We investigated a solution-derived Y2O3 film treated by ion beam (IB) irradiation as a liquid crystal (LC) alignment layer. With IB irradiation, homogeneous LC alignment was achieved irrespective of the annealing temperature. To verify the effect of IB irradiation, we conducted surface analyses such as X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). As Y2O3 is a high-k material, the electro-optical properties of the twisted nematic (TN) cells were superior to those of conventional TN cells based on a rubbed polymer, with an LC rising time of 4.1ms and falling time of 2.9ms. The IB-irradiated Y2O3 is a good alternative as an alignment layer for fast-switching TN LC displays.
For the measurements of surface shape milled using FIB (focused ion beam), the silicon bulk,Si3N4/Si, and Al/Si samples are used and observed the shapes milled from different sputtering rates,incident angles of Ga+ ions bombardment, beam current, and target material. These conditions also can beinfluenced the sputtering rate, raster image, and milled shape. The fundamental ion-solid interactions ofFIB milling are discussed and explained using TRIM programs (SRIM, TC, and T-dyn). The damagedlayers caused by bombarding of Ga+ ions were observed on the surface of target materials. The simulatedresults were shown a little bit deviation with the experimental data due to relatively small sputtering rateon the sample surface. The simulation results showed about 10.6% tolerance from the measured data at200 pA. On the other hand, the improved analytical model of damaged layer was matched well withexperimental XTEM (cross-sectional transmission electron microscopy) data.