Ge/sub x/Si/sub 1-x//silicon inversion-base transistors: theory of operation

A theoretical study of the device characteristics of the Ge/sub x/Si/sub 1-x//silicon inversion-base transistor (BICFET) is presented. This transistor uses the space charge of holes in a modulation-doped inversion channel to control vertical electron transport. This study is of interest not only because of the unique interaction of transport mechanisms in the BICFET but also because the BICFET is very well suited to the Ge/sub x/Si/sub 1-x//Si system, and offers substantial performance advantages over the BJT. The device characteristics presented are based on a numerical and analytical analysis using the drift-diffusion formalism. The effects that quantum confinement and non-semi-classical transport have on this structure are presented. The authors conclude with a comparison between the Ge/sub x/Si/sub 1-x//Si BICFET and Ge/sub x/Si/sub 1-x//Si HBT.<
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