Electrode for light-emitting semiconductor devices and method of producing the electrode
An electrode for a light-emitting semiconductor device includes a light-permeable electrode formed to come into contact with the surface of the semiconductor, and a wire-bonding electrode that is in electrical contact with the light-permeable electrode and is formed to come into partial contact with the surface of the semiconductor with at least a region in contact with the semiconductor having a higher contact resistance per unit area with respect to the semiconductor than a region of the light-permeable electrode in contact with the semiconductor. This device electrode is formed by forming a wire-bonding electrode on a portion of the surface of a p-type GaN-base compound semiconductor, forming on the surface of the semiconductor a first layer that is of at least one member selected from the group consisting of Au, Pt and Pd and is formed to overlay the upper surface of the wire-bonding electrode at a portion at which the wire-bonding electrode is located, forming on the first layer a second layer that is of at least one metal selected from the group consisting of Ni, Ti, Sn, Cr, Co, Zn, Cu, Mg and In, and forming a light-permeable electrode by heat-treating the first and second layers in an atmosphere that contains oxygen.
1. An electrode for a light-emitting semiconductor device, formed on a surface of a p-type GaN-base compound semiconductor, comprising:
a light-permeable electrode comprised of a first layer containing Au contacting the surface of the p-type GaN-base compound semiconductor, and a second layer, having a thickness in a range of 1 nm to 60 nm, formed on the first layer and comprising a light-permeable metal oxide containing an oxide of Ni; and
a wire-bonding electrode that is electrically contacting the light-permeable electrode and partially contacting the surface of the p-type GaN-base compound semiconductor.
2. The electrode according to claim 1 , wherein the wire-bonding electrode contacting the p-type GaN-base compound semiconductor having a higher contact resistance per unit area with respect to the p-type GaN-base compound semiconductor than a region of the light-permeable electrode in contact with the p-type GaN-base compound semiconductor.