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

Claim 0:
1. A method for manufacturing a solar cell composed of a single crystal silicon, comprising:
producing a silicon single crystal ingot doped with gallium that contains oxygen atoms of at least 12 ppm;
slicing a silicon substrate from the silicon single crystal ingot; and
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,
wherein the silicon substrate is subjected to high temperature thermal treatment at a temperature of more than 1200° C. for 5 minutes or more and 30 minutes or less and oxide precipitate nuclei are dissolved and a solid solution of oxide precipitate nuclei is formed in the whole of the substrate and spiral oxygen-caused defects are eliminated such that a spiral defect pattern is not observed in an electroluminescence image in the fabricated solar cell,
the high temperature thermal treatment is performed in an atmosphere consisting of either phosphoryl chloride or nitrogen, and
after slicing the silicon substrate from the silicon single crystal ingot and either before or after the high temperature thermal treatment, the silicon substrate is subjected to texture etching.