Electronic grade polysilicon: the “food” of the electronic information industry
With the vigorous development of the photovoltaic industry, the domestic polysilicon industry has reached the world’s largest output in just over ten years, and the production cost has also reached the world’s advanced level. High-purity polysilicon material is the basic raw material for the information industry and solar photovoltaic power generation industry, and many developed countries in the world regard it as a strategic material.
The purity requirements of electronic grade polysilicon are extremely high, and it is the purest substance that can be obtained by human industrialization.
Electronic grade polysilicon can be divided into electronic grade polysilicon for zone melting and electronic grade Czochralski polysilicon. The quality requirements of polysilicon for electronic grade zone melting are more stringent. The monocrystalline silicon produced by the zone melting method has low oxygen and carbon content, low carrier concentration and high resistivity. It is mainly used in the manufacture of IGBTs, high-voltage rectifiers, thyristors, and high-voltage transistors. and other high-voltage and high-power semiconductor devices. The monocrystalline silicon wafers produced by the Czochralski method are widely used in integrated circuit memories, microprocessors, mobile phone chips, low-voltage transistors, electronic devices and other electronic products. %above.
In addition, my country’s electronic-grade polysilicon testing equipment still relies on imports. On the manufacturing side, my country has basically solved the localized substitution of related equipment and materials. However, the core testing equipment for polysilicon products is completely dependent on imports, such as low-temperature Fourier transform infrared spectrometer LT-FTIR, inductively coupled plasma mass spectrometer ICP-MS, etc., and the testing process requires extremely high levels of testing personnel.
Judging from the current international development of electronic-grade polysilicon production technology, the production processes mainly include silane method, gas-liquid deposition method, fluidized bed, and improved Siemens.
The production cost of silane method is high, and the silane used is explosive, flammable, and has poor safety. Even at room temperature, there will be a fire hazard. The gas-liquid deposition method was developed and controlled by Japan. In production, a tubular reactor is mainly used, and the operating temperature condition is controlled at 1500 °C to generate liquid silicon directly in the gas. Currently, it is still in the research and test stage. Not used for mass production. The fluidized bed process method is mainly to carry out comprehensive control of product impurities, so it cannot produce high-quality electronic-grade polysilicon.
Electronic grade polysilicon is the most basic strategic material in the electronic information industry, which is related to my country’s national economy, society and national defense security. How to continuously and stably produce high-purity electronic-grade polysilicon to meet the needs of downstream enterprises for electronic-grade silicon materials is an important research topic faced by polysilicon enterprises. It is necessary to strictly control all processes in the whole process of polysilicon production, reduce various factors that may cause pollution to a minimum, and further implement lean and refined operations in the operation process, change bad habits, and improve management. Electronic grade polysilicon has a place in the market.