Structuring surface of N-doped silicon@ substrate - by contacting with fluoride-contg. acidic electrolyte, illuminating, and applying potential between electrolyte and substrate

摘要

Structuring the surface of an n-doped Si-substrate comprises: (a) contacing the surface with an F-contg. acidic electrolyte (3); (b) using light source of wavelength less than 1100 NM to produce an illuminated sample (8) on the surface; (c) applying a potential between the electrolyte (3) and the Si-substrate (1) so that, on illuminated sites, an anodic minority charge carrier stream flows over the substrate effecting etching; and (d) producing the sample (8) of illuminating strength that the local current density reaches a value on no site, above which electropolishing of the surface occurs. The sample (8) is produced using laser, pref. HeNe laser of 1-10 MW output. The sample may also be produced using mask sepd. from the surface. A voltage of -1 to 20 V is applied between the Si-substrate (1) and a Pt-counter electrode (5) in the electrolyte (3). USE/ADVANTAGE - The process can be used in the mfr. of semiconductor components in Si wafers, esp. in the prodn. of trenches in wafers. There are no surface limitations in surface topology.