Semiconductor with magnetron sputtering color coating and preparation method

Abstract

The invention belongs to the technical field of semiconductor surface films and physical vapor deposition, and relates to a semiconductor with a magnetron sputtering color coating and a preparation method. According to the method, argon and nitrogen are introduced into a vacuum cavity, a colored film is formed by adopting iron target magnetron sputtering, and the surface of the crystal presents transparent colors such as orange, golden yellow and light yellow by adjusting the air pressure, the power and the flow ratio; and a SiO2 protective film is deposited on the outer layer of the film by adopting a silicon target through magnetron sputtering, so that the compactness, the adhesive force and the wear and corrosion resistance of the film layer are improved. Compared with a traditional electroplating or dyeing method, the technological process is simple and convenient, color changing is flexible, and the obtained composite film is bright in color, stable and durable, is visually pure and transparent, is not prone to fading or damage and is suitable for semiconductor crystal decoration and optical functional film application.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor surface thin film and physical vapor deposition technology, and particularly relates to a semiconductor with a magnetron sputtering colored coating and its preparation method. Background Technology

[0002] Silicon carbide crystals, due to their high hardness and high refractive index, have significant application value in optoelectronic devices, functional coatings, and decorative applications. However, their naturally colorless and transparent appearance limits the diversity of surface colors, necessitating the use of surface deposition coatings to achieve specific colors and functional effects. While traditional electroplating or organic coating methods can impart color, they suffer from drawbacks such as limited color options, poor adhesion, and susceptibility to aging and fading.

[0003] In recent years, vacuum deposition technology has been widely used in the semiconductor and optical fields to prepare dense, uniform, and color-controllable functional thin films. Traditional vacuum evaporation technology forms thin films by evaporating materials and obtains colors using interference colors, and is often used for optical and decorative coatings. However, the films have poor density and low adhesion. High-vacuum molecular beam epitaxy (HBE) produces films with high uniformity and good adhesion, but it suffers from low deposition rates, high costs, and is not suitable for large-scale fabrication. In contrast, magnetron sputtering technology is widely used due to its advantages of low cost, high deposition rate, high uniformity, applicability to complex targets, reactive sputtering, and co-sputtering. Since silicon carbide substrate is a brittle semiconductor material, how to optimize sputtering parameters and rationally select target materials and multilayer film structures to obtain a semiconductor crystal surface coating with controllable color, strong adhesion and stable durability is a technical problem that this invention urgently needs to solve. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a semiconductor with a magnetron sputtered colored coating and its preparation method. This invention utilizes magnetron sputtering to deposit colored thin films on semiconductor crystals. By precisely controlling the film composition and thickness, color variations such as orange, golden yellow, and light yellow are achieved. The resulting coating exhibits a bright and pure visual effect, unlike the specular reflective appearance of traditional metal coatings. The technical solution of the present invention is as follows: A method for preparing a semiconductor with a color coating by magnetron sputtering includes the following steps: (1) The semiconductor crystal substrate is ultrasonically cleaned and then dried; (2) Place the substrate into the vacuum chamber, evacuate to a high vacuum and heat it; (3) A working gas and a reactive gas are introduced into a vacuum chamber to ionize the working gas and form plasma; the working gas is argon, and the reactive gas is oxygen, nitrogen or a mixture thereof, with a flow ratio of 1 to 20:1, a working pressure of 0.5 to 3.0 Pa, a sputtering power of 20 to 200 W, a working temperature of 25 to 300 ℃, and a sputtering time of 1 to 300 min; a colored thin film is deposited on the substrate surface using magnetron sputtering on a high-purity iron target; (4) A silicon target is used to magnetron sputter on the surface of the colored thin film. The flow ratio of argon to nitrogen is controlled to be 3:2, the working pressure is 1.0-1.5 Pa, the sputtering power is 80-100W, and the sputtering time is 1-300min. A transparent protective film of SiO2 is deposited to obtain a semiconductor with a colored coating.

