Improved Fabrication of Nonpolar InGaN Thin Films, Heterostructures, and Devices

Brief Description

A method for fabricating high-quality indium-containing epitaxial layers, heterostructures, and devices based on InGaN growth on GaN substrates. 

Background

GaN and its alloys (AlGaN, InGaN, AlInGaN) have been established as effective for fabrication of visible and ultraviolet optoelectronic devices and high-power electronic devices. These devices are most often grown along the polar c-direction, using a variety of growth techniques, including molecular beam epitaxy (MBE), metalorganic chemical vapor deposition (MOCVD), or hydride vapor phase epitaxy (HVPE). Growing devices in the polar c-direction results in charge separation, spontaneous polarization, and degraded device performance. Growth of such devices along a nonpolar axis could significantly improve their performance, but InGaN-based devices have previously encountered problems with growth conditions and material quality. 

Description

UC Santa Barbara researchers have developed a method for fabricating high-quality indium-containing epitaxial layers, heterostructures, and devices based on InGaN growth on GaN substrates. These InGaN films are grown along the nonpolar direction using a metalorganic chemical vapor deposition technique, and result in the successful creation of violet and near-ultraviolet LEDs and LDs. Previous issues related to the growth of InGaN-based devices, such as gross surface roughening, low indium incorporation, and indium desorption in InGaN heterostructures have been overcome with this technique.   

Advantages

·         Variability in layer thickness

·         Violet and near-ultraviolet light emission

·         Growth of nonpolar InGaN at a reduced temperature

·         Growth of InGaN layers at or near atmospheric pressure

Applications

·         LEDs

·         Laser diodes (LDs)

Patent Status