| 摘要 |
PROBLEM TO BE SOLVED: To provide a device using the maximum oscillation frequency by a method wherein high resistance polycrystalline semiconductor layers in contact with a subcollector layer, a collector layer and a base layer in a specific shortest distance from the intrinsic region of a HBT specified by a plane shape of an emitter layer and in a specific particle diameter are provided. SOLUTION: The high resistance polycrystalline compound semiconductor layers 8 are partly substituted for a parasitic subcollector region, a parasitic collector region and an outer base leading-out region of a hetero-junction bypolar transistor(HBT). Resultantly, the distance between a transistor true region and said semiconductor layers 8 is to exceed 0.1μm - but not to exceed 2μm. Besides, the particle diameter of the polycrystalline is to exceed 30 nm but not to exceed 100 nm. Furthermore, in the case of the HBT, within the formation of the high resistance polycrystalline compound semiconductor layers 8, a sub-collector layer 3, a collector layer 4 and a base layer 5 can be simultaneously formed with the other transistor intrinsic layer and parasitic regions, etc., by previously forming an SiO2 film 2.
|
