A silicon member for a semiconductor apparatus is provided. The silicon member has an equivalent performance to one fabricated from a single-crystalline silicon even though it is fabricated from a unidirectionally solidified silicon. In addition, it can be applied for producing a relatively large-sized part. The silicon member is fabricated by sawing a columnar crystal silicon ingot obtained by growing a single-crystal from each of seed crystals by placing the seed crystals that are made of a single-crystalline silicon plate on a bottom part of a crucible and unidirectionally solidifying a molten silicon in the crucible.

A method for producing a substrate (10) for an optical element (11) includes: introducing a starting material, preferably a metal or a semimetal, into a container and melting the starting material, producing a material body having a quasi-monocrystalline volume region (8) by directionally solidifying the molten starting material proceeding from a plurality of monocrystalline seed plates arranged in the region of a base of the container, and producing the substrate by processing the material body to form an optical surface (12). An associated reflective optical element (11), in particular for reflecting EUV radiation (14) includes: a substrate having an optical surface on which a reflective coating (13) is applied. The substrate is typically produced in accordance with the associated method and has a quasi-monocrystalline volume region (8).

A method for producing a substrate (10) for an optical element (11) includes: introducing a starting material, preferably a metal or a semimetal, into a container and melting the starting material, producing a material body having a quasi-monocrystalline volume region (8) by directionally solidifying the molten starting material proceeding from a plurality of monocrystalline seed plates arranged in the region of a base of the container, and producing the substrate by processing the material body to form an optical surface (12). An associated reflective optical element (11), in particular for reflecting EUV radiation (14) includes: a substrate having an optical surface on which a reflective coating (13) is applied. The substrate is typically produced in accordance with the associated method and has a quasi-monocrystalline volume region (8).

Disclosed is a method for preparing polycrystalline silicon ingot. The preparation method comprises: coating inner wall of the crucible with a layer of silicon nitride, followed by laying a layer of crushed silicon and feeding silicon in the crucible; the crushed silicon is laid in random order, and the layer of crushed silicon forms a supporting structure having numerous holes; melting the silicon to form molten silicon by heating, when solid-liquid interface reach the surface of the layer of crushed silicon or when the layer of crushed silicon melt partially, regulating thermal field to achieve supercooled state to grow crystals;after the crystallization of molten silicon is completely finished, performing annealing and cooling to obtain polycrystalline silicon ingot. By adopting the preparation method, a desirable initial nucleus can be obtained for a polycrystalline silicon ingot, so as to reduce dislocation multiplication during the growth of the polycrystalline silicon ingot.

A method of growing a zirconia single crystal includes preparing a mixture of ZrO.sub.2 and Y.sub.2O.sub.3 for growing the zirconia single crystal, charging the raw material and a melting seed in a skull crucible for growing the zirconia single crystal using a high-frequency induction heating device, supplying power to the high-frequency induction heating device to melt the raw material, maintaining an output power of the high-frequency induction heating device to soak the melted raw material, first-elevating an induction coil of the high-frequency induction heating device to produce a seed, second-elevating the induction coil of the high-frequency induction heating device to grow a single crystal, cutting off power to the high-frequency induction heating device when completing growth of the zirconia single crystal, and cooling the zirconia single crystal. The method has excellent physical properties free from low-temperature degradation and thus enables precise machining.

A method of growing a zirconia single crystal includes preparing a mixture of ZrO.sub.2 and Y.sub.2O.sub.3 for growing the zirconia single crystal, charging the raw material and a melting seed in a skull crucible for growing the zirconia single crystal using a high-frequency induction heating device, supplying power to the high-frequency induction heating device to melt the raw material, maintaining an output power of the high-frequency induction heating device to soak the melted raw material, first-elevating an induction coil of the high-frequency induction heating device to produce a seed, second-elevating the induction coil of the high-frequency induction heating device to grow a single crystal, cutting off power to the high-frequency induction heating device when completing growth of the zirconia single crystal, and cooling the zirconia single crystal. The method has excellent physical properties free from low-temperature degradation and thus enables precise machining.

A single-crystalline metal is created on a substrate by liquefying a metal material contained within a crucible while in contact with a surface of the substrate, cooling the metal material by causing a temperature gradient effected in the substrate in a direction that is neutral along the surface of the substrate and, therein, growing the single-crystalline metal in the crucible.

A non-polar blue light LED epitaxial wafer based on an LAO substrate comprises the LAO substrate, and a buffer layer, a first non-doped layer, a first doped layer, a quantum well layer, an electron barrier layer and a second doped layer that are sequentially arranged on the LAO substrate. A preparation method of the non-polar blue light LED epitaxial wafer includes: a) adopting the LAO substrate, selecting a crystal orientation, and cleaning a surface of the LAO substrate; b) annealing the LAO substrate, and forming an AlN seed crystal layer on the surface of the LAO substrate; and c) sequentially forming a non-polar m face GaN buffer layer, a non-polar non-doped u-GaN layer, a non-polar n-type doped GaN film, a non-polar InGaN/GaN quantum well, a non-polar m face AlGaN electron barrier layer and a non-polar p-type doped GaN film on the LAO substrate by adopting metal organic chemical vapor deposition.

Disclosed is a method for preparing polycrystalline silicon ingot. The preparation method comprises: randomly laying seed crystals with unlimited crystal orientation at the bottom of crucible to form a layer of seed crystals and obtaining disordered crystalline orientations; providing molten silicon above the layer of seed crystals, controlling the temperature at the bottom of the crucible, making the layer of seed crystals not completely melted; controlling the temperature inside the crucible, making the molten silicon growing above the seed crystals, the molten silicon inheriting the structure of the seed crystals, then obtaining polycrystalline silicon ingot. By adopting the preparation method, a desirable initial nucleus can be obtained for a polycrystalline silicon ingot, so as to reduce dislocation multiplication during the growth of the polycrystalline silicon ingot.

An apparatus for processing a melt may include a crucible configured to contain the melt, where the melt has an exposed surface that is separated from a floor of the crucible by a first distance. The apparatus may further include a submerged heater comprising a heating element and a shell disposed between the heating element and the melt, wherein the heating element does not contact the melt. The heating element may be disposed at a second distance with respect to the exposed surface of the melt that is less than the first distance.