Assessment of Analog/RF and Linearity Parameters of n-Channel Germanium Nanosheet FETs

This research examines the analog, RF, and linearity performance of a Germanium nanosheet transistor with a 16nm gate length, comparing it against a similar Silicon nanosheet transistor to assess its viability at these scaled dimensions. While the Germanium device exhibits a higher subthreshold swing due to increased short-channel effects, its higher electron mobility leads to significant improvements in drive current and transconductance. Specifically, the Germanium nanosheet transistor demonstrates 1.7 times greater ON current, 2.75 times higher transconductance, and a 1.71 times improvement in transition frequency compared to the silicon device. These enhancements in current and transconductance also translate to better RF performance, including higher gain-frequency and transconductance-frequency products. However, an analysis of transconductance derivatives reveals that the germanium nanosheet transistor exhibits reduced linearity compared to its silicon counterpart.