Frequency dispersion and dielectric relaxation in postdeposition annealed high-κ erbium oxide metal–oxide–semiconductor capacitors

Abstract

The origin of frequency dispersion in postdeposition rapid thermal and furnace annealing treated Pt/Er2O3/Si/Pt, metal–insulator–semiconductor–metal (MISM) structure is systematically investigated. The cause of frequency dispersion in Pt/Er2O3/Si/Pt, MISM structure is attributed to the dielectric relaxation in high-κ Er2O3, after suppressing the extrinsic effects such as parasitic, lossy interfacial layer, surface roughness, polysilicon depletion, quantum confinement, and oxide tunneling. Further, the Havrilian–Negami law is used to model the frequency dispersion in postdeposition rapid thermal and furnace annealing treated Pt/Er2O3/Si/Pt, MISM structure up to 250 kHz. It is suggested that to obtain an accurate capacitance value, the dissipation factor must be minimum for the MISM structure with nanometer scale oxides/insulators. Additionally, a methodology is proposed for simple and efficient correction of measured capacitance from capacitance–voltage and capacitance–frequency characteristics. Moreover, the flatband voltage shift/hysteresis, frequency dependent border traps are estimated ∼0.45 V, ∼3.35 × 1012 traps/cm2 and ∼0.18 V, ∼1.84 × 1012 traps/cm2 for postdeposition rapid thermal and furnace annealing treated Pt/Er2O3/Si/Pt, MISM structures, respectively. Therefore, postdeposition furnace annealing treatment is superior to achieve high-quality high-κ Er2O3 (κ ∼16), with low frequency dispersion of ∼9% up to 250 kHz and minimal hysteresis (∼0.18 V) for next-generation complementary metal–oxide–semiconductor technology.