[0005] Preferably, the semiconductor crystal substrate in step (1) is one or more of silicon carbide, silicon, gallium oxide, gallium nitride, aluminum nitride, or diamond.

[0006] Preferably, the heating temperature in step (2) is 25-300℃.

[0007] Preferably, in step (3), the target material is pre-sputtered before the gas is introduced to remove surface impurities, and the pre-sputtering time is 20 to 30 minutes.

[0008] Preferably, the color of the colored functional film in step (3) is orange, golden yellow, or light yellow.

[0009] More preferably, in step (3), when the color of the colored film is orange, the flow ratio of argon to nitrogen is 8-20:1; the working pressure is 0.5-2.0 Pa; and the sputtering power is 80-100W.

[0010] More preferably, in step (3), when the colored film is golden yellow, the flow ratio of argon to nitrogen is 5-10:1; the working pressure is 1.0-2.0 Pa; and the sputtering power is 80-100W.

[0011] More preferably, in step (3), when the color of the colored film is light yellow, the flow ratio of argon to nitrogen is 4-8:1; the working pressure is 1.5-3.0 Pa; and the sputtering power is 80-100W.

[0012] Preferably, during the sputtering deposition process in steps (3) and (4), the substrate is rotated at a constant speed to ensure the uniformity of the film layer.

[0013] The method is applicable to the surface coloring and optical functional film preparation of semiconductor crystal substrates such as silicon carbide single crystals, silicon, gallium oxide, gallium nitride, aluminum nitride, or diamond.

[0014] This invention is not only applicable to decorative coloring of silicon carbide semiconductor crystals, but can also be extended to the preparation of surface optical coatings for semiconductor crystals such as silicon, gallium oxide, gallium nitride, aluminum nitride, and diamond.

[0015] In the magnetron sputtering process, high-purity iron and high-purity silicon are used as the target materials, argon is used as the sputtering working gas, and oxygen, nitrogen or a mixture of gases are used as the reaction gas to sputter colored thin film / SiO2 composite film targets.

[0016] High-energy ions in the plasma bombard the target surface under the influence of an electric field, sputtering out free target atoms. These target atoms react with reactive gases near the substrate to form compounds, which are then deposited on the surface of the semiconductor crystal substrate, thus forming a dense and uniform colored thin film.

[0017] The iron nitride colored film exhibits bright colors such as orange, golden yellow, or light yellow in reflected light through optical interference and the optical absorption / reflection mechanism of metal nitrides.

[0018] Compared with the prior art, the present invention has the following beneficial effects: The magnetron sputtering process employed in this invention is simple, and the deposition conditions are easy to control, enabling the preparation of iron nitride colored thin films / SiO2 composite films on semiconductor crystal surfaces. These composite films not only exhibit bright and pure decorative colors such as orange, golden yellow, and light yellow, but also allow for flexible color-changing effects by adjusting the film thickness and deposition parameters. Simultaneously, a colorless silicon dioxide (SiO2) dielectric film is sputtered onto the deposited metallic colored layer as a protective layer. The resulting film structure is dense, has high hardness, and exhibits good adhesion, wear resistance, and corrosion resistance. Compared to traditional electroplating or dyeing methods, the colored thin films obtained by this invention have more stable and lasting colors, and appear visually pure and bright, resisting fading or damage. Attached Figure Description

[0019] Figure 1 This is a structural diagram of the film system in which the color film in this invention displays color on a silicon carbide semiconductor crystal; Figure 2 The images show the semiconductor crystals before (a) and after (b), (c), and (d) plating in Examples 1-3 of this invention. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. Example 1 A method for depositing an orange thin film on the surface of a silicon carbide semiconductor crystal includes the following steps: (1) Substrate pretreatment The sample was ultrasonically cleaned sequentially in acetone (purity ≥99.5%), anhydrous ethanol (purity ≥99.7%), and deionized water, each step lasting 5–10 minutes, to ensure the removal of different types of impurities. After cleaning, the sample surface was immediately dried with high-purity nitrogen to prevent moisture condensation and secondary contamination.

