METHOD FOR FABRICATING SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for fabricating a semiconductor device is provided to simplify a fabrication process and increase yield by forming impurity diffusion layers of different densities in a high voltage area and a low voltage area while using a screen insulation layer without a photolithography process. CONSTITUTION: A semiconductor substrate(100) having the high voltage area(b) and the low voltage area(a) is prepared. A low voltage gate pattern(109) is formed in the low voltage area. The first screen insulation layer covering a high voltage gate pattern(111) and the semiconductor substrate at both sides of the high voltage gate pattern is formed in the high voltage area. The first ion implantation process is performed on the semiconductor substrate by using the high voltage gate pattern and the low voltage gate pattern as an ion implantation mask. The second screen insulation layer is conformally formed on the semiconductor substrate. The second ion implantation process is performed on the semiconductor substrate by using the high voltage gate pattern and the low voltage gate pattern as an ion implantation mask, wherein the second ion implantation depth is shallower than the total thickness of the first and second screen insulation layers.