Electrochemical Solution Growth: Gallium Nitride Crystal Growth

Technology Summary

Sandia National Laboratories has developed a disruptive new crystal growth technology, called Electrochemical Solution Growth (ESG). This technology has a high potential for producing the high-quality, large-area, and economical bulk gallium nitride (GaN) substrates needed to meet the performance requirements of high-efficiency LED and high-power transistors. Substrates are the bulk wafer material on which opto/electronic thin film devices are fabricated; they dictate the crystalline quality and thus the performance of these devices. GaN substrates, which currently do not exist, are necessary for these devices to reach their full market potential.

Description

ESG represents a revolution in crystal growth technology that borrows well-developed concepts from Rotating Disk Reactor metalorganic chemical vapor deposition (MOCVD) technology. The ions are delivered to a rotating seed crystal surface by way of the fluid dynamics imposed by the rotating seed and/or susceptor. The ions then diffuse across a fluid boundary layer near the surface of the seed, where they react and deposit to form single crystal GaN. The nitride and gallium ionic precursors can be controlled reliably and precisely using common electrochemical techniques programmed through the potentiostat. Because the growth conditions remain steady-state throughout the process, a single crystal boule may be pulled from the surface. The reactor design is fully laterally scalable, and the vertical direction can be grown as long as the supply of gallium and nitrogen gas allow. The growth rate is high for high throughput, and the technology is low cost. Wafers may be sliced out of the boule from any direction to produce substrates of any desired orientation.

Publications:

Karen Waldrip. (2010, November). "Enabling Next-Generation Power Electronics: Electrochemical Solution Growth (ESG) Technique for Bulk Gallium Nitride Substrates." DOE Peer Review, Washington DC. [online]. Available:
http://www.sandia.gov/ess/docs/pr_conferences/2010/waldrip_snl.pdf

Karen Waldrip. (2008, February). "Electrolysis a Surprising Method for Scaling GaN Crystal Growth?" Compound Semiconductor. [online]. Available: http://compoundsemiconductor.net/csc/features-details.php?cat=features&id=32553

Karen Waldrip, Stan Atcitty, John Boyes. (2008, September). "Development of the Electromechanical Solution Growth (ESG) Technique for Native GaN Substrates." DOE Energy Storage & Power Electronics Reasearch Program. [online]. Available: http://www.sandia.gov/ess/docs/pr_conferences/2008/waldrip(growthtech)_snl.pdf

S. Lee, A. West, A. Allerman, K. Waldrip, D. Follstaedt, P. Provencio, D. Koleske, C. Abernathy. (2005. June). "Effect of Threading dislocations on the Bragg peakwidths of GaN, AIGaN, and AIN heterolayers." Applied Physics Letters. [online]. 86(24), pp 241904-241904-3. Available: http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?tp=&arnumber=4877506&abstractAccess=no&userType=inst

S. Lee, D. Koleske, K. Cross, J. Floro, K. Waldrip, A. Wise, S. Mahajan. (2004, December). "In situ measurements of the critical thickness for strain relaxation in AlGaN/GaN heterostructures." Applied Physics Letters. [online]. 85 (25), p 6164. Available: http://ieeexplore.ieee.org/search/freesrchabstract.jsp?tp=&arnumber=4875417&searchWithin%3DAuthors%3A.QT.+Waldrip%2C+K.+E..QT.%26openedRefinements%3D*%26searchField%3DSearch+All&abstractAccess=no&userType=inst

K. Waldrip, J.Han, J. Figiel, H. Zhou, E. Makarona, A. Nurmikko . (2001, May). "Stress engineering during metalorganic chemical vapor deposition of AlGaN/GaN distributed Bragg reflectors." Applied Physics Letters. [online]. 78(21), p 3205. Available: http://ieeexplore.ieee.org/search/freesrchabstract.jsp?tp=&arnumber=4896640&queryText%3Dmetalorganic+chemical+vapor+deposition+of+AlGaN%2FGaN%26openedRefinements%3D*%26searchField%3DSearch+All&abstractAccess=no&userType=inst

Roland Haitz, Fred Kish, Jeff Tsao, Jeff Nelson. (1999, October) . "The Case for a National Research Program on Semiconductor Lighting." White paper presented publicly at the 1999 Optoelectronics Industry Development Association (OIDA) forum in Washington DC. [online]. Available: http://lighting.sandia.gov/lightingdocs/HaitzR200004.pdf

Benefits

  • High potential for producing superior-quality, economical bulk GaN substrates
  • Helps fully realize GaN's true potential
  • Less expensive than alternate approaches

Applications and Industries

  • LEDs--general illumination, backlighting, displays, and automotive
  • Lasers (ultraviolet through green wavelengths)--homeland security and military, illumination, and data storage
  • Vehicle electrification
  • Down-hole drilling diagnostics--future market
  • Utility grid modernization (incorporation of renewable energy using energy storage)

Intellectual Property

Title
ID Number
Patent Number
Date
Molten-salt-based growth of group III nitrides 7721.1 7,435,297 10/14/2008
Issued
Technology IDSD#7721Development StageDevelopmentAvailabilityAvailablePublished09/29/2011Last Updated01/31/2013