单晶硅表面微结构调节技术的改进

Improvement of Adjustment Technique on Surface Microstructure of Monocrystalline Silicon

提出改变碱液腐蚀单晶硅表面特性的一个简单方法,即在碱液中加入活性剂改变碱液在硅表面的润湿性能从而改变其腐蚀特性。分别采用普通碱液、四甲基氢氧化铵(tetramethylammonium hydroxide,TMAH)溶液和加入阴离子有机氟表面活性剂的普通碱液腐蚀硅表面。结果发现:普通碱液和TMAH腐蚀液腐蚀的硅表面的金字塔大小差异大、有许多蜂窝状的小金字塔,反射率较高;用加入阴离子有机氟表面活性剂的普通碱液腐蚀的单晶硅表面,能形成比较规则的金字塔,金字塔尺寸为4～6μm、均匀性好、覆盖率高、表面反射率下降到12.65%。有机氟表面活性剂能提高硅在碱中腐蚀速率,有效调控单晶硅金字塔形貌、大小与分布,为精确调控单晶硅表面微结构提供了可能。

This paper presents a method to change an alkaline solution etching Si surface characteristics, namely, an anionic organic fluorine surfactant was added in the alkaline solution to change the wettability of etching solution on silicon surface and furthermore change the texture characteristics. The Si surface was etched by the alkaline solution, tetramethylammonium hydroxide （TMAH） solution and the alkaline solution added with an anionic organic fluorine surfactant, respectively. The results showed that the pyramids size on the Si surface etched in the alkaline solution and TMAH solution were different, and the both existed numerous small honeycomb pyramids and had higher reflectance. The Si surface etched in the alkaline solution added with the anionic organic fluorine surfactant appeared uniformity distributed pyramids with the sizes of 4-45μm, resulting in that the reflectance reduced to 12.65%. It is also indicated that the anionic organic fluorine surfactant added to the alkaline solution can effectively modify the topology, size and distribution of pyramids on the monocrystalline silicon surface. This provides a possible approach to precisely control the microstructure topology.