摘要
等离子体磁化鞘层在半导体加工、材料表面改性、薄膜沉积等方面都发挥着重要作用.在等离子体实验和放电应用中,常存在由两种以上离子组成的多离子等离子体;对于长程相互作用的等离子体系统,非麦克斯韦分布的电子可通过Tsallis的非广延分布来描述.本文针对多离子等离子体鞘层建立一维空间坐标三维速度坐标的流体模型,假设鞘层中电子速度服从非广延分布,本底氦离子和不同种类的杂质离子在有一定倾斜角度的磁场中被磁化,通过数值模拟探究了非广延参量、杂质离子及斜磁场对多离子磁鞘中离子的数密度、速度、壁面电势和离子动能等物理量的影响.结果表明,在氦氢或氦氩混合等离子体鞘层中,随着非广延参量增大,离子沿垂直壁方向的速度减小,鞘层中离子、电子数密度均减小,鞘层厚度减小,壁面处离子动能减小;当杂质离子浓度增大时,壁面处离子动能与离子种类无关.随着磁场强度的增大,氦离子数密度和沿垂直壁方向的速度在鞘边出现起伏,且波动幅度随着非广延参量的减小而增大,而重离子则无明显的波动.此外,还分析了杂质离子种类和浓度对鞘层相关特性的影响.
Magnetized plasma sheath plays an important role in semiconductor processing,material surface modification,film deposition,etc.In plasma experiments and discharge applications,multi-ion plasma consisting of more than two kinds of ions often exists.For a long range interacting plasma system,non-Maxwellian electrons can be described by the non-extensive distribution of Tsallis.In this work,a fluid model with onedimensional spatial coordinates and three-dimensional velocity coordinates is established for the multi-ion plasma sheath.It is assumed that the electron velocity in the sheath follows a non-extensive distribution,and the background helium ions and different kinds of impurity ions are magnetized in a magnetic field with a certain tilt angle.The effects of non-extensive parameters,impurity ions and oblique magnetic field on the number density,velocity,wall potential and kinetic energy of ions in the multi-ion magnetic sheath are investigated by numerical simulation.The results show that in the helium-hydrogen or helium-argon mixed plasma sheath,the ionic velocity along the vertical wall direction decreases with the increase of the nonextensive parameters,the number density of ions and electrons in the sheath,the sheath thickness,and the kinetic energy of ions at the wall decrease.When the concentration of impurity ions increases,the kinetic energy of ions on the wall is independent of the type of ions.With the increase of magnetic field intensity,the number density of helium ions and the velocity along the vertical wall fluctuate along the sheath edge,and the fluctuation amplitude increases with the decrease of non-extensive parameters,while the heavy ions have no obvious fluctuation.In addition,the effects of the types and concentrations of impurity ions on the related properties of the sheath are also analyzed.With the increase of the magnetic field intensity,the number density and the velocity along the vertical wall direction fluctuate at the sheath edge,and the fluctuation amplitude increases with the decrease of the non-extensive parameter,whereas there are no significant fluctuations for heavy ions.In addition,when impurity ions are heavy ions,the absolute value of wall potential increases with the increase of impurity ion concentration and the decrease of non-extensibility parameters,and the kinetic energy of background ions increases at the wall surface.When the impurity ion is a light ion,the absolute value of the wall potential decreases with the increase of the impurity ion concentration and the decrease of the nonextensibility parameter,and the kinetic energy of the background ion at the wall decreases.
作者
陈龙
檀聪琦
崔作君
段萍
安宇豪
陈俊宇
周丽娜
Chen Long;Tan Cong-Qi;Cui Zuo-Jun;Duan Ping;An Yu-Hao;Chen Jun-Yu;Zhou Li-Na(School of Science,Dalian Maritime University,Dalian 116026,China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2024年第5期217-227,共11页
Acta Physica Sinica
基金
国家自然科学基金(批准号:11975062,11605021,12205033)
中央高校基本科研业务费(批准号:3132023192)资助的课题.
关键词
多离子等离子体
非广延分布
磁化鞘层
玻姆判据
multi-ion plasma
non-extensive distribution
magnetized sheath
Bohm criterion
作者简介
通信作者:段萍.E-mail:duanping@dlmu.edu.cn。
