NASA 1996 SBIR Phase I


PROPOSAL NUMBER : 96-1 13.04-6000

PROJECT TITLE : InPSb/InAs Heterojunctions for High-speed, Low-noise Electronics

TECHNICAL ABSTRACT (LIMIT 200 WORDS)

Spire proposes a SBIR Phase I project to develop InAs-channel high electron mobility transistors (HEMTs) which have the best predicted performance for high-speed, low-noise applications at room and cryogenic temperatures. Advantages of InAs include high electron mobility and high-carrier-saturation velocity combined with a high satellite valley separation. Current research efforts are focused on (Al, Ga)Sb alloys in the barrier layer; although these alloys provide large conduction band discontinuities, they are not well lattice- matched to InAs, are difficult to grow and are susceptible to oxidation. To date, best device performance is still far from predicted. Spire proposes a new ternary alloy, InP0.69Sb0.31, as the barrier layer for InAs. InP0.69Sb0.31 is lattice-matched to InAs, aluminum-free, and can be grown successfully by metalorganic chemical vapor deposition. These advantages should greatly enhance carrier transport in the InAs channel by providing better interface quality.

In Phase I, we will demonstrate carrier confinement and mobility enhancement in an InP0.69Sb0.31/InAs heterojunction. We will use trimethyl- indium, tertiarybutylphosphine and tridimethylaminoantimony to grow high quality InP0.69Sb0.31 films. These metalorganic sources were specially selected for their low pyrolysis temperature and potential for very low carbon incorporation in the grown films. In Phase II, we will optimize device design and growth, fabricate, and test InP0.69Sb0.31/InAs HEMT devices.

POTENTIAL COMMERCIAL APPLICATIONS
Applications include high-speed, low-noise digital circuits for microwave and millimeter wave sensing for commercial and military uses. The advantages of such devices are small switching delays per gate and very low-power dissipation. InP0.69Sb0.31/InAs heterostructures are also promising for integration in resonant tunneling diodes for submillimeter-wave power generation and signal processing.
NAME AND ADDRESS OF PRINCIPAL INVESTIGATOR
Dr. Dhrupad Trivedi
Spire Corporation
One Patriots Park
Bedford, MA 01730-2396
NAME AND ADDRESS OF OFFEROR
Spire Corporation
One Patriots Park
Bedford, MA 01730-2396