Abstract: The present invention relates to a novel process for producing (Al, Ga)N and AlGaN single crystals by means of a modified HVPE process, and also to (Al, Ga)N and AlGaN single crystals of high quality. The III-V compound semiconductors produced by the process according to the invention are used in optoelectronics, in particular for blue, white and green LEDs and also for high-power, high-temperature and high-frequency field effect transistors.

Abstract: The invention relates to an adhesive system which is based on a non-reactive thermoplastic adhesive melt. The adhesive melt (A) contains a mixture of at least two metallocene-catalytically produced copolymers which are different from each other, and which are based on at least two a-olefins, whereby the copolymers of the mixture, which are different from each other, have different melt indices (MFIs); (B) optionally, at least one additional polymer; and (C) optionally, at least one resin and/or at least one wax. The inventive adhesive system is particularly suitable for use in the wood and furniture industry, e.g. for covering profiles or for gluing edges, in particular, by comparing copolymer adhesives to EVA melt adhesives which are used in a traditional manner, and the system enables considerably lower application temperatures to be used, and at the same time exhibiting improved adhesion capacity.

Abstract: An epitaxial growth process for producing a thick III-N layer, wherein III denotes at least one element of group III of the periodic table of elements, is disclosed, wherein a thick III-N layer is deposited above a foreign substrate. The epitaxial growth process preferably is carried out by HVPE. The substrate can also be a template comprising the foreign substrate and at least one thin III-N intermediate layer. The surface quality is improved by providing a slight intentional misorientation of the substrate, and/or a reduction of the N/III ratio and/or the reactor pressure towards the end of the epitaxial growth process. Substrates and semiconductor devices with such improved III-N layers are also disclosed.

Abstract: A process for producing a doped III-N bulk crystal, wherein III denotes at least one element of the main group III of the periodic system, selected from Al, Ga and In, wherein the doped crystalline III-N layer or the doped III-N bulk crystal is deposited on a substrate or template in a reactor, and wherein the feeding of at least one dopant into the reactor is carried out in admixture with at least one group III material. In this manner, III-N bulk crystals and III-N single crystal substrates separated therefrom can be obtained with a very homogeneous distribution of dopants in the growth direction as well as in the growth plane perpendicular thereto, a very homogeneous distribution of charge carriers and/or of the specific electric resistivity in the growth direction as well as in the growth plane perpendicular thereto, and a very good crystal quality.

Abstract: In a process for forming a mask material on a III-N layer, wherein III denotes an element of the group III of the Periodic Table of Elements, selected from Al, Ga and In, a III-N layer having a surface is provided which comprises more than one facet. Mask material is selectively deposited only on one or multiple, but not on all facets. The deposition of mask material may be particularly carried out during epitaxial growth of a III-N layer under growth conditions, by which (i) growth of at least a further III-N layer selectively on a first type or a first group of facet(s) and (ii) a deposition of mask material selectively on a second type or a second group of facet(s) proceed simultaneously. By the process according to the invention, it is possible to produce free-standing thick III-N layers. Further, semiconductor devices or components having special structures and layers can be produced.

Abstract: A radiation-emitting optoelectronic component with an active zone having a quantum well structure (5) containing at least one first nitride compound semiconductor material. The quantum well structure (5) is grown on at least one side facet (9) of a nonplanar structure (4) containing at least one second nitride compound semiconductor material. As a result of the quantum well structure (5) being grown onto a side facet (9), piezoelectric fields caused by lattice mismatches are advantageously reduced and the homogeneity of the quantum well structure (5) is improved.