Improved adhesion and interface ohmic contact on n-type 4H-SiC substrate by using Ni/Ti/Ni

• Published in: Journal of semiconductors Vol. 35; no. 7; pp. 15 - 18
• Main Author: 韩林超 申华军 刘可安 王弋宇 汤益丹 白云 许恒宇 吴煜东 刘新宇
• Format: Journal Article
• Language: English
• Published: 01.07.2014
• Subjects: 4H-SiC; Adhesion; Carbon; Contact resistance; Nickel; Raman spectroscopy; Semiconductors; Silicon carbide; Titanium; Titanium base alloys; 复合材料结构; 欧姆接触; 界面相; 粘合性; 衬底; 钛; 镍硅化物
• ISSN: 1674-4926
• DOI: 10.1088/1674-4926/35/7/072003

The Ni/Ti/Ni multilayer ohmic contact properties on a 4H-SiC substrate and improved adhesion with the Ti/Au overlayer have been investigated. The best specific contact resistivity of 3.16 × 10^-5 Ω.cm^2 was obtained at 1050 ℃. Compared with Ni/SiC ohmic contact, the adhesion between Ni/Ti/Ni/SiC and the Ti/Au overlayer was greatly improved and the physical mechanism under this behavior was analyzed by using Raman spectroscopy and X-ray energy dispersive spectroscopy （EDS） measurement. It is shown that a Ti-carbide and Ni-silicide compound exist at the surface and there is no graphitic carbon at the surface of the Ni/Ti/Ni structure by Raman spectroscopy, while a large amount of graphitic carbon appears at the surface of the Ni/SiC structure, which results in its bad adhesion. Moreover, the interface of the Ni/Ti/Ni/SiC is improved compared to the interface of Ni/SiC.