| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a high-quality solar-cell silicon substrate with suppressed etch pit density in relation with an Fe concentration. <P>SOLUTION: The solar cell silicon substrate is composed so that the Fe concentration (a) and etch pit density (b) of the substrate satisfy an expression of log(b)<0.5 log(a)-2.5. A dash liquid expressed by HF:HNO<SB>3</SB>:CH<SB>3</SB>COOH=1:3:15 is used as a selective etchant. The manufacturing method includes a process for forming the solar cell silicon substrate by cutting a silicon ingot formed by unidirectionally solidifying a silicon melt in a mold. A liquid-surface temperature of the silicon melt at the central part is different as≥20°C from that at the end in the unidirectional solidification process. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
