Kyma Technologies Inc., Research Triangle Park, NC, an RTP-based developer and supplier of nitride substrates, has shipped what it says is the world’s first single crystal 2-inch gallium nitride wafer to a global micro- and optoelectronic company for use as a base technology.

GaN wafers may also be used as base material in a variety of applications within the communications and semiconductor industries.

The GaN n-type substrates are single crystal, 50mm in diameter, 500-microns thick, and have greater than 90% usable area. Novel free standing GaN substrates mean high IR, visible, and UV transmission, high thermal conductivity and exact lattice matching for
manufacturers who rely on substrates as core material for GaN-based wide bandgap semiconductor devices. Kyma’s unique 2-in GaN substrates will be commercially available by the end of the second quarter of this year, with development of 4-inch GaN wafers underway.

Kyma has focused on improving the quality of high purity GaN since 2000, when it received funding through a Missile Defense Agency (MDA, formerly BMDO) SBIR contract to explore the feasibility of developing GaN materials. Since then, Kyma has received additional contract awards to expand GaN research efforts.

Until now, according to Kyma, there were no GaN substrates available for commercial use. High purity GaN substrates allow GaN-based device manufacturers to eliminate processing steps and improve device quality over those grown on other substrates, such as sapphire and silicon carbide.

GaN substrates are exactly matched in lattice constant and thermal expansion properties for epitaxial growth of doped GaN layers needed for fabrication of GaN-based devices. This eliminates stress and defects induced by growing GaN epi-layers on non-nitride substrates, which increases device fabrication complexity and cost and compromise device performance.