Gallium nitride-based heterojunction field-effect transistors for high-power high-frequency MMIC power amplifiers.

Abstract

The use of wide bandgap devices and circuits has increased dramatically in recent years in step with significant advancements in material quality and device technology. Devices made with silicon carbide and gallium nitride have shown exceptional chemical and electrical stability and are extremely promising high power, high temperature, and high frequency operation. The use of III-V nitride material specifically have found applications in blue and UV emission optoelectronic devices such as LEDs, semiconductor layers, as well as solar-blind sensors and reflectors. The strong piezoelectric nature of III-V nitrides also allows for their use in chemical and pressure sensors. III-V nitride devices are now in limited commercial production for optical, electronic, and sensor application. The expected demand and technological maturation for devices made form this material system is extremely promising, but there is still quite a bit of work to be done before the promise becomes a reality. In this study, the viability of GaN-based HFETs for high frequency and high power MMIC amplifier applications will be demonstrated through fabrication process optimization and investigation of HFET performance through the optimization of layer design and device geometry. DC, pulsed I-V, low frequency noise, small and large signal characterization will be used to determine optimum operation points and structures to yield optimum large signal performance. Single- and two-stage amplifiers will be designed and simulated to indicate the potential RF MMIC performance at 12GHz and 20GHz large signal operation. SAW filter fabrication and integration with active GaN HFETs devices for sensing and low frequency RF application will also be addressed.