DEVICE ISOLATION STRUCTURE INCORPORATED IN SEMICONDUCTOR DEVICE AND METHOD OF FORMING THE SAME

摘要

A method for forming an isolation structure of a semiconductor device is provided to prevent the generation of cracks after a planarization process on an isolation layer by inducing voids to be formed at a predetermined portion in a trench lower than a surface of a semiconductor substrate using a funnel portion of the trench capable of increasing the width of an upper portion of the trench. A hard mask pattern is formed on a semiconductor substrate(50). A trench region(62) is formed on the substrate by performing an etching process using the hard mask pattern as an etch mask. A funnel portion(65) is formed at an upper portion of the trench region by etching. At this time, a bottom portion and a portion of an inner wall of the trench region are blocked. An isolation layer(66p) is formed on the resultant structure by filling the trench region with an insulating layer, wherein the isolation layer has voids(68) lower than the funnel portion. The isolation layer is planarized and the hard mask pattern is removed.