Study of the Characteristics of Inductively-Coupled Fluorocarbon Plasmas

首先，用粒子模拟方法研究了顶面装有单圈天线的等离子体反应器中CF_4的等离子体结构。等离子体电流的表达式采用冷等离子体近似。等离子体特性为：（1）大功率沉积的区域仅限于天线附近区域，（2）总功率沉积与天线内电流幅值成正比，（3）正离子的产生速率比负离子大一个数量级，（4）CF_4^+的产生速率最大，在一定阶段停止CF_4等离子体的研究后，由于Cl_2等离子体中的物种数远小于CF_4等离子体中的物种数，因此计算量不太大，因此我们对Cl_2等离子体的电感耦合等离子体进行了全面的研究。特别是发展了自洽地考虑等离子体与气流耦合的方法，对CF_4等离子体也进行了实验研究。系统地研究了硅片偏压对SiO_2薄膜刻蚀速率的影响。

First the plasma structure of fluorocarbon CF_4 in a plasma reactor having one-turn antenna on its ceiling is examined using the particle modeling. The cold plasma approximation is employed in the expression for plasma current. The plasma characteristics are : (1)The region of large power deposition is limited to the region near the antenna, (2)the total power deposition is proportional to the current amplitude in the antenna, (3)the production rate of positive ion is one order larger than that of negative ion, and (4)CF_4^+ has the largest production rate.After stopping the study of CF_4 plasma in a certain stage, we examined fully the inductively coupled plasma of Cl_2 since the number of species in plasma is much smaller than that of CF_4 plasma and hence the computation is not so intensive. In particular, the method to consider the coupling between plasma and gas flow self-consistently is newly developed.As for CF_4 plasma, we carried out also experimental research. The effect of wafer biasing on the etch rate of SiO_2 film is systematically examined.