Patent attributes
A fabricating method of a semiconductor device is provided. The method comprises the steps of preparing a semiconductor substrate having an active area with a high voltage device area and a low voltage device area and an inactive area, forming a trench in the inactive area of the semiconductor substrate, forming a sacrifice oxide layer on an inner surface of the trench, forming a liner oxide layer on the sacrifice oxide layer, forming a gap-fill oxide layer as a device isolation layer on the liner oxide layer to fill up the trench, forming a buffer oxide layer on top surfaces of the liner and sacrifice oxide layers of the device isolation layer, and forming a gate oxide layer on the high voltage device area of the semiconductor substrate to have a uniform thickness.
