The depletion influence on the non-planar vertical MOSFET threshold voltage

The continuous scaling of transistors in nano scale leads to the invention of more sophisticated devices which may possess non-planar structures. As a consequence, the model for respective devices is of importance in order to predict the performance and behaviour throughout its operation. In non-planar structure, the thickness of silicon layer strongly affects the overall performance of the device. In this paper, we investigate the influence of depletion in the silicon layer of vertical MOSFET and develop an analytical model for devices with vertical pillar using parabolic approximation. The model for floating body channel structure which may form either partial or fully depleted channel was developed and elaborated as well. The simulation result shows the shift in threshold voltage characteristics with the different depletion widths and pillar thicknesses in the variation of channel length.