Abstract: A small amount of oxygen is ion-implanted in a wafer surface layer, and then heat treatment is performed so as to form an incomplete implanted oxide film in the surface layer. Thereby, wafer cost is reduced; a pit is prevented from forming in a surface of an epitaxial film; and a slip is prevented from forming in an external peripheral portion of a wafer.

Abstract: A bonded wafer is produced by comprising a step of implanting oxygen ions from a surface of a wafer for active layer to form an oxygen ion implanted layer at a given position inside the wafer for active layer; a step of bonding the wafer of active layer to a wafer for support substrate directly or through an insulating film; a step of subjecting the resulting bonded wafer to a heat treatment for increasing a bonding strength; a step of removing a portion of the wafer for active layer in the bonded wafer to a given position not exposing the oxygen ion implanted layer by a given method; a step of exposing the entire surface of the oxygen ion implanted layer; and a step of removing the exposed oxygen ion implanted layer to obtain an active layer of a given thickness, wherein the step of exposing the entire surface of the oxygen ion implanted layer is carried out by a dry etching under given conditions.

Abstract: A thickness of silicon oxide film of a wafer for active layer is controlled to be thinner than that of buried silicon oxide film. Consequently, uniformity in film thickness of the active layer of a bonded wafer is improved even if a variation in the in-plane thickness of the silicon oxide film is large at a time of ion implantation. Furthermore, since the silicon oxide film is rather thinner and thereby the ion implantation depth is relatively deeper, damages to the active layer and the buried silicon oxide film caused by the ion implantation can be reduced.

Abstract: In a method of producing a bonded wafer, a volume fraction of SiO2 particles dispersed into silicon in an oxygen ion implanted layer formed at a step of implanting oxygen ions into a wafer for active layer and a subsequent heat treatment step is set to not less than 30% but not more than 80%; and at a step of thinning a portion of the wafer for active layer, the oxygen ion implanted layer formed in the above step is used as a polishing stop layer to polish at least the portion of the wafer for active layer.

Abstract: Even if an oxygen ion implanted layer in a wafer for active layer is not a completely continuous SiO2 layer but a layer mixed partially with Si or SiOx, it is removed by here is provided a method for producing a bonded wafer in which it is possible to remove an oxygen ion implanted layer effectively as it is by repetitive treatment with an oxidizing solution and HF solution at a step of removing the oxygen ion implanted layer in a bonded wafer.

Abstract: In the method for producing a bonded wafer by bonding a wafer for active layer to a wafer for support layer and then thinning the wafer for active layer, when oxygen ions are implanted into the wafer for active layer, the implantation step is divided into two stages conducted under specified conditions.

Abstract: Since a supporting wafer contains nitrogen of 1×1014 atmos/cm3 and interstitial oxygen atom concentration, Oi, (old ASTM) of 13×1017 atoms/cm3, therefore a part of the metal impurities in an active layer wafer and the metal impurities in a bonded wafer can be captured by the BMD and the OSF in the wafer during the heat treatment after the bonding. Consequently, the contamination from the metal impurities in the active layer can be reduced.

Abstract: A method for manufacturing an SOI substrate includes steps of forming a first oxide film on a surface of a first silicon substrate; implanting hydrogen ions into the surface of the first silicon substrate on which the first oxide film is formed to form an ion implant region inside the first silicon substrate; removing the entire or the portion of first oxide film; forming a laminate by bonding the second silicon substrate to a hydrogen ion-implanted surface of the first silicon substrate with the first oxide film, or second oxide film formed on a surface of the second silicon substrate, or the first oxide film and second oxide film, interposed therebetween; and subjecting the laminate to a heat treatment at a predetermined temperature to separate the first silicon substrate along the ion implant region, thereby obtaining an SOI substrate including a thin SOI layer formed on the second silicon substrate with the oxide film interposed therebetween.

Abstract: In a method for producing a bonded wafer by bonding a wafer for active layer to wafer for support layer and then thinning the wafer for active layer, a terrace grinding for forming a terrace portion is carried out prior to a step of exposing the oxygen ion implanted layer to thereby leave an oxide film on a terrace portion of the wafer for support layer.

Abstract: There is provided a method for suppressing the occurrence of defects such as voids or blisters even in the laminated wafer having an oxide film of a thickness thinner than the conventional one, wherein hydrogen ions are implanted into a wafer for active layer having an oxide film of not more than 50 nm in thickness to form a hydrogen ion implanted layer, and ions other than hydrogen are implanted up to a position that a depth from the surface side the hydrogen ion implantation is shallower than the hydrogen ion implanted layer, and the wafer for active layer is laminated onto a wafer for support substrate through the oxide film, and then the wafer for active layer is exfoliated at the hydrogen ion implanted layer.

