MECHANISTIC STUDIES OF THE INITIAL-STAGES OF ETCHING OF SI AND SIO2 IN A CHF3 PLASMA
MECHANISTIC STUDIES OF THE INITIAL-STAGES OF ETCHING OF SI AND SIO2 IN A CHF3 PLASMA
复制标题
DOI：
10.1016/0169-4332(90)90061-4
复制
发表时间：
1990-09-01
影响因子：
6.7
通讯作者：
TURBAN, G
中科院分区：
文献类型：
--
作者：
CARDINAUD, C;TURBAN, G
本文的目的是比较研究CHF_3对Si和SiO_2衬底的反应离子刻蚀机理。利用可见光中的XPS和椭偏仪跟踪表面修饰与等离子体曝光时间的关系。对于硅，在达到稳态刻蚀区域之前观察到了一个瞬变阶段。该过渡阶段分为两个不同的阶段，分别对应于氟碳覆盖层的生长和硅刻蚀的开始。对于二氧化硅，没有观察到瞬变阶段，因此一旦产生等离子体，就会得到稳定的刻蚀状态。这些结果表明，氟碳覆盖层不是简单的阻挡覆盖层，而是硅刻蚀机制的一部分：该覆盖层提供了刻蚀所需的氟原子。相反，等离子体物种直接与二氧化硅表面反应，形成腐蚀产物的前体。因此，在二氧化硅刻蚀机制中不需要氟碳覆盖层。
The objective of this paper is do to a comparative study of the mechanism of reactive ion etching of both Si and SiO2substrates using CHF3. XPS and ellipsometry in the visible are used to follow the surface modifications in relation to the plasma exposure time. For Si, a transient stage is observed before a steady-state etching regime is attained. This transient stage is separated into two distinct phases corresponding to the growth of a fluorocarbon overlayer and to the initiation of the Si etching, respectively. For SiO2no transient stage is noted so a stationary etching situation is obtained as soon as the plasma is created.These results suggest that the fluorocarbon overlayer is not a simple blocking overlayer, but is part and parcel of the Si etching mechanism: this overlayer provides fluorine atoms necessary for the etching. On the contrary, the plasma species react directly with an SiO2surface to form precursors of etch products. Consequently, no fluorocarbon overlayer is needed in the SiO2etching mechanism.