9424478 Chang The objectives of this research are to investigate the stability of intermetallic contacts to two compound semiconductor alloys, InGaAs and InAlAs, which are lattice-matched to InP, and to study the electrical behavior of selected intermetallic contacts to these two compound semiconductor alloys. The thermodynamic stabilities of the quaternary systems will be studied by determining relevant phase equilibria. Both the four-point probe and transmission line methods will be used to study the electrical behavior of the ohmic contacts. For those material combinations giving significant Schottky contacts, both I-V and C-V methods will be used. Films of intermetallics will be deposited on the compound semiconductor alloys by sputter deposition, and annealing of the contacts will be carried out using a rapid thermal annealing furnace. The metal/semiconductor interfaces will be characterized in the as-deposited state and after annealing using a variety of surface-sensitive techniques, including TEM, SAM and GAXRD (glancing angle x-ray diffraction). %%% The results of the proposed study are expected to provide improved fundamental understanding of the relationship between electrical behavior of intermetallics/compound semiconductor alloy combinations, and the thermodynamic and kinetic stabilities at their interfaces. Concurrently, the research investigation can have a significant impact on the design and development of optoelectronic and high-speed electronic devices for practical applications. An important feature of the program is the training of students in a fundamentally and technologically significant area of materials research. ***