DEVICE ISOLATION METHOD OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A device isolation method of semiconductor device is provided which is capable of decreasing the size of the bird's beak and improving the smoothness by decreasing the projection of the field oxidation film on the surface of the semiconductor substrate. CONSTITUTION: A method comprises steps of: forming a mask layer(25) exposing a certain portion on the semiconductor substrate(21) to define the field region(27); recess etching the exposed field region(27) of the semiconductor substrate(21) to form a groove and forming the sidewalls(29) on the sides of the mask layer(25) and the groove; oxidizing the surface of the groove to form a field oxidation film(31) at the field region(27); and removing the mask layer(25) and sidewalls(29).