Epitaxial samarium disilicide films on silicon (0 0 1) substrates: growth, structural and electrical properties

Abstract

In this paper the effect of the growth temperature on the structural and electrical properties of samarium silicide films is investigated. The growth of the epitaxial films is performed under ultrahigh vacuum by reactive-deposition epitaxy on silicon (0 0 1) substrates. The structural properties are assessed by reflection high-energy electron diffraction and x-ray diffractometry. Random and channelling Rutherford backscattering experiments show that the films have the correct stoichiometry, i.e. Sm/Si ratio = 1 : 2, with channelling yields as low as 20% for the best samples. The electrical properties of these films are studied by Hall effect and resistivity measurements. The films have a metallic character, with a high concentration of n-type charge carriers (>1022 cm−3) and a resistivity lower than 200 µΩ cm at room temperature. The metallic character is confirmed by the experimental optical conductivity deduced from ellipsometry experiments. Finally, evidence is presented showing the potential of SmSi2/n-type Si junctions for electronic application with a Schottky barrier height of about 0.32 eV.