Preparation method of silicon-germanium rotating target material

Abstract

The invention relates to a preparation method of a silicon-germanium rotating target material, which comprises the following steps: S1, preparing raw materials: preparing silicon powder and germanium powder, and mixing according to a required proportion; s2, powder mixing treatment is conducted, specifically, mechanical powder mixing is conducted through a V-shaped powder mixing machine, after powder mixing is finished, drying is conducted through a hot air drying oven, it is guaranteed that powder is dry, and adhesion is prevented; s3, the back pipe is pretreated, whether jumping and the thickness of the back pipe are normal or not is checked, and industrial alcohol is used for cleaning the surface of the back pipe. According to the preparation method of the silicon-germanium rotating target material, the silicon-germanium target material layer surrounding the base body pipe is formed by adopting the plasma thermal spraying technology, the silicon-germanium rotating target material which is high in structural density and free of cracks and has the length and thickness meeting the sputter coating requirement is obtained, the size of the silicon-germanium rotating target material is integrated, and the yield of the silicon-germanium rotating target material is improved. The length and the thickness of the silicon-germanium rotating target material are not limited, the preparation process of the silicon-germanium rotating target material can be simplified, and the preparation cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor manufacturing, and in particular to a method for preparing a silicon-germanium rotating target material. Background Art

[0002] Thin-film silicon solar cells excel in photovoltaic technology due to their efficient light absorption capabilities and flexibility in material composition, which can optimize cell performance and improve energy conversion efficiency. In addition, their production process is suitable for large-scale automated production, which helps reduce costs and ensure consistency and stability of product quality.

[0003] In order to further improve the efficiency and stability of thin-film silicon solar cells, scientists introduced the SiGe / Si superlattice heterojunction structure. By adding germanium elements, the band structure can be adjusted so that the absorption layer can better absorb long-wavelength light, thereby expanding the spectral response range and improving the utilization rate of light energy. Using SiGe thin film instead of pure silicon not only enhances the optoelectronic performance, but also reduces the preparation temperature. It is also compatible with existing silicon processes and supports multi-layer structure design to make full use of sunlight.

[0004] In the process of preparing SiGe thin films, one of the commonly used physical vapor deposition (PVD) methods is magnetron sputtering. This method uses high-energy particles generated by gas discharge to bombard the target surface, causing the target atoms to deposit on the substrate to form a thin film. Compared with planar targets, rotating targets provide higher material utilization, better film uniformity and faster deposition rate, which is very suitable for large-scale industrial production.

[0005] However, there are some limitations when preparing rotary targets by traditional sintering and casting methods:

[0006] Sintering method: It is difficult to prepare a large-sized single target and requires segmented processing, which increases cost and complexity.

[0007] Casting method: It is not suitable for ceramic materials because these materials are prone to defects during the casting process, affecting the quality of the final product.

[0008] Therefore, there is an urgent need to develop a method for preparing a silicon germanium rotating target with simple process and low cost. Summary of the invention

[0009] The purpose of the present invention is to overcome the above-mentioned shortcomings and provide a method for preparing a silicon germanium rotating target with simple process and low cost.

[0010] The object of the present invention is achieved in that:

[0011] A method for preparing a silicon germanium rotating target comprises the following steps:

[0012] S1, preparing raw materials, preparing silicon powder and germanium powder, and mixing them according to the required proportion;

[0013] S2, powder mixing, using a V-shaped powder mixer for mechanical powder mixing. After the powder mixing is completed, it is dried in a hot air oven to ensure that the powder is dry and prevent adhesion;

[0014] S3, back tube pretreatment, check whether the back tube runout and thickness are normal, and use industrial alcohol to clean the back tube surface;

[0015] S4, back tube surface treatment, using steel sand to sandblast the cleaned back tube surface to enhance adhesion, and then spraying a bonding layer on the back tube surface to promote the bonding between the target material and the back tube;

[0016] S5, plasma thermal spraying, the main gas of the thermal spraying process gas is Ar, the auxiliary gas is H2, the cooling gas is compressed air, the powder carrier gas is Ar, and thermal spraying is performed through a spray gun;

[0017] S6, spraying operation. During the thermal spraying process, the back tube rotates around the central axis, the inside is cooled by water, and the outside is cooled by compressed air to control the surface temperature of the silicon germanium target. The spray gun moves back and forth at a uniform speed along the back tube axis.

[0018] S7, turning and polishing, turning and polishing the target material after spraying;

[0019] S8, quality inspection, checks the target after spraying and customizes the target length according to customer needs.

