Light-emitting semiconductor device using a Group III nitride compound and having a contact layer upon which an electrode is formed

US5753939A · kind A · utility

Inventors

• Michinari Sassa · Miyoshi, JP
• Naoki Shibata · Osaka, JP
• Shinya Asami · Ebeye, US
• Masayoshi Koike · Miyoshi, JP
• Junichi Umezaki · Miyoshi, JP
• Takahiro Kozawa · Miyoshi, JP

Key dates

• Filing date: Mar 7, 1997
• Grant date: May 19, 1998
• Expiry date: Mar 7, 2017

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10H20/832

Abstract

A light-emitting semiconductor device having an improved metal electrode and semiconductor structure that lowers the driving voltage of the device. The device has a hetero p-n junction structure. This structure includes: (1) an n-layer having n-type conduction and a Group III nitride compound semiconductor satisfying the formula Al.sub.x Ga.sub.y In.sub.1-x-y N, inclusive of x=0, y=0, and x=y=0; (2) a p-layer having p-type conduction and a Group III nitride compound semiconductor satisfying the formula Al.sub.x Ga.sub.y In.sub.1-x-y N, inclusive of x=0, y=0, and x=y=0; and (3) an emission layer disposed between the n-layer and the p-layer. The device also has a metal electrode and a contact layer that is disposed between the p-layer and the metal electrode. The contact layer is doped with an acceptor impurity more heavily that is the p-layer. The acceptor impurity may be magnesium (Mg). The contact layer may be doped within the range of 1.times.10.sup.20 /cm.sup.3 to 1.times.10.sup.2l /cm.sup.3 and may comprise a first and a second contact layer.