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 (>10 22 cm −3) and a resistivity lower than 200 µ 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 SmSi 2 /n-type Si junctions for electronic application with a Schottky barrier height of about 0.32 eV.

Growth and structure characterization of EuSi 2 films and nanoislands on vicinal Si(001) surface

“…The in plane lattice parameter obtained from the RHEED patterns is 4.28(9) Å that is in agreement with the bulk value of 4.30 Å for EuSi 2 with tetragonal symmetry [23]. Therefore we conclude that, similarly to the other RESi 2 [24,25] the EuSi 2 grows with a 451 rotation relative to the Si unit cell, i.e. EuSi 2 [100] || Si[110] on the Si(001) surface.…”

Optical Properties of Rare Earth Nitrides

“…For the epitaxial growth MgO (100) has been used 74,102 but it is found that once the film thickness exceeds 60 nm, its surface quality gets affected. Silicon on the other hand reacts with RE elements to form disilicides 103 therefore buffer layers are needed between film and substrate, adding an extra complication in the process of growth. Yttria stabilized zirconia (YSZ) is the most closely lattice matched substrate.…”