RESUMO
In this study, room-temperature wafer bonding of Al2O3 thin films on Si thermal oxide wafers, which were deposited using atomic layer deposition (ALD), was realized using the surface-activated bonding (SAB) method. Transmission electron microscopy (TEM) observations indicated that these room-temperature-bonded Al2O3 thin films appeared to work well as nanoadhesives that formed strong bond between thermally oxidized Si films. The perfect dicing of the bonded wafer into dimensions of 0.5 mm × 0.5 mm was successful, and the surface energy, which is indicative of the bond strength, was estimated to be approximately 1.5 J/m2. These results indicate that strong bonds can be formed, which may be sufficient for device applications. In addition, the applicability of different Al2O3 microstructures in the SAB method was investigated, and the effectiveness of applying ALD Al2O3 was experimentally verified. This successful SAB of Al2O3 thin films, which is a promising insulator material, opens the possibility of future room-temperature heterogenous integration and wafer-level packaging.
RESUMO
We examined a method to produce bread from crystalline rice flour without using thickening agents such as gluten, polysaccharide thickening, and amorphous rice flour. Rice grains were pulverized by a jet mill to produce flour. Samples of rice flours of various particle size distributions were prepared by using a size shifter. The degree of starch damage and the dynamic viscoelasticity of rice batter were measured in this work. We also baked bread of the flour of each size distribution to study processability for making bread. The batter made by the pulverized flour of rice particle size ranging from 75 to 106 µm had the highest expansion ratio and a good processability for baking breads compared to other particle size batters. The rice bread with high expansion ratio was produced by controlling particle size of crystalline rice flour without using thickening agents.