| FREIBERGER COMPOUND MATERIALS GmbH Patent applications |
| Patent application number | Title | Published |
|---|
| 20120076968 | METHOD AND APPARATUS FOR FABRICATING CRACK-FREE GROUP III NITRIDE SEMICONDUCTOR MATERIALS - Method for producing a III-N (AlN, GaN, Al | 03-29-2012 |
| 20110318221 | METHOD OF CUTTING SINGLE CRYSTALS - An embodiment of the invention provides a single crystal cleaved from a larger crystal and having a cleavage surface that extends along a natural crystallographic plane of the single crystal, the cleavage surface produced by generating a stress field to propagate a crack in the larger crystal along the natural plane, so that during cracking by the stress field a magnitude of a derivative of an energy release rate, G(α), generated by the stress field at a front of the crack as a function of angular deviation, α, from the natural plane, is less than or equal to twice an effective step energy, β | 12-29-2011 |
| 20110227198 | SEMIPOLAR SEMICONDUCTOR CRYSTAL AND METHOD FOR MANUFACTURING THE SAME - A method of manufacturing a semipolar semiconductor crystal comprising a group-III-nitride (III-N), the method comprising: providing a substrate comprising sapphire (Al | 09-22-2011 |
| 20110114015 | METHOD AND APPARATUS FOR FABRICATING CRACK-FREE GROUP III NITRIDE SEMICONDUCTOR MATERIALS - Method for producing a III-N (AlN, GaN, Al | 05-19-2011 |
| 20110018106 | METHOD FOR PRODUCING III-N LAYERS, AND III-N LAYERS OR III-N SUBSTRATES, AND DEVICES BASED THEREON - 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. | 01-27-2011 |
| 20090286331 | METHOD FOR SIMULATENOUSLY PRODUCING MULTIPLE WAFERS DURING A SINGLE EPITAXIAL GROWTH RUN AND SEMICONDUCTOR STRUCTURE GROWN THEREBY - HVPE method for simultaneously fabricating multiple Group III nitride semiconductor structures during a single reactor run. A HVPE reactor includes a reactor tube, a growth zone, a heating element and a plurality of gas blocks. A substrate holder is capable of holding multiple substrates and can be a single or multi-level substrate holder. The gas delivery blocks are independently controllable. Gas flows from the delivery blocks are mixed to provide a substantially uniform gas environment within the growth zone. The substrate holder can be controlled, e.g., rotated and/or tilted, for uniform material growth. Multiple Group III nitride semiconductor structures can be grown on each substrate during a single fabrication run of the HVPE reactor. Growth on different substrates is substantially uniform and can be performed on larger area substrates, such as 3-12″ substrates. | 11-19-2009 |
| 20090286063 | METHOD AND APPARATUS FOR FABRICATING CRACK-FREE GROUP III NITRIDE SEMICONDUCTOR MATERIALS - A method and apparatus for growing low defect, optically transparent, colorless, crack-free, substantially flat, single crystal Group III nitride epitaxial layers with a thickness of at least 10 microns is provided. These layers can be grown on large area substrates comprised of Si, SiC, sapphire, GaN, AlN, GaAs, AlGaN and others. In one aspect, the crack-free Group III nitride layers are grown using a modified HVPE technique. If desired, the shape and the stress of Group III nitride layers can be controlled, thus allowing concave, convex and flat layers to be controllably grown. After the growth of the Group III nitride layer is complete, the substrate can be removed and the freestanding Group III nitride layer used as a seed for the growth of a boule of Group III nitride material. The boule can be sliced into individual wafers for use in the fabrication of a variety of semiconductor structures (e.g., HEMTs, LEDs, etc.). | 11-19-2009 |
| 20090050913 | METHOD FOR ACHIEVING LOW DEFECT DENSITY ALGAN SINGLE CRYSTAL BOULES - A method for growing bulk GaN and AlGaN single crystal boules, preferably using a modified HVPE process, is provided. The single crystal boules typically have a volume in excess of 4 cubic centimeters with a minimum dimension of approximately 1 centimeter. If desired, the bulk material can be doped during growth to achieve n-, i-, or p-type conductivity. In order to have growth cycles of sufficient duration, preferably an extended Ga source is used in which a portion of the Ga source is maintained at a relatively high temperature while most of the Ga source is maintained at a temperature close to, and just above, the melting temperature of Ga. To grow large boules of AlGaN, preferably multiple Al sources are used, the Al sources being sequentially activated to avoid Al source depletion and excessive degradation. In order to achieve high growth rates, preferably a dual growth zone reactor is used in which a first, high temperature zone is used for crystal nucleation and a second, low temperature zone is used for rapid crystal growth. Although the process can be used to grow crystals in which the as-grown material and the seed crystal are of different composition, preferably the two crystalline structures have the same composition, thus yielding improved crystal quality. | 02-26-2009 |
| 20080203409 | PROCESS FOR PRODUCING (Al, Ga)N CRYSTALS - 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. | 08-28-2008 |
| 20080203408 | PROCESS FOR PRODUCING (Al, Ga)lnN CRYSTALS - The present invention relates to a novel process for producing (Al, Ga)InN and AlGaInN single crystals by means of a modified HVPE process, and also to (Al, Ga)InN and AlGaInN bulk crystals of high quality, in particular homogeneity. | 08-28-2008 |
