| 摘要 |
PURPOSE:To form a channel stopper layer of high concentration with few defects, by implanting borons in a plurality of times into a semiconductor substrate having the surface made indefectible, with different implantation energies, so that the impurity concentration of borons just after the implantation be of a specified value or below. CONSTITUTION:A method wherein borons are implanted in a plurality of times into a semiconductor substrate having the surface made indefectible substantially, with different implantation energies, so that the impurity concentration of borons immediately after the implantation be about 1X10<18>cm<-3> or below is adopted for isolation of elements in a semiconductor device. The adoption of this method eliminates the generation of oxidation-induced stacking fault OSF on the occasion of isolation oxidation notwithstanding the high impurity concentration of a channel stopper layer, enables the attainment of a sufficient inversion voltage even with a small thickness of an isolation oxide film, as well as the reduction of a time for isolation oxidation, and lessens the steps of a surface and the expansion of the oxide film. The channel stopper layer thus formed displays the remarkable features thereof in the case of a semiconductor device of a high-integrated circuit. |
