Development of On-Demand Non-Polar and Semi-Polar Bulk Gallium Nitride Materials for Next Generation Electronic and Optoelectronic Devices

Inlustra Technologies and the University of California, Santa Barbara propose a Phase II STTR project to grow and characterize single-crystal boules of gallium nitride (GaN) along non-polar directions. These boules will have sufficient size to yield multiple two-inch (50.8 mm) diameter non-polar GaN substrates with n-type conductivity. During Phase II, GaN boules will be grown from high-quality non-polar GaN seed wafers initially developed during and subsequent to the Phase I effort. These 50.8 mm seed wafers will have smooth surfaces, low average microscopic defect density, and low residual strain – factors critical to successful GaN boule growth. Inlustra personnel will initially focus on seed wafer refinement, and then transition into development of optimal bulk GaN growth conditions for each non-polar seed wafer orientation. By the end of the program, boules of 50.8 mm diameter and at least 15 mm thickness will be sliced into free-standing, n-type conductive non-polar GaN substrates. UCSB personnel will conduct extensive micro¬structural, optical, and electrical characterization on seed wafers, boules, and the non-polar GaN substrates derived from them. Regular feedback on crystal surface and microstructural quality in particular will provide Inlustra with the means of improving key GaN crystal growth parameters.