A new concept for etch and deposition chamber pressure control

A variable-speed vacuum system using compact dry pumps, provides a production-worthy alternative to traditional methods of chamber pressure control for aluminum etch and LPCVD nitride deposition. Application to a single-wafer metal-etch tool allowed the elimination of a throttle valve close to the process chamber, thereby removing one source of contamination and tool downtime. similarly, applied to an LPCVD nitride furnace the new system eliminated the need for upstream pressure control and nitrogen ballasting, significantly reducing particles.