METHOD FOR FORMING TRENCH ISOLATION LAYER AND SEMICONDUCTOR DEVICE HAVING THE TRENCH ISOLATION LAYER

摘要

PURPOSE: A method for forming a trench isolation layer and a semiconductor device having the trench isolation layer are provided to be capable of improving isolation characteristics and securing gap-fill margin enough. CONSTITUTION: The first trench(116) is formed on a silicon substrate(100) by carrying out an etching process. The first trench isolation layer(120a) is formed by filling an oxide layer in the first trench. A photoresist pattern(124) is selectively formed on the resultant structure. At this time, both neighboring side portions of the first trench isolation layer are exposed to the outside. The second trench(128) is formed by carrying out an etching process using the photoresist pattern as an etching mask. The photoresist pattern is then removed. The second trench isolation layer is formed by filling the second trench using a thermal oxidation method.