SEMICONDUCTOR DEVICE WITH GATE INSULATION LAYERS OF DIFFERENT THICKNESSES BY NITROGEN ION IMPLANTATION PROCESS AND FABRICATING METHOD THEREOF TO PREVENT SEMICONDUCTOR SUBSTRATE FROM BEING DAMAGED BY PLURAL PHOTOLITHOGRAPHY PROCESSES

摘要

PURPOSE: A method for fabricating a semiconductor device with gate insulation layers of different thicknesses by a nitrogen ion implantation process is provided to prevent a semiconductor substrate from being damaged by a plurality of photolithography processes by eliminating the necessity of an oxidation process and a photolithography process. CONSTITUTION: A semiconductor substrate(20) is prepared which is divided into a plurality of regions for forming gate insulation layers(26A,26B,26C) of different thicknesses. Oxidation preventing ions are implanted into the plurality of regions, having different densities according to the thickness of the gate insulation layer. An oxidation process is performed to form gate insulation layers having different thicknesses in the respective regions.