U.S. Philips Corporation

Bernard Latorre

Guy N Martin

Claude Foucher

Manuel Montero

The invention relates to a method of manufacturing a spring (10) of the cylindrical type to be used at high temperatures. This spring (10) is made of refractory material, such as quartz, boron nitride or graphite. It is constituted by recesses (11.sub.1 to 11.sub.7) not adjoining each other, having a height h and which are distributed along a helical line. The method of manufacturing utilizes a wire saw for forming these recesses in a cylindrical tube, which is subjected to a rotation after each sawing operation. The absence of microcracks imparts a high elasticity to the spring up to high temperatures. It is used for transmitting movements at high temperatures, more particularly when conditions of perfect cleanliness are desired, as, for example, in the case of semiconductor metallurgy.

Method of manufacturing a spring of the cylindrical type to be used at

The invention relates to a crucible for growing epitaxial layers having a chemical composition formed by several chemical elements, of which at least one is volatile, by the method of epitaxy from the liquid phase, comprising an elongated support (72) on which a movable part (73) slides longitudinally, with the elongated support comprising at least one recess for accommodating a substrate (76) on which at least one epitaxial layer is to be deposited. The movable part (73) comprises at least one cavity (77) receiving a mother source (79) formed by initial material for epitaxy with the cavity having on the surface adjoining the elongated support a lower opening whose dimensions correspond to the dimensions of the substrates (76) present therein. At least one receptacle (80) accommodates a source for each volatile element of the chemical composition. It is characterized in that at least one of the cavities (77) of the movable part (73), for which a substrate (76) is present below the lower opening, has at least one upper opening formed solely by a calibrated conduit ( 78) connected to the receptacle (80) accommodating a source of each volatile element. Each calibrated conduit (78) controls the supply of the element to the mother source by the surface of the mother source which is not in contact with the epitaxial layer. The calibrated conduit (78) maintains a substantially constant composition for the mother source.

Crucible for epitaxy from the liquid phase of semiconductor layers

The invention relates to a crucible for the growth of epitaxial layers of chemical compounds formed from several chemical elements by means of epitaxial growth from the liquid phase comprising an elongated support (72), on which a movable part (73) slides longitudinally, the elongated support comprising at least one recess for accommodating a substrate (76) on which is to be deposited at least one epitaxial layer, the movable part comprising at least one cavity (77) receiving a mother source (79) formed from initial epitaxy materials, the cavity having on the surface adjoining the elongated support a lower opening whose dimensions correspond to the dimensions of the substrate (76) present therein. It is characterized in that the movable part (73) has throughout its length a longitudinal groove (81) on the surface which slides longitudinally on the elongated support, this groove having a depth slightly exceeding the irregularities of the substrate and sufficiently small in order that the mother source cannot pass by means of a capillary effect and a width smaller than the dimensions of the substrate in order that the latter cannot penetrate into it, and in that the recess of the elongated support accommodates an elevator (75) on which the substrate is placed, which holds the latter positioned on the lateral edges (82) of the groove (81), the elevator (75) being held in place by means of a small force developed by a pressure system, more particularly as asymmetrical lever (90) movable about an axis or a spring (85) of quartz.

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Vincennes, France

Bernard Latorre