Gate Underlap Design for Short Channel Effects Control in Cylindrical Gate-all-around MOSFETs based on an Analytical Model.

Lining Zhang; Shaodi Wang; Chenyue Ma; Jin He; Chunkai Xu; Yutao Ma; Yun Ye; Hailang Liang; Qin Chen; Mansun Chan

Gate underlap structure can be utilized to improve the immunity to short channel effects in MOSFET devices. In this work, gate underlap design scheme in cylindrical gate-all-around MOSFETs is explored based on an analytical model. This model takes into account the fringing field from gate electrode to underlap regions based on conformal mapping and a channel length transformation method. By solving Poisson equations in the underlap and channel regions and matching the boundary conditions, this model reproduces the channel potential profile in subthreshold operation region. Both symmetric and asymmetric underlap structures are covered. The developed model is verified extensively with TCAD simulations. A gate underlap design scheme is then provided based on this analytical model.

METAL oxide semiconductor field-effect transistors; ELECTRODES; POISSON'S equation; MATHEMATICAL transformations; SIMULATION methods & models; SYMMETRIC operators

IETE Technical Review, 2012, Vol 29, Issue 1, p29

0256-4602

Academic Journal

10.4103/0256-4602.93125