Potential and electron distribution model for the buried-channel MOSFET

Abstract

The authors present a novel analytic model for the potential and electron distribution in the channel-depth direction for the buried-channel (BC) MOSFET (metal-oxide-semiconductor field-effect transistor). The purpose of the model is to aid in the fundamental physical understanding of the operational modes of the BC-MOSFET and the mechanisms affecting these modes. Using Poisson's equation, individual analytic expressions are formulated to predict the potential distribution and electron concentration profile under conditions of depletion, inversion, pinchoff, and accumulation as a function of the gate bias, substrate bias, and applied channel potential. While the potential distribution in the channel-depth direction enables the band-bending within the device to be visualized, the signal electron concentration profile leads to an easy physical interpretation of the modes of operation and the location of mobile charge relative to the channel surface: this is important for mobility and device speed considerations. In addition, the model can be used for device design.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>