Effects of the Mo composition of Mo-alloyed Yb/Si contacts on the microstructures and electrical properties

Abstract

In this study, we investigate the effects of the Mo composition of Mo-alloyed Yb/Si contacts on the microstructures during silicidation and the electrical properties of the contacts. We co-sputter Mo and Yb to produce Mo-alloyed Yb films with different Mo compositions (5, 20, 40, and 50 at. %) and anneal them at elevated temperatures (500–700 °C). Our material characterization elucidates a series of material reactions, including solid-state amorphization and the nucleation and growth of epitaxial YbSi2− x . The increase of the Mo content hinders the growth of the epitaxial layer, producing a thinner epitaxial layer, and increases the stability of the epitaxial layer against oxidation at high temperatures. Electrical measurement of the contact properties indicates that the Mo 20% sample has the best contact properties.