Silicon Electron Nano-Aspirator - Current enhancement based on electron-electron scattering

Current enhancement without increasing the input power is a critical issue to be pursued for electronic circuits. However, the input current or the drivability of the MOS-transistor is inherently limited by the momentum-nonconserving back scattering, and electrons that have passed through the source merely waste their momentum to the phonon bath. This dissipation process is unavoidable in the transistor. In this talk, we discuss the electron aspirator, a nanometer-scaled MOS device with a T-shaped branch, to find clues that can allow MOS-transistors to go beyond this limit. The device enjoys the hydrodynamic nature of electrons due to the momentum-conserving electron-electron (e-e) scattering, by which the momentum of hot electrons in the channel is transferred to cold electrons before being dissipated into the phonon bath. This momentum transfer induces an electron flow from the grounded side terminal, resulting in the enhancement of the output current without any additional power source. This aspirator operation demonstrates that the e-e scattering can govern the electron transport in highly scaled MOS devices.