Method of manufacturing a semiconductor device including reduction of a catalyst

A method for fabricating a semiconductor device, comprising steps of:

• introducing a catalyst which promotes crystallization of silicon to an amorphous semiconductor film comprising silicon;
• crystallizing said amorphous semiconductor film by a first heat treatment to obtain a crystalline semiconductor film comprising silicon;
• reducing said catalyst existing within said crystalline semiconductor film by a second heat treatment within an oxidizing atmosphere containing a halogen element to form a first thermal oxide film on the crystalline semiconductor film and by making said first thermal oxide film getter said catalyst;
• removing said first thermal oxide film;
• and
• forming a second thermal oxide film on the crystalline semiconductor film by third heat treatment after removing said first thermal oxide film.

A method for fabricating a semiconductor device, comprising steps of:

• introducing a catalyst which promotes crystallization of silicon to an amorphous semiconductor film comprising silicon;
• crystallizing said amorphous semiconductor film by a first heat treatment to obtain a crystalline semiconductor film comprising silicon;
• reducing said catalyst existing within said crystalline semiconductor film by a second heat treatment within an oxidizing atmosphere containing halogen element;
• removing a first thermal oxide film formed by said second heat treatment;
• forming an active layer of a thin film transistor by patterning said crystalline semiconductor film;
• and
• forming a second thermal oxide film which composes at least a part of a gate insulating film on said active layer by a third heat treatment.

A method of fabricating a semiconductor device, comprising the steps of:

• selectively introducing a catalyst which promotes crystallization of silicon to a portion of an amorphous semiconductor film comprising silicon;
• growing crystal by a first heat treatment in a direction parallel to the semiconductor film from the portion;
• forming a first thermal oxide film on a surface of the semiconductor film by implementing a second heat treatment within an oxidizing atmosphere containing a halogen element;
• removing said first thermal oxide film;
• forming an active layer having at least a channel region of said semiconductor device by patterning said semiconductor film after removing said first thermal oxide film;
• and
• forming a second thermal oxide film on said active layer by a third heat treatment.