Patent ID: 6325848
Filing Date: 2001-12-04
Classification: C30B

Abstract:
A fabrication method of a silicon substrate, comprising the steps of:(a) preparing a single-crystal Si base material with a flat main surface;said base material having a first oxygen concentration;(b) growing a single-crystal Si epitaxial layer on said main surface of said base material in such a way that said epitaxial layer has a second oxygen concentration lower than said first oxygen concentration;(c) ion implanting dopant atoms into the epitaxial layer; and(d) controlling a concentration of the dopant atoms in the epitaxial layer when activating the implanted dopant atoms by activating the implanted dopant atoms at a temperature lower than 700.degree. C. with one of heat treatment and annealing, whereby a diffusion length of the dopant atoms is reduced and a concentration of the dopant is controlled.