Interface Treatment of Epitaxial SI FINFET Channel in Replace Metal Gate with Simultaneously Performance Improvement and Leakage Reduction

Channel surface defects are an important factor causing poor device interface characteristics and deterioration of sub-threshold characteristics. In order to reduce the interface trap density (Dit) of epitaxial silicon FinFET devices and improve device performance, an in-situ steam generation (ISSG) oxidation and diluted hydrofluoric acid (DHF) cleaning method was proposed to repair the damaged channel surface and reduce the interface defect charge (Q <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">it</inf> ) replace metal gate (RMG) module. The thickness of Fin top narrows, and Fin's steepness decreases, after interfacial ISSG oxidation treatment. The electrical results demonstrate that the SS for the NFET with interface treatment are decreased from 74.2 mv/dec to 70.97 mV/dec due to the interface improvement. At the same time, the leakage current reduced from 1.0E-2 μA to 5.67E-4 μA, and the Ion is increased by 16.89% compared with that of conventional FinFET without interface treatment.