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9.2 Short Channel Effect Reduction with Pocket Implants

 

Reducing the gate-length of a MOS transistor to dimensions smaller than about 2 tex2html_wrap_inline8291 alters the electrical behavior of the device in a characteristic way. The influence of the source and drain regions on the channel grow, i.e., the fraction of the channel that is controlled by the gate decreases with respect to the long channel devicegif, where the transition region from the channel to the source and drain regions is small in comparison to the gate length. These short channel effects gif cause considerable distress for the device designers, because one-dimensional device equations - widely used in circuit-design applications - do not any more give accurate results. In consequence, it is a declared goal of VLSI process design to sustain long-channel behavior even for short-channel devices.





Christoph Pichler
Thu Mar 13 14:30:47 MET 1997