Fabrication, and direct current and cryogenic analysis of SF6-treated AlGaN/GaN Schottky barrier diodes

Schottky contacts on fluorine implanted AlGaN/GaN heterostructures with the ideality factor close to unity and low on-voltage threshold are presented in this paper. An SF6 plasma anode pretreatment followed by a specific low-temperature annealing is also compared to a nonannealed sample. In addition, physical-model parameters are extracted by means of cryogenic temperature measurements to understand the conduction mechanisms involved in annealed diodes, showing better DC performances than their nonannealed counterparts. Furthermore, annealing induces a decrease of the ideality factor, which sets the field-enhanced thermionic emission as the main conduction mechanism, and reduces the tunneling reverse current leakage. This effect is attributed to the recovery of the plasma-induced damages.