Si(100)在碱性氟化物溶液中的腐蚀行为

Si(100) Etching in Alkaline Fluoride Solution

本文用碱性氟化物溶液对单晶硅(100)表面进行了处理。结果发现其表面完全布满了类似金字塔的小凸起。在整个腐蚀过程中,小凸起随时间的延长变大,但数量却不断减少,这说明部分小凸起的成长是通过其周边小凸起的消亡实现的。在碱性氟化物溶液中,≡Si-H结构是稳定的,腐蚀主要发生在=SiH2或-SiH3的原子阶梯或缺陷存在的粗糙表面处。根据腐蚀速率和表面形貌的变化,我们对整个腐蚀过程作了进一步的阐释。

Si（100） surface was etched in alkaline fluoride solution. Pyramid-like hillocks are found distributing over the whole surface during the etching process. The average size of hillocks increases but the population decreases with the etch time. It suggests that the growth of a hillock is accompanied with the disappearance of its vicinal ones. In alkaline fluoride solution, monohydride （≡Si-H） is stable whereas the surface steps and defects where dihydride （= SiH2 ） and trihydride （-SiHa3） terminating are preferentially attacked. Further explanation for the whole etching process has been given in terms of etch rate variation and surface morphology changing.