Studies of Electron Behavior in Magnetic Neutral-Loop Discharge (NLD) Plasmas for Processing Applications

用于加工应用的磁中性环路放电 (NLD) 等离子体中电子行为的研究

基本信息

批准号：
08558045
负责人：
MURAOKA Katsunori
金额：
$ 8.51万
依托单位：
KYUSHU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1998
项目状态：
已结题

项目摘要

In this project, the formation mechanism of a magnetic neutral-loop discharge (NLD) plasma was studied theoretically and experimentally. Also, application possibilities of the NLD plasma were studied.Electron behavior in the NLD plasma was theoretically modeled using a two-dimensional electromagnetic field configuration. The model predicted that the electron motion around the neutral loop (NL) became chaotic, and electrons could be effectively heated by the rf electric field in the collisionless low pressure regime. Then, the electron behavior was examined experimentally. The experimental results showed that the energy deposition to electrons in the vicinity of the NL played an essential role in the formation of the NLD plasma. This result was consistent with the prediction of the two-dimensional model. However, the dependence of the plasma production efficiency on the gradient of the magnetic field strength showed disagreement between the experiment and the model. The model predicted … More that plasma production became more efficient for a smaller magnetic field gradient. On the other hand, the experimental results showed the existence of an optimum value of the magnetic field gradient. In order to improve the situation, a new model which included effects of the three-dimensional electromagnetic field configuration, a spatially varied rf electric field and electron collisions with neutral particles was proposed. The model gave optimum values of the magnetic field strength for given discharge conditions, and those predictions were found to be consistent with experimental results. In conclusion, the model gives a guideline for the design of NLD plasma devices.NLD plasmas were successfully applied to a high-rate etch process with satisfactory uniformity. In the application to the SiO_2 etch process, an etch rate of about 1 mum/min was obtained. When the hole pattern was etched, the etched profile was almost vertical. These results were found to be superior to the etching results using an inductively coupled plasma. In order to open sputtering applications, an NLD plasma based on capacitive coupling was proposed and a prototype device was designed. Less

在该项目中，从理论上和实验上研究了磁中性环路放电（NLD）等离子体的形成机制，并研究了NLD等离子体的应用可能性。使用二维电磁场对NLD等离子体中的电子行为进行了理论建模。该模型预测中性环（NL）周围的电子运动变得混沌，并且电子可以在无碰撞低压区域被射频电场有效加热，然后通过实验检验了电子行为。显示NL附近电子的能量沉积在NLD等离子体的形成中发挥了重要作用，该结果与二维模型的预测一致，但是等离子体产生效率对梯度的依赖性。磁场强度的变化表明实验与模型之间存在分歧，模型预测，磁场梯度越小，等离子体的产生就越有效。另一方面，实验结果表明存在最佳的磁场值。为了改善这种情况，提出了一种新的模型。提出了包括三维电磁场配置、空间变化的射频电场以及电子与中性粒子碰撞的影响的模型，给出了给定放电条件下的磁场强度的最佳值，并且发现这些预测是正确的。与实验结果一致，该模型为NLD等离子体器件的设计提供了指导。NLD等离子体成功应用于SiO_2刻蚀工艺中，刻蚀速率令人满意。关于当蚀刻孔图案时，蚀刻轮廓几乎是垂直的，这些结果优于使用感应耦合等离子体的蚀刻结果，基于 NLD 等离子体。提出了电容耦合并设计了原型装置。