| 摘要 |
PROBLEM TO BE SOLVED: To prevent the deterioration of element characteristic due to ion implantation by forming the side wall of an Si insulator in the periphery of first to third collector layers and an emitter layer in a manner that it is brought into contact with their side surfaces, providing a second base layer in the upper side, connecting it to the base layer on a substrate, and providing a base electrode on the Si insulator. SOLUTION: Spaces are formed respectively surrounded by a substrate 1, a first highly doped p-type base layer 4 made of GaAs, a first n-type collector layer 3 and a first highly doped n-type sub-collector layer 2, a second highly doped p-type base layer 4', a second n-type collector layer 3' and a second highly doped n-type sub-collector layer 2', and a third highly doped p-type base layer 4", a third n-type collector layer 3" and a third highly doped n-type sub- collector layer 2". An SiO2 film 12 is filled in the clearance and a base electrode 13 connecting layers 4 and 4' extending thereon is provided. Since a parastic collector area and an interelement isolating area are formed by the clearance and SiO2 film 12, no change in element characteristic occurs during heat treatment step. |
