Title:
SILICON WAFER FOR SOLAR CELLS AND METHOD FOR PRODUCING SAME
Document Type and Number:
WIPO Patent Application WO/2014/175072
Kind Code:
A1
Abstract:
Provided are: a silicon wafer for solar cells, which is obtained using a slice that is obtained by slicing a polycrystalline silicon ingot by bonded abrasive machining, and which has low reflectance and less gloss unevenness; and a method for producing the silicon wafer for solar cells. A method for producing a silicon wafer for solar cells, wherein a polycrystalline silicon slice, which has been sliced out with use of a fixed abrasive wire saw, is etched by means of an etching liquid that contains a mixed acid composed of hydrofluoric acid, nitric acid and sulfuric acid. The composition range of the mixed acid is within a region that is surrounded by four line segments connecting point A at which hydrofluoric acid is 2.82% by weight, nitric acid is 0.18% by weight and sulfuric acid is 97% by weight, point B at which hydrofluoric acid is 0.18% by weight, nitric acid is 2.82% by weight and sulfuric acid is 97% by weight, point C at which hydrofluoric acid is 8.47% by weight, nitric acid is 0.53% by weight and sulfuric acid is 91% by weight, and point D at which hydrofluoric acid is 0.53% by weight, nitric acid is 8.47% by weight and sulfuric acid is 91% by weight in this order in a ternary diagram that expresses the composition in terms of weight percentage. The density of water in the etching liquid is 0-10.5% by weight.
Inventors:
IKEUCHI MASAHIKO (JP)
TSUDA OSAMU (JP)
ENDO TADASHI (JP)
TSUDA OSAMU (JP)
ENDO TADASHI (JP)
Application Number:
PCT/JP2014/060349
Publication Date:
October 30, 2014
Filing Date:
April 09, 2014
Export Citation:
Assignee:
TKX CORP (JP)
International Classes:
H01L21/304; B24B27/06; H01L21/308
Domestic Patent References:
| WO2012102368A1 | 2012-08-02 |
Foreign References:
| JP2013505562A | 2013-02-14 | |||
| JP2012169420A | 2012-09-06 | |||
| JP2004193369A | 2004-07-08 | |||
| US20100151678A1 | 2010-06-17 |
Attorney, Agent or Firm:
KUSUMOTO, Takayoshi et al. (JP)
Takayoshi Kusumoto (JP)
Takayoshi Kusumoto (JP)
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