Henssge Antje, Acker Jörg, Müller Constanze
Leibniz-Institute for Solid State and Materials Research Dresden (IFW Dresden), Dresden, Germany.
Talanta. 2006 Jan 15;68(3):581-5. doi: 10.1016/j.talanta.2005.04.049. Epub 2005 May 31.
The wet chemical etching of silicon by concentrated HF-HNO(3) mixtures in solar and semiconductor wafer fabrication requires the strict control of the etching conditions. Surface morphology and etch rates are mainly affected by the amount of dissolved silicon, that is continuously enriched in the etching solution with each etching run. A fast and robust method for the titrimetric determination of the total dissolved silicon content out of the concentrated etching solution is presented. This method is based on the difference between the two equivalence points of the total amount of acid and the hydrolysis of the hexafluorosilicic anion. This approach allows a silicon determination directly from the etching process in spite of the presence of dissolved nitric oxides in the etching solution. The influences of different acid mixing ratios and of the etching solution density depending on the silicon content is considered and discussed in detail.
在太阳能和半导体晶圆制造中，使用浓氢氟酸 - 硝酸混合物对硅进行湿化学蚀刻需要严格控制蚀刻条件。表面形态和蚀刻速率主要受溶解硅量的影响，每次蚀刻过程中，蚀刻溶液中的溶解硅量都会不断增加。本文提出了一种快速且可靠的方法，用于滴定测定浓蚀刻溶液中的总溶解硅含量。该方法基于酸总量的两个滴定终点与六氟硅酸根阴离子水解之间的差异。尽管蚀刻溶液中存在溶解的氮氧化物，但这种方法仍能直接根据蚀刻过程测定硅含量。详细考虑并讨论了不同酸混合比例以及蚀刻溶液密度对硅含量的影响。
