Interface diffusion between ZNO: Eu thin film and the Si(100) substrate

Eu doped ZnO thin films were deposited on a Si(100) substrate using a spraying pyrolysis method. The precursor solution was sprayed by N-2 carrier gas. To form polycrystalline ZnO material, the substrates were set into a tube furnace to maintain the deposition temperature at 350 degrees C. Using a Rutherford backscattering (RBS) system, the atom distribution of elements between the ZnO:Eu thin films and Si(100) substrates was examined. The experiments show that the transition layers exist between ZnO thin films and the Si (100) substrate. The RBS measurements and simulation reveal that the formation of the layer is controlled by the diffusion of Si into the ZnO thin films. This fact indicates that the diffusion of Si into oxide thin films should not be neglected, even at low temperature of 350 degrees C. By applying the Fick's Diffusion Law, the diffusion capability of Si into ZnO thin films with different Eu3(+) doping was studied and calculated. It is concluded that the doping Eu3+ will strongly hinder the diffusion of Si into ZnO films due to the precipitation of Eu3+ at the grain boundary.