The importance of the spacer region to explain short channels mobility collapse in 28nm Bulk and FDSOI technologies

This work focuses on what drives the access resistance. Based on TCAD simulations, we evidence that the access resistance does depend on gate voltage. From this statement, after considering an access resistance compact model, we show that the access resistance voltage dependence generates an artificial short channel mobility collapse. Based on actual silicon data we establish link between μo-L and Rac-Vg. In particular this relation predicts that negative resistance could be extracted for narrow devices in agreement with experiments.