Characteristics of vertical p-channel MOSFETs for high density circuit application

Vertical p-channel MOSFETs have been experimentally fabricated and characterized. Device characteristics of vertical p-channel MOSFETs are comparable to those of planar surface devices. Conduction current of a vertical transistor can be increased as much as four times that of a planar transistor for the same device area. The feature of large W/L ratio allows further increase in device density. Conduction current increases linearly with the channel width. No 3D current conduction degradation effect has been observed. It is found that the crystallographic orientation of the conduction channel has some effect on the threshold and sub-threshold characteristics, due to oxide thickness difference or fixed charges in the oxide interface.