Effects of titanium liners prepared by ionized physical vapor deposition on source/drain series resistance

The resistivity of 100-nm-thick Ti films was ∼60 μΩ cm and the stress was tensile irrespective of the alternating current plasma power. With increasing alternating current power, the stress of the films decreased slightly to ∼−2×109 dyn/cm2. The step coverage was ∼50% for IPVD and better for collimated PVD Ti. The contact resistance of 30-nm-thick Ti films deposited by IPVD on both P+ and N+ silicon was better than that of 20-nm-thick IPVD Ti films and 60-nm-thick collimated PVD Ti films.