A deposition device for providing a thin film on a substrate. The device comprises a material source for providing at least one first metallic element which does not re-evaporate substantially from the substrate under particular growth conditions, at least one second metallic element or metal based molecule which does re-evaporate substantially from the substrate under the same growth conditions, and a component suitable for forming an at least one first compound with the at least one first metallic element and an at least one second compound with the at least one second metallic element or metal based molecule. The device comprises a controller configured to control the growth conditions, and the amounts of the at least one first metallic element, the at least one second metallic element or metal based molecule, and the component so as to obtain a substantially stoichiometric thin film.

A deposition device for providing a thin film on a substrate. The device comprises a material source for providing at least one first metallic element which does not re-evaporate substantially from the substrate under particular growth conditions, at least one second metallic element or metal based molecule which does re-evaporate substantially from the substrate under the same growth conditions, and a component suitable for forming an at least one first compound with the at least one first metallic element and an at least one second compound with the at least one second metallic element or metal based molecule. The device comprises a controller configured to control the growth conditions, and the amounts of the at least one first metallic element, the at least one second metallic element or metal based molecule, and the component so as to obtain a substantially stoichiometric thin film.

A TiAl intermetallic compound single crystal material and a preparation method therefor are disclosed. The alloy composition of the material comprises Ti.sub.aAl.sub.bNb.sub.c(C, Si).sub.d, wherein 43≦b≦49, 2≦c≦10, a+b+c=100, and 0≦d≦1 (at. %).

A TiAl intermetallic compound single crystal material and a preparation method therefor are disclosed. The alloy composition of the material comprises Ti.sub.aAl.sub.bNb.sub.c(C, Si).sub.d, wherein 43≦b≦49, 2≦c≦10, a+b+c=100, and 0≦d≦1 (at. %).

A composite substrate includes a sapphire substrate and a layer of a nitride of a group 13 element provided on the sapphire substrate. The layer of the nitride of the group 13 element is composed of gallium nitride, aluminum nitride or gallium aluminum nitride. The composite substrate satisfies the following formulas (1), (2) and (3). A laser light is irradiated to the composite substrate from the side of the sapphire substrate to decompose crystal lattice structure at an interface between the sapphire substrate and the layer of the nitride of the group 13 element. 5.0≦(an average thickness (μm) of the layer of the nitride of the group 13 element/a diameter (mm) of the sapphire substrate)≦10.0 . . . (1); 0.1≦ a warpage (mm) of said composite substrate×(50/a diameter (mm) of said composite substrate).sup.20.6 . . . (2); 1.10≦a maximum value (μm) of a thickness of said layer of said nitride of said group 13 element/a minimum value (μm) of said thickness of said layer of said nitride of said group 13 element . . . (3)

A composite substrate includes a sapphire substrate and a layer of a nitride of a group 13 element provided on the sapphire substrate. The layer of the nitride of the group 13 element is composed of gallium nitride, aluminum nitride or gallium aluminum nitride. The composite substrate satisfies the following formulas (1), (2) and (3). A laser light is irradiated to the composite substrate from the side of the sapphire substrate to decompose crystal lattice structure at an interface between the sapphire substrate and the layer of the nitride of the group 13 element. 5.0≦(an average thickness (μm) of the layer of the nitride of the group 13 element/a diameter (mm) of the sapphire substrate)≦10.0 . . . (1); 0.1≦ a warpage (mm) of said composite substrate×(50/a diameter (mm) of said composite substrate).sup.20.6 . . . (2); 1.10≦a maximum value (μm) of a thickness of said layer of said nitride of said group 13 element/a minimum value (μm) of said thickness of said layer of said nitride of said group 13 element . . . (3)

In order to address the high recycling cost, high complexity and other problems encountered by the prior art, the present invention proposes a method for recycling a sapphire substrate, which is applicable to both patterned and smooth sapphire substrates and involves only two steps: high-temperature baking and high-temperature rinsing in a concentrated acid. It entails a simple process which can be completed with high efficiency in a short period by easy operations at significantly reduced cost.

In order to address the high recycling cost, high complexity and other problems encountered by the prior art, the present invention proposes a method for recycling a sapphire substrate, which is applicable to both patterned and smooth sapphire substrates and involves only two steps: high-temperature baking and high-temperature rinsing in a concentrated acid. It entails a simple process which can be completed with high efficiency in a short period by easy operations at significantly reduced cost.

A bismuth and magnesium co-doped lithium niobate crystal includes Li.sub.2CO.sub.3, Nb.sub.2O.sub.5, Bi.sub.2O.sub.3 and MgO, wherein the molar ratio of [Li] and [Nb] is 0.90-1.00, the molar percentage of Bi.sub.2O.sub.3 in the mixture is 0.25-0.80%, and the molar percentage of MgO in the mixture is 3.0-7.0%. The bismuth and magnesium co-doped lithium niobate crystal has enhanced photorefraction, improved photorefractive sensitivity, shortened holographic grating saturation writing time, and the photorefractive diffraction efficiency can reach up to 17%. The response time is only 170 ms, when the holographic storage experiment is carried out using 488 nm continuous laser. Therefore, this crystal can be used in the field of holographic imaging.

A method for heat-treating a silicon single crystal wafer by an RTA treatment, including: putting a silicon single crystal wafer having an Nv region for the entire plane of the silicon single crystal wafer or an Nv region containing an OSF region for the silicon single crystal wafer entire plane into an RTA furnace, performing pre-heating at temperature lower than temperature at which silicon reacts with NH3 while supplying gas that contains NH3 into the RTA furnace, subsequently stopping the supply of the gas containing NH3 and starting supply of Ar gas to start an RTA treatment under Ar gas atmosphere in which the NH3 gas remains. This provide a method for heat-treating a silicon single crystal wafer that give gettering capability without degrading TDDB properties even to a silicon single crystal wafer in which the entire plane is an Nv region or an Nv region containing an OSF region.