Channel edge doping (CED) method for reducing the short-channel effect

A new fabrication process for short-channel MOSFET´s, the channel edge doping method (CED), is proposed. In this method, highly doped regions are self-aligned with the channel edges by using a silicon dioxide liftoff technique. The spread of source/drain depletion-regions toward the channel is suppressed by the highly doped regions. Thus the short-channel effect can be prevented. Using the CED method, n-channel MOSFET´s with effective channel length down to 0.9 µm are fabricated. Their characteristics are compared with those for conventionally processed MOSFET´s and the effect of the CED method for reducing the short-channel effect is confirmed.