TRANSCONDUCTANCE DEGRADATION IN SILICON FIELD-EFFECT TRANSISTORS RESULTING FROM INVERSION LAYER DEGENERACY

The process parameters used for fabricating a metal-oxide-silicon field-effect transistor (MOSFET) with submicron channel length are shown to lead to a degenerate channel inversion. The Fermi-Dirac statistics inherent in a dense electron gas are incorporated into the MOSFET model and compared with measured transconductance data. Only those electrons within a few kT of the Fermi level contribute to the current, while the Pauli exclusion principle prevents other electrons from participating in conduction. This distinction between conducting and nonconducting electrons in a degenerate gas can bridge in part a large discrepancy existing between observed transconductance and conventional MOSFET theories.