Studies on rarefied gas flow of radicals and surface reactions in a high-density plasma reactor

高密度等离子体反应器中自由基稀薄气流及表面反应研究

• 批准号: 10305016
• 负责人: NANBU Kenichi
• 金额: $ 19.46万
• 依托单位: TOHOKU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A).
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10305016/
• 关键词: Inductively coupled plasma; Chlorine plasma; Etching; Radical flow; Wafer biasing; Surface reaction; PIC; MC method; DSMC method; 誘導結合型プラズマ; プラズマエッチング; モンテカルロ法; ヘリカルコイル; Cl_2プラズマ

We describe the theoretical and experimental results of this study.1 Theoretical results(1) The physical and chemical phenomena in an ICP reactor are analyzed using DSMC and PIC/MC methods.The etch rate increases with increasing mass flow rate and the region of nonuniform etch rate becomes wider as the flow rate decreases.The deviation of EEDF from the Maxwellian becomes small due to Coulomb collisions for smaller coil current.(2) Etching of silicon wafer by chlorine gas in a CCP reactor is studied by use of a combined analysis of the DSMC and PIC/MC methods.The etch rate is uniform in most of tea wafer. It shows a sharp rise near the wafer edge.The electron density is two-order lower than the negative chlorine radical ion density in the afterglow of RF chlorine discharge plasma.(3) We proposed a new useful particle modeling to simulate the ICP reactor. In this work, production and transport of plasma and radicals are calculated using this modeling. Our simulation and experiment show a good agreement with each other.2 Experimental results(1) We examined the argon plasma properties in an ICP reactor.The electron density is in the region of 1×10^<10>〜1×10^<11> cm^3, electron temperature 4〜6eV, and plasma potential 35〜45V.(2) We examined the silicon etching properties of cw discharge and pulsed discharge in the chlorine plasma. The results of the cw discharge are as follows :The distribution of the etch rate is very uniform over the wafer surface.The etch depth depends on the etching time linearly.(3) The results of the pulsed discharge are as follows :The etch rate increases with decreasing the duty ratio butit is saturated about 33% of duty ratio.As the duty ratio decreases, the distribution of the etch rate becomes more nonuniform.

1理论结果（1）用DSMC和PIC/MC方法分析了ICP反应器中的物理和化学现象，发现刻蚀速率随质量流率的增加而增加，刻蚀速率不均匀区域随质量流率的减小而变宽，在较小的线圈电流下，由于库仑碰撞，EEDF与麦克斯韦方程的偏差变小。(2)本文用DSMC和PIC/MC相结合的方法研究了CCP反应器中氯气对硅片的腐蚀，发现大部分硅片的腐蚀速率是均匀的。在射频氯放电等离子体的余辉中，电子密度比负氯自由基离子密度低两个数量级。(3)我们提出了一种新的有用的粒子模型来模拟ICP反应器。在这项工作中，等离子体和自由基的生产和运输计算使用此模型。2实验结果（1）研究了ICP反应器中氩等离子体的特性，其电子密度为1×10^~（-1<10>）×10^<11>cm ^~ 3，电子温度为4 ~ 6 eV，等离子体电位为35 ~ 45 V。(2)研究了氯等离子体中连续放电和脉冲放电对硅的刻蚀特性。结果表明：连续放电的刻蚀速率在硅片表面分布很均匀，刻蚀深度与刻蚀时间呈线性关系。(3)脉冲放电的结果表明：刻蚀速率随占空比的减小而增大，但在占空比为33%时达到饱和，随着占空比的减小，刻蚀速率的分布变得更加不均匀。

项目成果

Masakazu Shiozawa: "Particle Modeling of Plasma and Flow in an Inductively Coupled Plasma"Proc.of 22nd Int.Symp.on Rarefied Gas Dynamics. (2000)

Masakazu Shiozawa：“电感耦合等离子体中等离子体和流动的粒子模型”Proc.of 22nd Int.Symp.on Rarefied Gas Dynamics。

Kenichi Nanbu: "Direct Simulation Monte Carlo Analysis of Flows and Etch Rate in an Inductively Coupled Plasma Reactor."IEEE Trans.Plasma Sci.. Vol.27. 1379-1388 (1999)

Kenichi Nanb​​u：“电感耦合等离子体反应器中流动和蚀刻速率的直接模拟蒙特卡罗分析。”IEEE Trans.Plasma Sci.. 第 27 卷。

Kenichi Nanbu: "Monte Carlo Collision Simulation of Positive-Negative Ion Recombination for a Given Rate Constant" J.Phys.Soc.Jpn.67・4. 1288-1290 (1998)

Kenichi Nanb​​u：“给定速率常数的正负离子复合的蒙特卡罗碰撞模拟”J.Phys.Soc.Jpn.67・4（1998）。

Hiroshi Sasaki: "Basic Plasma Properties in a High-Density ICP Etching Apparatus."Proc.of 17^<th> Symp.on Plasma Processing. 125-128 (2000)

Hiroshi Sasaki：“高密度 ICP 蚀刻设备中的基本等离子体特性。”Proc.of 17^<th> Symp.on 等离子体处理。

Kenichi Nanbu: "Detailed Structure of the Afterglow of Radio-Frequency Chlorine Discharge."Jpn.J.Appl.Phys.. Vol.38. L951-L953 (1999)

Kenichi Nanb​​u：“射频氯放电余辉的详细结构。”Jpn.J.Appl.Phys.. Vol.38。