Patent ID: 7244306

Claim:
A method for measuring the point defect distribution of a silicon single crystal ingot, comprising (a1) a step of preparing a sample for measurement including regions [V], [Pv], [Pi] and [I] by cutting to an axial direction a silicon single crystal ingot which is pulled up by changing a pulling-up speed from silicon melt so as to include the central axis of the single crystal ingot, (b1) a step of preparing a first sample and a second sample by dividing the sample for measurement into two so as to be symmetrical against the central axis of the ingot, (c1) a step of coating a first transition metal solution dissolving a first transition metal at a concentration of 1 to 1000 ppm on the surface of the first sample to stain the sample with the metal, (d1) a step of coating a second transition metal solution dissolving a second transition metal different from the first transition metal at a concentration of 1 to 1000 ppm on the surface of the second sample to stain the sample with the metal, (e1) a diffusion thermal treatment step of thermally treating the first and second samples stained with the metals at 600° C. to 1150° C. for 0.5 hour to 30 hours under argon, nitrogen, oxygen, hydrogen or mixed gas atmosphere thereof and diffusing the first and second transition metals which are respectively coated on the surface of the first and second samples into the inside of the samples, (f1) a step of respectively measuring recombination lifetimes in the whole of the first and second samples which are thermally treated, (g1) a step of overlapping the vertical measurement of the first sample of the step (f1) on the vertical measurement of the second sample, and (h1) a step of respectively specifying the boundary between the regions [Pi] and [I] and the boundary between the regions [V] and [Pv] from the measurement result of the step (g1), Provided that the region [V] is a region having defects where the vacancy type point defect is dominant and excessive vacancies are agglomerated, the region [Pv] is a region having defects where the vacancy type point defect is dominant and vacancies are not agglomerated, the region [Pi] is a region having defects where the interstitial silicon type point defect is dominant and interstitial silicons are not agglomerated, and the region [I] is a region having defects where the interstitial silicon type point defect is dominant and interstitial silicons are agglomerated.