Robust silicon nitride LPCVD recipe development

A furnace process recipe for nitride film deposition to minimize any back-stream of particle or gas by-products on the wafers, impact of out-gassing from chamber materials and gas turbulence in the chamber at any time during the process has been developed. The new recipe will maintain a permanent and as much as possible constant and positive delta pressure between the chamber and the pumpline, and also between the chamber and incoming gas lines. In this new recipe, a more systematic cleaning of chamber, gas line and pumpline after deposition is also incorporated. Significant reductions of process particles were seen. Longer time between tube and boat clean were also achieved.