Investigation of Optical, Electrical, and Mechanical Properties of MOCVD-grown ZrO sub(2) Films

Metal-organic (MO)CVD of ZrO sub(2) thin films is performed using the precursor [Zr(NMe sub(2)) sub(2)(guan) sub(2)] (guan= eta super(2)-( super(i)PrN) sub(2)CNMe sub(2)) as the Zr source, together with oxygen. Film deposition is carried out on both Si(100) and glass substrates at various deposition temperatures. The resulting films are characterized by X-ray diffraction (XRD) and atomic force microscopy (AFM) for investigating the crystallinity and morphology, respectively. Optical properties are measured by ellipsometry and UV-vis on Si substrates and glass substrates, respectively, showing a high average refractive index of 2.14 and transmittance of more than 80% in visible light for the film deposited at 500 degree C. The potential of ZrO sub(2) thin films as gate dielectrics is verified by carrying out capacitance-voltage (C-V) and current-voltage (I-V) measurements. Dielectric constants are estimated from the accumulation capacitance, and found to be in the range 12 - 19 at an AC frequency of 1MHz, and a leakage current of the order of 10 super(-6) A cm super(-2) at the applied field of 1 to 2 MV cm super(-1) is measured for the films deposited at temperatures from 500 to 700 degree C. The low leakage current and high dielectric constant implies the good quality of the film, relevant for high-k applications. The hardness of the film ranges from 4.2 to 6.3GPa for the 400nm thick film, as determined by nano-indentation measurements. The optimum dielectric and hardness is found for the film deposited at 600 degree C, while the highest refractive index is found to be 2.14 for the film deposited at 500 degree C, due to higher density of the layers. Full Paper: ZrO sub(2) thin films are deposited by metal-organic (MO)CVD using the precursor (Zr(NMe sub(2)) sub(2)(guan) sub(2)) as the Zr source, together with oxygen. Functional properties, including the optical, electrical, and mechanical properties, of the resulting ZrO sub(2) films are investigated.