The influence of titanium doping on the electric properties of amorphous alumina films prepared by sol–gel technology

The influence of titanium doping on the electric properties of amorphous alumina (Al 2 O 3 ) films prepared by sol–gel technology was investigated. EDX mapping analysis indicates that the titanium cations are uniformly distributed in the film as Al 2−x Ti x O y . The XPS analysis reveals that the titanium exists in the form of TiO 2 . The breakdown strength of the doped film can be much enhanced by the titanium doping. The dielectric strength of undoped Al 2 O 3 films is 3.4 MV/cm, while the breakdown strength of the 10 % Ti-doped Al 2 O 3 films is 5.3 MV/cm. Compared with the undoped Al 2 O 3 films, the soft breakdown of Ti-doped Al 2 O 3 films is gradually suppressed with the increasing of the titanium doping amount. Especially, there is hardly any soft breakdown observed for 10 % Ti-doped Al 2 O 3 films.