930 Ka/Cm(2) Peak Tunneling Current Density In Gan/Aln Resonant Tunneling Diodes Grown On Mocvd Gan-On-Sapphire Template

We report on the design and fabrication of ultrahigh current density GaN/AlN double barrier resonant tunneling diodes grown via rf-plasma assisted molecular-beam epitaxy. The device structure was grown on a metal-organic chemical vapor deposition GaN-on-sapphire template. The devices displayed repeatable room temperature negative differential resistance with peak tunneling current densities (J(p)) between 637 and 930kA/cm(2). Analysis of temperature dependent measurements revealed the presence of severe self-heating effects, which allow strong phonon scattering that deteriorates the electron quantum transport. Finally, a qualitative comparison to the same structure grown on a low dislocation density freestanding GaN substrate has shown that sapphire-based templates are a feasible alternative.