| 摘要 |
PURPOSE:To suppress generation of haze by adding the specified amount of nonionic surface-active agent having HLB value within the particular range to alkali colloidal silica having a mean grain size within the particular range. CONSTITUTION:The alkali colloidal silica used has the mean grain size of 7 to 100mmu measured, for example, by the nitrogen absorption method (BET method). The nonionic active-surface agent is required to have the HLB value in the range from 13.0 under 20. The amount of nonion surface-active agent to be added is 1ppm to 1.0wt.% for the solidified silica included in the colloidal silica in terms of the effective total amount under the independent use or mixed use thereof. Thereby, haze-free silicon wafer surface can be obtained. |