[0021] (2) Power-on preparation Turn on the main power supply and gas cylinder valve, start the chiller, set the temperature to 13°C, and transfer the silicon carbide semiconductor crystal substrate into the sputtering chamber for loading.

[0022] (3) Vacuum and heating First, start the mechanical pump and open the pre-evacuation valve to perform low-vacuum evacuation. When the vacuum level in the sputtering chamber drops to 1.0 × 10⁻⁶... -1 Below Pa, close the pre-evacuation valve and open the solenoid valve and gate valve. Simultaneously start the molecular pump to perform high-vacuum evacuation until the chamber pressure stabilizes at 4.0 × 10⁻⁶ Pa. -3 The temperature is approximately Pa. At this point, the heating module is activated to heat the sample stage to 240°C, and the stepper motor is started to rotate the sample stage at a uniform speed, ensuring uniform film deposition. (4) Splashing After the pressure and temperature reach the preset parameters, sputtering preparation begins. Gas is introduced into the sputtering chamber, and the flow ratio of argon to nitrogen is controlled at 17:1 using a gas flow meter. The chamber pressure is fine-tuned using a gate valve, with the working pressure set to 1.6 Pa. After adjusting the sputtering power to 80 W, the DC power supply is connected. The sample baffle is closed for 30 minutes of pre-sputtering to remove oxides or impurities from the target surface. After pre-sputtering, the baffle is opened to deposit a thin film on the semiconductor crystal substrate for 10 minutes, completing the colored film. During the process, a blue glow is observed through the sputtering chamber observation window to ensure the equipment is functioning correctly. The baffle is then closed, and the flow ratio of argon to oxygen is adjusted to 3:2, the working pressure is set to 1.2 Pa, and the sputtering power is adjusted to 80 W. The baffle is then opened again to begin film deposition, which takes 20 minutes to complete the sputtering of the SiO2 film. The final semiconductor crystal is orange in color.

[0023] (5) Sampling and shutdown After sputtering is complete, close the baffle, and sequentially disconnect the DC power supply, inlet valve, mixing chamber valve, and gas cylinder valve. After the molecular pump speed returns to zero and the machine stops, turn off the molecular pump, solenoid valve, and mechanical pump. Open the vent valve and remove the sample that has cooled to room temperature. Separately package the prepared sample into a clean sample box for storage. After sampling, evacuate the sputtering chamber to a low vacuum state, then turn off the power and shut down the machine.

[0024] Thin film structures such as Figure 1As shown, the physical images of the silicon carbide semiconductor crystal before and after color plating are as follows: Figure 2 As shown, (a) is uncoated moissanite, and (b) is moissanite after coating for this example.

[0025] Example 2 A method for depositing a golden yellow thin film on the surface of a silicon carbide semiconductor crystal includes the following steps: (1) Substrate pretreatment The sample was ultrasonically cleaned sequentially in acetone (purity ≥99.5%), anhydrous ethanol (purity ≥99.7%), and deionized water, each step lasting 5–10 minutes, to ensure the removal of different types of impurities. After cleaning, the sample surface was immediately dried with high-purity nitrogen to prevent moisture condensation and secondary contamination.

[0026] (1) Power-on preparation Turn on the main power supply and gas cylinder valve, start the chiller, set the temperature to 13°C, and transfer the silicon carbide semiconductor crystal substrate into the sputtering chamber for loading.

