GaN/HBT SUPERLATTICE BASE STRUCTURE

摘要

PROBLEM TO BE SOLVED: To provide a heterojunction bipolar transistor(HBT) having higher efficiency and operability at high frequencies. ;SOLUTION: The alternate layers of a gallium nitride(GaN) layer and an aluminum/gallium nitride(AlGaN) layer having various Al compositions are provided, and an HBT (20) where an inclined superlattice structure is formed in a base layer (28) is included. Base p type carrier concentration is increased by he AlGaN thin layer in the base layer (28). Inclination in the Al composition in the AlGaN thin layer crosses the base layer (28) for inducing an electrostatic field, thus increasing a carrier speed, and hence reducing the carrier traveling time. Therefore, the traveling time is reduced, and at the same time the p type carrier concentration is increased, thus improving operation efficiency in a device.;COPYRIGHT: (C)2003,JPO