Thin HfO2 Films Deposited via Alternating Pulses of Hf(NO3)4 and HfCl4

Abstract

AbstractA novel technique for deposition of metal oxide films is demonstrated in which alternating pulses of metal-nitrate and metal-chloride precursors are used. The metal nitrate, Hf(NO3)4, acts as the oxidizing agent, avoiding the use of a separate oxidizing species such as H2O. This method results in greater than one monolayer per cycle deposition rate of HfO2 films compared to the use of a single precursor and enables deposition directly on H-terminated Si due to the reactivity of Hf(NO3)4. It was found that performing a short in-situ anneal after every deposition cycle increases film density and improves electrical characteristics. Films are characterized via capacitance vs. voltage, current vs. voltage, spectroscopic ellipsometry, and x-ray diffraction and reflectivity.