Effects of Post-Deposition Annealing on ZrO2/n-GaN MOS Capacitors with H2O and O3 as the Oxidizers

Meijuan Zheng,Hao Wu,Jiaxian Wan,Xiao Wang,Chang Liu,Guozhen Zhang

doi:10.1186/s11671-017-2024-x

Abstract

GaN-based metal-oxide-semiconductor capacitors with ZrO2 as the dielectric layer have been prepared by atomic layer deposition. The accumulation and depletion regions can be clearly distinguished when the voltage was swept from −4 to 4 V. Post-annealing results suggested that the capacitance in accumulation region went up gradually as the annealing temperature increased from 300 to 500 °C. A minimum leakage current density of 3 × 10−9 A/cm2 at 1 V was obtained when O3 was used for the growth of ZrO2. Leakage analysis revealed that Schottky emission and Fowler-Nordheim tunneling were the main leakage mechanisms.

Highlights

Gallium nitride (GaN)-based wide bandgap semiconductors have seen enormous success during the past few decades due to their intriguing properties such as high breakdown electric field (4.2 MV/cm), high saturation velocity (~3 × 107 cm/s) [1], excellent chemical stability, and the ability to resist radiation damage [2]
We systematically studied the properties of ZrO2 films grown on n-GaN substrates by
N-GaN substrates were transferred into atomic layer deposition (ALD) (Beneq TFS-200) chamber, and ZrO2 films with a thickness of 20 nm were deposited at 200 °C

Summary

Background

Gallium nitride (GaN)-based wide bandgap semiconductors have seen enormous success during the past few decades due to their intriguing properties such as high breakdown electric field (4.2 MV/cm), high saturation velocity (~3 × 107 cm/s) [1], excellent chemical stability, and the ability to resist radiation damage [2]. Owing to these characteristics, GaN and its alloys can be applied in high-power electronics, such as thin film transistors and high electron-mobility transistors (HEMTs) [3, 4]. The leakage mechanisms of the MOS capacitors were discussed

Methods

Results and Discussion

Conclusions