GaN Bulk Growth and Epitaxy from Ca-Ga-N Solutions

This SBIR proposal addresses the liquid phase epitaxy (LPE) of gallium nitride (GaN) films using nitrogen-enriched metal solutions. Growth of GaN from solutions offers the possibility of drastically reducing the density of line defects. As these defects adversely affect both breakdown voltages and electron velocities, their reduction can significantly increase the performance of high power Ka-band HEMT structures used for satellite communications. To achieve low defect densities in GaN films and efficient, large scale manufacturing, IIIAN will utilize new chemical growth methods based on nitrogen-enriched metal solutions, in particular the Ca-Ga-N ternary system. In the binary calcium-gallium alloy system it is possible to achieve a nitrogen atomic fraction of 2% at 900 oC and 2 bar. This is a significantly higher fraction than is possible in pure gallium solutions. For example, a temperature of ~1700 oC and pressure of ~10 kbar are necessary to achieve even 0.1% atomic nitrogen fraction in pure gallium solvent.

Group III-nitride optoelectronics have become prevalent in commercial applications for shortwavelength blue and UV LEDs. Laser diodes made from this material system are still limited in lifetime by thermal degradation due to scattering effects IR-loss at line defects. The approach presented here for defect density reduction will benefit these commercial optoelectronics.

This proposal addresses the specification stated in solicitation topic O1.07 for "Epitaxial GaN films with threading dislocations less than 106 per cm2 for use in space qualified wide band-gap semiconductor devices at X- and Ka-band." The goal of The IIIAN Company is to provide these low defect density GaN films on 6" diameter substrates as starting templates for subsequent growth of GaN/AlGaN HEMT structures. With the common epitaxial growth techniques for group III-nitrides, Molecular Beam Epitaxy (MBE) and Metal-Organic Chemical Vapor Deposition (MOCVD), line defects follow through from those in the initial buffer layer. By utilizing LPE to produce low defect density GaN films on 6" substrates, IIIAN will enable compound semiconductor manufacturers (i.e. RFMD, TriQuint, Anadigics) to better utilize the group III-nitride material system for the high frequency, high power SSPAs requested in this topic for future NASA missions to the moon and the planets.

This is early/mid-stage (TRL 3) — the most realistic path in is NASA SBIR/STTR, which funds small businesses and research institutions to develop technology aligned with NASA's needs (equity-free, phased funding). Check whether a current SBIR/STTR solicitation topic overlaps with this project's technology area, or contact the project directly (above) to ask.

None of these are guaranteed paths for this specific project — TechPort itself doesn't have an "apply" button. Reaching out to the contact(s) above with a specific question is usually the fastest way to find out what's actually open.