Ion Transport to a Photoresist Trench in a Radio Frequency Sheath  

作　　者：张赛谦 戴忠玲 王友年 

机构地区：[1]School of Physics and Optoelectronic Technology,Dalian University of Technology

出　　处：《Plasma Science and Technology》2012年第11期958-964,共7页等离子体科学和技术（英文版）

基　　金：supported by National Natural Science Foundation of China(Nos.11075029,10975030)

摘　　要：We present a model which is used to study ion transport in capacitively coupled plasma （CCP） discharge driven by a radio-frequency （rf） source for an etching process. The model combines a collisional sheath model with a trench model. The sheath model can calculate the ion energy distributions （IEDs） and ion angular distributions （IADs） to specify the initial conditions of the ions incident into the trench domain （a simulation area near and in the trench）. Then, considering the charging effect on the photoresist sidewalls and the rf-bias applied to the substrate, the electric potentials in the trench domain are computed by solving the Laplace equation. Finally, the trajectories, IEDs and IADs of ions impacting on the bottom of the trench are obtained using the trench model. Numerical results show that as the pressure increases, ions tend to strike the trench bottom with smaller impact energies and larger incident angles due to the collision processes, and the existence of the trench has distinct influences on the shape of the IEDs and IADs. In addition, as the bias amplitude increases, heights of both peaks decrease and the IEDs spread to a higher energy region.We present a model which is used to study ion transport in capacitively coupled plasma （CCP） discharge driven by a radio-frequency （rf） source for an etching process. The model combines a collisional sheath model with a trench model. The sheath model can calculate the ion energy distributions （IEDs） and ion angular distributions （IADs） to specify the initial conditions of the ions incident into the trench domain （a simulation area near and in the trench）. Then, considering the charging effect on the photoresist sidewalls and the rf-bias applied to the substrate, the electric potentials in the trench domain are computed by solving the Laplace equation. Finally, the trajectories, IEDs and IADs of ions impacting on the bottom of the trench are obtained using the trench model. Numerical results show that as the pressure increases, ions tend to strike the trench bottom with smaller impact energies and larger incident angles due to the collision processes, and the existence of the trench has distinct influences on the shape of the IEDs and IADs. In addition, as the bias amplitude increases, heights of both peaks decrease and the IEDs spread to a higher energy region.

关 键 词：ion motion IED IAD charging effect SHEATH plasma etching CCP 

分 类 号：TN305.7[电子电信—物理电子学]