Browsing by Author "Ostreng, Erik"

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AlN Surface Passivation of GaN-Based High Electron Mobility Transistors by Plasma-Enhanced Atomic Layer Deposition
(2017-04-27)
Tzou, An-Jye
;
Chu, Kuo-Hsiung
;
Lin, I-Feng
;
Ostreng, Erik
;
Fang, Yung-Sheng
We report a low current collapse GaN-based high electron mobility transistor (HEMT) with an excellent thermal stability at 150 degrees C. The AlN was grown by N-2-based plasma enhanced atomic layer deposition (PEALD) and shown a refractive index of 1.94 at 633 nm of wavelength. Prior to deposit AlN on III-nitrides, the H-2/NH3 plasma pretreatment led to remove the native gallium oxide. The X-ray photoelectron spectroscopy (XPS) spectroscopy confirmed that the native oxide can be effectively decomposed by hydrogen plasma. Following the in situ ALD-AlN passivation, the surface traps can be eliminated and corresponding to a 22.1% of current collapse with quiescent drain bias (V-DSQ) at 40 V. Furthermore, the high temperature measurement exhibited a shift-free threshold voltage (V-th), corresponding to a 40.2% of current collapse at 150 degrees C. The thermal stable HEMT enabled a breakdown voltage (BV) to 687 V at high temperature, promising a good thermal reliability under high power operation.