Artificial superlattices consisting of antiferroelectric PbZrO3 (PZO) and ferroelectric PbTiO3 (PTO) have been fabricated by a multi-ion-beam sputtering technique. The epitaxial PZO and PTO layers were sequentially grown on (100)Pt/MgO substrates at a low substrate temperature of 415 °C with a periodicity from 5 to 100 perovskite unit cells. X-ray diffraction studies revealed the superlattice structures with a-axis oriented PTO layers on a-axis oriented PZO layers. The dielectric and ferroelectric properties of the superlattice films were enhanced with increasing periodicity.

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Lateral grain with a maximum grain size of ∼60 µm was grown by high speed scanning of a molten region in amorphous Si (a-Si) films formed by micro-thermal-plasma-jet irradiation. The a-Si transformed into crystalline through solid phase crystallization, followed by melting and recrystallization induced by the movement of molten region. The laterally crystallized Si films show a high crystalline volume fraction of ∼100%. Thin film transistors were fabricated using Si films formed by high-speed (4000 mm/s) lateral crystallization, and a very high field effect mobility of 350 cm2 V-1 s-1 was successfully obtained.

The origin of expanded single Shockley-type stacking faults in forward-current degradation of 4H-SiC p-i-n diodes was investigated by the stresscurrent test. At a stress-current density lower than 25 A cm %2 , triangular stacking faults were formed from basal-plane dislocations in the epitaxial layer. At a stress-current density higher than 350 A cm %2, both triangular and long-zone-shaped stacking faults were formed from basal-plane dislocations that converted into threading edge dislocations near the interface between the epitaxial layer and the substrate. In addition, the conversion depth of basal-plane dislocations that expanded into the stacking fault was inside the substrate deeper than the interface. These results indicate that the conversion depth of basal-plane dislocations strongly affects the threshold stress-current density at which the expansion of stacking faults occurs.

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Stacking faults expanded by the application of forward current to 4H-SiC p–i–n diodes were observed using a transmission electron microscope to investigate the expansion origin. It was experimentally confirmed that long-zonal-shaped stacking faults expanded from basal-plane dislocations converted into threading edge dislocations. In addition, stacking fault expansion clearly penetrated into the substrate to a greater depth than the dislocation conversion point. This downward expansion of stacking faults strongly depends on the degree of high-density minority carrier injection.

High-resolution NMR spectra of chlorinated polyethylenes with various chlorine contents were measured on a-dichlorobenzene solutions at ca. 160°C. The chemical shifts for the resonances associated with the distribution of chlorine atoms along the polymer chain were resolved by the triad or pentad units, and content of the chemical units was quantitatively obtained. Chemical units containing geminal dichloride were observed when chlorine content approached ca. 40 wt %. The structure of chlorinated polyethylenes in the region of chlorine content below 40 wt% is characteristic of the statistically random distribution of chlorine atoms along the polymer chain. Various methylenes and methynes in various proton environments were observed, but chemical units such as vinylidene chloride sequences were not observed in the chain. It was found that a chlorination condition slightly affected the chlorine distribution, namely the solution chlorination increased vicinal-dichloride units rather than geminaldichloride units. However, the molecular weight of the parent polymer did not affect the chlorine distribution of chlorinated polyethylenes. The sequence-length distribution of methylenes was also obtained and the contents of longer methylene sequences (-(CH2)n-, were computed using the results of Frensdorff and Ekiner's theoretical treatment. KEY WORDS Chlorinated Polyethylenes I High-Resolution NMR I Assignment I Chlorine Distribution I Methylene-Sequence Length I a, w-Dichloroparaffins I Vinyl Chloride-Ethylene Copolymer I Hydrogenated Poly(Vinyl Chloride) I

Phase transformation of amorphous-silicon during millisecond annealing using micro-thermal-plasma-jet irradiation was directly observed using a high-speed camera with microsecond time resolution. An oval-shaped molten-silicon region adjacent to the solid phase crystallization region was clearly observed, followed by lateral large grain growth perpendicular to a liquid-solid interface. Furthermore, leading wave crystallization (LWC), which showed intermittent explosive crystallization, was discovered in front of the moving molten region. The growth mechanism of LWC has been investigated on the basis of numerical simulation implementing explosive movement of a thin liquid layer driven by released latent heat diffusion in a lateral direction.