A semiconductor light emitting device has a structure of stacked semiconductor layers including a double hetero junction, and a electrode having a plurality of stacked metal layers exhibiting a light transmitting property and an oxygen rich layer exhibiting the light transmitting property and interposed between said metal layers. The oxygen rich layer is preferably oxide layer. Such structure exhibits high light emission.
The present invention provides an electrode making good ohmic contact with an n-type nitride semiconductor without requiring heat treatment at high temperature, wherein an aluminum layer, a silicon layer, a nickel layer and a gold layer are laminated in this order on an n-type gallium nitride based semiconductor, to form an n-type 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.
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.
A gallium nitride compound semiconductor light emitting element has a nitride layered body formed on a translucent substrate. A P type pad electrode, an N type pad electrode and a P type electrode are formed at the layered body, each having the desired reflectance. The thickness of the translucent substrate and the nitride layered body stacked thereon of the semiconductor light emitting element is 60 .mu.m to 460 .mu.m.
A surface acoustic wave device includes interdigital transducer (IDT) electrode and reflectors disposed on a piezoelectric substrate. Each of the IDT electrode and the reflectors has a multi-layer film structure including at least one layer (high specific gravity metal component containing layer) including as a major component a metal with a specific gravity of at least about 15 and having a film-thickness of at least about 10 nm, and at least one layer (low specific gravity metal component containing layer) including as a major component a metal with a specific gravity of up to about 10 and a volume resistivity as a bulk value (at about 20.degree. C.) of up to about 10.times.10.sup.-8 .OMEGA..multidot.m, and having a film-thickness of at least about 10 nm. For example, the multi-layer structure includes an Ni film (low specific gravity metal component containing layer) with a film-thickness of about 150 nm disposed on a Ti film, a Cu film (low specific gravity metal component containing layer) with a film-thickness of about 250 nm disposed on the Ni film, and an Au film (high specific gravity metal component containing layer) with a film-thickness of about 50 nm disposed on the Cu film.
