Semi-polar LED/LD Devices on Relaxed Template with Misfit Dislocation at Hetero-interface

Tech ID: 24136 / UC Case 2009-742-0

Brief Description

An efficient method to significantly reduce defects in non-polar and semi-polar group-III nitride films.

 

Background

The usefulness of non-polar and semi-polar group-III nitrides such as gallium nitride (GaN) and its alloys has been well established for its use in the fabrication of optoelectronic and high-powered electronic devices. Given recent trends in industry standards there is considerable interest in the growth of nonpolar (a- and m-plane) GaN based epitaxial films. The problems associated with the growth of these nonpolar GaN based films is characterized by high defect density, reduced carrier mobility, and low reliability which all contribute to an overall lower efficiency. However, high performance devices can be achieved by eliminating these defects by improving the structural quality of the nonpolar GaN films.

 

Description

Researchers at the University of California, Santa Barbara have developed an efficient method to significantly reduce defects in non-polar and semi-polar group-III nitride films. Through the use of in-situ SiNx as a nanomask when growing GaN substrates, researchers have demonstrated reduced stacking fault density, reduced thread dislocation density, reduced surface roughness, reduced sub-micron pits, and increased luminescence. Compared to the lateral epitaxial overgrowth (LEO) technique, this invention has the advantage of being a simple process that avoids contamination characteristic of the ex-situ process used in LEO. Unlike LEO, this new process also facilitates nanometer scale lateral epitaxial overgrowth at the open pores of the film which reduces the differences between the wing and window regions of film which has adverse effects on devices if untreated. All structure improvements contribute to an overall reduction of defects uniformly across the film which significantly increases the efficiency of the material.

Advantages

  • Uniform defect reduction across film
  • Highly efficient process capable of being done on the nanometer scale
  • Improved performance of semi-polar and non-polar group-III nitride based devices
  • Highly adaptable and easily controllable process


Applications

  • LDs and LEDs
  • Group-III nitride materials
  • High powered electronic and optoelectronic devices


Patent Status

Country Type Number Dated Case
United States Of America Issued Patent 9,159,553 10/13/2015 2009-742
 

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Inventors

  • Chakraborty, Arpan
  • DenBaars, Steven P.
  • Nakamura, Shuji
  • Ohta, Hiroaki
  • Speck, James S.
  • Tyagi, Anurag
  • Wu, Feng
  • Young, Erin C.

Other Information

Keywords

indSSL, indLED, LED, group-III nitrides, misfit dislocation

Categorized As

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