Electrical characteristics of high quality La₂O₃ gate dielectric with equivalent oxide thickness of 5 /spl Aring/

Abstract

Electrical and reliability properties of ultrathin La <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> gate dielectric have been investigated. The measured capacitance of 33 /spl Aring/ La <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> gate dielectric is 7.2 μF/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> that gives an effective K value of 27 and an equivalent oxide thickness of 4.8 /spl Aring/. Good dielectric integrity is evidenced from the low leakage current density of 0.06 A/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> at -1 V, high effective breakdown field of 13.5 MV/cm, low interface-trap density of 3×10/sup 10/ eV/sup -1//cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , and excellent reliability with more than 10 years lifetime even at 2 V bias. In addition to high K, these dielectric properties are very close to conventional thermal SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> .