Effective Schottky Barrier Height modulation using dielectric dipoles for source/drain specific contact resistivity improvement

We demonstrate statistically significant data for specific contact resistivity (ρ_c) of sub-10^-8Ω-cm² and sub-2×10^-8Ω-cm² for N-type and P-type Si respectively on 300mm wafer by introducing ultra-thin ALD high-k dielectric layer(s) between the metal and Si. A 6-terminal Cross-Bridge Kelvin (6T-CBK) structure was used for the extraction to achieve excellent resolution in this small ρ_c range. With the help of measurements from multiple dielectric stacks and Non-Equilibrium Green´s Function (NEGF) based quantum transport calculations, we clearly show that the suppression of evanescent metal induced gap states (MIGS) and formation of interface dipole play significant role to reduce the ρ_c as long as the tunneling resistance of the dielectric stack is small. Finally, transient response, break down mechanism and technology benchmarking are discussed which show promise for sub-14nm node applications.