Feasibility of a-face bulk growth of AlN for fabrication of improved RF devices for Radar Performance Enhancement

GaN/AlGaN devices offer outstanding potential for high power, high frequency, and low-noise devices for severe-environment applications. Realization of these benefits for DoD systems is compromised by existing substrate quality and high substrate costs.In addition, the use of polar interfaces is believed to cause a number of reliability and performance problems due to interface states and defects. A better understanding and possible elimination of these problems would be obtained by eliminatinginterface polarization effects through the use of high-quality a-face bulk-grown aluminum nitride substrates. This effort explores the feasibility of high-rate a-face bulk growth of AlN where growth rates may be 5-10x higher than the 0.5 - 1 mm/hr and 3W/cm-K). Improved high power, high frequency nitride devices will result from improvements in nitride substrate technology. These improvements will lead to better radar systems for the DOD as well as commercial application in wireless base stations.