Method for manufacturing a heterostructure transistor having a germanium layer on gallium arsenide using molecular beam epitaxial growth
AssigneeNEC Corporation
InventorsMasafumi Kawanaka, Jun'ichi Sone, Tooru Kimura
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Abstract
A heterostructure bipolar transistor is formed by a process of steps of holding an N-type gallium arsenide body using as an emitter region in a high vacuum of 10.sup.-9 torr to 10.sup.-13 torr at a first temperature of 400.degree. C. to 1,000.degree. C. where arsenic on a surface of the gallium arsenide body drifts away, lowering the first temperature to a second temperature of 300.degree. C. to 400.degree. C. to start a molecular beam epitaxial growth of a germanium, and forming an N-type germanium layer using as a collector region.
Claims6
A method for manufacturing a heterostructure bipolar transistor comprising the steps of (1) forming on a substrate an N-type gallium arsenide layer serving as an emitter region by molecular beam epitaxial growth;
- (2) holding said gallium arsenide layer in a high vacuum at a first temperature causing arsenic atoms on a surface of said gallium arsenide layer to evaporate from said surface, and (3) forming a germanium layer serving as a collector region on said gallium arsenide layer at a second temperature lower than said first temperature to form simultaneously a P-type germanium region serving as a base region at the interface of said gallium arsenide layer and said germanium layer by diffusing of gallium atoms from said gallium arsenide layer.
A method for forming a P-type germanium region on a gallium arsenide layer comprising the steps of (1) forming on a substrate a gallium arsenide layer by molecular beam epitaxial growth;
- (2) holding said gallium arsenide layer in a high vacuum at a first temperature where arsenic atoms on a surface of said gallium arsenide layer evaporate;
- and (3) lowering said first temperature to a second temperature and growing a germanium layer on said gallium arsenide layer at said second temperature, said P-type germanium region being simultaneously formed at the interface of said gallium arsenide layer and said germanium layer by the diffusion of gallium from said gallium arsenide layer.
Dependencies are inferred from the claim text.