Patent ID: 6048776
Filing Date: 2000-04-11
Classification: H01L

Abstract:
A method of fabricating a semiconductor device comprising the steps of:forming a trench in a semiconductor substrate by using a selective etching process;forming an insulating layer at least on the inner surface of said trench;forming a film containing silicon at least on said insulation layer in said trench;doping a first impurity of a first conductivity type by a first ion implantation to a depth of said semiconductor substrate at least through said film containing silicon,wherein said first impurity doped into said semiconductor substrate by said first ion implantation is at a level deeper than the bottom of said trench,doping a second impurity of the first conductivity type by a second ion implantation into said film containing silicon;activating the first and second impurities by annealing said semiconductor substrate to form a substrate region of the first conductivity type in said semiconductor substrate and to make said film containing silicon to have the first conductivity type;then forming said semiconductor substrate doped with said first impurity into a well diffusion layer; andforming said film containing silicon doped with said second impurity into a gate or field shield electrode within said trench.