Substrate Treating Method

Abstract

A substrate processing method includes the step of forming an oxide film by oxidizing a silicon substrate surface and the step of nitriding the oxide film to form an oxynitride film, wherein there is provided a step of purging oxygen after the oxidizing step but before said nitriding step from an ambient in which said nitriding processing is conducted.

1 . A substrate processing method, comprising the steps of:
 forming an oxide film by carrying out an oxidizing processing with a gas containing oxygen to a silicon substrate surface held in a processing vessel;   supplying a gas containing nitrogen into said processing vessel;   forming plasma of the gas containing nitrogen over said silicon substrate surface in said processing vessel by supplying microwave power into said processing vessel;   forming an oxynitride film by carrying out a vacuum nitriding processing to said oxide film with said plasma at a temperature of 600° C. or less,   wherein said nitriding processing is started with a delay of 1-600 seconds from an end of said oxidizing processing, and   wherein purging of oxygen is carried out during an interval from an end of said oxidizing processing to a start of said nitriding processing so as to suppress increase of film thickness of said oxide film during said nitriding processing.   
     
     
         2 . The method as claimed in  claim 1 , wherein said oxidizing processing is carried out by thermal processing or plasma processing. 
     
     
         3 . The method as claimed in  claim 1 , wherein said oxidizing processing is carried out by plasma processing. 
     
     
         4 . The method as claimed in  claim 1 , wherein said oxidizing processing and said nitriding processing are carried out by using an identical processing vessel, said oxidizing processing is carried out by a plasma processing, said purging of oxygen is carried out after the end of said oxidizing processing but before the start of said nitriding processing by continuously evacuating said processing vessel for said duration of 1-600 seconds. 
     
     
         5 . The method as claimed in  claim 4 , wherein said purging of oxygen is carried out by supplying one or more of a nitrogen gas or a rare gas into said processing vessel during said duration of 1-600 seconds. 
     
     
         6 . The method as claimed in  claim 4 , wherein said purging of oxygen is carried out by supplying one or more of a nitrogen gas or a rare gas intermittently and repeatedly over said duration of 1-600 seconds. 
     
     
         7 . The method as claimed in  claim 4 , wherein said oxidizing processing is carried out by using first plasma and said nitriding processing is carried out by using second plasma, said first plasma is extinguished when said oxidizing processing is finished, said second plasma is ignited after a predetermined duration from extinguishing said first plasma, and said nitriding processing is started by supplying said gas containing nitrogen after 1-600 seconds from said extinguishing of said first plasma. 
     
     
         8 . The method as claimed in  claim 4 , wherein said oxidizing processing is carried out by supplying said gas containing oxygen for a predetermined duration and further disconnecting supply of said gas containing oxygen, said plasma processing is continued for a duration of 1-600 seconds until said nitriding processing is started, and said nitriding processing is carried out by a plasma processing while supplying said gas containing nitrogen. 
     
     
         9 . The method as claimed in  claim 3 , wherein said plasma is formed by a microwave. 
     
     
         10 . The method as claimed in  claim 4 , wherein said plasma is formed by emitting a microwave via a planar antenna member.