Optimization of RF Performance of Metallic Source/Drain SOI MOSFETs Using Dopant Segregation at the Schottky Interface

摘要

This letter presents a detailed investigation of the impact of dopant segregation (DS) on radio-frequency (RF) performance of p-type 110-nm undoped ultrathin-body Schottky-barrier (SB) silicon-on-insulator MOSFETs. It is shown that optimizing this dopant-segregated layer via careful control of the dopant concentration $(N_{rm SEG})$ and lateral extension $(L_{rm SEG})$ reduces the apparent potential barrier height at the Schottky junctions. This results in highly reduced source/drain (S/D) contact resistances, along with a peak $f_{T}$ value obtained at very low dc power consumption (45 $muhbox{W}/muhbox{m}$ at $V_{rm DS} = -hbox{2} hbox{V}$), which is very promising to address low-power low-voltage analog applications. Finally, the source resistance extracted from this RF study $(sim !!hbox{120} Omega cdotmuhbox{m})$ clearly demonstrates the ability of the DS SB S/D architecture to pursue the silicon roadmap beyond the 22-nm node.