Abstract: A method for polishing a germanium wafer having a surface composed of germanium, including: adding aqueous hydrogen peroxide to a first polishing slurry of an aqueous alkaline solution containing colloidal silica to make a second polishing slurry, and polishing the surface of the germanium wafer by using the second polishing slurry; wherein the aqueous hydrogen peroxide is added to the first polishing slurry in a concentration such that 30 wt % aqueous hydrogen peroxide is added in a volume of more than 0 vol % and 0.1 vol % or less based on the volume of the first polishing slurry, and the polishing is performed by using the second polishing slurry. A method for polishing a germanium wafer that can make the surface roughness of a polished Ge surface be sufficiently small, and can sufficiently suppress generation of interface defects such as voids and blisters when used for a wafer to be bonded.

Abstract: The present invention is a semi conductor-wafer cleaning tank in which semiconductor wafers are immersed in a cleaning solution and cleaned, including a tank body, composed of quartz, for storing the cleaning solution to immerse the semiconductor wafers in the cleaning solution, an overflow-receiving part, composed of quarts and provided around an opening of the tank body, for receiving the cleaning solution overflowing from an upper end of the opening of the tank body, and a heat-insulating wall-provided around the tank body, in which the heat-insulating wall forms an unbroken enclosure around the tank body with a hollow layer formed between the heat-insulating wall and a side wall of the tank body. As a result, there is provided a cleaning tank for use in an etching step that allows bonded wafers keeping film-thickness uniformity even after the etching step for adjusting the film thickness to be manufactured in high yield.

Abstract: The present invention is a method for manufacturing a bonded wafer by an ion implantation delamination method including at least the steps of, bonding a bond wafer having a micro bubble layer formed by gas ion implantation with a base wafer to be a supporting substrate, delaminating the bond wafer along the micro bubble layer as a boundary to form a thin film on the base wafer, the method comprising, cleaning the bonded wafer after delaminating the bond wafer using ozone water; performing rapid thermal anneal process under a hydrogen containing atmosphere; forming a thermal oxide film on a surface layer of the bonded wafer by subjecting to heat treatment under an oxidizing gas atmosphere and removing the thermal oxide film; subjecting to heat treatment under a non-oxidizing gas atmosphere.

Abstract: The present invention is a method for manufacturing a bonded wafer by an ion implantation delamination method including at least the steps of, bonding a bond wafer having a micro bubble layer formed by gas ion implantation with a base wafer to be a supporting substrate, delaminating the bond wafer along the micro bubble layer as a boundary to form a thin film on the base wafer, the method comprising, cleaning the bonded wafer after delaminating the bond wafer using ozone water; performing rapid thermal anneal process under a hydrogen containing atmosphere; forming a thermal oxide film on a surface layer of the bonded wafer by subjecting to heat treatment under an oxidizing gas atmosphere and removing the thermal oxide film; subjecting to heat treatment under a non-oxidizing gas atmosphere.

Abstract: There is provided a method of manufacturing an SOI wafer by an ion implantation delamination method, comprising at least: forming an oxide film on a surface of at least one of a base wafer and a bond wafer functioning as an SOI layer; implanting at least one of a hydrogen ion and a rare gas ion from a surface of the bond wafer to form an ion implanted layer; subsequently bringing the bond wafer into close contact with the base wafer via the oxide film; performing a heat treatment to cause delamination in the ion implanted layer so that the SOI layer is formed; then conducing a heat treatment in an oxidizing atmosphere to form an oxide film on the surface of the SOI layer; subsequently removing the oxide film by etching; then cleaning the surface of the SOI layer by using ozone water; and polishing the same.

Abstract: A method for producing a direct bonded wafer comprising: forming a thermal oxide film or a CVD oxide film on a surface of at least one of a bond wafer and a base wafer, and bonding the wafer to the other wafer via the oxide film; subsequently thinning the bond wafer to prepare a bonded wafer; and thereafter conducting a process of annealing the bonded wafer under an atmosphere including any one of an inert gas, hydrogen and a mixed gas of an inert gas and hydrogen so that the oxide film between the bond wafer and the base wafer is removed to bond the bond wafer directly to the base wafer. Thereby, there is provided a method for producing a direct bonded wafer in which generation of voids is reduced, and a direct bonded wafer with a low void count.

Abstract: A method for producing a direct bonded wafer comprising: forming a thermal oxide film or a CVD oxide film on a surface of at least one of a bond wafer and a base wafer, and bonding the wafer to the other wafer via the oxide film; subsequently thinning the bond wafer to prepare a bonded wafer; and thereafter conducting a process of annealing the bonded wafer under an atmosphere including any one of an inert gas, hydrogen and a mixed gas of an inert gas and hydrogen so that the oxide film between the bond wafer and the base wafer is removed to bond the bond wafer directly to the base wafer. Thereby, there is provided a method for producing a direct bonded wafer in which generation of voids is reduced, and a direct bonded wafer with a low void count.