[0020] Preferably, in step S1, the purity of silicon powder is greater than or equal to 99.99%, the particle size is 200μm to 300μm, the purity of germanium powder is greater than or equal to 99.999%, the particle size is 30μm to 70μm, and the mixing ratio is 60%-80% for silicon powder and 20%-40% for germanium powder.

[0021] Preferably, in step S2, the mixing time of the powder mixer is 2 to 4 hours, the rotation speed is 12 rpm, the temperature of the hot air oven is 50°C, and the drying time is 6 to 8 hours.

[0022] Preferably, in step S5, the main gas flow rate is 20L / min to 35L / min, the pressure is 10bar to 12bar, the auxiliary gas flow rate is 10L / min to 15L / min, the pressure is 5bar to 8bar, and the cooling gas flow rate is 50L / min to 100L / min.

[0023] Preferably, in step S5, the spraying process parameters of the spray gun are: current of 300A to 350A, voltage of 65V to 75V, powder supply of 60g / min to 70g / min, and carrier gas flow rate of 5L / min to 6L / min.

[0024] Preferably, in step S6, the rotation speed of the back tube is 90 rpm to 150 rpm, and the surface temperature of the silicon germanium target is controlled between 75°C and 150°C.

[0025] Preferably, in step S6, the movement speed of the spray gun is 600 mm / min to 900 mm / min, and the distance between the spray gun and the back tube is maintained at 50 mm to 80 mm, and the spray gun mouth is perpendicular to the back tube.

[0026] Preferably, in step S7, the surface roughness after polishing reaches a standard of Ra3 μm to Ra5 ​​μm.

[0027] Preferably, in step S8, the target material detection standard after spraying is: purity greater than or equal to 99.99%, target material thickness is 6 mm to 9 mm, target material density is greater than or equal to 2.2 g / cm3, and target material porosity is less than or equal to 5.0%.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The invention discloses a method for preparing a silicon germanium rotary target material. The method adopts a plasma thermal spraying process to form a silicon germanium target material layer surrounding a substrate tube, so as to obtain a silicon germanium rotary target material having a length and thickness that meets the requirements of sputtering coating, a high structural density, and no cracks. The size of the silicon germanium rotary target material is integrated, and the length and thickness of the silicon germanium rotary target material are not restricted. The method can simplify the preparation process of the silicon germanium rotary target material and reduce the preparation cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The present invention is a flow chart of a method for preparing a silicon germanium rotating target. DETAILED DESCRIPTION

[0031] See also Figure 1 The present invention relates to a method for preparing a silicon germanium rotating target, comprising the following steps:

[0032] S1, preparing raw materials, including silicon powder with a purity of 99.99% or more and a particle size of 200 μm to 300 μm and germanium powder with a purity of 99.999% or more and a particle size of 30 μm to 70 μm; and mixing the silicon powder and the germanium powder in a required proportion, with the silicon powder accounting for 60%-80% and the germanium powder accounting for 20%-40%;

[0033] S2, powder mixing treatment, using a V-type powder mixer for mechanical powder mixing, the mixing time is 2h to 4h, the speed is 12rpm, and after the powder mixing is completed, it is dried in a hot air oven at 50℃ for 6h to 8h to ensure that the powder is dry and prevent adhesion;

[0034] S3, back tube pretreatment, check whether the back tube runout and thickness are normal, and use industrial alcohol to clean the back tube surface;

[0035] S4, back tube surface treatment, using steel sand to sandblast the cleaned back tube surface to enhance adhesion, and then spraying a bonding layer on the back tube surface to promote the bonding between the target material and the back tube;

[0036] S5, plasma thermal spraying, the main gas of the thermal spraying process gas is Ar, the auxiliary gas is H2, the cooling gas is compressed air, the powder carrier gas is Ar, the main gas flow rate is 20L / min to 35L / min, the pressure is 10bar to 12bar, the auxiliary gas flow rate is 10L / min to 15L / min, the pressure is 5bar to 8bar, and the cooling gas flow rate is 50L / min to 100L / min;

[0037] During the thermal spraying process, the spraying process parameters of the spray gun are: current is 300A to 350A, voltage is 65V to 75V, powder supply is 60g / min to 70g / min, and carrier gas flow rate is 5L / min to 6L / min;

