Equivalent Oxide Thickness of Trigate SOI MOSFETs With High-$\kappa$ Insulators

Abstract

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> The evolution of traditional metal–oxide–semiconductor field-effect transistors (MOSFETs) from planar single-gate devices into 3-D ones with multiple gates and high-<formula formulatype="inline"><tex Notation="TeX">$\kappa$ </tex></formula> insulators imposes the use of new electrical models that accurately reproduce their behavior. This paper demonstrates that the typical expression of equivalent oxide thickness (EOT) for planar devices with high- <formula formulatype="inline"><tex Notation="TeX">$\kappa$</tex></formula> gate insulators becomes useless for nonplanar ones such as triple-gate (trigate) silicon-on-insulator MOSFETs. An alternative expression of the EOT for these trigate devices has been developed through a semianalytical approach to the gate-insulator capacitance. The proposed model correctly reproduces the total electron density in a wide range of device dimensions and applied biases. </para>