Optimization of the Epilayer Design for the Fabrication of Doped GaN Planar Gunn Diodes

By means of Monte Carlo simulations of gallium nitride (GaN) planar Gunn diodes, the epilayer structure on which they are fabricated is optimized in order to achieve ultrahigh-frequency oscillations. Practical considerations, such as the limitations of the technological fabrication process and the mitigation of the huge self-heating effects expected to appear in the devices, have been also contemplated for the choice of the optimal epilayer parameters. The best results are obtained for an active layer thickness of 150 nm with doping of 5
$\times 10^{{18}}$
cm
⁻³
, which would provide 350 GHz Gunn oscillations when using a contact separation of
$0.5~\mu \text{m}$
.