Enhancement of hot-electron generation rate in Schottky source metal-oxide-semiconductor field-effect transistors

Source-side hot-electron generation is experimentally demonstrated in Schottky source metal-oxide-semiconductor field-effect transistors (MOSFETs). An asymmetric n-type MOSFET having a CoSi₂ layer in place of one of the n⁺ source/drain regions has been fabricated and intensively investigated. When the CoSi₂ layer is used as the source, large gate current and negative-differential conductance (NDC) are simultaneously observed, whereas, when the n⁺ region is used as the source, both gate current and NDC are not observed. By comparing the device characteristics before and after the NDC observation, it is concluded that the gate current is due to hot electrons generated at the Schottky source side and the NDC is caused by trapped electrons in the oxide. These source-side hot electrons will open up the way to the realization of deca-nanoscaled high-speed devices.