Comparison between bulk and SOI MOSFETs for sub-100nm mixed mode applications

This paper presents a systematic and quantitative comparison between the analog characteristics of bulk and SOI technology. An analog performance metric of intrinsic gain, f/sub T/ and g/sub m//I/sub ds/ ratio is considered. The impact of device scaling on this performance metric has been analyzed. It is shown that, even for the frequencies in the range of GHz (where the AC kink effect is totally suppressed), the analog performance of SOI devices is inferior to that of the bulk devices due to capacitive drain-to-body coupling. Based on our study, we propose that gate-workfunction engineering is essential in FDSOI devices for improving analog performance at a threshold voltage compatible with the bulk technology.