METHOD OF PRODUCING A FREESTANDING BULK POLYCRYSTALLINE GALLIUM NITRIDE SUBSTRATE

The present invention relates to an improved method of producing a freestanding bulk polycrystalline Gallium Nitride, GaN, substrate (12). The method comprising the steps of compressing a GaN powder with a hydraulic compressor for forming a GaN pellets (2), subjecting the GaN pellets (2) and a silicon substrate (4) in a reaction chamber (24) of an e-beam evaporator (1), wherein the GaN pellets (2) and the silicon substrate (4) are positioned facing directly to each other and separated at a predefined distance from each other, depositing (10) the GaN pellets (2) onto the silicon substrate (4) for forming a first semiconductor material by evaporating the GaN pellets (2) with an electron beam from the e-beam evaporator (1), annealing (20) the first semiconductor material (8) produced thereof in an ammonia environment, and removing (30) the silicon substrate (4) from the first semiconductor material (10) by chemically etching the resulting annealed first semiconductor material (10), thereby forming the freestanding bulk polycrystalline GaN substrate (12). The present invention produces the freestanding bulk polycrystalline GaN substrate that is high in density and formable in various size and shape in a simple and affordable manner, which allows mass production of the said freestanding substrate. (Figure 1)