Method of fabricating a shallow trench isolation structure

摘要

A method for fabricating STI for semiconductor device. The method includes the following steps. A trench is formed on the semiconductor substrate, a liner oxide is formed on the bottom and sidewall of the trench, and then a liner nitride is formed on the liner oxide. The first oxide layer is deposited in the trench by high density plasma chemical vapor deposition. The first oxide layer is spray-etched to a predetermined depth, wherein the recipe of the spray etching solution is HF/H2SO4=0.3~0.4. A second oxide layer is deposited to fill the trench by high density plasma chemical vapor deposition to form a shallow trench isolation structure.