Interface Reactions and Electrical Properties of Ta/4H-SiC Contacts
This study deals with the interfacial reactions and electrical properties of Ta/4H-SiC contacts. Tantalum thin films (~100 nm) were deposited onto SiC wafer at room temperature by argon ion beam sputtering. The samples were then heated in high vacuum at 650°C, 800°C or 950°C for 30 min. X-ray photoelectron spectroscopy (XPS), glancing angle X-ray diffraction (XRD), Auger electron spectroscopy (AES) and current-voltage (I-V) technique were used for characterising the samples. Ohmic contact is formed in the studied samples after annealing at or above 800°C even though considerable amount of metallic Ta still exists. The reaction zone possesses a layered structure of Ta2C/Ta2C+Ta5Si3/SiC. High enough temperature is needed to provide for sufficient interface change to tailor the contact properties.
N. Wright, C.M. Johnson, K. Vassilevski, I. Nikitina and A. Horsfall
Y. Cao et al., "Interface Reactions and Electrical Properties of Ta/4H-SiC Contacts ", Materials Science Forum, Vols. 556-557, pp. 713-716, 2007