Patent ID: 11901475
Assignee: SHIN-ETSU CHEMICAL CO., LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H  C  Y | IPC C  H

Claim 9:
10. A method for manufacturing a solar cell, comprising:
producing a Czochralski silicon single crystal ingot doped with a p-type dopant or an n-type dopant and containing at least 12 ppm of oxygen atoms;
slicing a silicon substrate from the Czochralski silicon single crystal ingot;
subjecting the silicon substrate to high temperature thermal treatment at a temperature of more than 1200° C. for 5 minutes or more and 30 minutes or less in an atmosphere consisting of either phosphoryl chloride or nitrogen, so that oxide precipitate nuclei are dissolved and a homogenous solid solution of oxide precipitate nuclei is formed throughout the silicon substrate;
subjecting the silicon substrate to texture etching either before or after the high temperature thermal treatment;
subjecting the silicon substrate to low temperature thermal treatment at a temperature of 800° C. or more and less than 1200° C. so as to fabricate a solar cell; and
subjecting the fabricated solar cell to an electroluminescence image test that can observe spiral oxygen-induced defect patterns.