Metamorphic heterojunction bipolar transistor for high power transistor amplifier has heavily doped n type InGaAs layer which represents ohmic contact for emitter

摘要

A heavily doped n type InGaAs layer (26) represents an ohmic contact for an emitter represented by a n type InAlAs layer or a graded n type AlInGaAs layer or a n type InP layer (25). A heavily doped p type layer (24) represents a base and an ohmic contact or the base. A heavily doped n type InGaAs layer (22) represents an ohmic contact for a collector. The collector is represented by a n type InGaAs layer or a n type InP layer or a n type InAlAs layer (23). A non doped metamorphic buffer layer (21), the heavily doped n type InGaAs layer, the n type InAlAs layer, the heavily doped p type layer, the n type InP layer, and the heavily doped n type InGaAs layer are sequentially laminated on a semiconducting GaAs substrate (20).