Abstract: A cutting method includes: forming a reformed region in a workpiece; and after forming the reformed region in the workpiece, cutting the workpiece along an intended cut line. In the cutting the workpiece, a dry etching process is performed from a front surface toward a rear surface of the workpiece while the workpiece is fixed on a support member at least under its own weight or by suction, to form a groove from the front surface to reach the rear surface of the workpiece.

Abstract: A cutting method includes: forming a reformed region in a workpiece; and after forming the reformed region in the workpiece, forming a groove in the workpiece along an intended cut line. In the forming a groove, a first dry etching process is performed from a front surface toward a rear surface of the workpiece. After the first dry etching process, a first pressure-reducing process is performed in which the workpiece is placed under an atmosphere of reduced pressure as compared to pressure during the first dry etching process. After the first pressure-reducing process, a second dry etching process is performed from the front surface toward the rear surface of the workpiece.

Abstract: A cutting method includes: forming a reformed region in a workpiece; and after forming the reformed region in the workpiece, cutting the workpiece along an intended cut line. In the cutting the workpiece, a dry etching process is performed from a front surface toward a rear surface of the workpiece while the workpiece is fixed on a support member at least under its own weight or by suction, to form a groove from the front surface to reach the rear surface of the workpiece.

Abstract: A cutting method includes: forming a reformed region in a workpiece; and after forming the reformed region in the workpiece, forming a groove in the workpiece along an intended cut line. In the forming a groove, a first dry etching process is performed from a front surface toward a rear surface of the workpiece. After the first dry etching process, a first pressure-reducing process is performed in which the workpiece is placed under an atmosphere of reduced pressure as compared to pressure during the first dry etching process. After the first pressure-reducing process, a second dry etching process is performed from the front surface toward the rear surface of the workpiece.

Abstract: Provided is a method for treating the inner surface of a chlorine trifluoride supply passage that enables reliable prevention of the reduction in the concentration of ClF3 in a reaction chamber during process operation. The method includes: integrally connecting a gas supply passage (2) and a gas discharge passage (3) to a processing chamber (1) of a processing apparatus in which chlorine trifluoride is used as an etching gas; and applying chlorine trifluoride gas having a concentration equal to or higher than the concentration of chlorine trifluoride gas supplied during etching process operation on inner surfaces of at least the processing chamber (1) and the gas supply passage (2) among the processing chamber (1), the gas supply passage (2), and the gas discharge passage (3), which are integrally formed, to coat the inner surfaces of at least the processing chamber (1) and the gas supply passage (2) with a fluoride film.

Abstract: Provided is a method for treating the inner surface of a chlorine trifluoride supply passage that enables reliable prevention of the reduction in the concentration of ClF3 in a reaction chamber during process operation. The method includes: integrally connecting a gas supply passage (2) and a gas discharge passage (3) to a processing chamber (1) of a processing apparatus in which chlorine trifluoride is used as an etching gas; and applying chlorine trifluoride gas having a concentration equal to or higher than the concentration of chlorine trifluoride gas supplied during etching process operation on inner surfaces of at least the processing chamber (1) and the gas supply passage (2) among the processing chamber (1), the gas supply passage (2), and the gas discharge passage (3), which are integrally formed, to coat the inner surfaces of at least the processing chamber (1) and the gas supply passage (2) with a fluoride film.

Abstract: A method for producing pure water is provided which reduces non-ionic silica in pure or ultrapure water. With the method, non-ionic silica which is contained in water is brought into contact with ozone having a concentration of at least 1 ppm for at least 20 minutes to react therewith and, simultaneously with or after this reaction process, irradiated with ultraviolet rays to undergo ionization and passed through an anion exchange column. The processed water passed through this ion exchange resin column contains practically no non-ionic silica.

Abstract: An apparatus for producing pure water is provided which includes means for ionizing non-ionic silica which is contained in water comprising a vessel for allowing the water to pass therethrough and stay therein for predetermined lengths of time; means for dissolving ozone in the water in this vessel; means for irradiating the water in which ozone has been dissolved with ultraviolet rays; means for separating gases from liquids located between the means for dissolving ozone and the means for irradiating water; and means for fixing ionized silica in the water to a solid electrolyte by ion exchange.

Abstract: In an aeration apparatus and method for producing ultrapure water, a device for vigorously mixing an aeration gas with untreated water is attached to a water pipe through which the water is fed to a reaction tank. The device vigorously mixes the aeration gas with the untreated water in the water pipe before the water reaches the reaction tank. The reaction tank can be smaller, an aeration system for producing ultrapure water can be simpler, and the efficiency of the aeration system can be improved.