A.C. Callegari, P.D. Hoh, et al.
Applied Physics Letters
Schottky gates for self-aligned GaAs metal semiconductor field-effect transistors (MESFETs) have been formed by dc magnetron sputtering of WSi 0.11 onto sputter-cleaned GaAs surfaces. The WSi0.11/GaAs diodes showed good current-voltage and capacitance-voltage characteristics after annealing at 800 °C. Schottky barrier heights measured by current-voltage were φI-VB ≅0.73 eV with an ideality factor n≅1.14 for large diodes and φI-VB ≅0.67 eV with n≅1.3 for 1×10 μm gates without a self-aligned n+ implant. The n+ self-aligned implant was found to cause leakage current, which was interpreted as a parallel small-area, low-barrier diode at the gate edge. FETs formed with this gate material showed good threshold voltage uniformity with a standard deviation as low as 31 mV for 1 μm enhancement-mode FETs and 49 mV for 1 μm depletion-mode FETs on a 51-mm wafer.
A.C. Callegari, P.D. Hoh, et al.
Applied Physics Letters
C. Vanneste, C.C. Chi, et al.
Physical Review B
M. Eizenberg, A.C. Callegari, et al.
Applied Physics Letters
D.A. Buchanan, E. Gusev, et al.
IEDM 2000