Method of fabricating an insulating layer

Abstract

A method of fabricating an insulating layer starts by forming at least one gate, having at least a conductive layer and a cap oxide layer, on a surface of a semiconductor substrate. An insulating layer thicker than a height of the gate on the semiconductor substrate is then formed to follow the topography of the gate to produce an uneven surface. A planar layer is then formed on the insulating layer to form an approximately flat surface for the semiconductor substrate. By performing a planarization process, a portion of the planar layer is removed down to the surface of the insulating layer. A first etching process is then performed to completely remove the remaining portions of the planar layer. Finally, a second etching process is performed to remove the insulating layer and the cap oxide layer atop the gate, so that the remaining insulating layer outside the gate has a protrusive surface after the second etching process.