Studies on rarefied gas flow of radicals and surface reactions in a high-density plasma reactor

我们描述了本研究的理论和实验结果理论结果(1)采用DSMC和PIC/MC方法分析了ICP反应器中的物理和化学现象。腐蚀速率随质量流量的增大而增大，腐蚀速率不均匀区域随质量流量的减小而变宽。线圈电流越小，由于库仑碰撞的影响，EEDF与麦克斯韦方程组的偏差越小。(2)采用DSMC和PIC/MC相结合的方法，研究了氯气在CCP反应器中蚀刻硅片的工艺。在大多数茶叶中，腐蚀速率是均匀的。在晶圆边缘附近有一个急剧的上升。射频氯放电等离子体余辉中的电子密度比负氯离子密度低两个量级。(3)提出了一种新的粒子模型来模拟ICP反应器。在这项工作中，使用该模型计算了等离子体和自由基的产生和输运。仿真结果与实验结果吻合较好实验结果(1)研究了ICP反应器中氩等离子体的特性。电子密度为1×10^<10> ~ 1×10^<11> cm^3，电子温度为4 ~ 6eV，等离子体电位为35 ~ 45V。(2)研究了连续放电和脉冲放电在氯等离子体中的硅刻蚀特性。结果表明：晶圆表面的蚀刻速率分布非常均匀。蚀刻深度与蚀刻时间呈线性关系。(3)脉冲放电的结果表明：腐蚀速率随占空比的减小而增大，但在占空比33%左右达到饱和。随着占空比的减小，腐蚀速率的分布变得更加不均匀。

We describe the theoretical and experimental results of this study.1 Theoretical results(1) The physical and chemical phenomena in an ICP reactor are analyzed using DSMC and PIC/MC methods.The etch rate increases with increasing mass flow rate and the region of nonuniform etch rate becomes wider as the flow rate decreases.The deviation of EEDF from the Maxwellian becomes small due to Coulomb collisions for smaller coil current.(2) Etching of silicon wafer by chlorine gas in a CCP reactor is studied by use of a combined analysis of the DSMC and PIC/MC methods.The etch rate is uniform in most of tea wafer. It shows a sharp rise near the wafer edge.The electron density is two-order lower than the negative chlorine radical ion density in the afterglow of RF chlorine discharge plasma.(3) We proposed a new useful particle modeling to simulate the ICP reactor. In this work, production and transport of plasma and radicals are calculated using this modeling. Our simulation and experiment show a good agreement with each other.2 Experimental results(1) We examined the argon plasma properties in an ICP reactor.The electron density is in the region of 1×10^<10>〜1×10^<11> cm^3, electron temperature 4〜6eV, and plasma potential 35〜45V.(2) We examined the silicon etching properties of cw discharge and pulsed discharge in the chlorine plasma. The results of the cw discharge are as follows :The distribution of the etch rate is very uniform over the wafer surface.The etch depth depends on the etching time linearly.(3) The results of the pulsed discharge are as follows :The etch rate increases with decreasing the duty ratio butit is saturated about 33% of duty ratio.As the duty ratio decreases, the distribution of the etch rate becomes more nonuniform.