Abstract: A method for processing a wafer includes subjecting the wafer to a reduction treatment with heat and a reducing agent that has a melting point of lower than 600° C. The wafer is made of a material selected from the group consisting of lithium tantalate, lithium niobate, and a combination thereof. The wafer and the reducing agent are spaced apart from each other so that the reducing agent indirectly interacts with the wafer during the reduction treatment. Also disclosed is a processed wafer obtained by the method.

Abstract: A substrate for epitaxial growth includes a central region that has a center of the substrate and that serves as a non-modified region, and a peripheral region that surrounds the central region in a manner to be spaced apart from the center of the substrate by a distance and that serves as a modified region having a plurality of modified points. A method for manufacturing a substrate for epitaxial growth includes providing a substrate and forming a plurality of modified points in an interior of the substrate in position corresponding to the modified region. A semiconductor device including the substrate and a method for manufacturing the semiconductor device are also disclosed.

Abstract: A method for making a composite substrate of a filter includes: processing a base substrate to form a centrally protruding structure having a height that decreases in a radially outward direction from a center of the base substrate to an outer periphery of the base substrate; connecting a first side of the base substrate having the centrally protruding structure to a piezoelectric layer so as to obtain a multilayer substrate; and thinning the piezoelectric layer of the multilayer substrate followed by polishing a surface of the piezoelectric layer.

Abstract: A method for blackening at least one wafer includes: (a) performing a reduction treatment on the at least one wafer; and (b) illuminating the at least one wafer with an ultraviolet light. The at least one wafer after the illumination of the UV light has a blackening uniformity value (DE value) smaller than 0.6, and a chromatic value (L value) smaller than 54. In addition, a blackened wafer made from the method is also provided.

Abstract: A method for growing a crystal boule includes the steps of: periodically pulling upwardly a seed crystal dipped into a melt in a crucible to grow a first neck of the crystal boule below the seed crystal; and continuously pulling upwardly the seed crystal and the first neck of the crystal boule to grow a second neck of the crystal boule below the first neck.

Abstract: A method for processing a lithium tantalate crystal substrate includes providing a lithium tantalate crystal substrate, roughening the lithium tantalate crystal substrate, providing a catalytic agent, bringing the lithium tantalate crystal substrate and the catalytic agent into contact with each other after the lithium tantalate crystal substrate is roughened, and subjecting the lithium tantalate crystal substrate to a reduction treatment. The reduction treatment is conducted at a temperature not higher than a Curie temperature of the lithium tantalate crystal substrate. The catalytic agent is selected from the group consisting of metal powder, metal gas, and metal carbonate powder.

Abstract: A processed wafer includes an outer surface, and a treated portion having a depth of 0 to 50 ?m measured from the outer surface. At least a part of the treated portion has an oxygen concentration of less than 13 wt %. A method for processing a wafer includes the steps of: applying a reducing medium on the wafer, the reducing medium is in powder form and including a reducing agent, and at least one of a catalyst and a releasing agent; subjecting the wafer to a reduction reaction at a temperature below Curie temperature of the and under a non-oxidizing atmosphere so as to obtain the aforesaid processed wafer.

Abstract: A method for processing a lithium tantalate crystal substrate includes providing a lithium tantalate crystal substrate, roughening the lithium tantalate crystal substrate, providing a catalytic agent, bringing the lithium tantalate crystal substrate and the catalytic agent into contact with each other after the lithium tantalate crystal substrate is roughened, and subjecting the lithium tantalate crystal substrate to a reduction treatment. The reduction treatment is conducted at a temperature not higher than a Curie temperature of the lithium tantalate crystal substrate. The catalytic agent is selected from the group consisting of metal powder, metal gas, and metal carbonate powder.

Abstract: A method for processing a lithium tantalate crystal substrate includes providing a lithium tantalate crystal substrate and a metallic sheet, roughening at least one of the lithium tantalate crystal substrate and the metallic sheet, bringing the lithium tantalate crystal substrate and the metallic sheet into contact with each other after the at least one thereof is roughened, and subjecting the lithium tantalate crystal substrate to a reduction treatment. The reduction treatment is conducted at a temperature not higher than a Curie temperature of the lithium tantalate crystal substrate.

Abstract: A method for growing a crystal boule includes the steps of: periodically pulling upwardly a seed crystal dipped into a melt in a crucible to grow a first neck of the crystal boule below the seed crystal; and continuously pulling upwardly the seed crystal and the first neck of the crystal boule to grow a second neck of the crystal boule below the first neck.

Abstract: A method for processing a lithium tantalate crystal substrate includes providing a lithium tantalate crystal substrate and a metallic sheet, roughening at least one of the lithium tantalate crystal substrate and the metallic sheet, bringing the lithium tantalate crystal substrate and the metallic sheet into contact with each other after the at least one thereof is roughened, and subjecting the lithium tantalate crystal substrate to a reduction treatment. The reduction treatment is conducted at a temperature not higher than a Curie temperature of the lithium tantalate crystal substrate.

Abstract: A method for manufacturing a crystal ingot includes the steps of forming a crystal boule, cutting the crystal boule so as to obtain a crystal ingot from the crystal boule, and subjecting the crystal ingot to an annealing treatment which includes a heating stage, a constant temperature stage and a cooling stage.