Structure of trench isolation and a method of forming the same

Abstract

The present invention is directed toward a structure and method by which trench isolation for a wide trench and a narrow trench formed in first and second regions of a substrate may be achieved without formation of a void in an isolation layer, a groove exposing an isolation layer, or an electrical bridge between gates in a subsequent process. A lower isolation layer is formed on the substrate in a first and second trench. The lower isolation layer is patterned to fill a lower region of the first trench, and an upper isolation pattern is formed to fill the second trench and a remainder of the first trench. An aspect ratio of first trench is reduced, thereby preventing the occurrence of a void in the upper isolation layer, or a gap between the upper isolation layer and the substrate.

Dependencies are inferred from the claim text.