METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for manufacturing a semiconductor device is provided to form a multilayer having etch rate difference by burying an insulating film to fill a trench formed at an element isolation layer. CONSTITUTION: In a method for manufacturing a semiconductor device, a first insulating layer(112), a conductive film(114) and an isolation mask film are formed on an active area. A semiconductor substrate having trench is formed in the element isolation. A second insulating layer is formed on the semiconductor substrate to fill a part of the trench. The second insulating layer is etched through a first etching process to extend an interval of the first insulating layer formed on the sidewall of a multilayer. A third dielectric layer having the etch rate difference of the second insulating film and it is formed on the second insulating layer. An element isolation film(123) is formed by performing second etching process through etch rate difference of the second and the third dielectric layer.