HETEROJUNCTION BIPOLAR TRANSISTOR AND FABRICATING METHOD THEREOF

摘要

PURPOSE: A heterojunction bipolar transistor and a fabricating method thereof are provided to increase a breakdown voltage between a base and a collector by forming a concave groove on a surface of a collector layer. CONSTITUTION: An N type collector layer(120) is formed on a part of a surface of a semi-insulating substrate(110) formed with GaAs. A P+ type base layer is formed on a center of a surface of the N type collector layer(120). A collector electrode(125) is formed on an edge of the collector layer(120). An emitter layer(140) and an emitter contact layer(145) are formed on a center of a base layer. A base electrode(135) is formed on an edge of the base layer(130). A concave groove(A) is formed on a surface of the collector layer(120) between the base layer(130) and the collector electrode(125). A path of current is determined by a depth of the concave groove(A). An interval between the base layer(140) and the collector electrode(125) can be increased regardless of a thickness of the collector layer(120).