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Reduced Dislocation Density of Non-Polar GaN Grown by Hydride Vapor Phase Epitaxy
Technology Benefits
Significantly improves film quality by allowing fabrication of enhanced GaN substrate layers for subsequent non-polar device fabrication; Greatly improves subsequent device performance.
Technology Application
Fabrication of low-dislocation density GaN by HVPE. This technology is available for a non-exclusive license. See below for a selection of the patents and patent applications related to this invention. Please inquire for full patent portfolio status.
Detailed Technology Description
Scientists at the University of California have developed a novel method for producing low-dislocation density non-polar GaN by hydride vapor phase epitaxy (HVPE). This invention complements the method for producing thick planar films of a-plane GaN by HVPE (UC Case 2003-225) by allowing single-step fabrication of reduced defect density material.
Supplementary Information
Patent Number: US7220658B2 Application Number: US2003537644A Inventor: Haskell, Benjamin A | Craven, Michael D. | Fini, Paul T. | DenBaars, Steven P. | Speck, James S. | Nakamura, Shuji Priority Date: 16 Dec 2002 Priority Number: US7220658B2 Application Date: 6 Jun 2005 Publication Date: 22 May 2007 IPC Current: H01L002120 | C30B002502 | H01L0021205 US Class: 438481 | 257E21097 | 257E21113 | 257E21131 | 257E21132 Assignee Applicant: The Regents of the University of California Title: Growth of reduced dislocation density non-polar gallium nitride by hydride vapor phase epitaxy Usefulness: Growth of reduced dislocation density non-polar gallium nitride by hydride vapor phase epitaxy Summary: For manufacturing free-standing a-plane GaN film in the manufacture of laser diode, light emitting diode or transistor (claimed). Novelty: Performing a lateral hydride vapor phase epitaxial overgrowth of planar, non-planar, a-plane gallium nitride film useful for laser diode involves masking sapphire and over growing the film under reduced pressure using hydrogen carrier gas
Industry
Optics
Sub Group
LED/OLED
Application No.
7220658
Others
Background
Gallium nitride (GaN) and its ternary and quaternary compounds incorporating aluminum and indium (AlGaN, InGaN, AlInGaN) have proven useful in fabricating visible and ultraviolet optoelectronic devices and high-power electronic devices. GaN and its alloys are most stable in the hexagonal w'rtzite crystal structure. However, the positions of the gallium and nitrogen atoms in this structure leads to polarization of the GaN crystals along the c-axis. Virtually all GaN-based devices are grown parallel to the polar c-axis, due to the relative ease of growing planar Ga-face planes. In addition, strain at the interfaces between adjacent dissimilar layers causes piezoelectric polarization and subsequent charge separation. These polarization effects decrease the likelihood of electron and hole interaction, which is essential for the operation of light-emitting devices. As a result, eliminating these polarization effects inherent to c-axis oriented devices could greatly enhance the efficiency of GaN light-emitting devices. In addition, defect densities in directly grown GaN films are much higher that those found in more traditional III/V semiconductor systems, such as the arsenides and phosphides.
