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 600degreesC using cyclopentadienyl cobalt, Co(eta(5)-C5H5)(CO)(2). The grown epitaxial CoSi2 layers remain thermally stable at the annealing temperature, T-A less than or equal to 800degreesC. The CoSi2/p-Si0.83Ge0.17/P-Si(001) samples annealed at T-A less than or equal to 850degreesC showed the sheet resistance values as low as congruent to5.6 Omega/square. At T-A = 900degreesC, the observed increase in the sheet resistance value to congruent to14.7 Omega/square 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 (phi(Bp)), measured for the first time, ranged from 0.103 to 0.194 eV at the reverse bias of -5-0 V.