Preferential diffusion and orientation effects of Schottky barrier GaAs field-effect transistors

Preferential diffusion and the corresonding orientation effect was examined for GaAs Schottky barrier field-effect transistors. Unreported orientation effects of devices with no n+ implants are presented and compared to self-aligned n+-implanted devices. Characteristics of the intrinsic and extrinsic field-effect transistors were measured for devices oriented in the [011] and [011̄] directions. Enhanced diffusion due to anisotropic stress is proposed as the mechanism. Criteria for preferred device orientation and ambiguities in previous literature are discussed.