EVALUATION METHOD OF SILICA GLASS CRUCIBLE, AND MANUFACTURING METHOD OF SILICON SINGLE CRYSTAL

摘要

PROBLEM TO BE SOLVED: To provide a method for evaluating a quality of a silica glass crucible by highly accurately determining a three-dimensional distribution of an infrared absorption spectrum thereof.SOLUTION: A method for evaluating a quality of a silica glass crucible 11 includes: contactlessly moving an inner distance measuring unit 17 along an inner surface of the silica glass crucible 11; obliquely irradiating the inner surface of the silica glass crucible 11 with a laser beam from the inner distance measuring unit 17 at plural measuring points on a moving route, measuring the reflected light by using a laser displacement gauge and changing a distance between the inner distance measuring unit 17 and the inner surface and an emitted direction of the laser beam so that two peaks are observed, and measuring an inner surface distance between the inner distance measuring unit 17 and the inner surface on the basis of a position of peak on the inner surface side among the two peaks; obtaining a three-dimensional shape of the inner surface of the silica glass crucible 11 by associating three-dimensional coordinates at each measuring point with the inner surface distance; determining a three-dimensional distribution of an infrared absorption spectrum; and determining whether the infrared absorption spectrum is located within a regulated region.SELECTED DRAWING: Figure 1