Ion transport anisotropy in low pressure, high density plasmas
Ion transport anisotropy in low pressure, high density plasmas
复制标题
低压、高密度等离子体中的离子传输各向异性
DOI：
10.1116/1.586516
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发表时间：
1993
影响因子：
1.4
通讯作者：
R. Gottscho
中科院分区：
文献类型：
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作者：
R. Gottscho
在超大规模集成电路的亚微米结构的等离子体蚀刻过程中，控制离子传输对于控制线条轮廓至关重要。幸运的是，最新一代的等离子体反应器在足够低的压力下运行，使得将等离子体与晶片分离的鞘层区域变得无碰撞。在这些情况下，在晶片表面处的离子角分布函数可以从鞘层电压和鞘层边缘处的离子速度分布函数计算。在这项工作中，考虑了离子角分布函数的几种极限情况。一个很好的近似的角度分布在晶片表面的推导通过假设垂直的速度分布是高斯分布，与实验一致，而平行的速度分布是一个δ函数的大小的平行速度简单地给出的鞘层电压的大小。平行的速度分布与有限的宽度在SH…
Controlling ion transport is critical for controlling line profiles during the plasma etching of submicron structures for ultra‐large‐scale integrated circuits. Fortunately, the newest generation of plasma reactors are operated at low enough pressures that the sheath region separating the plasma from the wafer becomes collisionless. Under these circumstances, the ion angular distribution function at the wafer surface can be calculated from the sheath voltage and the ion velocity distribution function at the sheath edge. In this work, several limiting cases for the ion angular distribution function are considered. A good approximation for the angular distribution at the wafer surface is derived by assuming that the perpendicular velocity distribution is Gaussian, in agreement with experiment, while the parallel velocity distribution is a delta function with the magnitude of the parallel velocity simply given by the magnitude of the sheath voltage. Parallel velocity distributions with finite width at the sh...