Electronic transport properties of epitaxial erbium silicide/silicon heterostructures

Abstract

We studied electrical parallel and perpendicular transport in thin epitaxial erbium silicide films obtained by solid phase reaction and by codeposition of Er and Si on (111) Si. Resistivity measurements show that the silicide is metallic with a room-temperature resistivity of 34 μΩ cm; the dependence of the Hall coefficient on temperature can be explained by a two-band conduction model. Magnetic effects are shown to affect the low-temperature resistivity and the Hall coefficient. Perpendicular transport properties are studied by electrical [current-voltage I(V) and capacitance-voltage C(V) characteristics] and internal photoemission methods on erbium silicide/n- or p-type Si diodes. The p-type diodes have a perfect rectifying behavior with a Schottky barrier height of about 0.74 eV measured by I(V) and photoemission methods. The n-type junction is ohmic at room temperature and rectifying at low temperatures; C(V) and optical measurements yield a Schottky barrier height of about 0.28 eV. Some potential applications of erbium silicide/Si heterostructures are presented.