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Hexagonal Wurtzite Type Epitaxial Layer with a Low Alkali-Metal Concentration

Technology Benefits

Low alkali-metal diffusionImproved device performance

Technology Application

LEDs and Laser DiodesHigh Electron Mobility Transistors (HEMTs)Power switching devices

Detailed Technology Description

Researchers at the University of California, Santa Barbara have developed a method to produce hexagonal würtzite type epitaxial layers possessing low alkali-metal concentration. While incorporation of alkali-metals is essential to the growth process, they have a negative impact on device properties. We have found that the diffusion of alkali-metals into the epitaxial layer strongly depends on the crystal plane of the substrate and therefore can be effectively suppressed. This method produces bow-free GaN substrates containing low structural defect densities in a cost effective manner, allowing manufacturers of both devices and substrates to benefit.

Application No.

8647967

Others

Background

A high-quality substrate is essential for fabrication of GaN devices, which has led to various approaches for growing GaN single crystal substrates. In most approaches, alkali-metals are added to the growth system, causing the grown GaN crystals to contain high concentrations of alkali-metals.  This high concentration of alkali metals severely increases the likelihood that alkali-metals will diffuse into the epitaxial layers, having a negative impact on the electrical properties and performance of devices.

 

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Tech ID/UC Case

23657/2008-658-0

Related Cases

2008-658-0

*Abstract

A method to produce hexagonal würtzite type epitaxial layers possessing low alkali-metal concentration.

*IP Issue Date

Feb 11, 2014

*Principal Investigator

Name: Steven DenBaars

Department:

Name: Derrick Kamber

Department:

Name: Makoto Saito

Department:

Name: James Speck

Department:

Name: Shinichiro Kawabata

Department:

Name: Shuji Nakamura

Department:

Country/Region

USA