Abstract: In a thin film capacitor of a random access memory including a lower electrode, a dielectric film and an upper electrode, generation of defects in the dielectric film is suppressed. In another way, impurity diffusion into the dielectric film is prevented. In still another way, lattice matching of the dielectric film and the electrodes is realized. Thus, a reduced dielectric constant of the capacitor is prevented, and a quality of the semiconductor device is increased.

Abstract: A zero-phase sequence current detector have three circular cores provided around three phases overhead lines of AC power lines, three magnetoptic sensors provided on respective cores for detecting currents flowing on respective power lines, and a processing circuit containing an adding circuit for adding outputs of the magnetoptic sensors and a compensation processing circuit for canceling erroneous components due to the differences of the temperature characteristics among the magnetoptic sensors.

Abstract: A pattern defect detecting system for an integrated semiconductor circuit or the like, utilizing the phenomenon that in the case of a test pattern having regularity, the intensity of diffracted light appearing on a back-focal plane of a lens is high, while defects or foreign matters not having regularity are low in the intensity of diffracted light. As a concrete example, an optical space modulator is used to record only an intense light portion in real time. The recorded diffraction pattern can be erased easily by, for example, application of voltage and radiation of light. A spatial filter can be prepared in real time in 1:1 correspondence to a test sample. Besides, even in the case of change of test pattern, an immediate action can be taken for continuous detection of defects, thus permitting test on-line.

Abstract: A horn speaker capable of forming a uniform sound field of a high fidelity and uniform tone quality and clearness, regardless of the position of listeners, suitable for use in broadcastings in a hall, station yard, playground and so forth. The horn speaker has a horn defined by four wall surface each of which is given by the equation of:a=a.sub.o (l+.alpha.x).sup.nwhere, a.sub.o represents the size of the throat, a represents the size of cross-section at a distance x from the throat and .alpha. represents the divergence coefficient. The n takes a value n.sub.1 (n.sub.1 .gtoreq.2) at the open end side of the horn and a different value n.sub.2 (n.sub.2 .gtoreq.n.sub.1) at the throat side. In addition, the tangential angle at the open end of the horn is selected to fall between 1.5.theta. and 2.0.theta., where .theta. represents a half of the directivity angle which is an angle causing a 6 dB drop of the sound pressure from the sound pressure on the axis of the polar directivity characteristics.