Effects of air annealing on DC characteristics of InAlN/GaN MOS high-electron-mobility transistors using atomic-layer-deposited Al₂O₃

Abstract

We evaluated the DC characteristics of InAlN/GaN metal–oxide–semiconductor high-electron-mobility transistors (MOS-HEMTs) using atomic-layer-deposited (ALD-)Al2O3 by focusing on air annealing to control defect levels in Al2O3 and electronic states at the Al2O3/InAlN interface. We clarified that the transconductance linearity and subthreshold slope were improved by air annealing, indicating a reduction in the number of electronic states at the Al2O3/InAlN interface. Furthermore, the cathodoluminescence study demonstrated that the oxygen-related defects in ALD-Al2O3 were decreased by air annealing. Consequently, we could successfully reduce the threshold voltage shift of InAlN/GaN MOS-HEMTs by using air-annealed ALD-Al2O3.

Effects of postmetallization annealing on interface properties of Al2O3/GaN structures

“…Consequently, a MIS-HEMT can accommodate a wide range of input signal sweep, boosting a maximum output power. [3][4][5] Different insulator materials have been applied to GaNbased MIS structures. 1) Since the semiconductor=insulator interfacial quality significantly affects the transistor performance, a chemically stable MIS structure with low interface state densities should be developed for practical device applications.…”

Comparative Study of Characteristics and Interface States with and without Post‐Gate‐Annealing Treatment for AlGaN/GaN‐Recessed Metal–Insulator–Semiconductor High Electron Mobility Transistors Using HfO2 Gate Insulator on Si Substrates

“…Due to the influence of PGA treatment on the V th , the fixed charges at the HfO 2 /AlGaN interface can be reduced effectively from 6.69 × 10 13 to 3.65 × 10 13 cm −2 . The decrease of the fixed charge density may be due to the decrease of oxygen‐related defects at the HfO 2 /AlGaN interface . The interface states that could be reduced by annealing were limited.…”

Improved f T/f max in wide bias range by steam-annealed ultrathin-Al2O3 gate dielectrics for InP-based high-electron-mobility transistors

“…21,22) To minimize the defects in Al 2 O 3 films, we applied steam annealing at 300 °C for 1 h post-deposition. According to previous studies, 23,24) annealing in an oxygen-containing environment enhances the passivation of dangling bonds, including oxygen vacancies in oxide films. Moreover, it is expected that H 2 O vapor (steam) accelerates the hydrolysis of carbon impurities in Al 2 O 3 films caused by TMA.…”