Liquid Crystal Alignment Properties of Inorganic SiO_2 Layers Prepared by Reactive Sputtering in Nitrogen-Argon Mixtures

摘要

According to the advent of ubiquitous world, the requirement for the mobile information devices with high display quality and compact device size is surpris?ingly increased. Among the diverse candidates for this mobile display system for mobile devices, Liquid Crystal on Silicon (LCoS) is the most competitive device due to the high aperture ratio and simple fabrication process. The inorganic liquid crystal (LC) alignment layers are widely used for LCoS devices because of the ther?mal and photochemical stability. In this work, the reactive sputtering was selected for the preparation method of inorganic LC alignment layers. The nitrogen (N_2) gas had the effect on the deposition process of SiO_2 and the surface morphology of SiO_2 thin layers were affected by the N_2 mixing ratio of sputtering gas. In addi?tion, the LC alignment properties on SiO_2 thin layer were also closely related with the N_2 mixing ratio and other sputtering conditions. In the case of high RF power of reactive sputtering, the N_2 mixing ratio has little effect on the LC alignment on SiO_2 thin layers. However, in the case of low RF power of reactive sputtering, the LC alignment properties were enfeebled by increasing the N_2 mixing ratio. This result might be attributed to the change of the surface morphology of inorganic SiO_2 thin layers.