Toyoda Gosei Co., Ltd.

Naoyuki Nakada

Yasuhisa Ushida

Koji Okuno

Yoshiki Saito

Shugo Nitta

Shinya Boyama

A semiconductor substrate includes a sapphire substrate including a c-plane main surface and a groove in a surface thereof, the groove including side surfaces and a bottom surface, and a Group III nitride semiconductor layer formed on the sapphire substrate. The side surfaces of the groove are an a-plane of sapphire. An axis of the Group III nitride semiconductor layer, perpendicular to one of the side surface of the groove, is a c-axis of Group III nitride semiconductor. A plane of the Group III nitride semiconductor, parallel to the main surface of the sapphire substrate, is an a-plane of Group III nitride semiconductor.

Method for producing group III nitride semiconductor and template substrate

The surface of a sapphire substrate having a c-plane main surface is patterned by ICP dry etching. The patterned sapphire substrate is thermally treated in a hydrogen or nitrogen atmosphere at a temperature of less than 700&#xb0; C. or at a temperature of more than 800&#xb0; C. to 1100&#xb0; C. An AlN buffer layer is formed by magnetron sputtering on the surface on the patterned side of the sapphire substrate heated at a temperature of 200&#xb0; C. to less than 700&#xb0; C. On the buffer layer, a Group III nitride semiconductor layer having a c-plane main surface is formed so as to have a thickness of 1 &#x3bc;m to 10 &#x3bc;m by MOCVD.

Method for producing a group III nitride semiconductor

A semiconductor substrate includes a sapphire substrate including an a-plane main surface and a groove in a surface thereof, the groove includes side surfaces and a bottom surface, and a Group III nitride semiconductor layer formed on the sapphire substrate. Both side surfaces of the groove assume a c-plane of sapphire. An axis perpendicular to one of the side surfaces of the groove of the Group III nitride semiconductor layer assumes a c-axis of Group III nitride semiconductor. A plane parallel to the main surface of the sapphire substrate of the Group III nitride semiconductor layer assumes an m-plane of Group III nitride semiconductor.

The present invention provides a Group III nitride semiconductor light-emitting device exhibiting improved light extraction performance. In the production method, a p cladding layer of p-AlGaN is formed by the MOCVD method on a light-emitting layer at a pressure of 30 kPa and with an Mg concentration of 1.5&#xd7;10/cm. A plurality of regions with a nitrogen polarity is formed in the crystals with a Group III element polarity, and thus the p cladding layer has a hexagonal columnar concave and convex configuration on the surface thereof. Subsequently, a p contact layer of GaN is formed by the MOCVD method, in a film along the concave and convex configuration on the p cladding layer.

Method for producing a group III nitride semiconductor light-emitting device

The present invention provides a method for producing a Group III nitride semiconductor. The method includes forming a groove in a surface of a growth substrate through etching; forming a buffer film on the groove-formed surface of the growth substrate through sputtering; heating, in an atmosphere containing hydrogen and ammonia, the substrate to a temperature at which a Group III nitride semiconductor of interest is grown; and epitaxially growing the Group III nitride semiconductor on side surfaces of the groove at the growth temperature. The thickness of the buffer film or the growth temperature is regulated so that the Group III nitride semiconductor is grown primarily on the side surfaces of the groove in a direction parallel to the main surface of the growth substrate. The thickness of the buffer film is regulated to be smaller than that of a buffer film which is employed for epitaxially growing the Group III nitride semiconductor on a planar growth substrate uniformly in a direction perpendicular to the growth substrate. The growth temperature is regulated to be lower than a temperature at which the Group III nitride semiconductor is epitaxially grown on a planar growth substrate uniformly in a direction perpendicular to the growth substrate. The growth temperature is preferably 1,020 to 1,100&#xb0; C. The buffer film employed is an AlN film having a thickness of 150 &#x212b; or less.

To produce a Group III nitride-based compound semiconductor having a m-plane main surface and uniformly oriented crystal axes. A mesa having a side surface having an off-angle of 45&#xb0; or less from c-plane is formed in a a-plane main surface of a sapphire substrate. Subsequently, trimethylaluminum is supplied at 300&#xb0; C. to 420&#xb0; C., to thereby form an aluminum layer having a thickness of 40 &#x212b; or less. The aluminum layer is nitridated to form an aluminum nitride layer. Through the procedure, a Group III nitride-based compound semiconductor is epitaxially grown only from a side surface of the mesa having an off-angle of 45&#xb0; or less from c-plane in the sapphire substrate having an a-plane main surface. Thus, a Group III nitride-based compound semiconductor having m-plane which is parallel to the main surface of the sapphire substrate can be formed.

Method for producing group III nitride-based compound semiconductor, wafer including group III nitride-based compound semiconductor, and group III nitrided-based compound semiconductor device

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Kiyosu, Japan

Naoyuki Nakada