A low resistive tungsten (W) Schottky contact to GaAs has been developed by plasma enhanced chemical vapor deposition. The resistivity of tungsten (W) films deposited on GaAs at 300 °C is about 18 μΩ cm and the film structure is (111) oriented α-phase W coexisting with (200) and (211) oriented β-phase tungsten. The resistivity of W films deposited above 350 °C is increased due to the diffusion of Ga and As atoms from GaAs into W films. This has been confirmed by secondary ion mass spectroscopy. I-V characteristics of GaAs Schottky contacts formed at 300 °C show that the maximum barrier height is 0.81 eV and the ideality factor is 1.04. They are not degraded during rapid thermal annealing at temperatures ranging from 500 to 700 °C for 10 s without an arsenic overpressure.

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