Abstract: The present invention provides a method for reusing a delaminated wafer, which is a method for applying reprocessing that is at least polishing to a delaminated wafer 17 byproduced when manufacturing an SOI wafer based on an ion implantation delamination method and thereby again reusing the delaminated wafer 17 as a bond wafer 21 in an SOI wafer manufacturing process, wherein, at least, a CZ wafer 11 used as the bond wafer is a low-defect wafer whose entire surface is formed of an N region, and an RTA treatment is carried out in the reprocessing with respect to the delaminated wafer 17 at a higher temperature than a temperature in formation of a thermal oxide film 12 performed with respect to the bond wafer in the SOI wafer manufacturing process.

Abstract: The present invention provides a method for producing a solar cell comprising forming the solar cell from a CZ silicon single crystal wafer, wherein a CZ silicon single crystal wafer having an initial interstitial oxygen concentration of 15 ppma or less is used as the CZ silicon single crystal wafer; a solar cell produced from a CZ silicon single crystal wafer, wherein the CZ silicon single crystal wafer has an interstitial oxygen concentration of 15 ppma or less; and a solar cell produced from a CZ silicon single crystal wafer, wherein the CZ silicon single crystal wafer has a BMD density of 5×108/cm3 or less. Thus, there can be obtained a solar cell showing little fluctuation of characteristics.

Abstract: The present invention provides a method for producing a solar cell comprising forming the solar cell from a CZ silicon single crystal wafer, wherein a CZ silicon single crystal wafer having an initial interstitial oxygen concentration of 15 ppma or less is used as the CZ silicon single crystal wafer; a solar cell produced from a CZ silicon single crystal wafer, wherein the CZ silicon single crystal wafer has an interstitial oxygen concentration of 15 ppma or less; and a solar cell produced from a CZ silicon single crystal wafer, wherein the CZ silicon single crystal wafer has a BMD density of 5×108/cm3 or less. Thus, there can be obtained a solar cell showing little fluctuation of characteristics.