A unique simulation method of epoxy-based chemically-amplified resist by coarse-grained molecular dynamics was proposed. The mechanical properties of an epoxy-based chemically-amplified resists with various cross-linking ratios were simulated using a newly developed coarse-grained molecular dynamics simulation that employs a bead-spring model. Models with the different cross-linking ratios were created in the molecular dynamics calculation step and uniaxial elongation simulations were performed. The results reveal that the simulated elastic modulus of the resist modeled by the bead-spring model with an extended angle bending potential depends on the cross-linking ratio; its dependency exhibits good agreement with that determined by nanoindentation tests.

Fatigue fracture under cyclic loading of single crystal silicon (SCS) is concerned and fatigue properties and mechanism are investigated widely. Surface oxide is considered to have an important role on fatigue fractures. In this paper, the tensile testing of SCS whose surface was intentionally oxidized and the effect of the oxide thickness on the mechanical properties were reported. After fabrication of SCS specimens, they were oxidized in dry oxidization at 1100 ºC. Quasi-static tensile testing of SCS specimens with no, 100-nm-oxide, and 200-nm-oxide thick oxide was performed. As the results, the deviation in fracture strain was decreased by oxidation, and the fracture origin was observed to be the inner silicon part. These results might be caused by the decrease of surface roughness and defects formation by oxygen precipitation during thermal oxidation.

Single-crystal silicon films of sub-micrometer thicknesses were tensile tested using a thin film tensile tester with an electrostatic force grip. The tester has been newly designed for this thin film. It uses a servo-controlled balance for small-force measurement with a resolution of less than 100 νN. The specimens were fabricated using bulk- and surface-micromachining starting with a SIMOX wafer, and an epi-SOI wafer. The bulk micromachined specimens were released from a wafer by anisotropic etching from the backside of the wafer. The specimen size was 0 to 500 νm long, 20 or 50 νm wide and 0.14 νm thick. The thinner specimens were fabricated by surface micromachining and dry release process using XeF2 and vapor HF etching to avoid stiction of the specimens. The size was 0 to 600 νm long, 1 to 20 νm wide and 0.05 νm thick. These wafers were (100) oriented and the loading axis of the specimen was <110>. The tensile strength of the bulk micromachined specimens ranged from 1.4 to 4.8 GPa for twelve samples and that of the surface micromachined specimens ranged from 1.0 to 6.8 GPa for seven samples.

A new tensile tester for thin films was developed to evaluate the reliability of the microelectro- mechanical devices. This tester uses the grip that fixes a thin film specimen to a probe by electrostatic force. We applied this tester for polycrystalline silicon (poly-Si) thin films prepared under various conditions. The microstructure of the film is controlled by the crystallizing temperature. The process conditions and the microstructures that contribute to the strength of poly-Si film are identified by the tensile strength and the fracture toughness. The mean tensile strength of each specimen size ranges from 1.8 to 3.7 GPa, and the fracture toughness calculated from the strength of the notched specimen ranges from 1.9 to 4.5 MN/m3/2. The 1000°C annealed film has higher strength and toughness than the other films because of the high annealing temperature and the small grain size. The contributions to the strength are evaluated by the additional annealing at 1000°C for the low temperature annealed films.