Abstract: A bottom structure of a bed having a bottom formed so as to be bendable by a series of parallel strips mutually sequentially connected such that the strips are shorter in width on the side away from the sequentially connected side. In this way the bottom structure of the bed allows a portion of a bed bottom to be bent in a large curvature, thus is provided a bed which is comfortable and highly adaptable for patients of various body sizes.

Abstract: A polycrystalline silicon rod for preparing a monocrystalline silicon rod by a floating zone method, wherein at least a central portion of the section of the polycrystalline silicon rod has coarsened silicon monocrystalline grains around the center over an area of or above the minimum section of a molten zone during progress in the floating zone method and the outer peripheral portion of the coarsened region has fine monocrystalline grains. From the polycrystalline silicon rod, the monocrystalline silicon rod for a semiconductor is prepared with a high yield by the single floating zone method.

Abstract: According to this invention, a semiconductor rod zone melting apparatus for manufacturing single-crystal semiconductor such as silicon, germanium, and the like and compound semiconductors such as gallium phosphate, and the like by the FZ process is disclosed. In this invention, a substantially U-shaped metal piece is arranged near one of upper and lower side surfaces of an induction heating coil surrounding a floating zone of a semiconductor rod to be melted, the floating zone surrounding space can be varied upon relative movement between the coil and the metal piece toward the radial direction of the coil. The floating zone of the semiconductor rod can be homogeneously and concentratively heated, and zone melting of a large-diameter semiconductor rod is facilitated.

Abstract: An RF induction heating apparatus for manufacturing single-crystal semiconductors having large diameters using the floating-zone melting process is provided in which a single turn induction heating coil suitable for zone melting and another heating coil suitable for controlling single-crystal growth are concentrically or eccentrically positioned to surround an outer surface of a floating zone in a crystalline semiconductor rod. Either the upper or lower peripheral edge of the outer surface of the single-turn induction heating coil is surrounded by and coupled to a annular collar, while both ends of the collar are arranged opposite each other across a gap. At least one conductive sector plate is affixed to a coil lower surface opposite a region of the semiconductor to be heated, so that even if both ends of the coil are spaced apart from each other due to the presence of a supply tube or the like, any gap between the two ends is shielded by the conductive sector plate(s).

Abstract: A supporting apparatus for a semiconductor noncrystal rod comprises a movable ring adapted to move freely in horizontal directions unless it is engaged with the monocrystal rod, a lock means to prevent the movable ring from horizontally moving, and a drive means to elevate the movable ring.

Abstract: In a method of controlling a floating zone of a semiconductor rod of the present invention shown in FIG. 1, the diameter D.sub.s at a crystallization boundary of a crystal and the axial length of the floating zone are indirectly controlled by controlling a diameter D.sub.m of a crystallizing-side melt shoulder portion and the diameter D.sub.n of a constricted melt portion, respectively. Since these diameters D.sub.m and D.sub.n are used for predicting D.sub.s and L to be obtained after a given time has passed, the response speed and stability of the control are improved as compared with the direct control of D.sub.s and L. An apparatus for controlling a floating zone of a semiconductor rod of the present invention performs the above-described method. In another method, the zone length is directly or indirectly controlled by regulating a relative moving speed of the melting-side semiconductor rod relative to the heater, and the diameter D.sub.