Electrical and Materials Characterization of Reactive and Co-Sputtered Tantalum Carbide Metal Electrodes for High-K Gate Applications

In this work, co-sputtered TaC (tantalum + carbon targets + argon) and reactive sputtered TaC (tantalum + methane + argon) were evaluated and compared for application as metal electrodes in high-K/metal gate stacks aimed at 22 nm and beyond technology nodes. The electrical properties of field effect transistors (FETs) were evaluated as a function of TaC deposition conditions and optimized to achieve Tinv scaling. Controlling the deposition conditions as well as the composition of the TaC films was found to be critical to achieve Tinv < 11 Aa.