[Chemical Knowledge]：Manufacturing method and process flow of polysilicon

Manufacturing Methods
of Polysilicon
1. Introduction

Polysilicon is an important raw material in the production of chemical products, especially in the field of semiconductor and solar cell manufacturing has a wide range of applications. With the continuous development of science and technology, the manufacturing method of polysilicon is also constantly improving and optimizing. This paper will introduce the manufacturing method of polysilicon in detail, including process, process, equipment and so on.

2. polysilicon manufacturing method

1. trichlorosilane method

trichlorosilane method is currently one of the most commonly used methods in polysilicon production. The principle of this method is that under the condition of high temperature and high pressure, the metal silicon and hydrogen chloride gas react to generate trichlorosilane gas, and then the trichlorosilane gas is fractionated and purified to obtain high-purity trichlorosilane. Next, high-purity trichlorosilane is thermally decomposed at high temperature to produce polycrystalline silicon and hydrogen chloride gas. Finally, the polycrystalline silicon is purified and processed to obtain the final product.

The advantage of this method is that the production process is relatively mature, the product quality is relatively stable, and high-purity polysilicon products can be produced. However, a large amount of hydrogen chloride gas needs to be used in the production process of this method, and the requirements for the environment and equipment are relatively high. At the same time, a large amount of waste will be generated in the production process, which needs to be properly treated.

2. Silane method

Silane method is a new type of polysilicon manufacturing method. The principle of this method is to react metal silicon with hydrogen to generate silane gas, and then decompose the silane gas to generate polysilicon and hydrogen. Compared with the trichlorosilane method, the production process of the silane method is relatively simple, does not require the use of a large amount of hydrogen chloride gas, and produces less waste in the production process.

However, the production cost of the silane method is relatively high, a large amount of hydrogen and precious metal catalysts need to be used, and safety issues in the production process need to be strictly controlled.

3. fluidized bed method

fluidized bed method is a relatively new polysilicon manufacturing method. The principle of this method is to react metal silicon powder with hydrogen in a fluidized bed reactor to produce polysilicon and hydrogen. The fluidized bed reactor can make the metal silicon powder fully contact with hydrogen and improve the reaction efficiency. At the same time, the method can also use waste silicon wafers as raw materials, which has certain environmental protection.

However, the production process of fluidized bed method is not yet fully mature and needs to be further improved and optimized.

3. Polysilicon Manufacturing Equipment

Polysilicon manufacturing process requires the use of a variety of equipment, including reactors, fractionation towers, thermal decomposition furnaces, purification equipment. The selection and configuration of these equipment needs to be determined according to the specific production process and output. At the same time, because the polysilicon manufacturing process involves harsh conditions such as high temperature, high pressure, and corrosion, the material and quality of the equipment also need to be strictly controlled.

safety problems in the manufacturing process of 4. polysilicon

polysilicon manufacturing process involves harsh conditions such as high temperature, high pressure, corrosion, etc., and there are harmful gases such as hydrogen and hydrogen chloride, so safety problems need to be strictly controlled in the production process. It is necessary to take effective measures to prevent the occurrence of safety accidents such as equipment failure and leakage, and to ensure the smooth progress of the production process.

5. conclusion

polysilicon is an important raw material in the production of chemical products, and its manufacturing methods include trichlorosilane method, silane method and fluidized bed method. Different manufacturing methods have different advantages and disadvantages and scope of application, and it is necessary to choose the appropriate method according to the specific production process and output. At the same time, the polysilicon manufacturing process requires the use of a variety of equipment, and the need to strictly control safety issues to ensure the smooth progress of the production process.