| abstract |
(57) [Summary] [Problem] In addition to the absence of point defect aggregates, A wafer that sufficiently expresses oxygen precipitation nuclei and exerts an IG effect by heat treatment in a device manufacturing process is obtained. SOLUTION: The minimum interstitial lattice which belongs to a perfect region [P] adjacent to a region [I] in which interstitial silicon type point defects are predominantly present and in which no point defect aggregates are present, and which can form interstitial dislocations. A region having a concentration lower than the silicon concentration is referred to as [P I ]. When the area is [P V ], [P V ] And a mixed region of [P I ] and an oxygen concentration of 0.8 × 10 18 to 1.4 × 10 18 atoms / cm 3 (old AST M) in a nitrogen, argon, hydrogen, oxygen or mixed gas atmosphere thereof at 600 to 850 ° C. for 30 to 30 minutes. Hold for 90 minutes, or 120- Hold for 250 minutes. |