Apa Optics, Inc.

Other

Donald T Olson

James M VanHove

Muhammad A Khan

Jon N Kuznia

James M Van Hove

Muhammed A Khan

Margaret C Blasingame

Muhammad A Kahn

Aluminum gallium nitride laser

A high electron mobility transistor is disclosed, which takes advantage of the increased mobility due to a two dimensional electron gas occurring in GaN/Al.sub.x Ga.sub.1-x N heterojunctions. These structures are deposited on basal plane sapphire using low pressure metalorganic chemical vapor deposition. The electron mobility of the heterojunction is approximately 620 cm.sup.2 per volt second at room temperature as compared to 56 cm.sup.2 per volt second for bulk GaN of the same thickness deposited under identical conditions. The mobility of the bulk sample peaked at 62 cm.sup.2 per volt second at 180.degree. K. and decreased to 19 cm.sup.2 per volt second at 77.degree. K. The mobility for the heterostructure, however, increased to a value of 1,600 cm.sup.2 per volt second at 77.degree. K. and saturated at 4.degree. K.

Method of making a high electron mobility transistor

The invention is an Al.sub.x Ga.sub.1-x N ultraviolet detector with extremely high responsivity at over 200 to 365 nanometers and a very sharp long wavelength cutoff. The active layer for the sensors is a single crystal Al.sub.x Ga.sub.1-x N preferably deposited over a basal plane sapphire substrate using a switched atomic layer epitaxy process.

High responsivity ultraviolet gallium nitride detector

A high electron mobility transistor is disclosed, which takes advantage of the increased mobility due to a two dimensional electron gas occurring in GaN/Al.sub.x Ga.sub.1-x N heterojunctions. These structures are deposited on basal plane sapphire using low pressure metalorganic chemical vapor deposition. The electron mobility of the heterojunction is aproximately 620 cm.sup.2 per volt second at room temperature as compared to 56 cm.sup.2 per volt second at 180.degree. K. and decreased to 19 cm.sup.2 per volt second at 77.degree. K. The mobility for the heterostructure, however, increased to a value of 1,600 cm.sup.2 per volt second at 77.degree. K. and saturated at 4.degree. K.

High electron mobility transistor with GaN/Al.sub.x Ga.sub.1-x N

An improved aluminum gallium nitride material is disclosed, which permits the fabrication of improved optical devices such as laser mirrors (1, 2), as well as quantum wells and optical filters. The optical devices are constructed by depositing a buffer layer (7) of aluminum nitride onto a substrate (6), with alternating layers (10, 12, 14, etc.) of Al.sub.x Ga.sub.1-x N and Al.sub.y Ga.sub.1-y N, where x and y have values of between 0 and 1. Edge emitting lasers (31), surface emitting lasers (52) and quantum wells operating in the ultraviolet region are disclosed. The method of the present invention permits the ability to deposit thin, reproducible and abrupt layers of the improved material to permit the construction of rugged, solid state devices operating at ultraviolet wavelengths.

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Circle Pines, MN, United States of America

Donald T Olson