[0038] S6, spraying operation, the back tube rotates around the central axis at a speed of 90rpm to 150rpm, with water cooling inside and compressed air cooling outside, and the surface temperature of the silicon germanium target is controlled between 75℃ and 150℃; the spray gun moves back and forth at a uniform speed of 600mm / min to 900mm / min along the axial direction of the back tube, the distance between the spray gun and the back tube is maintained at 50mm to 80mm, and the spray gun mouth is perpendicular to the back tube;

[0039] S7, turning and polishing, turning and polishing the target material after spraying to achieve the surface roughness standard of Ra3μm to Ra5μm;

[0040] S8, quality inspection, check the target material after spraying, the purity is greater than or equal to 99.99%, the target material thickness is 6mm to 9mm, the target material density is greater than or equal to 2.2g / cm3, the target material porosity is less than or equal to 5.0%, and the target material length is customized according to customer needs.

[0041] In addition: It should be noted that the above specific implementation is only an optimization scheme of this patent. Any changes or improvements made by technicians in this field based on the above concept are within the scope of protection of this patent.

Claims

1. A method for preparing a silicon germanium rotating target, characterized in that: The following steps are involved: S1, preparing raw materials, preparing silicon powder and germanium powder, and mixing them according to the required proportion; S2, powder mixing, using a V-shaped powder mixer for mechanical powder mixing. After the powder mixing is completed, it is dried in a hot air oven to ensure that the powder is dry and prevent adhesion; S3, back tube pretreatment, check whether the back tube runout and thickness are normal, and use industrial alcohol to clean the back tube surface; S4, back tube surface treatment, using steel sand to sandblast the cleaned back tube surface to enhance adhesion, and then spraying a bonding layer on the back tube surface to promote the bonding between the target material and the back tube; S5, plasma thermal spraying, the main gas of the thermal spraying process gas is Ar, the auxiliary gas is H2, the cooling gas is compressed air, the powder carrier gas is Ar, and thermal spraying is performed through a spray gun; S6, spraying operation. During the thermal spraying process, the back tube rotates around the central axis, the inside is cooled by water, and the outside is cooled by compressed air to control the surface temperature of the silicon germanium target. The spray gun moves back and forth at a uniform speed along the back tube axis. S7, turning and polishing, turning and polishing the target material after spraying; S8, quality inspection, checks the target after spraying and customizes the target length according to customer needs.

2. The method for preparing a silicon germanium rotary target according to claim 1, characterized in that: In step S1, the purity of silicon powder is greater than or equal to 99.99%, and the particle size is 200μm to 300μm, the purity of germanium powder is greater than or equal to 99.999%, and the particle size is 30μm to 70μm, and the mixing ratio is 60%-80% for silicon powder and 20%-40% for germanium powder.

3. The method for preparing a silicon germanium rotary target according to claim 1, characterized in that: In step S2, the mixing time of the powder mixer is 2 to 4 hours, the rotation speed is 12 rpm, the temperature of the hot air oven is 50°C, and the drying time is 6 to 8 hours.

4. The method for preparing a silicon germanium rotary target according to claim 1, characterized in that: In step S5, the main gas flow rate is 20L / min to 35L / min, the pressure is 10bar to 12bar, the auxiliary gas flow rate is 10L / min to 15L / min, the pressure is 5bar to 8bar, and the cooling gas flow rate is 50L / min to 100L / min.

5. The method for preparing a silicon germanium rotary target according to claim 4, characterized in that: In step S5, the spraying process parameters of the spray gun are: current of 300A to 350A, voltage of 65V to 75V, powder supply of 60g / min to 70g / min, and carrier gas flow rate of 5L / min to 6L / min.

6. The method for preparing a silicon germanium rotary target according to claim 1, characterized in that: In step S6, the rotation speed of the back tube is 90 rpm to 150 rpm, and the surface temperature of the silicon germanium target is controlled between 75°C and 150°C.

7. The method for preparing a silicon germanium rotary target according to claim 6, characterized in that: In step S6, the movement speed of the spray gun is 600 mm / min to 900 mm / min, and the distance between the spray gun and the back tube is maintained at 50 mm to 80 mm, and the spray gun mouth is perpendicular to the back tube.

8. The method for preparing a silicon germanium rotary target according to claim 1, characterized in that: In step S7, the surface roughness after polishing reaches a standard of Ra3 μm to Ra5 ​​μm.

9. The method for preparing a silicon germanium rotary target according to claim 1, characterized in that: In step S8, the target material detection standards after spraying are: purity greater than or equal to 99.99%, target material thickness is 6 mm to 9 mm, target material density is greater than or equal to 2.2 g / cm3, and target material porosity is less than or equal to 5.0%.

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