Dowa Electronics Materials Co., Ltd.

Yoshikazu Ooshika

Tetsuya Matsuura

Masatoshi Iwata

Yutaka Ohta

A III nitride semiconductor epitaxial substrate having more excellent surface flatness is provided, in which the problems of crack formation and the double peaks in the shape of the EL spectrum are mitigated by employing appropriate conditions for Si doping on an AlN layer on a substrate; a III nitride semiconductor light emitting device; and methods of producing the same. A III nitride semiconductor epitaxial substrate has a substrate of which at least a surface portion is made of AlN, an undoped AlN layer formed on the substrate, an Si-doped AlN buffer layer formed on the undoped AlN layer, and a superlattice laminate formed on the Si-doped AlN buffer layer. The Si-doped AlN buffer layer has an Si concentration of 2.0&#xd7;10/cmor more and a thickness of 4 nm to 10 nm.

III nitride semiconductor epitaxial substrate and III nitride semiconductor light emitting device, and methods of producing the same

The method according to the present invention includes a first step of supplying the Group V source gas at a flow rate B(0&#x3c;B) and supplying the gas containing magnesium at a flow rate C(0&#x3c;C) while supplying the Group III source gas at a flow rate A(0&#x2266;A); and a second step of supplying a Group V source gas at a flow rate B(0&#x3c;B) and supplying a gas containing magnesium at a flow rate C(0&#x3c;C) while supplying a Group III source gas at a flow rate A(0&#x3c;A). The first step and the second step are repeated a plurality of times to form a p-AlGaN (0&#x2266;x&#x3c;1) layer, and the flow rate Ais a flow rate which allows no p-AlGaN layer to grow and satisfies A&#x2266;0.5 A.

Method of manufacturing a p-AlGaN layer

A III nitride epitaxial substrate which makes it possible to obtain a deep ultraviolet light emitting device with improved light output power is provided. A III nitride epitaxial substrate includes a substrate, an AlN buffer layer, a first superlattice laminate, a second superlattice laminate and a III nitride laminate in this order. The III nitride laminate includes an active layer including an AlGaN (0.03&#x2266;&#x3b1;) layer. The first superlattice laminate includes AlGaN layers and AlGaN (0.9&#x3c;b&#x2266;1) layers which are alternately stacked, where &#x3b1;(alpha)&#x3c;a and a&#x3c;b. The second superlattice laminate includes repeated layer sets each having an AlGaN layer, an AlGaN layer, and an AlGaN (0.9&#x3c;z&#x2266;1) layer, where &#x3b1;(alpha)&#x3c;x and x&#x3c;y&#x3c;z.

III nitride epitaxial substrate and deep ultraviolet light emitting device using the same

To provide a semiconductor device including a functional laminate having flatness and crystallinity improved by effectively passing on the crystallinity and flatness improved in a buffer to the functional laminate, and to provide a method of producing the semiconductor device; in the semiconductor device including the buffer and the functional laminate having a plurality of nitride semiconductor layers, the functional laminate includes a first n-type or i-type AlGaN layer (0&#x2266;x&#x3c;1) on the buffer side, and an AlGaN adjustment layer containing p-type impurity, which has an approximately equal Al composition to the first AlGaN layer (x&#x2212;0.05&#x2266;z&#x2266;x+0.05, 0&#x2266;z&#x3c;1) is provided between the buffer and the functional laminate.

Semiconductor device and method of producing the same

A nitride semiconductor device is provided, in which a superlattice strain buffer layer using AlGaN layers having a low Al content or GaN layers is formed with good flatness, and a nitride semiconductor layer with good flatness and crystallinity is formed on the superlattice strain buffer layer. A nitride semiconductor device includes a substrate; an AlN strain buffer layer made of AlN formed on the substrate; a superlattice strain buffer layer formed on the AlN strain buffer layer; and a nitride semiconductor layer formed on the superlattice strain buffer layer, and is characterized in that the superlattice strain buffer layer has a superlattice structure formed by alternately stacking first layers made of AlGaN (0&#x2266;x&#x2266;0.25), which further contain p-type impurity, and second layers made of AlN.

Nitride semiconductor device and method of producing the same

An object of the present invention is to provide a nitride semiconductor light-emitting device in which contact resistance generated between an n-contact layer and an n-side electrode is effectively reduced while maintaining satisfactory external quantum efficiency, and a method of efficiently producing the nitride semiconductor light-emitting device. Specifically, the present invention characteristically provides a nitride semiconductor light-emitting device having a semiconductor laminated body including an n-type laminate, a light-emitting layer and a p-type laminate, and an n-side electrode and a p-side electrode, characterized in that: the n-type laminate includes an n-contact layer made of an AlGaN material (0.7&#x2266;x&#x2266;1.0) and an n-clad layer provided on the n-contact layer; and an interlayer made of an AlGaN material (0&#x2266;y&#x2266;0.5) is provided on a partially exposed portion, on the light-emitting layer side, of the n-contact layer.

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Tokyo, Japan

Yoshikazu Ooshika