Abstract: A temperature gradient is established in a crystallization crucible by means of a heat source and a cooling system. The cooling system comprises a heat exchanger and an adjustable additional heat source. The cooling system is preferably formed by an induction coil cooled by a coolant liquid circulating in the induction coil and by an electrically conductive induction susceptor positioned between the crucible and induction coil. The fabrication process comprises heating the crucible via the top and controlling heat extraction from the crucible downwards by means of the heat exchanger and by means of regulation of the adjustable additional heat source.

Abstract: The device for producing a sheet of crystalline material by directional solidification of a material in liquid phase composed of a crucible provided with a bottom, side walls and at least one horizontal outlet slot arranged on a bottom part of a side wall. On its external surface in immediate proximity to the slot, the crucible presents electromagnetic means for creating magnetic repulsion forces on the material in liquid phase, at least at the level of the slot. An alternating current with a frequency comprised between 10 kHz and 300 kHz flows through the electromagnetic means. To foster stirring of the material in liquid phase, a low frequency can be used in addition to the above frequencies.

Abstract: A temperature gradient is established in a crystallization crucible by means of a heat source and a cooling system. The cooling system comprises a heat exchanger and an adjustable additional heat source. The cooling system is preferably formed by an induction coil cooled by a coolant liquid circulating in the induction coil and by an electrically conductive induction susceptor positioned between the crucible and induction coil. The fabrication process comprises heating the crucible via the top and controlling heat extraction from the crucible downwards by means of the heat exchanger and by means of regulation of the adjustable additional heat source.

Abstract: The device comprises a crucible (1) having a bottom (2) and side walls (3). The crucible (1) comprises at least one lateral slit (4) arranged horizontally at a bottom part of the side walls (3). The lateral slit (4) presents a width of more than 50 mm and preferably comprised between 100 mm and 500 mm. The height (H) of the slit (4) is comprised between 50 and 1000 micrometers. The crystalline material is output from the crucible via the lateral slit (4) so as to form a crystalline ribbon (R). The method comprises a step of bringing a crystallization seed into contact with the material output via the lateral slit (4) and a horizontal displacement step of the ribbon (R).

Abstract: The bottom of the crucible has much greater thermal transfer properties, parallel to an axis substantially perpendicular to the bottom, than those of the side walls. The bottom and side walls are formed by materials having the same main chemical constituents. The bottom can be transparent to infrared radiation and the side walls opaque to infrared radiation. The bottom can be made of amorphous silica and the side walls of opaque quartz ceramic. The crucible can also be made of graphite. The device can comprise a graphite felt, arranged between the bottom of the crucible and cooling means, and compression means of the graphite felt. It is thus possible to define a temperature gradient comprised between 8° C./cm and 30° C./cm in the liquid phase.

Abstract: The invention relates to a method of separating into two wafers (2,4) a plate (1) of material for manufacturing substrates for electronics, optics, or optoelectronics, or for manufacturing microsystems, said wafers being situated on either side of a plane of weakness (6), the method being characterized in that it comprises the steps consisting in: exerting a deformation force on at least one of the wafers so as to cause the wafers (2, 4) to separate from each other in a zone of the plate (1) at said plane of weakness; and exerting guided separation movement on the wafers (2, 4). The invention also provides apparatus (100) for implementing the method, which apparatus has gripping members (30, 32) suitable for exerting said deformation force and for performing said separation.

Abstract: The invention relates to a process for the control of a monocrystal pulling machine.The process consists of recording in a computer memory parameters relating to the geometry of the monocrystal and the growth thereof, signals representative of the weight of the crystal and processed by processing circuits, then recording in said memory a programme so that the computer successively controls the raising to the appropriate temperature of the heating means for successively bringing about the melting of the product for forming the monocrystal, a fast automatic approach of the product bath by a pin carrying a nucleus up to a predetermined distance from the surface of said bath. Finally, the process consists of controlling a slower bath approach until the nucleus is in contact with the bath surface. Following this contact, the temperature of the heating means is automatically regulated for a zero growth of the crystal, the automatic pulling of the crystal and the cooling of the heating means at the end of pulling.

Abstract: The invention relates to a monocrystal pulling head.A carriage carrying the vertical pulling spindle, in which is placed a weight transducer, moves parallel to said axis under the action of a torque motor, which is controlled in position and speed and which is directly connected to the threaded rod of a screw - nut system. During its displacement, the carriage is guided by a rail, on which roll at least two pairs of rollers. A torque motor is mounted in the carriage for directly rotating the pulling spindle. Thus, the spindle displacement speeds are very accurately controlled. An electronic system integral with the pulling spindle processes the signals from the weight transducer. Contactless means make it possible to supply the electronic system, feed the useful information to the fixed parts and return thereto control instructions.