Ultra High-Stress Liner Comprising Diamond-Like Carbon for Performance Enhancement of p-Channel Multiple-Gate Transistors

We report the demonstration of strained p-channel multiple-gate transistors or FinFETs with a novel liner-stressor material comprising diamond-like carbon (DLC). In this work, a DLC film with very high intrinsic compressive stress up to 6 GPa was employed. For FinFET devices having a 20 nm thin DLC liner stressor, more than 30% enhancement in saturation drain current $I_{rm Dsat}$ is observed over FinFETs without a DLC liner. The performance enhancement is attributed to the coupling of compressive stress from the DLC liner to the channel, leading to hole mobility improvement. Due to its extremely high intrinsic stress value, significant $I_{rm Dsat}$ enhancement is observed even when the thickness of the DLC film deposited is less than 40 nm. The DLC liner stressor is a promising stressor material for performance enhancement of p-channel transistors in future technology nodes.