Semiconductor device and manufacturing method thereof

A method of manufacturing a semiconductor device comprising:

• forming an electrode supported by and separated from a main surface of a silicon substrate by an insulating film;
• forming a silicon nitride film on the main surface of said silicon substrate and covering said electrode;
• processing said silicon nitride film to form a protective layer on the surface of said silicon nitride film, said protective layer preventing epitaxial growth of silicon on said protective layer when silicon is epitaxially grown on the main surface of the silicon substrate, provided the epitaxial silicon is not grown to a thickness exceeding a critical film thickness;
• forming a sidewall insulating film protecting said electrode by removing said protective layer and said silicon nitride film from the main surface of said silicon substrate while leaving parts of said silicon nitride film and parts of said protective layer covering said parts of said silicon nitride film;
• forming first and second doped regions, in said silicon substrate at the main surface, spaced apart from each other, and on opposite sides of said electrode;
• and
• epitaxially growing first and second silicon films on said first and second doped regions, respectively, to a thickness no larger than the critical film thickness.

A method of manufacturing a semiconductor device comprising:

• forming an electrode supported by and separated from a main surface of a silicon substrate by an insulating film;
• forming a silicon nitride film on the main surface of said silicon substrate and covering said electrode;
• removing said silicon nitride film from the main surface of said silicon substrate while leaving parts of said silicon nitride film covering said electrode;
• processing said silicon nitride film covering said electrode to form a protective layer on the surface of said silicon nitride film, said protective layer preventing epitaxial growth of silicon on said protective layer when silicon is epitaxially grown on the main surface of the silicon substrate, provided the epitaxial silicon is not grown to a thickness exceeding a critical film thickness;
• and
• forming first and second doped regions in said silicon substrate at the main surface, spaced apart from each other, and on opposite sides of said electrode;
• and
• epitaxially growing firsthand second silicon films on said first and second doped regions, respectively, to a thickness no larger than the critical film thickness.