Thermal Stability of Al-doped ZrO_2 Films Prepared by Reactive RF Magnetron Sputtering

Al-doped ZrO_2 films with different microstructures were deposited on Si(100)substrates by using reactive RF magnetron sputtering process with metallic Zr and Al as targets in an argon- oxygen atmosphere.The films were characterized with high-resolution transmission electron microscope (HRTEM),X-ray diffraction(XRD),and atomic force microscope(AFM)to investigate variety of the thermal stability,the interfacial stability and the surface roughness of the films with different annealing temperatures.The influence of the microstructures of Al-doped ZrO_2 thin films on their electrical I-V characteristics was also discussed.The results show that the atomic content of Al in films has a significant influence on the microstructures,upon increasing the atomic content ratio of Al/Zr,the structure transition of the films is a-ZrO_2(pure)→t-(Zr,Al)O_2 and c-(Zr,Al)O_2(Al/Zr=1/4)→α- (Zr,Al)O_2(Al/Zr=4/5).Al-doped ZrO_2 thin films with Al/Zr atomic ratio of 4/5 has the increase in the crystallization temperature compared to a pure ZrO_2 film,so the thermal stability of the films is improved.