TRENCH ISOLATION METHODS OF SEMICONDUCTOR DEVICE

摘要

A method for isolating a trench in a semiconductor device is provided to fill completely a variety of trenches regardless of a high aspect ratio by restraining the generation of a plasma damage at sidewalls of a second trench using a lower isolation layer with a second thickness. A first trench(57) and a second trench(58) with a larger width than that of the first trench are formed on a semiconductor substrate(51). A first lower isolation layer with a first thickness and a second lower isolation layer(67) with a second thickness are formed within the first and the second trenches by using a first high density plasma chemical vapor deposition. The second thickness is larger than the first thickness. An upper isolation layer(69) is formed on the lower isolation layer by using a second high density plasma chemical vapor deposition.