Abstract: A semiconductor device includes a fuse transistor in an active region. In a first direction, the active region is defined by first and second element isolation films. The fuse transistor includes a gate dielectric film, a gate electrode, and semiconductor regions on both sides of the gate electrode in a second direction perpendicular to the first direction. In the first direction, the gate dielectric film has a central portion, a first peripheral portion and a second peripheral portion. The central portion is spaced apart from the first element isolation film and the second element isolation film, the first peripheral portion reaches the first element isolation film, and the second peripheral portion reaches the second element isolation film. The central portion of the gate dielectric film has a first thickness, and each of the first peripheral portion and the second peripheral portion has a second thickness greater than the first thickness.

Abstract: An .alpha., .beta.-unsaturated carboxylic acid is produced by catalytically reacting an .alpha.-hydroxycarboxylic acid amide of the formula (1), ##STR1## where R.sub.1 and R.sub.2 are independently selected from the group consisting of hydrogen and C.sub.1 -C.sub.4 alkyl groups, provided that at least one of R.sub.1 and R.sub.2 is the alkyl group, with water in the presence of a solid acid catalyst containing a high surface area rare earth phosphate anhydride having the monoclinic system structure producible by heating a rare earth phosphate of the hexagonal system structure at 60.degree.-200.degree. C. in a solution of an inorganic acid, an inorganic acid salt and/or an inorganic acid ester where the molar ratio of the inorganic acid component to the rare earth phosphate of the hexagonal system structure is 0.5-400.

Abstract: .alpha.,.beta.-Unsaturated carboxylic acid esters are produced by a catalytic reaction of .alpha.,.beta.-unsaturated carboxylic acids and/or .alpha.,.beta.-unsaturated carboxylic acid amides with aliphatic alcohols in the presence of a solid acid catalyst comprising zirconium oxide, titanium oxide or a composite oxide thereof containing phosphorus.