0167-9317/$ - see front matter Ó 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.mee.2007.04.015 www.elsevier.com/locate/mee Microelectronic Engineering 84 (2007) 1947–1950 Performance and reliability of ultra-thin oxide nMOSFETs under variable body bias F. Crupi a,* , L. Magnelli a , P. Falbo a , M. Lanuzza a , M. Nafría b , R. Rodríguez b a DEIS, University of Calabria, Via P. Bucci 41C, I-87036, Arcavacata di Rende (CS), Italy b Dept. Electronic Engineering, Universitat Autónoma de Barcelona, 08193 Bellaterra, Spain Abstract This experimental study investigates the performance and the reliability of nMOSFETs with channel length down to 90 nm and an equivalent oxide thickness of about 1.5 nm under variable body bias. Forward body bias allows to achieve a significant improvement in terms of drive capability especially for low voltage applications, while reverse body bias can be used to reduce the standby power. It is shown that forward body bias improves the lifetime associated with channel hot carrier stress, while it does not alter the time dependent dielectric breakdown process. This work indicates that the combined use of forward and reverse body bias is a powerful approach for extending the scalability of CMOS devices. Keywords: CMOS devices, forward body bias, reverse body bias, ultra-thin oxide, reliability 1. Introduction Variable body bias (VBB) can be used as a vector for improving CMOS performances in parallel to technology scaling [1-5]. Basically, VBB alters the MOSFET threshold voltage V T which can result in higher drive capability or lower leakage. Based on the biasing of the source-body pn junction, VBB is distinguished in active or forward body bias (FBB) and reverse body bias (RBB). VBB methods are Felice Crupi Tel.:+ 39 0984 494766; fax: +39 0984 494713. E-mail address:crupi@unical.it (F.Crupi ) classified in: i) static methods when each device is constantly biased in forward or reverse mode; ii) dynamic methods when the body bias of the same device changes during the circuit operation. A typical application is the dynamic V T MOSFET (DTMOSFET), first proposed by Assaderaghi et al. [1], characterized by gate and body tied together (V G =V B ). In this paper we report a detailed experimental study of the performance and the reliability of nMOSFETs with L down to 90 nm and an equivalent oxide thickness (EOT) of about 1.5 nm under VBB regime with main focus on FBB. B