Study On The Struction And Performance Of Transition Metal Doped Aluminum Nitride Thin Film

As one of the III-V components, the aluminum nitride(AlN) thin film has been one of the most popular film material due to its good chemical stability, high thermal conductivity, high electrical insulation and low expansion coefficient. Nowadays, the replacement of Al atoms in AlN lattice by other transition-metal such as Sc, Ta, Mg, may be an effective way to enhance the piezoelectric response. In recent years, transition metal doped AlN film causes great interest to scientists, it is regarded as a kind of the most effective ways to improve the film properties. Therefore, it has important significance on the study of transition metal doped AlN film in the aspect of theoretical basis and practical application.In this study, high quality AlN thin films and Zrx Al1-xN films had been deposited successfully on the quartz glass and molybdenum substrate by the unbalanced reactive magnetron sputtering. The influence of Zr concentration on the the structure, morphology and properties of ZrxAl1-xN films and the deposition parameters on the structure and properties of Zr0.11Al0.89 N films were investigated fully.The structure and morphology analysis of ZrxAl1-xN films demonstrated that Zr doping could significantly decrease the grain size and surface roughness, improve the preferential orientation and crystal quality, and the optimal value of Zr concentration is 11 at%. Besides the quality of the Zr0.11Al0.89 N films was very sensitive to the sputtering parameters, it showed the optimal deposition parameters of Zr0.11Al0.89 N films growth: 0.5 Pa for working pressure, 5:5 for N2/Ar ratio and 250℃ pre-heating for substrate temperature. Zr0.11Al0.89 N films prepared with these deposition parameters had compact and uniform structure with highly(002) orientation and the grain size was large.The microscopically mechanical properties, optimal properties and electrical properties of Zrx Al1-xN films were studied by in-situ nanomechanical testing suytem, ultraviolet and visible spectrophotometer, impedance Analyzer and semiconductor characterizaton system respectively, suggesting that Zr doping could decrease the band gap and transmittance, increase the hardness and Young’ modulus and improve the insulating properties and dielectric properties of ZrxAl1-xN films. The hardness, Young’ modulus, the resistivity and dielectric constant of AlN films were 17.2 GPa, 168 GPa, ~2.1×1011 Ω·cm and ~8 respectively. The hardness, Young’ modulus,the resistivity and dielectric constant of Zr0.11Al0.89 N films were 20 GPa, 170.6 GPa, ~4×1011 Ω·cm and ~16, which were superior than that of AlN films seperately. The band gap of Zr0.11Al0.89 N films were 3.7 eV which were less than 5.7 e V of AlN. The properties of the Zr0.11Al0.89 N films were very sensitive to the deposition parameters. Zr0.11Al0.89 N films with compact and uniform structure with highly(002) orientation exhibited optimal property, which were manifest as lager hardness, Young’ modulus and higher resistivity and dielectric constant. While there was no obvious relationship between the transistance, band gap and prefferred orientation of the Zr0.11Al0.89 N films.