Fabrication and measurements of ultra-short silicon MOSFETs

Abstract

Double Al gate silicon MOSFETs have been fabricated with channel lengths ranging from 125 nm to 7.7 nm using a novel step/edge technique. The devices exhibit lateral tunneling between inversion layer source/drain extensions in the sub-threshold region and inversion layer conduction above threshold. At 0.45K and in devices shorter than 21 nm periodic oscillations are observed at bias voltages where the short-gate region is inverted. These are attributed to quantum interference arising from the ultra-short channel length. At bias voltages where the short gate region is in depletion, lateral tunneling is observed between the two inversion layer contacts. The lateral tunneling consists of a superposition of resonant tunneling peaks caused by defect states in the short channel region.