Tri-gate channel structures were applied to polycrystalline silicon (poly-Si) thin-film transistors (TFTs) fabricated by continuous-wave (CW) laser lateral crystallization (CLC). We had two objectives in using tri-gate structures in CLC poly-Si TFTs. One was the enhancement of effective electron mobility ( eff ) by using the tensile strain induced by the CLC process and the lateral-strain-relaxation effect in tri-gate structures. The other was the reduction of eff variation caused by increasing the number of surfaces with different crystal orientations by up to a factor of three. By applying tri-gate structures to CLC poly-Si TFTs, both 8% eff enhancement and 41% reduction of eff variation were achieved at the surface carrier density of 5 Â 10 12 cm À2 . These results are expected to be useful for the device size shrinkage of high-performance poly-Si TFT circuits.

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Due to their very substantial fluorescence emission, pyrylium and thiopyrylium salts are widely used as laser dyes and photosensitizers. This paper deals with the fluorescence properties (quantum yields and wavelengths of the fluorescence maxima as well as the lifetimes of the singlet excited states) of eight pyrylium and ten thiopyrylium salts, with special emphasis on the effect of α and γ substitutions of the heterocycle.

IMS (injection molded solder) is an advanced solder bumping technology with solder alloy flexibility even at very fine pitch and small size. One of key materials for successful fine pitch bumping by IMS is a photoresist material. The photoresist material must be stable at high temperature during the IMS process and be perfectly stripped after the IMS process without any residue on the surface of the substrate. In this study, negative tone liquid photoresist materials were prepared to investigate effects of thermal cure of photoresist on IMS process and stripping performance. With appropriate cure conditions, successful bumping without any film damages at IMS process and any residue at stripping was achieved. Fine pitch bumping down to 40 μm pitch with 20 μm diameter was demonstrated with a Sn-3.0Ag-0.5Cu solder. Also physical and electrical connections for the solder joints of IMS bumps to Ni/Au pads were confirmed using a 80 μm pitch test vehicle.

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