A robust Ni/Au process and mechanism for p-type ohmic contact applied to GaN p-FETs

Tang，Chuying1,2; Fu，Chun2; Du，Fangzhou2; Deng，Chenkai1,2; Jiang，Yang2; Wen，Kangyao2; Zhang，Yi2; He，Jiaqi2; Li，Wenmao1,2; Hu，Qiaoyu2; Wang，Peiran2; Tao，Nick6; Wang，Qing2,3,4,5; Yu，Hong Yu2,3,4,5

2024-03-25

10.1016/j.jallcom.2024.173499

Journal of Alloys and Compounds   影响因子和分区

0925-8388

In this study, a new robust ohmic contact preparation process for GaN p-FETs application is developed on p-GaN/AlGaN/GaN, which excluded the commonly used descum step. A specific contact resistivity of approximately 2.0×10 Ω·cm is obtained based on Ni/Au metal stack. X-ray photoelectron spectroscopy (XPS) analysis revealed that the p-GaN surface underwent oxidation by O plasma in the descum step, forming GaO as a barrier layer between the metal and p-GaN. The resulting GaO could not be completely removed using a hydrochloric acid solution, resulting in a Schottky contact. Moreover, the Ni/Au ohmic contact mechanism was revealed for the first time by varying the O content in the annealing atmosphere. The X-ray transmission electron microscopy–energy-dispersive X-ray spectroscopy and XPS results proved that the Ni (III) oxide or NiO present at the metal/p-GaN interface and the Ga vacancies formed on the p-GaN surface played a crucial role in facilitating the formation of ohmic contacts.

GaN p-FETs Ni/Au ohmic contact P-GaN Schottky barrier height

SCI ; EI

英语

通讯

MATERIALS SCIENCE

2-s2.0-85182398557

Scopus

1.Harbin Institute of Technology,Harbin,150006,China
2.School of Microelectronics,Southern University of Science and Technology,Shenzhen,518055,China
3.Engineering Research Center of Integrated Circuits for Next-Generation Communications,Ministry of Education,Southern University of Science and Technology,Shenzhen,518055,China
4.GaN Device Engineering Technology Research Center of Guangdong,Southern University of Science and Technology,Shenzhen,518055,China
5.Engineering Research Center of Three Dimensional Integration in Guangdong Province,Southern University of Science and Technology,Shenzhen,518055,China
6.Maxscend Microelectrics Company Limited,Wuxi,214072,China

Tang，Chuying,Fu，Chun,Du，Fangzhou,et al. A robust Ni/Au process and mechanism for p-type ohmic contact applied to GaN p-FETs[J]. Journal of Alloys and Compounds,2024,978.

Tang，Chuying.,Fu，Chun.,Du，Fangzhou.,Deng，Chenkai.,Jiang，Yang.,...&Yu，Hong Yu.(2024).A robust Ni/Au process and mechanism for p-type ohmic contact applied to GaN p-FETs.Journal of Alloys and Compounds,978.

Tang，Chuying,et al."A robust Ni/Au process and mechanism for p-type ohmic contact applied to GaN p-FETs".Journal of Alloys and Compounds 978(2024).