Highly-selective superconformai CVD Ti silicide process enabling area-enhanced contacts for next-generation CMOS architectures

Abstract

We investigate a novel Ti Chemical Vapor Deposition (CVD Ti) technique for source/drain and trench contact silicidation. This work is a first demonstration of a highly selective, superconformal Ti process that exhibits a low p-type CVD Ti/SiGe:B contact resistivity (pc) down to 2.1×10-9 Ω.cm2 (a 40% reduction vs. PVD Ti), matching the lowest published values [1-5]. A competitive n-type CVD Ti/Si:P with a ρc at 2.6×10-9 Ω.cm2 is measured. We demonstrate up to 90% superconformality for this process, with a tunnel silicidation at lengths up to 500nm, showing an exceptional selectivity to oxide. This process is an enabler for the next generation of area-enhanced contact CMOS architectures.