METHOD FOR FABRICATING SHALLOW TRENCH ISOLATION AND SEMICONDUCTOR STRUCTURE USING THE SAME

摘要

A method for fabricating a shallow trench isolation includes forming a trench in a substrate, forming a bottom shallow trench isolation dielectric filling a gap of the trench, and forming a top shallow trench isolation dielectric on the bottom shallow trench isolation. The bottom shallow trench isolation dielectric has a concave center portion, and the top shallow trench isolation dielectric is deposited on the bottom shallow trench isolation by a high density plasma chemical vapor deposition process using low deposition to sputter ratio. A semiconductor structure having the shallow trench isolation is also disclosed.

主权项

1. A method for fabricating a shallow trench isolation, comprising:
forming a trench in a substrate; forming a bottom shallow trench isolation dielectric in the trench by a high density plasma chemical vapor deposition (HDP-CVD) process; and forming a top shallow trench isolation dielectric on the bottom shallow trench isolation dielectric by another HDP-CVD process with a different deposition to sputter ratio from that of the bottom shallow trench isolation dielectric.