METHOD FOR MANUFACTURING ISOLATING STRUCTURE OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for manufacturing an isolating structure of a semiconductor device is provided to improve a leakage current characteristic of the isolating structure, by reducing over-etching time of a nitride layer in forming a nitride layer pattern for a trench. CONSTITUTION: An oxide layer(11) and a nitride layer are sequentially stacked on a semiconductor substrate(10). A photoresist layer pattern is formed in a portion corresponding to an active region on the nitride layer. The nitride layer and the oxide layer are etched by using the photoresist layer pattern as a mask to expose the upper surface of the semiconductor substrate corresponding to a field region. The semiconductor substrate is exposed in the same etching condition as the etching process for the nitride layer and the oxide layer and for 30-100 percent of the interval of time for which the nitride layer and the oxide layer are etched. The semiconductor substrate is etched to form a trench(14). A high temperature thermal oxidation process is performed regarding the trench to make the profile of the upper corner portion of the trench gently round. The inside of the trench is filled with an oxidation material.