Improved Sub-threshold Slope in RF Vertical MOSFETS using a Frame Gate Architecture

We report a CMOS-compatible vertical MOSFET, which incorporates a frame gate architecture suitable for application in RF circuits. Fabricated surround gate vertical MOSFETs with the frame gate architecture show no degradation of short channel effects when the channel length is scaled, while control devices show significantly degraded sub threshold slope and DIBL. The frame gate vertical MOSFETs show near ideal sub-threshold slopes of 70-80mV/decade and DIBL of 30-35mV/V in a 100 nm gate length nMOS device. In contrast, the control vertical MOSFETs without the frame gate exhibit sub-threshold slopes of I 10 to 140 mV/decade and DIBL of 100 to 280 mV/V. This improved sub-threshold slope is explained by the elimination of etch damage during gate etch.