Methods for forming a device isolation structure in a semiconductor device

摘要

Methods of forming a device isolation structure in a semiconductor device are disclosed. A disclosed method comprises forming a p-type well and an n-type well in a semiconductor substrate; sequentially depositing a gate insulating layer and a gate electrode material layer; depositing a protective layer on the gate electrode material layer; removing a portion of the protective layer, a portion of the gate electrode material layer, and a portion of the gate insulating layer to expose a surface area of the semiconductor substrate; performing ion implantation and heat treatment processes to form a device isolation structure; forming a gate electrode by removing a portion of the gate electrode material layer; forming an LDD region by implanting low concentration impurity ions in the semiconductor substrate; forming a spacers on a sidewall of the gate electrode; and forming a source/drain region by implanting high concentration impurity ions.