MANUFACTURING METHOD OF A TRENCH ISOLATION

摘要

PURPOSE: A manufacturing method of an isolation trench is provided to prevent a dent of a nitride liner caused by an over-etch of the nitride liner, the dent generated at an edge part of an upper region of the isolation trench. CONSTITUTION: The manufacturing method comprises the steps of: forming a mask pattern for defining the isolation trench region by partially etching a pad oxidation layer and a nitride layer; forming a trench by using the mask pattern to partially etch a part of a semiconductor substrate; forming a thermal oxidation layer on the bottom and sidewalls of the trench; forming a nitride liner on the thermal oxidation layer of which an etch rate is lower than that of the nitride layer of the mask pattern; filling up the trench with a trench isolation layer on the nitride liner; etching the trench isolation layer until an upper part of the mask pattern on both sides of the trench is exposed; and etching the mask pattern.