Structure and electrical properties of TiN/GaAs Schottky contacts

The interface structure and morphology of TiN/GaAs contacts before and after annealing at 500, 700, and 850 °C have been investigated by transmission electron microscopy. Results reveal that pocket-like protrusions are formed beneath the interface after annealing at 500 °C. These pockets increased in number and maximum size with increased annealing temperature. Outdiffusion of Ga and/or As along high angle grain boundaries between columnar structure of the as-deposited TiN thin film has been proposed as being responsible for the pocket formation. The changes of electrical characteristics of these materials after annealing have been related to the formation of these pockets.