THEORETICAL-ANALYSIS OF TRANSCONDUCTANCE ENHANCEMENT CAUSED BY ELECTRON-CONCENTRATION-DEPENDENT SCREENING IN HEAVILY-DOPED SYSTEMS

A new mobility model dependent upon electron concentration is presente d for studying the screening effect on ionized impurity scattering. By coupling this model with the drift-diffusion and Hartree models, the effects of self-consistent and quasi-equilibrium screening on carrier transport in heavily doped systems are revealed for the first time. Th e transport mechanism is found to be dominated by the electron-concent ration-dependent mobility, and transconductance is shown to be determi ned by effective mobility and changes from degraded to enhanced charac teristics with electron concentration modulation.