Effects of plasma treatments on Ohmic formation for N polarity of n+-GaN substrates
Abstract
In this Letter, we demonstrate low-resistance Ohmic contacts on N-polar GaN via plasma surface treatment, systematically investigating optimization mechanisms. O2 plasma treatment induces the formation of an ultrathin (∼2 nm) oxide interlayer at the metal–semiconductor interface, which serves dual roles. It prevents direct metal–GaN interaction and reconstructs surface states through oxygen passivation. This dual functionality significantly mitigates Fermi-level pinning and reduces the effective Schottky barrier height. These interfacial modifications yield a remarkably low specific contact resistivity (ρc) of 3.84 × 10−6 Ω cm2, as measured by the multi-ring circular transmission line model. This plasma-based strategy establishes a scalable approach for high-performance Ohmic contacts in GaN devices.
Article Details
Journal Info
Applied Physics Letters
American Institute of Physics
Authors (7)
Xinke Liu
College of Materials Science and Engineering, State Key Laboratory of Radio Frequency Heterogeneous Integration, Institute of Power Devices and AI Energy Monitoring Technology, Shenzhen University 1 , Shenzhen 518060,
Kangkai Fan
College of Materials Science and Engineering, State Key Laboratory of Radio Frequency Heterogeneous Integration, Institute of Power Devices and AI Energy Monitoring Technology, Shenzhen University 1 , Shenzhen 518060,
Yeying Huang
College of Materials Science and Engineering, State Key Laboratory of Radio Frequency Heterogeneous Integration, Institute of Power Devices and AI Energy Monitoring Technology, Shenzhen University 1 , Shenzhen 518060,
Zhanwu Yang
Red and Blue Microelectronics (Shanghai) Co., Ltd 2 , Shanghai 200131,
Lixuan Chen
Unilumin Group 3 , Shenzhen 518103,
Hezhou Liu
Xiaohua Li