Title: Effect of GaN cap layer towards ohmic contact of open-gate Cr AlGaN/GaN high electron mobility transistor

Authors: Najihah Fauzi; Amirul Firdaus; Shaili Falina; Sabah M. Mohammad; Masafumi Inaba; Hiroshi Kawarada; Mohd Syamsul

Addresses: Institute of Nano Optoelectronics Research and Technology (INOR), Universiti Sains Malaysia, 11800 USM, Penang, Malaysia ' Institute of Nano Optoelectronics Research and Technology (INOR), Universiti Sains Malaysia, 11800 USM, Penang, Malaysia ' Collaborative Microelectronic Design Excellence Center (CEDEC), Universiti Sains Malaysia, Sains@USM, Bayan Lepas 11900, Pulau Pinang, Malaysia; Faculty of Science and Engineering and Institute of Nano Science and Nano Engineering, Waseda University, Shinjuku, Tokyo, 169-8555, Japan ' Institute of Nano Optoelectronics Research and Technology (INOR), Universiti Sains Malaysia, 11800 USM, Penang, Malaysia ' Faculty of Information Science and Electrical Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan ' Faculty of Science and Engineering and Institute of Nano Science and Nano Engineering, Waseda University, Shinjuku, Tokyo, 169-8555, Japan; Power Diamond Systems Inc., Shinjuku, Tokyo, 169-0051, Japan ' Institute of Nano Optoelectronics Research and Technology (INOR), Universiti Sains Malaysia, 11800 USM, Penang, Malaysia; Faculty of Science and Engineering and Institute of Nano Science and Nano Engineering, Waseda University, Shinjuku, Tokyo, 169-8555, Japan

Abstract: Metal-organic chemical vapour deposition (MOCVD) was used to grow AlGaN/GaN high electron mobility transistor (HEMT) on a sapphire substrate with different thicknesses of the GaN cap layer from 1.5 nm to 2.5 nm for open-gate chromium (Cr) AlGaN/GaN HEMT structures. High-resolution X-ray diffraction (HRXRD) was utilised to investigate the structural characteristics of the materials. A non-annealing technique was used to reduce the negatively impacted on the electrical properties is bad for the function of the device. The use of the GaN cap layer improved the performance of the devices as the resistance decreased with increasing the thickness of the GaN cap layer. Here we demonstrate the comparison between different thicknesses of GaN cap layers to improve the resistivity of the device.

Keywords: GaN cap; AlGaN/GaN; HEMT; high electron mobility transistor; TLM; transmission linear method; ohmic contact.

DOI: 10.1504/IJNT.2024.141755

International Journal of Nanotechnology, 2024 Vol.21 No.4/5, pp.226 - 235

Published online: 01 Oct 2024 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article