Semiconductor device and method for manufacturing the same

A semiconductor device, comprising:

• a semiconductor substrate having a collector formed thereon;
• an insulation film formed on said semiconductor substrate, said insulation film having an opening formed on a portion that corresponds to the collector;
• a semiconductor film formed inside the opening and on said insulation film, a portion in contact with the collector of said semiconductor film being formed of single crystal, and a portion of said semiconductor film on said insulation film being composed of a single layer which is thicker than the portion in contact with the collector;
• and
• an emitter formed on the portion in contact with the collector of said semiconductor film.

A method for manufacturing a semiconductor device having a bipolar transistor, comprising the steps of:

• forming a collector on a surface of a semiconductor substrate, and forming an insulation film on said semiconductor substrate;
• forming a conductive film on said insulation film;
• forming an opening in said insulation film and said conductive film, said opening exposing at least a part of said collector;
• forming a semiconductor film by non-selective epitaxial growth inside said opening, said semiconductor film being connected to said collector and said conductive film;
• and
• forming an emitter on said semiconductor film,
• wherein, in said step of forming a semiconductor film, a portion in contact with said collector of said semiconductor film is formed of single crystal, a portion in contact with said conductive film is formed of polycrystal, and the portion in contact with said conductive film is one to two times as thick as the portion in contact with said collector.

A method for manufacturing a semiconductor device having a bipolar transistor, comprising the steps of:

• forming a collector on a surface of a semiconductor substrate;
• forming an insulation film on said semiconductor substrate, said insulation film having an opening on a portion corresponding to said collector;
• forming a semiconductor film by non-selective epitaxial growth inside the opening and on said insulation film, a portion in contact with said collector of said semiconductor film being functioning as a base of single crystal, and a portion on said insulation film of said semiconductor film being composed of a single layer which is thicker than the portion in contact with said collector;
• and
• forming an emitter on a portion in contact with said collector of said semiconductor film.