Abstract: A method for producing an electrical contact of an optoelectronic semiconductor chip (1), comprising providing a mirror layer (2), comprised of a metal or metal alloy, over the semiconductor chip; providing a protective layer (3) over said mirror layer; providing a layer sequence of a barrier layer and a coupling layer (5) over said protective layer; and providing a solder layer (8) over said layer sequence.

Abstract: Method for fabricating a semiconductor chip which emits electromagnetic radiation, wherein to improve the light yield of semiconductor chips which emit electromagnetic radiation, a textured reflection surface is integrated on the p-side of a semiconductor chip. The semiconductor chip has an epitaxially produced semiconductor layer stack based on GaN, which comprises an n-conducting semiconductor layer, a p-conducting semiconductor layer and an electromagnetic radiation generating region which is arranged between these two semiconductor layers. The surface of the p-conducting semiconductor layer which faces away from the radiation-generating region is provided with three-dimensional pyramid-like structures. A mirror layer is arranged over the whole of this textured surface. A textured reflection surface is formed between the mirror layer and the p-conducting semiconductor layer.

Abstract: A process for the preparation of vinyl chloride copolymers involves free radical suspension polymerization or emulsion polymerization of a mixture of vinyl chloride, epoxide-containing vinyl monomers and further comonomers copolymerizable therewith, wherein a) from 49.5 to 90% by weight of vinyl chloride, b) from 0.01 to 0.7% by weight of epoxide-containing vinyl monomers and c) from 9.5 to 50% by weight of further comonomers copolymerizable with a) and b) are polymerized, the data in % by weight totaling 100% by weight, and from 0.001 to 0.1% by weight of one or more aliphatic or alicyclic, saturated or unsaturated dicarboxylic acids having 1 to 10 carbon atoms, or aliphatic and alicyclic, saturated and unsaturated hydroxymono-, hydroxydi- and hydroxytricarboxylic acids having 3 to 10 carbon atoms and 1 to 4 hydroxyl groups are added during or after the polymerization, and the vinyl chloride copolymer is isolated as a solid resin.

Abstract: For semiconductor chips (1) using thin film technology, an active layer sequence (20) is applied to a growth substrate (3), on which a reflective electrically conductive contact material layer (40) is then formed. The active layer sequence is patterned to form active layer stacks (2), and reflective electrically conductive contact material layer (40) is patterned to be located on each active layer stack (2). Then, a flexible, electrically conductive foil (6) is applied to the contact material layers as an auxiliary carrier layer, and the growth substrate is removed.

Abstract: A process for the preparation of epoxy-modified vinyl chloride-vinyl ester copolymers in the form of the solid resins involves aqueous, free radical polymerization of a mixture comprising a) from 50 to 90% by weight of vinyl chloride, b) from 5 to 25% by weight of epoxide-containing vinyl monomers and c) from 5 to 25% by weight of one or more vinyl esters of straight-chain or branched alkylcarboxylic acids having 1 to 18 carbon atoms, d) from 0 to 40% by weight of further comonomers copolymerizable with a), b) and c), the data in % by weight summing to 100% by weight, and subsequent drying of the aqueous dispersions obtained thereby, polymerization being effected by means of suspension polymerization in the presence of aldehyde regulators.

Abstract: Presented is a method for producing an optoelectronic component. The method includes separating a semiconductor layer based on a III-V-compound semiconductor material from a substrate by irradiation with a laser beam having a plateau-like spatial beam profile, where individual regions of the semiconductor layer are irradiated successively.

Abstract: In at least one embodiment, the optoelectronic semiconductor component includes an optically active area that is formed with a crystalline semiconductor material that contains at least one of the substances gallium or aluminum. Furthermore, the semiconductor component contains at least one facet on the optically active area. Furthermore, the semiconductor component contains at least one boundary layer, containing sulfur or selenium, with a thickness of up to five monolayers, wherein the boundary layer is located on the facet. Such a semiconductor component has a high destruction threshold relative to the optical powers that occur during operation of the semiconductor component.

Abstract: A method for producing a semiconductor component, in particular a thin-film component, a semiconductor layer being separated from a substrate by irradiation with a laser beam having a plateaulike spatial beam profile. Furthermore, the semiconductor layer, prior to separation, is applied to a carrier with an adapted thermal expansion coefficient. The method is suitable in particular for semiconductor layers containing a nitride compound semiconductor.

Abstract: The invention relates to a method and a circuit arrangement for controlling and regulating the supply of pressure medium to at least two hydraulic consumers, which are assigned in each case a directional valve for setting the flow and a setpoint signal source, by means of a pump with a variable displacement, which can be regulated by means of a displacement controller. The pump displacement is regulated according to the flow required by the setpoint signals. The individual load pressure of the consumers and of the consumer having the highest load pressure are determined. The directional valve of the highest loaded consumer is controlled to a valve-spool position y1, with y1=K·y1,max=const., which lies by a factor K, with 0<K<1, below the valve-spool position y1,max representing the maximum opening of the directional valve.

Abstract: Method for fabricating a semiconductor chip which emits electromagnetic radiation, wherein to improve the light yield of semiconductor chips which emit electromagnetic radiation, a textured reflection surface is integrated on the p-side of a semiconductor chip. The semiconductor chip has an epitaxially produced semiconductor layer stack based on GaN, which comprises an n-conducting semiconductor layer, a p-conducting semiconductor layer and an electromagnetic radiation generating region which is arranged between these two semiconductor layers. The surface of the p-conducting semiconductor layer which faces away from the radiation-generating region is provided with three-dimensional pyramid-like structures. A mirror layer is arranged over the whole of this textured surface. A textured reflection surface is formed between the mirror layer and the p-conducting semiconductor layer.

