METHOD OF PROTECTING SILICON WAFER Russian patent published in 2024 - IPC H01L21/31 

FIELD: various technological processes.

SUBSTANCE: invention relates to the technology of manufacturing elements of nano- and microsystems and can be used in production of silicon sensitive elements of pressure transducers, angular velocity, gas sensors and accelerometers. Method of protecting a silicon wafer consists in that layers 2, 3 of silicon oxide and silicon nitride are deposited on silicon wafer 1 on both sides, protective thin-film coating 4 based on polyacrylonitrile is applied on the front side of silicon wafer 1. Before application, polyacrylonitrile in form of microdispersed powder is dissolved in dimethylformamide to form a solution with kinematic viscosity from 6 to 10 mm²/s, applying the resulting solution using a centrifuge, rotating at speed of 300 to 1,500 rpm, on the front side of silicon wafer 1, coated with layers 2, 3 of silicon oxide and silicon nitride, in vacuum at pressure 2.0⋅10^-4-1⋅10^-2 Pa silicon wafer with applied solution based on polyacrylonitrile is heated at a heating rate of 10 to 20 °C/min to temperature from 770 to 850 °C and a silicon wafer coated with a solution based on polyacrylonitrile is dried for 50 to 70 minutes to form a protective thin-film coating 4 based on polyacrylonitrile.

EFFECT: reduced defectiveness of front side of silicon wafer during etching in heated alkali.

1 cl, 2 dwg