A study of the effect of surface pretreatment on atomic layer deposited Al2O3 interface with GaN

Jianyi Gao; Wenwen Li; Saptarshi Mandal; Srabanti Chowdhury

doi:10.1117/12.2279313

23 August 2017 A study of the effect of surface pretreatment on atomic layer deposited Al₂O₃ interface with GaN

Jianyi Gao, Wenwen Li, Saptarshi Mandal, Srabanti Chowdhury

Proceedings Volume 10381, Wide Bandgap Power Devices and Applications II; 1038103 (2017) https://doi.org/10.1117/12.2279313
Event: SPIE Optical Engineering + Applications, 2017, San Diego, California, United States

Abstract

Al₂O₃ has been an attractive gate dielectric for GaN power devices owing to its large conduction band offset with GaN (~2.13eV), relatively high dielectric constant (~9.0) and high breakdown electric field (~10 MV/cm). Due to exceptional control over film uniformity and deposition rate, atomic layer deposition (ALD) has been widely used for Al₂O₃ deposition. The major obstacle to ALD Al₂O₃ on GaN is its high interface-state density (Dit) caused by incomplete chemical bonds, native oxide layer and impurities at the Al2O3/GaN interface. Therefore, an appropriate surface pretreatment prior to deposition is essential for obtaining high-quality interface. In this study, we investigated the effect of TMA, H₂O and Ar/N₂plasma pretreatment on D_it and border traps (N_bt). 5 cycles of TMA purge, 5 cycles of H₂O purge and Ar/N₂ plasma pretreatment were conducted on GaN prior to deposition of ALD Al₂O₃. Al₂O₃/GaN metaloxide-semiconductor capacitors (MOSCAPs) were fabricated for the characterization of D_it and N_bt using UV-assisted capacitance-voltage (C-V) technique. The results show that TMA and H₂O pretreatment had trivial effects on interface engineering whereas Ar/N₂ plasma pretreatment slightly reduced D^it and significantly reduced N_bt.

Conference Presentation

Citation Download Citation

Jianyi Gao, Wenwen Li, Saptarshi Mandal, and Srabanti Chowdhury "A study of the effect of surface pretreatment on atomic layer deposited Al₂O₃ interface with GaN", Proc. SPIE 10381, Wide Bandgap Power Devices and Applications II, 1038103 (23 August 2017); https://doi.org/10.1117/12.2279313

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available