SF_6/O_2气氛下Al对反应离子刻蚀Si的增强作用机理研究

Study on Mechanism of Al-enhanced Etching of Silicon by Reactive Ions in SF_6/O_2 Environment

通过实验和统计分析方法研究了Al在SF6/O2气体干法刻蚀Si中的增强作用机理。研究表明,Al在SF6/O2刻蚀Si中具有增强作用,而且Al的增强作用基本独立,受其它刻蚀条件的影响较小。Al对Si刻蚀速率的增强作用并非都是由于衬底温度升高所致,而是Al表面形成的AlF单原子层起到了催化作用,使SF6分解出更多的F自由基,从而提高了Si的刻蚀速率。

The mechanism of Al-enhanced etching of silicon by reactive ions in SF6/O2 environment was studied by experiment and statistical analysis. The results indicate that the Al-enhanced etching of silicon in SF6/O2 environment is little affected by other etching conditions. Simultaneously, the results also indicate that the enhancement effect of Al on etching rate of silicon does not result from the rise of the substrate temperature, but it mainly results from catalytic action of an AlF monolayer formed by Al, which A1F promotes decomposition of SF6 to produce more F radicals.