| 摘要 |
<p>Polycrystalline silicon has polycrystalline silicon fragments, where at least 90% of the fragments have a size of 10-40 mm, 20-60 mm, greater than 45 mm, 3-15 mm or 0.5-5 mm, where the proportions of silicon dust particles is: less than 15 ppmw, 45 ppmw or 70 ppmw for particle sizes of less than 400 mu m; less than 14 ppmw,30 ppmw or 62 ppmw for particle sizes of less than 50 mu m; less than 10 ppmw, 20 ppmw or 60 ppmw for particle sizes of less than 10 mu m; and less than 3 ppmw, 10 ppmw or 40 ppmw for particle sizes of less than 1 mu m. Polycrystalline silicon comprises polycrystalline silicon fragments, where at least 90% of the fragments have a size of 10-40 mm, 20-60 mm, greater than 45 mm, 3-15 mm or 0.5-5 mm, where the proportion of silicon dust particles is: less than 15 ppmw, 45 ppmw or 70 ppmw for particle sizes of less than 400 mu m; less than 14 ppmw,30 ppmw or 62 ppmw for particle sizes of less than 50 mu m; less than 10 ppmw, 20 ppmw or 60 ppmw for particle sizes of less than 10 mu m; and less than 3 ppmw, 10 ppmw or 40 ppmw for particle sizes of less than 1 mu m. The polycrystalline silicon has surface contamination with metals of >= 0.1-= 100 ppbw. An independent claim is also included for producing polycrystalline silicon comprising breaking of thin rods of deposited polycrystalline silicon into fragments in a Siemens reactor, classifying the fragments into size classes of 0.5 mm to greater than 45 mm and treating the fragments by means of compressed air or dry ice to remove silicon dust from the fragments, where no chemical wet cleaning is carried out.</p> |
