Wells and/or trench formation, in manufacture of integrated circuit, involves simultaneously etching trenches and wells, and depositing thick silicon oxide layer by non-conformal deposition in trenches and wells to close openings

摘要

The method involves simultaneously etching trenches (4, 6) and wells (5). A silicon nitride layer (8) is deposited over an entire structure of the trenches and wells to cover walls and bottom of the trenches and wells. A thick silicon oxide layer (9) is deposited by non-conformal deposition over the entire structure for closing openings of the trenches and wells. The layer (9) is selectively opened according to subsequent processings.