Spacer engineering on multi-channel FinFET for advanced wireless applications

Abstract

Wireless applications require a low power technology that enables DC/analog/RF functions on the same chip. It is well established fact that Multi-channel FinFET (Multifin) enhances the DC/analog/RF performance of the FET. The proposed design with spacer dielectric ensures reduced OFF current (IOFF), better subthreshold performance and improved ON current (ION) towards high performance and low power applications. Along with single-k spacer a dual-k spacer combination of (Air + Si3N4) called hybrid spacer (low-k towards gate and high-k near source/drain) is studied for the first time towards DC/analog/RF and linearity metrics of Multifin FET. The Air spacer shows extravagant performance towards RF domain and HfO2 shows better for DC and analog perspective. With Air spacer dielectric the Multifin FET exhibits terahertz (THz) frequency ranges and ensures high frequency applications. The linearity and harmonic distortion metrics towards wireless communication applications with various spacer dielectric is also analysed. The hybrid spacer shows better linearity and harmonic distortion performance along with Air and shows a strong contender towards RF applications. Moreover, the reduced capacitances ensure hybrid spacer is potential towards driving circuit applications at advanced nodes.