Characterization of the electron mobility in the inverted <100> Si surface

Abstract

The effective mobility of electrons in the inverted 〈100〉 Si surface was measured over a wide range of temperatures, gate voltages, and back-bias voltages. At a first glance the mobility appears to be strongly dependent on the channel surface doping. When the data were reanalyzed under a new approach where the mobility is plotted as a function of an effective perpendicular electric field experienced by the inversion layer, a universal curve has developed from the experimental data which indicates that the inversion layer mobility is not a function of doping density in the range (N <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">A</inf> < 1.0 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">17</sup> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> ) and not a function of nominal surface processing. Our model indicates that the MOSFET surface inversion layer mobility is a reproducible property associated with the Si/SiO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> system and not a parameter sensitive to nominal process variations encountered in the present n-channel Si-Gate Technology.