Dependence of growth temperature on the electrical properties and microstructure of MBE-grown AlN/GaN resonant tunneling diodes on sapphire Available to Purchase

AlN/GaN double-barrier resonant tunnel diodes have been grown by rf-plasma assisted molecular beam epitaxy at temperatures between 760 and 860 °C on metalorganic chemical vapor deposition-grown GaN templates with sapphire substrates. Room temperature negative differential resistance (NDR) was observed for all samples despite the presence of higher densities of threading dislocations in the device layers than in the MOCVD GaN template. The fraction of devices exhibiting NDR and the peak-to-valley current ratio was small for each sample (typically 1%–10% and 1.003–1.1, respectively). A clear trend of increasing peak current density with increasing growth temperature was observed.