Magnetron Sputtering Of Transparent Conductive Oxide Film Some Research

The semiconductor ZnO has been widely used in areas such as piezoelectric devices, luminated devices, ultra-violet detector, transparent conducting thin films etc, because of its large exciton binding energy (60meV). The development of ZnO transparent conducting thin films has attracted more and more attention.We have discussed the development and applications of the transparent conducting thin films especially the ZnO thin films, and have introduced some thin film preparing techniques and some character analyzing methods, moreover, we have studied how the preparing condition of ZnO thin film influences its optical and electrical properties. on the other hand, some suggestions about how to improving ZnO thin film's electrical conductivity have been given as we have found the influences on electrical conductivity of LaNiO₃ thin film by annealing process.First, we have prepared ZnO thin films at different oxygen ratio by DC magnetron sputtering method, We have found that when the oxygen ratio reaches more then 20%, The ZnO thin films are of good transparency and high resistor. and their refractive indices, interplanar distances, and stresses will increase as the oxygen ratio increases. The grain size is affected not only by stress but also by film's thickness and some other factors. The band gap shows obviously the size effect. ZnO thin film's resistivity gets as small as 0.3O?cm after annealed at 800℃ for 10 minutesThen, as the intrinsic ZnO is not conductive, we have doped ZnO thin film with aluminum which acts as donor. Al doped ZnO thin films are also prepared by DC sputtering method, two metal targets Zn and Al are used, O₂ and Ar being the background gases. Al ratio could be controlled by changing DC power of Al target. The refractive index differs greatly as we dope Al atoms into ZnO thin films, the reason is that as the Al atoms are doped, electronic distribution in the lattices varies, E_o and E_d get smaller, and then refractive index also gets smaller. Though spectral analyze shows that there are many carriers in our AZO thin films, but their electrical conductivities are still not quite satisfying, this may be caused by the defects which localizes the carriers. After annealed at 600℃ for 10 minutes, we have made the resistivity of AZO (ξ =2.68wt%) thin film as small as 0.3O·cm.For the last, we have analyzed the influence of annealing process on electrical conductivity of LaNiO₃ thin films, we have found that annealing process degrades LaNiO₃ thin film's lattice oxygen ratio, and results in descendent of electrical conductivity. In fact, annealing process could affect on thin film's chemical composition and lattice structure, which results in the transformation of thin film's electrical conductivity.