Abstract: A radiation-emitting semiconductor component having a semiconductor body (1), which has an active zone (2), in which, for the purpose of electrical contact connection, a patterned contact layer (3) is applied on a surface of the semiconductor body. Interspaces (4) are distributed over the contact layer (3) and are provided for the purpose of forming free areas (5) on the surface which are not covered by the contact layer (3). The free areas (5) are covered with a mirror (6). The separation of the two functions of contact connection and reflection makes it possible to achieve a particularly high performance of the component.

Abstract: A semiconductor chip which emits electromagnetic radiation is presented. The chip includes an epitaxially produced semiconductor layer stack based on nitride semiconductor material, which includes an n-conducting semiconductor layer, a p-conducting semiconductor layer, and an electromagnetic radiation generating region, which is arranged between these two semiconductor layers. The chip further includes a base on which the semiconductor layer stack is arranged, and a mirror layer, which is arranged between the semiconductor layer stack and the base. The n-conducting semiconductor layer faces away from the base, and the n-conducting semiconductor layer or an outcoupling layer located on the n-conducting semiconductor layer has a radiation-outcoupling surface which, in turn, includes planar outcoupling sub-surfaces, which are positioned obliquely with respect to a main plane of the radiation-generating region and each form an angle of between 15° and 70° with this plane.

Abstract: The invention provides a process for preparing vinyl chloride-vinyl acetate copolymers in the form of their solid resins by means of free-radically initiated suspension polymerization in aqueous medium of 70% to 90% by weight of vinyl chloride, 10% to 30% by weight of vinyl acetate and, if desired, further comonomers copolymerizable therewith, characterized in that 0.1% to 5% by weight of a vinyl acetate-vinyl chloride copolymer soluble in ethyl acetate is introduced as an initial charge, the amounts in % by weight being based in each case on the total weight of the comonomers.

Abstract: A method for micropatterning a radiation-emitting surface of a semiconductor layer sequence for a thin-film light-emitting diode chip. The semiconductor layer sequence is grown on a substrate. A mirror layer is formed or applied on the semiconductor layer sequence, which reflects back into the semiconductor layer sequence at least part of a radiation that is generated in the semiconductor layer sequence during the operation thereof and is directed toward the mirror layer. The semiconductor layer sequence is separated from the substrate by means of a lift-off method, in which a separation zone in the semiconductor layer sequence is at least partly decomposed in such a way that anisotropic residues of a constituent of the separation zone, in particular a metallic constituent of the separation layer, remain at the separation surface of the semiconductor layer sequence, from which the substrate is separated.

Abstract: A radiation-emitting semiconductor component has a semiconductor body containing a nitride compound semiconductor, and a contact metallization layer disposed on a surface of the semiconductor body. In this case, the contact metallization layer is covered with a radiation-transmissive, electrically conductive contact layer. The radiation generated is coupled out through the contact metallization layer or through openings in the contact metallization layer.

Abstract: A method for producing an electrical contact of an optoelectronic semiconductor chip (1), comprising providing a mirror layer (2), comprised of a metal or metal alloy, over the semiconductor chip; providing a protective layer (3) over said mirror layer; providing a layer sequence of a barrier layer and a coupling layer (5) over said protective layer; and providing a solder layer (8) over said layer sequence.

Abstract: A semiconductor chip which emits electromagnetic radiation is presented. The chip includes an epitaxially produced semiconductor layer stack based on nitride semiconductor material, which includes an n-conducting semiconductor layer, a p-conducting semiconductor layer, and an electromagnetic radiation generating region, which is arranged between these two semiconductor layers. The chip further includes a base on which the semiconductor layer stack is arranged, and a mirror layer, which is arranged between the semiconductor layer stack and the base. The n-conducting semiconductor layer faces away from the base, and the n-conducting semiconductor layer or an outcoupling layer located on the n-conducting semiconductor layer has a radiation-outcoupling surface which, in turn, includes planar outcoupling sub-surfaces, which are positioned obliquely with respect to a main plane of the radiation-generating region and each form an angle of between 15° and 70° with this plane.

Abstract: An electrical contact for an optoelectronic device which includes a mirror layer (2) of a metal or a metal alloy, a protective layer (3), which serves for reducing the corrosion of the mirror layer (2), a barrier layer (4), a coupling layer (5), and a solder layer (8). A contact of this type is distinguished by high reflectivity, good ohmic contact with respect to the semiconductor, good adhesion on the semiconductor and good adhesion of the layers forming the contact with one another, good thermal stability, high stability with respect to environmental influences, and also solderability and patternability.

Abstract: A method for producing a semiconductor component, in which a semiconductor layer (2) is separated from a substrate (1) by irradiation with laser pulses (6), the pulse duration of the laser pulses (6) being less than or equal to 10 ns. The laser pulses (6) have a spatial beam profile (7) with a flank slope chosen to be gentle enough to prevent cracks in the semiconductor layer (2) that arise as a result of thermally induced lateral stresses, during the separation of semiconductor layer (2) and substrate (1).

Abstract: Semiconductor chip which emits electromagnetic radiation, and method for fabricating it. To improve the light yield of semiconductor chips which emit electromagnetic radiation, a textured reflection surface (131) is integrated on the p-side of a semiconductor chip. The semiconductor chip has an epitaxially produced semiconductor layer stack (1) based on GaN, which comprises an n-conducting semiconductor layer (11), a p-conducting semiconductor layer (13) and an electromagnetic radiation generating region (12) which is arranged between these two semiconductor layers (11, 13). The surface of the p-conducting semiconductor layer (13) which faces away from the radiation-generating region (12) is provided with three-dimensional pyramid-like structures (15). A mirror layer (40) is arranged over the whole of this textured surface. A textured reflection surface (131) is formed between the mirror layer (40) and the p-conducting semiconductor layer (13).