TO FURTHER THE DEVELOPMENT of aluminum-indium-nitride/gallium-nitride (AlInN/GaN) -based HFETs on free-standing bulk GaN substrates, Sensor Electronic Technology, Inc. (SETi) has been awarded a Small Business Technology Transfer (STTR) Phase II program. That program was awarded through the Missile Defense Agency (MDA), following a demonstration of the epitaxial growth of a strain-free HFET structure in the Phase I program. The structure comprised lattice-matched AlInN on bulk GaN substrates.
In Phase I, AlInN/GaN heterostructures were deposited on bulk GaN substrates with Indium compositions ranging from 0% to 25%. Minimum sheet resistances were ~235 Ω/square. The new program will seek further reductions in defect density in the epitaxial GaN and AlInN layers. It also will strive to demonstrate increased device reliability over conventional AlGaN/ GaN HFETs. Such reliability is crucial in the defense and satellite markets, which account for over a quarter of the entire GaN RF-device market.