[0027] (2) Vacuum and heating First, start the mechanical pump and open the pre-evacuation valve to perform low-vacuum evacuation. When the vacuum level in the sputtering chamber drops to 1.0 × 10⁻⁶... -1 Below Pa, close the pre-evacuation valve and open the solenoid valve and gate valve. Simultaneously start the molecular pump to perform high-vacuum evacuation until the chamber pressure stabilizes at 4.0 × 10⁻⁶ Pa. -3 The temperature is approximately Pa. At this point, the heating module is activated to heat the sample stage to 240°C, and the stepper motor is started to rotate the sample stage at a uniform speed, ensuring uniform film deposition. (3) Sputtering After the pressure and temperature reach the preset parameters, sputtering preparation begins. Gas is introduced into the sputtering chamber, and the flow ratio of argon to nitrogen is controlled at 8:1 using a gas flow meter. The chamber pressure is fine-tuned using a gate valve, with the working pressure set to 1.7 Pa. After adjusting the sputtering power to 80 W, the DC power supply is connected. The sample baffle is closed for 30 minutes of pre-sputtering to remove oxides or impurities from the target surface. After pre-sputtering, the baffle is opened to deposit a thin film on the semiconductor crystal substrate for 10 minutes. After deposition, the baffle is closed, and the flow ratio of argon to oxygen is adjusted to 3:2. The working pressure is set to 1.2 Pa, and the sputtering power is adjusted to 80 W. The baffle is then opened to begin film deposition for 20 minutes, completing the sputtering of the SiO2 film. The final semiconductor crystal is golden yellow.

[0028] (4) Sampling and shutdown After sputtering is complete, close the baffle, and sequentially disconnect the DC power supply, inlet valve, mixing chamber valve, and gas cylinder valve. After the molecular pump speed returns to zero and the machine stops, turn off the molecular pump, solenoid valve, and mechanical pump. Open the vent valve and remove the sample that has cooled to room temperature. Separately package the prepared sample into a clean sample box for storage. After sampling, evacuate the sputtering chamber to a low vacuum state, then turn off the power and shut down the machine.

[0029] Thin film structures such as Figure 1 As shown, the physical images of the silicon carbide semiconductor crystal before and after color plating are as follows: Figure 2 As shown, (a) is uncoated moissanite, and (c) is moissanite after coating for this example.

[0030] Example 3 A method for depositing a light yellow thin film on the surface of a silicon carbide semiconductor crystal includes the following steps: (1) Substrate pretreatment The sample was ultrasonically cleaned sequentially in acetone (purity ≥99.5%), anhydrous ethanol (purity ≥99.7%), and deionized water, each step lasting 5–10 minutes, to ensure the removal of different types of impurities. After cleaning, the sample surface was immediately dried with high-purity nitrogen to prevent moisture condensation and secondary contamination.

[0031] (1) Power-on preparation Turn on the main power supply and gas cylinder valve, start the chiller, set the temperature to 13°C, and transfer the silicon carbide semiconductor crystal substrate into the sputtering chamber for loading.

[0032] (2) Vacuum and heating First, start the mechanical pump and open the pre-evacuation valve to perform low-vacuum evacuation. When the vacuum level in the sputtering chamber drops to 1.0 × 10⁻⁶... -1 Below Pa, close the pre-evacuation valve and open the solenoid valve and gate valve. Simultaneously start the molecular pump to perform high-vacuum evacuation until the chamber pressure stabilizes at 4.0 × 10⁻⁶ Pa. -3 The temperature is approximately Pa. At this point, the heating module is activated to heat the sample stage to 240°C, and the stepper motor is started to rotate the sample stage at a uniform speed, ensuring uniform film deposition. (3) Sputtering After the pressure and temperature reach the preset parameters, sputtering preparation begins. Gas is introduced into the sputtering chamber, and the flow ratio of argon to nitrogen is controlled at 6:1 using a gas flow meter. The chamber pressure is fine-tuned using a gate valve, with the working pressure set to 1.7 Pa. After adjusting the sputtering power to 80 W, the DC power supply is connected. The sample baffle is closed for 30 minutes of pre-sputtering to remove oxides or impurities from the target surface. After pre-sputtering, the baffle is opened to deposit a thin film on the semiconductor crystal substrate for 10 minutes. After deposition, the baffle is closed, and the flow ratio of argon to oxygen is adjusted to 3:2. The working pressure is set to 1.2 Pa, and the sputtering power is adjusted to 80 W. The baffle is then opened to begin film deposition for 20 minutes, completing the sputtering of the SiO2 film. The final semiconductor crystal is light yellow in color.

