US Patent 7897993 GaN based luminescent device on a metal substrate

A compound semiconductor luminescent device characterized by comprising an electroconductive substrate, a compound semiconductor function layer including a GaN layer, an electrode, an adhesiveness-enhancing layer, and a bonding layer, which are stacked in this order wherein the above-described electroconductive substrate includes a metal material that indicates a thermal expansion coefficient different by 1.5×10−6/° C. or less from GaN.