Electrical and reliability characteristics of ZrO2 deposited directly on Si for gate dielectric application

Abstract

ZrO 2 thin film has been studied as an alternative gate dielectric. It was deposited directly on a Si substrate by reactive sputtering. An equivalent oxide thickness of less than 11 Å with a leakage current of 1.9×10−3 A/cm2 at −1.5 V relative to the flat band voltage has been obtained. Well-behaved capacitance–voltage characteristics with an interface state density of less than 1011 cm−2 eV−1 and no significant frequency dispersion have been achieved. Excellent reliability properties (e.g., low charge trapping rate, good time-dependent dielectric breakdown, low stress-induced leakage current, and high dielectric breakdown) have also been obtained.