Formation and Properties of Epitaxial CoSi2 Layers on p-Si0.83Ge0.17/p-Si(001) using a Si Capping Layer by Metal-Organic Chemical Vapor Deposition

Abstract

Epitaxial CoSi2 layers were in-situ grown using a sacrificial Si capping layer on p-Si0.83Ge0.17/p-Si(001) by metal organic vapor deposition (MOCVD) at 600°C using cyclopentadienyl cobalt, Co(η5-C5H5)(CO)2. The grown epitaxial CoSi2 layers remain thermally stable at the annealing temperature, TA≤800°C. The CoSi2/p-Si0.83Ge0.17/p-Si(001) samples annealed at TA≤850°C showed the sheet resistance values as low as \\cong5.6 Ω/□. At TA=900°C, the observed increase in the sheet resistance value to \\cong14.7 Ω/□ was attributed to the formation of CoSi phase with higher resistivity resulting from the direct interaction of Co with the SiGe alloy layer. The effective Schottky barrier heights (φBp), measured for the first time, ranged from 0.103 to 0.194 eV at the reverse bias of -5–0 V.