Seasoning method for film-forming apparatus
A seasoning method for a film-forming apparatus configured to form a silicon nitride film on a substrate placed in a process chamber. The method is conducted for reducing particles in the apparatus. The method comprises executing the plasma cleaning of the process chamber to remove a film deposited on the inner wall thereof (step S 1 ), subsequently depositing an amorphous silicon film (step S 2 ), depositing thereon a silicon nitride film in which the nitrogen content gradually increases in the thickness direction (step S 3 ), and keeping the inside of the process chamber being filled with a rare-gas plasma until film formation on the substrate is initiated (step S 4 ).
1. A seasoning method for a silicon nitride film-forming apparatus configured to make an electromagnetic wave incident on a processing chamber of the silicon nitride film-forming apparatus from an antenna of a circular ring shape disposed outside the processing chamber through an electromagnetic wave transmissive window provided on the processing chamber and thus to convert a silicon-containing gas and a nitrogen-containing gas supplied into the processing chamber into a plasma state, thereby forming a silicon nitride film on a substrate placed in the processing chamber, characterized by comprising the steps of:
supplying a cleaning gas into the processing chamber, and etching the silicon nitride film attached to an inner wall of the processing chamber while converting the cleaning gas into a plasma state;
supplying the silicon-containing gas into the processing chamber, and depositing an amorphous silicon film on the inner wall of the processing chamber while converting the silicon-containing gas into a plasma state;
supplying the silicon-containing gas into the processing chamber, while supplying the nitrogen-containing gas in a gradually increasing manner up to a predetermined flow rate, and thus depositing, on the amorphous silicon film, a silicon nitride film with the nitrogen content gradually increasing in a thickness direction, while converting the silicon-containing gas and the nitrogen-containing gas into a plasma state; and
supplying a rare gas into the processing chamber and maintaining a plasma state of the rare gas until film formation of the silicon nitride film on the substrate is initiated including a period of conveying the substrate to the processing chamber.
2. The seasoning method for a silicon nitride film-forming apparatus according to claim 1 ,
characterized in that the nitrogen-containing gas is supplied in a gradually increasing manner up to the predetermined flow rate gently in the beginning and more rapidly thereafter when depositing the silicon nitride film on the amorphous silicon film.