| 摘要 |
PURPOSE: To form an insulating film or a region which do not apply stress to the periphery, by a method wherein, after an insulating film is formed in a part on a semiconductor substrate, and a high resistance semiconductor layer and a low resistance semiconductor layer are laminated in the region except the insulating film, a collector layer, a base layer and an emitter layer are grown in a trench or an aperture which are formed by eliminating the insulating film. CONSTITUTION: On a semi-insulating GaAs substrate 1, an undoped GaAs buffer layer 2 of 5000Åin thickness and an N<+> GaAs subcollector layer 3 of 5000Åin thickness are formed, on which the following are formed; a high resistance GaAs layer 5 of 1000Åin thickness which has a trench or an aperture, a p<+> GaAs layer 6 of 1000Åin thickness which turns to an base outer region, and a high resistance GaAs layer 7 of 1000Åin thickness. An N-GaAs collector layer 10, P-GaAs base layer 11 and an N-AlGaAs emitter layer 12 which turn to the active region of HBT crystal are formed in the trench or the aperture. A collector electrode 13 is formed around the subcollector layer 3, and a base electrode 14 is formed around the p<+> GaAs layer 6.
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