METHOD FOR FORMING TRENCH TYPE ISOLATION LAYER OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for forming a trench type isolation layer is to reduce a leakage current resulting from an interface trap charge generated at an interface between a side wall oxide which is formed by a side wall oxidation process and a silicon substrate. CONSTITUTION: The method comprises the steps of: forming a pad oxide layer(21) and a nitride layer(22) on a silicon substrate(20); etching the exposed silicon substrate to form a trench; forming a thermal oxide(23) on an inner wall of the trench; performing an annealing process in a hydrogen atmosphere; and burying insulating material into the trench. The method further comprises the step of forming a sacrificial oxide layer on the inner wall of the trench using a sacrificial oxide process and wet-etching the sacrificial oxide layer, after performing the etching step.