Effect of additional silicon on titanium/4H-SiC contacts properties

Abstract

The Ti electrode was deposited on the (0001) face of an n-type 4H-SiC substrate by magnetron sputtering. The effect of the electrode placement method during the annealing treatment on the contact property was carefully investigated. When the electrode was faced to the Si tray and annealed, it showed ohmic behavior, otherwise it showed a non-ohmic property. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and atomic force microscopy (AFM) were used to characterize the electrode phase, composition, thickness, and surface morphology. The additional silicon introduced from the Si tray played a key role in the formation of the ohmic contact on the Ti/4H-SiC contact.

Effect of the annealing temperature on the long-term thermal stability of Pt/Si/Ta/Ti/4H–SiC contacts

“…[15] It is reported that Ti-based Ohmic contacts have been suggested as superior candidates due to their reproducible low specific contact resistances. [16][17][18][19][20] Ta is the refractory metal, with very good stability, high melting point, and excellent mechanical properties, which may increase the stability of the contact and improve the contact by reducing the formation of surface oxide. [21,22] Polysilicon has a lower contact resistance.…”

Electrical properties and microstructural characterization of Ni/Ta contacts to n-type 6H–SiC

“…[7,8] Moreover, a low contact resistivity and high thermal stablility Ohmic contact is very important for SiC devices. [9] Ni based metallization has a relatively low work function and has attracted great attention in preparing Ohmic contacts to n-type SiC. [10][11][12] High temperature annealing enables the chemical reaction between Ni and SiC to form nickel silicides.…”