Mixed-signal performance of sub-100nm fully-depleted SOI devices with metal gate, high K (HfO/sub 2/) dielectric and elevated source/drain extensions

Abstract

We report for the first time, the digital and analog performance of sub-100nm Fully-Depleted Silicon-On-Insulator (SOI) n and p-MOSFETs using TaSiN gate and HfO/sub 2/ dielectric with elevated Source/Drain (SD) extensions. As CMOS technology continues to scale down, the FDSOI technology offers a potential solution to control short channel effects by reducing the silicon film thickness and a concurrent scaling of the buried oxide thickness. The use of metal gate and thin undoped body offer the additional advantages of 1) suppression of polysilicon depletion effects, 2) elimination of boron penetration, 3) minimizing S/D junction capacitance (Cj), and 4) enhancing transistor matching performance for mixed signal application. High k dielectric is necessary to reduce gate leakage for EOT below 15 to 20/spl Aring/. The intrinsic low-leakage nature of the FDSOI device and it's immunity to floating body effect provides much opportunity for ultra-low power digital and analog applications. Physical and electrical analyses of the devices are presented to provide an assessment of the metal gates on high K gate dielectric in combination with fully-depleted device operation in the context of digital and analog circuits.