NITRIDE SEMICONDUCTOR STACK AND SEMICONDUCTOR DEVICE THEREFOR

摘要

PROBLEM TO BE SOLVED: To provide a transistor structure, with which a high current gain can be provided by causing electrons injected from an emitter layer to reach a collector layer. SOLUTION: An InGaN grated layer 85 changing an In composition from 0% to 10% is inserted between a p-type InGaN layer 86 and an n-type GaN layer 84. Such a thin film structure is in the state of gradually reducing a band gap from a wafer side to a front side. An AlN buffer layer 82 is grown for 100 nm on an SiC wafer 81, and an Si dope GaN layer 83 for ohmic electrode formation is grown. An Si dope GaN layer (n-type GaN layer) 84 is grown thereon. Further, an InGaN layer 85 changing the In composition is grown. Moreover, an Mg dope InGaN (p-type GaN layer) 86 is grown. Thus, a heterojunction diode is produced.