High performance metal/insulator/metal capacitors using HfTiO as dielectric

Abstract

Hafnium titanate (HfTiO) film was adapted as the insulator of MIM capacitors for RF/Analog ICs applications. Low leakage current of 3.4×10⁻⁸ A/cm² at −1V and high capacitance density of 17.5fF/µm² were obtained. A N2-plasma treatment on HfTiO films can further reduce leakage current by two orders of magnitude and no apparent degradation is observed on the capacitance density and voltage coefficient of capacitance (VCC) properties. Capacitance density of 5.1fF/µm², leakage current of 1.3×10⁻⁹A/cm², and parabolic VCC value of 40ppm/V² can be achieved by 51nm thick HfTiO film. These results meet the RF/analog requirements in 2012 predicted by ITRS.