III nitride compound semiconductor element an electrode forming method

摘要

An AlN buffer layer 2; a silicon (Si)-doped GaN high-carrier-concentration n+ layer 3; an Si-doped n-type Al0.07Ga0.93N n-cladding layer 4; an Si-doped n-type GaN n-guide layer 5; an active layer 6 having a multiple quantum well (MQW) structure, and including a Ga0.9In0.1N well layer 61 (thickness: about 2 nm) and a Ga0.97In0.03N barrier layer 62 (thickness: about 4 nm), the layers 61 and 62 being laminated alternately; an Mg-doped GaN p-guide layer 7; an Mg-doped Al0.07Ga0.93N p-cladding layer 8; and an Mg-doped GaN p-contact layer 9 are successively formed on a sapphire substrate. A p-electrode 10 is formed of a film of titanium nitride (TiN) or tantalum nitride (TaN) (thickness: 50 nm). The contact resistance of this electrode is reduced through heat treatment.