(A) novel doping technology via the iCVD process for conformal and controlled nanoscale junction of semiconductors

Abstract

As the semiconductor industry continues to succeed scaling down trend beyond the 7-nm technology node, an ultra-thin body Si in the form of a FinFET would be indispensable to obtain high performance with minimizing the undesirable short channel effects. Ge channel devices are also strongly required due to their high carrier mobility. However, fabricating CMOS ICs by implementing these approaches faces challenges with regards to process integration. Particularly, conventional doping process of ion implantation is limited to provide a conformal doping profile at a high concentration within Si fin arrays. High quality N+/P junction of Ge substrate is also not been achieved by inevitable structural damage of ion implantation process. These problems become a critical issue to result in the degradation of the device performance. In this dissertation, a novel doping technique using initiated CVD process on both Si and Ge substrate is successfully developed, facilitating conformal, wafer-scale, controlled nanoscale, and high quality junction. Dopant-containing polymer film is developed and deposited by the iCVD process. An optimized doping process provides a high doping level over 1 × 10$^{20}$ cm$^{-3}$ with a shallow junction depth. Conformal doping profile is also shown on high-aspect ratio (5:1) and a 40 nm-pitch fin arrays. Integrated with Ge and ultra-thin body Si nMOSFETs fabrication, improvement of electrical characteristics is shown.