Influence of Ni and Nb thickness on low specific contact resistance and high-temperature reliability of ohmic contacts to 4H-SiC. (15th October 2019)

• Record Type: Journal Article
• Authors: Van Cuong, Vuong; Ishikawa, Seiji; Maeda, Tomonori; Sezaki, Hiroshi; Yasuno, Satoshi; Koganezawa, Tomoyuki; Miyazaki, Takamichi; Kuroki, Shin-Ichiro
• Is Part Of: Japanese journal of applied physics. Volume 58:Number 11(2019)
• Publication Date: 2019-10-15
• Subjects: Physics -- Periodicals; 621.05
• DOI: 10.7567/1347-4065/ab47ac
• Languages: English
• ISSNs: 0021-4922

Abstract

Abstract: The influence of Ni and Nb thickness on the electrical properties and high-temperature reliability of Ni( x )/Nb(100 – x )/n-type 4H-SiC ohmic contacts, where x = 25, 50 or 75 nm, was investigated. Two-dimensional X-ray diffraction, hard X-ray photoelectron spectroscopy and transmission electron microscopy analyses indicated that a relatively high Ni concentration had a strong influence on low specific contact resistance due to the greater formation of Ni2 Si at the contact interface, whereas a higher density of Nb improved the ability to collect excess carbon atoms by the formation of Nb6 C5 at the interface, ensuring high-temperature reliability of the contacts. The experimental results showed that the Ni(50)/Nb(50)/4H-SiC ohmic contact is a potential candidate for high-temperature and harsh environment applications.