Characteristics and processing effects of ZrO2 thin films grown by metal-organic molecular beam epitaxy

ZrO2 dielectric layers were grown on the p-type Si(1 0 0) substrate by metal-organic molecular beam epitaxy (MOMBE). Zrconium t-butoxide, Zr(O t-C4H9)4 was used as a Zr precursor and argon gas was used as a carrier gas. The thickness of the ZrO2 film and intermediate SiO2 layer were measured by scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM). The properties of the ZrO2 layers were evaluated by X-ray diffraction, X-ray photoelectron spectroscopy (XPS), high frequency (HF) capacitance–voltage (C–V) measurement, and current–voltage (I–V) measurement. C–Vand I–V measurements have shown that ZrO2 layer grown by MOMBE has a high dielectric constant (k) of 18–19 and a lowlevel of leakage current density. The growth rate is affected by various process variables such as substrate temperature, bubbler temperature, Ar, and O2 gas flows. Since the ratio of O2 and Ar gas flows are closely correlated, the effect of variations in O2/Ar flow ratio on growth rate is also investigated using statistical modeling methodology. # 2003 Elsevier B.V. All rights reserved