[0033] (4) Sampling and shutdown After sputtering is complete, close the baffle, and sequentially disconnect the DC power supply, inlet valve, mixing chamber valve, and gas cylinder valve. After the molecular pump speed returns to zero and the machine stops, turn off the molecular pump, solenoid valve, and mechanical pump. Open the vent valve and remove the sample that has cooled to room temperature. Separately package the prepared sample into a clean sample box for storage. After sampling, evacuate the sputtering chamber to a low vacuum state, then turn off the power and shut down the machine.

[0034] Thin film structures such as Figure 1 As shown, the physical images of the silicon carbide semiconductor crystal before and after color plating are as follows: Figure 2 As shown, (a) is uncoated moissanite, and (d) is moissanite after coating for this example.

Claims

1. A method for preparing a semiconductor with a color coating by magnetron sputtering, characterized in that, The preparation method includes the following steps: (1) The semiconductor crystal substrate is ultrasonically cleaned and then dried; (2) Place the substrate into the vacuum chamber, evacuate to a high vacuum and heat it; (3) A working gas and a reactive gas are introduced into a vacuum chamber to ionize the working gas and form plasma; the working gas is argon, and the reactive gas is oxygen, nitrogen or a mixture thereof, with a flow ratio of 1 to 20:1, a working pressure of 0.5 to 3.0 Pa, a sputtering power of 20 to 200 W, a working temperature of 25 to 300 ℃, and a sputtering time of 1 to 300 min; a colored thin film of iron-nitrogen compound is deposited on the substrate surface by magnetron sputtering on a high-purity iron target; (4) A silicon target is used to magnetron sputter on the surface of the iron-nitrogen compound colored thin film. The flow ratio of argon to nitrogen is controlled at 3:2, the working pressure is 1.0-1.5 Pa, the sputtering power is 80-100W, and the sputtering time is 1-300min. A SiO2 transparent protective film is deposited to obtain a semiconductor with a colored coating.

2. The preparation method according to claim 1, characterized in that, In step (1), the semiconductor crystal substrate is at least one of silicon carbide, silicon, gallium oxide, gallium nitride, aluminum nitride, or diamond.

3. The preparation method according to claim 1, characterized in that, The heating temperature in step (2) is 25-300℃.

4. The preparation method according to claim 1, characterized in that, Before introducing gas in step (3), the target material is pre-sputtered for 20 to 30 minutes; during the sputtering deposition process in steps (3) and (4), the substrate rotates at a constant speed.

5. The preparation method according to claim 1, characterized in that, In step (3), the color of the colored functional film is orange, golden yellow, or light yellow.

6. The preparation method according to claim 5, characterized in that, In step (3), when the color of the colored functional film is orange, the flow ratio of argon to nitrogen is 8-20:1; the working pressure is 0.5-2.0 Pa; and the sputtering power is 80-100W.

7. The preparation method according to claim 5, characterized in that, In step (3), when the colored film is golden yellow, the flow ratio of argon to nitrogen is 5-10:1; the working pressure is 1.0-2.0 Pa; and the sputtering power is 80-100W.

8. The preparation method according to claim 1, characterized in that, In step (3), when the colored film is light yellow, the flow ratio of argon to nitrogen is 4-8:1; the working pressure is 1.5-3.0 Pa; and the sputtering power is 80-100W.

9. The application of the preparation method according to any one of claims 1-8 in the surface coloring and optical functional film preparation of semiconductor crystal substrates such as silicon carbide, silicon, gallium oxide, gallium nitride, aluminum nitride or diamond.

10. A semiconductor with a colored coating obtained by the preparation method according to any one of claims 1-8.

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