Contact Formation on Silicon Carbide by Use of Nickel and Tantalum in a Materials Science Point of View

Kapitel i bok, 2011

The advantageous electrical, thermal and mechanical properties make silicon carbide (SiC) a promising semiconductor for high temperature, high power and high frequency applications. Nickel (Ni) and tantalum (Ta) can be used to form both ohmic and Schottky contact. Since metallization represents one of the most important steps in the fabrication of electronic devices, the knowledge of the interaction between Ni, Ta and SiC are of primary importance for understanding and optimising the device performance. In this chapter, an introduction of thermodynamics in Ni (or Ta)-Si-C system is given. The reaction process and mechanisms of Ni-SiC during annealing are reviewed. The phases existing in the film or at the interface and the distribution of elements in-depth are clarified. The impact of pre-treatment on SiC substrate and Ni layer thickness on phase distribution is summarized. The nature of the thermally induced solid-state reactions between Ta or Ni/Ta bilayer and SiC substrate over a wide temperature range is also discussed.