Fluorine plasma treatment induced deep level traps and their effect on current transportation in Al0.83In0.17N/AlN/GaN Schottky barrier diodes

Abstract

The deep level traps and the electrical properties of fluorine plasma treated (F-treated) and non-treated Al0.83In0.17N/AlN/GaN Schottky barrier diodes (SBDs) were investigated by the temperature-dependent current–voltage (I–V) and deep level transient spectroscopy (DLTS) measurements. Three deep level traps were detected in the SBD after F-treatment at ~Ec − 0.17 eV, ~Ec − 0.27 eV and ~Ec − 1.14 eV. One of the deep level traps at ~Ec − 1.14 eV is mainly located in the Al0.83In0.17N barrier layer with a captured cross section (σ) of ~6.50 × 10−18 cm2. This F-related deep level trap has 3–4 orders of magnitude of the larger σ and ~0.46 eV greater active energy than that of the dislocation-related one at ~Ec − 0.68 eV with σ of ~1.92 × 10−21 cm2. Meanwhile, the leakage current of F-treated SBD at −5 V is reduced by ~2 orders of magnitude compared with that of the non-treated one. This leakage current reduction is mainly attributed to the increase of the Poole–Frenkel emission barrier height from ~0.09 eV in non-treated SBD to ~0.46 eV in the F-treated one. It is believed that the main reverse current transportation is the Poole–Frenkel emission from the F-related deep level trap states into the continuum states of the dislocations in F-treated Al0.83In0.17N/AlN/GaN SBD.