Nitride-based semiconductor device and method for fabricating the same
AssigneePanasonic Corporation
InventorsMitsuaki OYA, Toshiya YOKOGAWA, Atsushi YAMADA, Akihiro ISOZAKI
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Abstract
A nitride-based semiconductor light-emitting device 100 includes: a GaN substrate 10 with an m-plane surface 12; a semiconductor multilayer structure 20 provided on the m-plane surface 12 of the GaN substrate 10; and an electrode 30 provided on the semiconductor multilayer structure 20. The electrode 30 includes an Mg layer 32 and an Ag layer 34 provided on the Mg layer 32. The Mg layer 32 is in contact with a surface of a p-type semiconductor region of the semiconductor multilayer structure 20.
Claims30
A nitride-based semiconductor device, comprising:
- a nitride-based semiconductor multilayer structure including a p-type semiconductor region, a surface of the p-type semiconductor region being an m-plane;
- and
- an electrode that is arranged on the p-type semiconductor region, wherein the p-type semiconductor region is made of an AlxInyGazN semiconductor (where x+y+z=1, x≧0, y≧0, and z≧0), and
- the electrode includes an Mg layer which is in contact with the surface of the p-type semiconductor region and an Ag layer which is provided on the Mg layer.
The nitride-based semiconductor device of claim 27, wherein the Ag layer is covered with a protector electrode which is made of a metal different from Ag.
The nitride-based semiconductor device of claim 27, wherein the Ag layer is covered with a protector layer which is made of a dielectric.
The nitride-based semiconductor device of claim 27, wherein the semiconductor multilayer structure includes an active layer which includes an AlaInbGacN layer (where a+b+c=1, a≧0, b≧0 and c≧0), the active layer being configured to emit light.
The nitride-based semiconductor device of claim 27, wherein the p-type GaN-based semiconductor region is a p-type contact layer.
The nitride-based semiconductor device of claim 27, wherein a thickness of the Mg layer is equal to or smaller than a thickness of the Ag layer.
The nitride-based semiconductor device of claim 27 wherein, in the Mg layer, a concentration of N is lower than a concentration of Ga.
The nitride-based semiconductor device of claim 27, further comprising a semiconductor substrate that supports the semiconductor multilayer structure.
The nitride-based semiconductor device of claim 27, wherein the p-type GaN-based semiconductor region is made of GaN.
The nitride-based semiconductor device of claim 27, wherein the Mg layer and the Ag layer are at least partially made of an alloy.
A light source, comprising:
- a nitride-based semiconductor light-emitting device;
- and
- a wavelength converter including a phosphor that converts a wavelength of light emitted from the nitride-based semiconductor light-emitting device,
- wherein the nitride-based semiconductor light-emitting device includes
- a nitride-based semiconductor multilayer structure including a p-type semiconductor region, a surface of the p-type semiconductor region being an m-plane, and
- an electrode that is arranged on the p-type semiconductor region,
- the p-type semiconductor region is made of an AlxInyGazN semiconductor (where x+y+z=1, x≧0, y≧0, and z≧0), and
- the electrode includes an Mg layer which is in contact with the surface of the p-type semiconductor region and an Ag layer which is provided on the Mg layer.
The light source of claim 28, wherein the p-type GaN-based semiconductor region is made of GaN.
The light source of claim 28, wherein the Mg layer and the Ag layer are at least partially made of an alloy.
A method for fabricating a nitride-based semiconductor device, comprising the steps of:
- (a) providing a substrate;
- (b) forming on the substrate a nitride-based semiconductor multilayer structure including a p-type semiconductor region, a surface of the p-type semiconductor region being an m-plane;
- and
- (c) forming an electrode on the surface of the p-type semiconductor region of the semiconductor multilayer structure,
- wherein step (c) includes
- forming an Mg layer on the surface of the p-type semiconductor region, and
- forming an Ag layer on the Mg layer.
The method of claim 29, wherein step (c) further includes performing a heat treatment on the Mg layer.
The method of claim 29, wherein the step of forming the Mg layer includes irradiating Mg with pulses of an electron beam such that Mg is deposited onto the surface of the p-type GaN-based semiconductor region.
The method of claim 29, further comprising removing the substrate after step (b).
The method of claim 29, wherein the p-type GaN-based semiconductor region is made of GaN.
The nitride-based semiconductor device of claim 27, wherein the Mg layer includes an Mg island provided on the surface of the p-type GaN-based semiconductor region.
The nitride-based semiconductor device of claim 27, wherein the Mg layer is made of an Mg—Ag alloy.
A nitride-based semiconductor device, comprising:
- a nitride-based semiconductor multilayer structure including a p-type semiconductor region, a surface of the p-type semiconductor region being an m-plane;
- and
- an electrode that is arranged on the p-type semiconductor region,
- wherein the p-type semiconductor region is made of an AlxInyGazN semiconductor (where x+y+z=1, x≧0, y≧0, and z≧0),
- the electrode is composed only of an alloy layer which is in contact with the surface of the p-type semiconductor region, and
- the alloy layer is made of Mg and Ag.
The nitride-based semiconductor device of claim 30, wherein the alloy layer is formed by forming an Mg layer so as to be in contact with the surface of the p-type GaN-based semiconductor region and an Ag layer on the Mg layer, and thereafter performing a heat treatment.
The nitride-based semiconductor device of claim 30, wherein the alloy layer is formed by depositing a mixture or compound of Mg and Ag onto the surface of the p-type GaN-based semiconductor region by means of evaporation, and thereafter performing a heat treatment.
Dependencies are inferred from the claim text.