Melt blending of Bisphenol A polycarbonate (PC) and poly(trimethylene terephthalate) (PTT) was carried out over the entire composition range. The mixing time was varied up to 90 min. The resulting samples were analyzed by FT-IR, DSC, XRD, DMTA, 1 H NMR, and SEM. The process of transesterification between the two polymers and their resulting compatibilization were observed. The behaviors of the PTT-rich and PC-rich blends were different and an equilibrium was found to exist. Peculiar behavior, which was different from that of the PTT-rich and PC-rich blends, was exhibited by the 50/50 (PTT/PC) blend.

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6-inch 4H-SiC crystal ingot was successfully separated from a seed holder by the contraction enhancement of adhesive. The resin used as an adhesive with 10~30% in contraction ratio during the cooling was selected. The crack between seed holder and grown SiC crystal was observed to be formed after the cooling procedure and the crystal was easily separated from the seed holder without any machining process for the separation. The warp value and the rocking curve value of SiC crystal grown with modified adhesive was observed to be smaller than those of SiC crystal with conventional method.

6-inch 4H-SiC single crystal was grown with modified hot-zone design for large diameter crystal. The simulation data confirmed reduced temperature gradient between center and edge region of growing front, and actual growth experiment exhibited that SiC crystal with good quality was obtained with modified hot-zone design without any quality degradation in edge region of bulk crystal. Based on the mapping measurement of FWHM (Full width at half maximum) value in X-ray rocking curve, the crystal quality of SiC crystals from middle and top region of grown ingot was observed to be almost identical. Furthermore, various properties of SiC crystal grown with modified hot-zone design have been systematically investigated.