An investigation of the silicon—Sapphire interface using the MIS capacitance method

Abstract

Measurements of the MIS capacitance as a function of voltage were carried out on aluminum-sapphire-silicon structures. The results were used to determine the doping of the silicon and the interface-state density and flat-band charge density at the silicon-sapphire interface. The density of states function D <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">s</inf> (cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> eV <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> ) is found to be qualitatively similar to that reported for the Si-SiO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> interface but is larger in magnitude by a factor of 5-10.