Method of making a stacked emitter in a bipolar transistor by selective laser irradiation
AssigneeHitachi, Ltd.
InventorsYasuo Wada, Takahide Ikeda, Masao Tamura
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Abstract
An insulating film is formed on a semiconductor substrate, and the insulating film on that part of the semiconductor substrate where an emitter is to be formed, is removed to expose the surface of the above part. A polycrystalline or amorphous silicon film is deposited on the entire surface, and then irradiated with a laser beam to convert that portion of the polycrystalline or amorphous silicon film which is deposited on the surface of the semiconductor substrate without interposing the insulating film therebetween, into a single crystal of silicon, thereby forming a stacked emitter.
Claims12
A method of fabricating a semiconductor device comprising the steps of:
- (a) forming an insulating film on a principal surface of a semiconductor substrate;
- (b) removing that part of said insulating film which overlies a portion of said semiconductor substrate where an emitter is to be formed;
- (c) depositing a polycrystalline or amorphous silicon film on the entire surface;
- and
- (d) irradiating a selected portion of said polycrystalline or amorphous silicon film with a laser beam to convert that portion of said polycrystalline or amorphous silicon film, which is deposited on said principal surface of said semiconductor substrate without said insulating film therebetween, to a single crystal of silicon, whereby a stacked emitter can be formed protruding from the semiconductor substrate.
Dependencies are inferred from the claim text.