Characterization of Tetrahedral Amorphous Carbon (Ta-C) Thin Films with >6GPa Compressive Stress and Application in Sub-32nm p-MOSFET Strain Engineering

Abstract

Tetrahedral Carbon (Ta-C) films with extremely high compressive stress (5~10GPa) were fabricated using double 90o-bend Filtered Cathodic Vacuum Arc (FCVA) technique. Sp3-bonding content in the film was estimated to be >65% determined by multi-wavelength Raman spectra and XPS analysis and it confirms the high quality of the deposited film. In comparison to conventional silicon nitride stress-liner, Ta-C is expected to generate several times higher compressive stress in the channel of sub-32nm p-MOSFET. The electrical performance enhancement induced by extremely high stress liner was investigated through TCAD simulations. The results indicate that a thin Ta-C stress-liner with extremely high compressive stress provides one promising solution for suppressing performance-enhancement degradation in conventional p-MOSFET structure while scaled into sub-32nm node.