摘要:
Objects of the invention are to further enhance crystallinity and crystallinity uniformity of a semiconductor crystal produced through the flux method, and to effectively enhance the production yield of the semiconductor crystal. The c-axis of a seed crystal including a GaN single-crystal layer is aligned in a horizontal direction (y-axis direction), one a-axis of the seed crystal is aligned in the vertical direction, and one m-axis is aligned in the x-axis direction. Thus, three contact points at which a supporting tool contacts the seed crystal are present on m-plane. The supporting tool has two supporting members, which extend in the vertical direction. One supporting member has an end part, which is inclined at 30° with respect to the horizontal plane α. The reasons for supporting a seed crystal at m-plane thereof are that m-plane exhibits a crystal growth rate, which is lower than that of a-plane, and that desired crystal growth on c-plane is not inhibited. Actually, a plurality of seed crystals and supporting tools are periodically placed along the y-axis direction.
摘要:
An object of the invention is to carry out the flux method with improved work efficiency while maintaining the purity of flux at high level and saving flux material cost. The sodium-purifying apparatus includes a sodium-holding-and-management apparatus for maintaining purified sodium (Na) in a liquid state. Liquid sodium is supplied into a sodium-holding-and-management apparatus through a liquid-sodium supply piping maintained at 100° C. to 200° C. The sodium-holding-and-management apparatus further has an argon-gas-purifying apparatus for controlling the condition of argon (Ar) gas that fills the internal space thereof. Thus, by opening and closing a faucet at desired timing, purified liquid sodium (Na) supplied from the sodium-purifying apparatus can be introduced into a crucible as appropriate via the liquid-sodium supply piping, the sodium-holding-and-management apparatus, and the piping.
摘要:
When a substrate layer (desired semiconductor crystal) made of a group III nitride compound is grown on a base substrate comprising a lot of projection parts, a cavity in which a semiconductor crystal is not deposited may be formed between each projection part although it depends on conditions such as the size of each projection part, arranging interval between each projection part and crystal growth. So when the thickness of the substrate layer is sufficiently larger compared with the height of the projection part, inner stress or outer stress become easier to act intensively to the projection part. As a result, such stress especially functions as shearing stress toward the projection part. When the shearing stress becomes larger, the projection part is ruptured. So utilizing the shearing stress enables to separate the base substrate and the substrate layer easily. The larger the cavities are formed, the more stress tends to concentrate to the projection parts, to thereby enable to separate the base substrate and the substrate layer more securely.
摘要:
A reaction prevention layer is formed to prevent Si from reacting with a gallium nitride group semiconductor (semiconductor crystal A) which is deposited after the reaction prevention layer is formed. By forming a reaction prevention layer comprising a material whose melting point or thermal stability is higher than that of a gallium nitride group semiconductor, e.g., AlN, on a sacrifice layer, a reaction part is not formed in the semiconductor substrate deposited on the reaction prevention layer when the gallium nitride group semiconductor is grown by crystal growth for a long time. In short, owing to the effect that the reaction prevention layer prevents silicon (Si) from diffusing, the reaction part is generated only in the sacrifice layer and it is never formed at the upper portion of the reaction prevention layer even by growing the semiconductor crystal A at a high temperature for a long time.
摘要:
In a rotation transfer device, a paper feeding apparatus and an image forming apparatus, transfer projections are disposed on coupling members provided on the ends of a driving shaft and a driven shaft, so that the movement of one transfer projection in the peripheral direction can be constrained by the other transfer projection and a positioning member. Thus, rotation irregularity caused by reverse rotation torque applied by a function from the side of paper can be prevented.
摘要:
A plurality of electrostatic recording units are arranged in series along a path for moving a recording sheet of paper, and charged toner images having different colors are formed on the sheet of paper travelled through the path. A paper feeder unit is arranged beneath a paper introduction side of the paper moving path. The sheet of paper carrying the toner image formed thereon is ejected from a paper ejection side of the paper moving path, and is sent to a fixer in which the toner image is fixed on the sheet of paper. The sheet of paper carrying the toner image fixed thereon is sent to a paper receiver tray positioned above the fixer.
摘要:
An instruction fetch control method is generally arranged so as to have a plurality of instruction buffers, issue an instruction read request to a memory when a part of the instruction buffers becomes in an empty state and store a fetched instruction in the instruction buffer in an empty state. A flag is provided for specifying another instruction buffer which becomes in an empty state after the instruction stored in the instruction buffer is transmitted to a decoder. The quantity of instructions to be stored in the instruction buffer is made variable in accordance with output of the flag latch, and the fetched instruction is stored in the instruction buffer in an empty state. This arrangement enables a plurality of instructions fetched upon an instruction read request to be stored in the empty instruction buffers, thereby reducing the number of read requests issued.
摘要:
There is disclosed the distribution of an amorphous refractory in a case where a lining frame is positioned within a molten metal vessel preliminarily lined with a permanent lining refractory and the amorphous refractory is cast into the space between the permanent lining refractory and the lining frame thereby applying a lining to the inner surface of the vessel.A conical distributor is arranged above the lining frame and the amorphous refractory is continuously delivered from a rotary chute onto the distributor so as to describe a concentric path of moving falling points.