Effect of ion-beam assisted deposition on the film stresses of TiO ₂ and SiO₂ and stress control

Based on Hartmann-Shack sensor technique, an online thin film stress measuring system was introduced to measure the film stresses of TiO₂ and SiO₂, and comparison was made between the film stresses prepared respectively by the conventional process and the ion-beam assisted deposition. The effect of ion-beam assisted deposition on the film stresses of TiO ₂ and SiO₂ was investigated in details, and the stress control methodologies using on-line adjustment and film doping were put forward. The results show that the film stress value of TiO₂ prepared by ion-beam assisted deposition is 40 MPa lower than that prepared by conventional process, and the stress of TiO₂ film changes gradually from tensile stress into compressive stress with increasing ion energy; while the film stress of SiO₂ is a tensile stress under ion-beam assisted deposition because of the ion-beam sputtering effect, and the film refractive index decreases with increasing ion energy. A dynamic film stress control can be achieved through in-situ adjustment of the processing parameters based on the online film stress measuring technique, and the intrinsic stress of film can be effectively changed through film doping.