METHOD FOR PRODUCTION OF BOROSILICATE LAYERS IN MANUFACTURE OF POWER TRANSISTORS Russian patent published in 2022 - IPC H01L21/316 

FIELD: electrical engineering.

SUBSTANCE: invention relates to a technology of manufacture of power silicon transistors and integrated circuits (hereinafter – IC), in particular for the formation of an active basic area. A process of boron diffusion is carried out using a liquid source – three-bromine boron (BBr₃) at the following gas flow rate: oxygen O₂=120 l/h, nitrogen N₂=240 l/h. A temperature of the process is 880°C, duration of the process is 14±2 minutes. Oxygen is added to carrier gas for oxidation of three-bromine boron (BBr₃) to boron oxide (B₂O₃) and for protection of a surface from the formation of black insoluble deposits. The essence of the method is in that a borosilicate layer is formed on the surface of a silicon plate at a temperature of 880°C due to a reaction: 4BBr₃+3O₂→2B₂O₃+6Br₂. Control of measurement of surface resistance (R_S) is carried out on an installation “FPP-5000”. At the same time, surface resistance is R_S=45±5 Ohm/cm.

EFFECT: uniformity of distribution of values of surface resistance along the entire surface of a silicon plate, reduction in a temperature and duration of a process.

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