Method for preparing electronic-grade polycrystalline silicon by inhibiting boron deposition

• Main Authors: ZHANG QI, ZHAO DAN, HOU YANQING, YUAN XINGPING, LYU QINGHUI, MA WENHUI, GUO LIJIE
• Format: Patent
• Language: Chinese; English
• Published: 28.05.2024
• Subjects: CHEMISTRY; COMPOUNDS THEREOF; INORGANIC CHEMISTRY; METALLURGY; NON-METALLIC ELEMENTS

The invention provides a method for preparing electronic-grade polycrystalline silicon by inhibiting boron deposition. The method comprises the following steps: (1) introducing mixed gas of trichlorosilane and hydrogen into a Siemens reactor; (2) increasing the surface temperature of the silicon rod, and performing chemical vapor deposition on silicon on the surface of the silicon rod; and (3) taking out boron and residual silicon through hydrogen, cooling, returning for rectification, recovering boron and silicon, and returning hydrogen to the reactor. According to the present invention, the existing improved Siemens method polysilicon production process is adjusted, and the deposition rate of the silicon and the boron is controlled by controlling the chemical vapor deposition condition so as to control the boron content in the polysilicon, such that the polysilicon of different specifications can be produced. The method is simple in process and simple and convenient to operate, provides a new way for removi