Method of manufacturing semiconductor device using laser beam crystallized poly/amorphous layer

A method of manufacturing a semiconductor device comprising:

• making a desired aperture in an insulating film on a single-crystal semiconductor substrate having an impurity-doped semiconductor region, thereby exposing part of said semiconductor region, the semiconductor substrate and the semiconductor region forming a base-collector junction;
• covering the surface of said insulating film and the exposed semiconductor region with an impurity-doped polycrystalline semiconductor layer;
• and
• irradiating said semiconductor layer with a laser beam, thereby retaining the portion of said semiconductor layer covering said insulating film in the polycrystalline state and converting the portion of said semiconductor layer covering the exposed semiconductor region into a single crystal semiconductor layer, forming thereby an emitter-base junction between said single-crystal semiconductor layer portion and said semiconductor region.

A method of manufacturing a semiconductor region comprising:

• forming a field insulating film on a single crystal semiconductor substrate;
• forming a thin insulating film on a device region of the semiconductor substrate;
• making apertures in said thin and film insulating films, thereby exposing portions of the semiconductor substrate surface therethrough and also forming a gate insulating film;
• forming an impurity-doped amorphous semiconductor layer covering the surfaces of said field insulating film, said gate insulating film and the exposed portions of said semiconductor substrate;
• irradiating said impurity-doped amorphous semiconductor layer with a laser beam, thus converting the portions of the semiconductor layer covering said field and gate insulating films into polycrystalline doped regions and converting the portions of said semiconductor layer covering the semiconductor substrate into single-crystal doped regions;
• removing the polycrystalline semiconductor layer from the field insulating film, thereby leaving the single-crystal doped regions on the semiconductor surface as source and drain regions and the polycrystalline doped region on the gate insulating film as a gate electrode;
• and
• oxidizing the surface of the polycrystalline doped region covering said gate insulating film, thereby insulating it from the single crystal doped regions.

A method of manufacturing a semiconductor region comprising:

• forming a field insulating film on a single crystal semiconductor substrate;
• forming a thin insulating film on a device region of the semiconductor substrate;
• making apertures in said thin and film insulating films, thereby exposing portions of the semiconductor substrate surface therethrough and also forming a gate insulating film;
• forming an impurity-doped polycrystalline semiconductor layer covering the surfaces of said field insulating film, said gate insulating film and the exposed portions of said semiconductor substrate;
• irradiating said impurity-doped polycrystalline semiconductor layer with a laser beam, thus retaining the portions of the semiconductor layer covering said field and gate insulating films as polycrystalline doped regions and converting the portions of said semiconductor layer covering the semiconductor substrate into single-crystal doped regions;
• removing the polycrystalline semiconductor layer from the field insulating film, thereby leaving the single-crystal doped regions on the semiconductor surface as source and drain regions and the polycrystalline doped region on the gate insulating film as a gate electrode;
• and
• oxidizing the surface of the polycrystalline doped region covering said gate insulating film, thereby insulating it from the single crystal doped regions.