METHOD OF FORMING SPECIFIC ARSENIC-DOPED REGION IN SEMICONDUCTOR SUBSTRATE

摘要

A method of producing a defined arsenic doping in silicon semiconductor substrates is provided. Preferably, the arsenic doping is produced in the sidewalls and floors of trenches having high aspect ratio which are etched into the substrates. An arseno-silicate glass layer is deposited into these trenches to be used as a diffusion source, the glass layer being removed after the diffusion. The arseno-silicate glass layer is deposited by thermal decomposition from the vapor phase of tetraethylortho silicate Si)OC2H5)4 and triethylarsenate AsO(OC2H5)3. A steep and reproducible doping profile having constant, maximum penetration depth and high arsenic concentration in the substrate surface which is needed for VLSI semiconductor circuits is obtained through the process of the present invention.