor material. In step 2, the electrolyte is obtained by adding a solution of tin-soluble ionic compound to water, wherein the concentration of tin ions in the tin-soluble ionic compound is 1 mg / mL and the water content is 100 mL; direct current is applied during the electrolysis process; in step 2, the voltage is 100~1000 V and the current is 10~50 mA.

2. The method for preparing a tin-terminated semiconductor material according to claim 1, characterized in that, In step 1, the plasma hydrogenation treatment method is radio frequency and microwave plasma hydrogenation, jet plasma hydrogenation, high-voltage pulsed plasma hydrogenation, or glow discharge plasma hydrogenation.

3. The method for preparing a tin-terminated semiconductor material according to claim 1, characterized in that, The soluble ionic compounds of tin are tin chloride, stannous chloride, tin bromide, stannous bromide, tin hydroxide, stannous nitrate, or stannous sulfate.

4. The method for preparing a tin-terminated semiconductor material according to claim 1, characterized in that, Step 2 is followed by a cleaning process.

5. The method for preparing a tin-terminated semiconductor material according to claim 4, characterized in that, In step 2, the cleaning process involves sequentially cleaning the tin-terminated semiconductor material with deionized water, organic solvent, acid solution, and alkaline solution.

6. A tin-terminated semiconductor material prepared by any one of the preparation methods of claims 1-5.

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