Abstract: An epitaxial wafer and a high-temperature heat treatment wafer having an excellent gettering capability are obtained by performing epitaxial growth or a high-temperature heat treatment. A relational equation relating the density to the radius of an oxygen precipitate introduced in a silicon crystal doped with nitrogen at the time of crystal growth can be derived from the nitrogen concentration and the cooling rate around 1100° C. during crystal growth, and the oxygen precipitate density to be obtained after a heat treatment can be predicted from the derived relational equation relating the oxygen precipitate density to the radius, the oxygen concentration, and the wafer heat treatment process. Also, an epitaxially grown wafer and a high-temperature annealed wafer whose oxygen precipitate density has been controlled to an appropriate density are obtained, using conditions predicted by the method.

Abstract: A method is provided capable of universally controlling the proximity gettering structure, the need for which can vary from manufacturer to manufacturer, by arbitrarily controlling an M-shaped distribution in a depth direction of a wafer BMD density after RTA in a nitrogen-containing atmosphere. The heat-treatment method is provided for forming a desired internal defect density distribution by controlling a nitrogen concentration distribution in a depth direction of the silicon wafer for heat-treatment, the method including heat-treating a predetermined silicon wafer used for manufacturing a silicon wafer having a denuded zone in the vicinity of the surface thereof.

Abstract: A method is provided capable of universally controlling the proximity gettering structure, the need for which can vary from manufacturer to manufacturer, by arbitrarily controlling an M-shaped distribution in a depth direction of a wafer BMD density after RTA in a nitrogen-containing atmosphere. The heat-treatment method is provided for forming a desired internal defect density distribution by controlling a nitrogen concentration distribution in a depth direction of the silicon wafer for heat-treatment, the method including heat-treating a predetermined silicon wafer used for manufacturing a silicon wafer having a denuded zone in the vicinity of the surface thereof.

Abstract: An epitaxial wafer and a high-temperature heat treatment wafer having an excellent gettering capability are obtained by performing epitaxial growth or a high-temperature heat treatment. A relational equation relating the density to the radius of an oxygen precipitate introduced in a silicon crystal doped with nitrogen at the time of crystal growth can be derived from the nitrogen concentration and the cooling rate around 1100° C. during crystal growth, and the oxygen precipitate density to be obtained after a heat treatment can be predicted from the derived relational equation relating the oxygen precipitate density to the radius, the oxygen concentration, and the wafer heat treatment process. Also, an epitaxially grown wafer and a high-temperature annealed wafer whose oxygen precipitate density has been controlled to an appropriate density are obtained, using conditions predicted by the method.

Abstract: A container closure includes a plastic shell, and a liner molded by fluidizing a plastic material within the shell. Depressions are formed at circumferentially spaced positions at an upper end portion of the inner peripheral surface of the skirt wall. The depressions each have a circumferential length increased radially outwardly at least in part thereof. A plurality of projections are formed on the outer peripheral surface of the liner in correspondence with the depressions.