STTR Phase I: Ultra-high Performance InAsN Transistor for RF Power Amplifiers

This Small Business Technology Transfer (STTR) Phase I project will develop ultra-high-performance heterojunction bipolar transistors. An exciting new material, the InAsN semiconductor alloy system, is the key element in the concept for a low-voltage, high-speed GaAs transistor platform that is suitable for high-volume manufacturing. The energy band gap of GaAs based materials drops substantially when small amounts of nitrogen are incorporated into the material. Since nitrogen pushes the lattice constant in the opposite direction from the inclusion of indium in GaAs, InAsN alloys can be grown lattice-matched to GaAs thereby eliminating any problems associated with strain, with very low band gap energies. The project's goal is to demonstrate next generation heterojunction bipolar transistors with performance benchmarks exceeding those of present-day technologies. This program will lead to the commercialization of solid-state power amplifiers combining the advantages and the maturity of GaAs technology with the lower turn-on voltages that can be achieved in InP- and SiGe-based devices. If successful, the proposed InAsN HBT leapfrogs beyond current technologies by being much more power efficient without sacrificing high-speed performance or increasing component cost. GaAs wafers dominate the market for solid state power amplifiers for wireless communication products. In 2003 cellular phone production alone reached 500 million handsets. It is predicted by Strategy Analytics that this output will double to 1 billion handsets in 2008. This enormous market growth will cause severe pressure on power amplifier component revenue. Moreover, with cellular phone handsets becoming ever more functional, strategies are required to significantly lower the device turn-on voltage so as to minimize power consumption and sustain operation over longer periods of time.