Development of Bulk Gallium Nitride Growth Technique for Low Defect Density Large Area Native Subs

Investigating Organization
Sandia National Laboratories

Principal Investigator(s)
Karen Waldrip

Subcontractor
None

Funding Source
Building Technologies Program/NETL

Award
DOE Share: $497,800

Contract Period
06/01/06 - 05/31/08

Bulk gallium nitride is difficult to grow from the melt due to a low solubility of nitrogen in liquid gallium, which forces the use of high temperatures and high nitrogen gas overpressures. Here, we propose the use of alternative molten-salt-based solvents in which the solubility of nitrogen may be intrinsically higher, and in which there is the opportunity to produce nitrogen directly through electrochemical methods. Indeed, our preliminary experiments have shown that nitrogen gas can be continuously electrochemically reduced to N^-3 in a molten chloride salt (a lithium-chloride/potassium-chloride eutectic) at 450◦ C and atmospheric pressure, and that bulk GaN crystals of mm-scale sizes could be grown in an afternoon using this technique.

Content dated 2/08