Analyses of Reactive Plasma Dynamics by Particle Simulations

通过粒子模拟分析反应等离子体动力学

基本信息

批准号：
11680484
负责人：
HAMAGUCHI Satoshi
金额：
$ 2.56万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11680484/
关键词：
plasma processing PIC-MCC RF discharge particle simulation dual frequency discharge capacitively coupled discharge

项目摘要

Plasma processing, such as thin-film formation and surface modification technologies based on reactive plasmas, is one of the most important technologies for the advanced electronics, including semiconductor chips and liquid-crystal displays. In the present research, we have employed particle simulations based on the Particle-in-Cell (PIC) and Monte-Carlo Collision (MCC) methods to analyze plasma-processing tools used in semiconductor manufacturing. The PIC and MCC methods are ideal for reactive plasma simulations as the former can resolve electron velocity distribution functions and the latter can determine chemical reaction rates using fundamental physical data such as reaction collision cross sections. In 1999, we have developed a PIC/MCC code to simulate capacitively coupled parallel-plate Ar discharges in 2D cylindrical geometry. As to collisions, we have included ionization, excitation, and elastic collisions for electron-neutral collisions, and charge exchange and elastic collisions for ion-neutral collisions. Currently the neutral gas is assumed to be uniform with the room temperature. In 2000, we have extended the simulation code to handle dual-frequency capacitively coupled discharges and also introduced external electrical circuits for realistic plasma processing tools. Furthermore, we have employed an acceleration scheme for ion dynamics calculations to increase efficiency of the simulation code. In our simulations we have observed that, in both single- and dual-frequency capacitively coupled discharges, as the gas pressure decreases, the electron heating mechanism changes from ohmic heating to collisionless heating, and the electron energy distribution function exhibits a bi-Maxwellian distribution due to the Ramsauer minimum of the elastic collision cross section for Ar.

等离子体处理，例如基于反应等离子体的薄膜形成和表面改性技术，是先进电子产品（包括半导体芯片和液晶显示器）最重要的技术之一。在目前的研究中，我们采用基于粒子在细胞（PIC）和蒙特卡罗碰撞（MCC）方法的粒子模拟来分析半导体制造中使用的等离子体处理工具。 PIC 和 MCC 方法是反应等离子体模拟的理想选择，因为前者可以解析电子速度分布函数，后者可以使用基本物理数据（例如反应碰撞截面）确定化学反应速率。 1999 年，我们开发了 PIC/MCC 代码来模拟二维圆柱形几何结构中的电容耦合平行板 Ar 放电。至于碰撞，我们包括电子中性碰撞的电离、激发和弹性碰撞，以及离子中性碰撞的电荷交换和弹性碰撞。目前假设中性气体与室温一致。 2000 年，我们扩展了模拟代码以处理双频电容耦合放电，并引入了用于实际等离子体处理工具的外部电路。此外，我们采用了离子动力学计算的加速方案，以提高模拟代码的效率。在我们的模拟中我们观察到，在单频和双频电容耦合放电中，随着气体压力的降低，电子加热机制从欧姆加热变为无碰撞加热，并且电子能量分布函数呈现双麦克斯韦分布由于 Ar 弹性碰撞截面的 Ramsauer 最小值。