METHOD FOR MANUFACTURING A SEMICONDUCTOR DEVICE

摘要

A method for element isolation utilizing insulating materials in a semiconductor substrate is proposed. In this method an oxidizable material layer of polycrystalline silicon or the like is formed and then the oxidizable material layer is selectively oxidized, using an oxidation-proof mask thereby forming a thick oxide layer. Thereafter, the oxidation-proof mask is removed and unoxidized oxidizable material below the mask is perpendicularly etched off, leaving part of the oxidizable material which is then oxidized to form together with the thick oxide layer an element isolation. This invention further proposes a semi-conductor device having element isolation layer whose bird's beak is very small in length.