Semiconductor device with Schottky and ohmic electrodes in contact with a heterojunction

摘要

To provide a semiconductor device that has a sufficiently low on-resistance and excellent low-capacitance and high-speed characteristics as compared with conventional GaN-based diodes. The semiconductor device includes: a substrate (101); a buffer layer (102); a stack structure (103 and 104) including at least one heterojunction unit (103 and 104) that is a stack of a layer (GaN layer 103) made of a nitride semiconductor and a layer (AlGaN layer 104) made of another nitride semiconductor having a larger band gap than the nitride semiconductor (GaN layer 103); a Schottky electrode (106) that is placed at a first end of the stack structure (103 and 104) and forms a Schottky barrier contact with the heterojunction unit (103 and 104); and an ohmic electrode (107) that is placed at a second end of the stack structure (103 and 104) and forms an ohmic contact with the heterojunction unit (103 and 104).