Abstract: This method for manufacturing a semiconductor substrate is characterized in that the method includes: a step of ion-implanting light element to a predetermined depth position in a single-crystal wafer of which a surface is a cleavage plane; and a step of heat-treating the single-crystal wafer so as to form light-element bubbles along a cleavage plane parallel to the surface of the single-crystal wafer within an ion-implanted region and thereby splitting off a portion of the single-crystal wafer on an ion-implanted side.

Abstract: There is provided a method of producing a bonded wafer by bonding two silicon wafers for active layer and support layer to each other and then thinning the wafer for active layer, in which nitrogen ions are implanted from the surface of the wafer for active layer to form a nitride layer in the interior of the wafer for active layer before the bonding.

Abstract: A bonded SOI substrate having an active layer which is free from crystal defects is obtained by adding more than 9×1018 atoms/cm3 of boron to a wafer for active layer (10). Since the boron concentration in the wafer for active layer is high, a silicon oxide film is formed at a high rate. Consequently, there can be obtained a Smart-Cut wafer with high throughput. Furthermore, damages to the active layer due to the ion implantation can be reduced, thereby improving the quality of the active layer.

Abstract: A high quality bonded substrate is obtained in which generation of microprotrusions and cracked particles are restricted on a surface of an active layer of the bonded substrate and the surface of the active layer is flattened. A laminated body is formed by overlapping a first semiconductor substrate serving as an active layer onto a second semiconductor substrate serving as a support substrate via an oxide film or without an oxide film; the active layer is formed by forming a thin film from the first semiconductor substrate; and the surface of the active layer is flattened by vapor-phase etching. After forming a thin film from the first semiconductor substrate and before flattening the surface of the active layer by the vapor-phase etching, an organic substance adhering to the surface of the active layer is removed and a native oxide film generated on the surface of the active layer is removed after removing the organic substance.

Abstract: The present invention provides a method of manufacturing a bonded wafer. The method includes forming an oxygen ion implantation layer in an active layer wafer having a substrate resistivity of 1 to 100 m?cm by implanting oxygen ions in the active layer wafer, bonding a base wafer and the active layer wafer directly or through an insulating layer to form a bonded wafer, heat treating the bonded wafer to strengthen the bond and convert the oxygen ion implantation layer into a stop layer, grinding, polishing, and/or etching, from the active layer wafer surface side, the bonded wafer in which the bond has been strengthened to expose the stop layer on a surface of the bonded wafer, removing the stop layer, and subjecting the bonded wafer from which the stop layer has been removed to a heat treatment under a reducing atmosphere to diffuse an electrically conductive component comprised in the active layer wafer.

Abstract: The present invention provides a method of manufacturing a bonded wafer. The method includes ozone washing two silicon wafers to form an oxide film equal to or less than 2.2 nm in thickness on each surface of the two silicon wafers, and bonding the two silicon wafers through the oxide films formed to obtain a bonded wafer.

Abstract: The present invention provides a method of manufacturing a bonded wafer. The method comprises an oxidation step in which an oxide film is formed on at least one surface of a base wafer, a bonding step in which the base wafer on which the oxide film has been formed is bonded to a top wafer to form a bonded wafer, and a thinning step in which the top wafer included in the bonded wafer is thinned. The oxidation step comprises heating the base wafer to a heating temperature ranging from 800 to 1300° C. at a rate of temperature increase ranging from 1 to 300° C./second in an oxidizing atmosphere, and the bonding step is carried out so as to position the oxide film formed in the oxidation step at an interface of the top wafer and the base wafer.

Abstract: The object of the invention is to provide a method for manufacturing an SOI layer which is devoid of damages, has a reduced variation in thickness, and is uniform in thickness.

Abstract: A thickness of silicon oxide film of a wafer for active layer is controlled to be thinner than that of buried silicon oxide film. Consequently, uniformity in film thickness of the active layer of a bonded wafer is improved even if a variation in the in-plane thickness of the silicon oxide film is large at a time of ion implantation. Furthermore, since the silicon oxide film is rather thinner and thereby the ion implantation depth is relatively deeper, damages to the active layer and the buried silicon oxide film caused by the ion implantation can be reduced.

Abstract: There is provided a layer transferred wafer subjected to a process for regenerating to be reused many times for an SOI layer wafer which is used to manufacture an SOI wafer with an excellent process yield in which oxygen precipitate nuclei or oxygen precipitates are eliminated and generation of HF defects are inhibited by performing the process for regenerating the layer transferred wafer generated as a by-product by an ion implantation separation method. The process for regenerating a layer transferred wafer in which the layer transferred wafer 11b obtained as a by-product in manufacturing a bonded SOI wafer 10 by an ion implantation separation method so as to be reused for an SOI layer wafer 11 of the bonded SOI wafer 10, comprises: rapidly heating the layer transferred wafer 11b in an oxidizing atmosphere, then holding it for a fixed time and subsequently rapidly cooling it; and mirror-polishing a surface of the layer transferred wafer 11b.