Method of evaluating silicon single-crystal ingot, method of evaluating silicon epitaxial wafer, method of manufacturing silicon epitaxial wafer, and method of evaluating silicon mirror polished wafer

A method of evaluating a silicon epitaxial wafer,

• wherein silicon epitaxial wafers to be evaluated are three or more silicon epitaxial wafers resulting from formation of an epitaxial layer on mirror polished surfaces of silicon mirror polished wafers having been cut out from a same silicon single-crystal ingot and having been processed to a mirror finish,
• the method comprises:
• acquiring light point defect maps of epitaxial layer surfaces of the plural silicon epitaxial wafers with a laser surface inspection device;
• and
• creating an overlay map resulting from overlaying of the light point defect maps acquired for the epitaxial layer surfaces of the plural silicon epitaxial wafers,
• in a case where a light point defect group in which three or more light point defects are linearly distributed is not confirmed in the overlay map, estimation is made that no twin-induced defect is present in the silicon epitaxial wafers to be evaluated, and
• in a case where the linearly-distributed light point defect group is confirmed, estimation is made that a twin-induced defect is present in the plural silicon epitaxial wafers for which light point defects included in the light point defect group have been confirmed.

A method of evaluating a silicon mirror polished wafer,

• wherein silicon mirror polished wafers to be evaluated are silicon mirror polished wafers cut out from a same silicon single-crystal ingot and having been processed to a mirror finish,
• the method comprises:
• processing the plural silicon mirror-surface wafers into silicon epitaxial wafers through formation of an epitaxial layer on the mirror polished surfaces;
• acquiring light point defect maps of epitaxial layer surfaces of the plural silicon epitaxial wafers with a laser surface inspection device;
• and
• creating an overlay map resulting from overlaying of the light point defect maps acquired for the epitaxial layer surfaces of the plural silicon epitaxial wafers,
• in a case where a light point defect group in which three or more light point defects are linearly distributed is not confirmed in the overlay map, estimation is made that no twin is present in the silicon mirror polished wafers to be evaluated, and
• in a case where the linearly-distributed light point defect group is confirmed, estimation is made that a twin is present in a silicon mirror polished wafer included in the plural silicon epitaxial wafers for which light point defects included in the light point defect group have been confirmed.