Patent ID: 7625609
Filing Date: 2009-12-01
Classification: C23C

Abstract:
1. A method of forming a silicon nitride film using dichlorosilane, hydrogen radicals and ammonia radicals as reaction gases, comprising the steps of: (a) supplying dichlorosilane into a reaction chamber containing a process object without supplying hydrogen radicals and ammonia radicals, thereby allowing chemical species originated from dichlorosilane as a precursor to be adsorbed on the process object; (b) supplying hydrogen radicals into the reaction chamber without supplying dichlorosilane and ammonia radicals, thereby hydrogenating chlorine contained in the chemical species to remove the chlorine from the chemical species; and (c) supplying ammonia radicals into the reaction chamber without supplying dichlorosilane and hydrogen radicals, thereby nitriding the chemical species, from which the chlorine has been removed, by the ammonia radicals, to deposit resultant silicon nitride on the process object, wherein the steps (a), (b) and (c) are performed repeatedly for plural times in that order, and wherein the reaction gases remaining in the reaction chamber are substantially removed from the reaction chamber during a period after completion of the step (a) and before starting of the step (b), a period after completion of the step (b) and before starting of the step (c), and a period after completion of the step (c) and before starting of the step (a).