Semiconductor device prodn. by ion implantation and oxidn. - to give thick and thin oxide films simultaneously on defect and untreated zones

摘要

Simplified prodn. of semiconductor devices involves forming selective defect layers in a predetermined pattern on the surface of a semiconductor substrate by the ion beam implantation technique and heating the substrate in an oxidising atmos. to cause the simultaneous formation of thick oxide films on the defect layers and thin oxide films on the rest of the surface. Ion implantation is carried out directly without masks or with masks. Only the side of the substrate with the defect layers is oxidised by thermal or plasma oxidn. The ions used consist of an element, e.g. inert gas, oxygen, phosphorus and boron, and are implanted with an energy of 50-300 keV in an amt. of 10 exp. 13 to 10 exp. 15 atoms/cm2 to a depth of 0.1-0.7 micron. Oxidn. is carried out at 800-1050 deg.C at normal or higher pressure, with a gaseous oxygen plasma or by plasma anodic oxidn.