GROUP III NITRIDE SEMICONDUCTOR DEVICE AND EPITAXIAL SUBSTRATE

摘要

PROBLEM TO BE SOLVED: To provide a group III nitride semiconductor that reduces a leak current from a Schottky electrode. SOLUTION: A high electron mobility transistor 1 has a support substrate 3 composed of A1N, A1GaN and GaN. An AIYGa1-YN epitaxial layer 5 has a surface roughness (Rms) of 0.25nm or less and this surface roughness is determined by an area of 1μm square. A GaN epitaxial layer 7 is established between an A1YGa1-YN support substrate and an A1YGa1-YN epitaxial layer 5. A Schottky electrode 9 is arranged on the A1YGa1-YN epitaxial layer 5. A first ohmic electrode 11 is arranged on the A1YGa1-YN epitaxial layer 5 and a second omic electrode 13 is also arranged on the A1YGa1-YN epitaxial layer 5. One of the first and second ohmic electrodes 11 and 13 is a source electrode and the other is a drain electrode. The Schottky electrode 9 is a gate electrode of the high electron mobility transistor 1. COPYRIGHT: (C)2007,JPO&INPIT