Process and Tooling for Slope Control of Etched Silicon Nitride Edges
Original Publication Date: 1986-Aug-01
Included in the Prior Art Database: 2005-Mar-09
By reducing temperature of a substrate environment during plasma-enhanced chemical vapor deposition (PECVD) of silicon nitride films, the slope of edges of plasma-etched patterns in the silicon nitride films thus formed is controlled. The etch rate of silicon nitride films increases with decreasing deposition temperature, such that reduction of temperature during film deposition results in shallower slopes at the etched edges. By introducing air cooling between an outer wall of a process tube and heater of a commercially available tubular PECVD tool, desired temperature reduction rate during normal silicon nitride film deposition time is controlled. Slope of pattern edges etched in PECVD silicon nitride films by plasma etching is generally very steep, e.g., 80-90 degrees.