METHOD FOR FORMING ISOLATION LAYER OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for forming a field oxide layer of a semiconductor device is provided to improve a characteristic of a semiconductor device and reduce a size of the semiconductor device. CONSTITUTION: The first buffer oxide layer and the first nitride layer are formed on a semiconductor substrate. The first buffer oxide layer and the first nitride layer are patterned. The first field oxidation process is performed by using the patterned the first nitride layer as a mask and the first field oxide layer is formed on a field region. The first field oxide layer is etched partially and the first nitride layer and the first buffer oxide layer are removed. The second buffer oxide layer and the second nitride layer are formed on the whole surface. The second buffer oxide layer and the second nitride layer are etched selectively. The second field oxidation process is performed by using the patterned the second nitride layer and the second buffer oxide layer as masks and the second field oxide layer is formed on the first field oxide layer.