THERMAL F2 ETCH PROCESS FOR CLEANING CVD CHAMBER

PROBLEM TO BE SOLVED: To provide a method of more effectively cleaning an LPCVD reactor having deposition of silicon nitride at low thermal activation temperatures. SOLUTION: A thermal process for cleaning equipment surfaces having deposition of undesired silicon nitride in a semiconductor processing chamber by using a thermally activated source of pre-diluted fluorine is provided. The process comprises: a step (a) of flowing pre-diluted fluorine in an inert gas through the chamber; a step (b) of maintaining the chamber at an elevated temperature of 230°C to 565°C to thermally dissociate the fluorine; a step (c) of cleaning undesired silicon nitride from the surfaces by using chemical reaction of the fluorine thermally dissociated in the step (b) with the undesired silicon nitride to form volatile reaction products; and a step (d) of removing the volatile reaction products from the chamber. COPYRIGHT: (C)2008,JPO&INPIT