Study of HfO 2-Based High-k Gate Insulators for GaN Power Device

Toshihide Nabatame, Erika Maeda, Mari Inoue, Masafumi Hirose, Ryota Ochi, Tomomi Sawada, Yoshihiro Irokawa, Tamotsu Hashizume, Koji Shiozaki, Takashi Onaya, Kazuhito Tsukagoshi, Yasuo Koide

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)


We discussed about usefulness of HfO 2-based high dielectric constant (High-k) materials such as HfO 2, HfSiO x and HfAlO x as gate insulator for GaN power device. Here, we systematically studied characteristics of Hf 0.55Al 0.45O x gate insulator which fabricated by plasma-enhanced atomic layer deposition and post-deposition annealing (PDA) at 800°C in N 2 ambient. The Hf 0.55Al 0.45O x film had an amorphous structure but Ga diffusion into Hf 0.55Al 0.45O x film was observed after PDA. The k-value of the Hf 0.55Al 0.45O x film was 17.2, which was larger than that of HfSiO x (13.5). The Hf 0.55Al 0.45O x also showed superior electrical properties such as a minimal flatband voltage (V fb) hysteresis ( +10 mV) and a relatively small V fb shift ( -0.95 V), as well as a low interface state density ( 1 1011 cm-2eV-1 at E c-E=0.25 eV), and a high breakdown electric field (8.6 MVcm-1). Based on these experimental data and previous our research of HfO 2 and HfSiO x films, we concluded the HfSiO x and HfAlO x had candidate materials as gate insulator for GaN power device.

Original languageEnglish
Title of host publication240th ECS Meeting - Semiconductor Process Integration 12
PublisherIOP Publishing Ltd.
Number of pages8
ISBN (Electronic)9781607685395
Publication statusPublished - 2021
Externally publishedYes
Event240th ECS Meeting - Orlando, United States
Duration: 2021 Oct 102021 Oct 14

Publication series

NameECS Transactions
ISSN (Print)1938-6737
ISSN (Electronic)1938-5862


Conference240th ECS Meeting
Country/TerritoryUnited States

ASJC Scopus subject areas

  • Engineering(all)


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