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Title: High performance AlGaN/GaN MISHEMTs using N 2 O treated TiO 2 as the gate dielectric
Abstract In this work, TiO2thin films deposited by the atomic layer deposition (ALD) method were treated with a special N2O plasma surface treatment and used as the gate dielectric for AlGaN/GaN metal insulator semiconductor high electron mobility transistors (MISHEMTs). The N2O plasma surface treatment effectively reduces defects in the oxide during low-temperature ALD growth. In addition, it allows oxygen atoms to diffuse into the device cap layer to increase the barrier height and thus reduce the gate leakage current. These TiO2films exhibit a dielectric constant of 54.8 and a two-terminal current of 1.96 × 10−10A mm−1in 2μm distance. When applied as the gate dielectric, the AlGaN/GaN MISHEMT with a 2μm-gate-length shows a high on/off ratio of 2.59 × 108and a low subthreshold slope (SS) of 84 mV dec−1among all GaN MISHEMTs using TiO2as the gate dielectric. This work provides a feasible way to significantly improve the TiO2film electrical property for gate dielectrics, and it suggests that the developed TiO2dielectric is a promising high-κgate oxide and a potential passivation layer for GaN-based MISHEMTs, which can be further extended to other transistors.  more » « less
Award ID(s):
2239302
PAR ID:
10623882
Author(s) / Creator(s):
; ; ; ; ; ; ; ;
Publisher / Repository:
IOP
Date Published:
Journal Name:
Semiconductor Science and Technology
Volume:
40
Issue:
1
ISSN:
0268-1242
Page Range / eLocation ID:
015004
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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