Design Considerations for Controlling Silicon Nanoparticle Nucleation and Growth in a Nonthermal Plasma
Design Considerations for Controlling Silicon Nanoparticle Nucleation and Growth in a Nonthermal Plasma
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DOI：
10.1007/s11090-022-10299-3
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发表时间：
2022-11
影响因子：
3.6
通讯作者：
E. Husmann;J. Polito;S. Lanham;M. Kushner;E. Thimsen
中科院分区：
文献类型：
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作者：
E. Husmann;J. Polito;S. Lanham;M. Kushner;E. Thimsen
在低温等离子体系统中控制纳米粒子的成核和生长对于控制纳米粒子的尺寸分布是必不可少的；对于微电子加工中的沉积和刻蚀等应用来说，防止粒子污染是必不可少的。本文以硅烷制备纳米硅(NP)为模型系统，研究了纳米硅的成核过程。尽管人们已经研究了硅纳米粒子的成核和生长机制，但如何使用可控的系统参数(如压力、系统几何形状和气体组成)来抑制或促进纳米粒子的形成还不清楚。例如，由于反应堆壁上的损失，活性硅烷物种的传输预计将显著影响成核硅NP所需的硅烷进料分数(成核起始分数)。在这项工作中，我们用Ar/H2/He/SiH4混合气体测定了管式流动射频等离子体的Np质量密度，它是系统压力、气体组成和反应器直径的函数。研制了一台石英晶体微天平冲击器，用于测量等离子体下游的总气溶胶质量密度，从而识别成核开始及其与工艺参数的关系。发展了一个反应机制，并将其纳入全球等离子体化学模型中，以更好地理解成核开始和NP生长。
Controlling the nucleation and growth of nanoparticles in low temperature plasma systems is imperative for controlling nanoparticle size distributions; and for some applications such as deposition and etching in microelectronic processing, preventing particle contamination. In this work, silicon nanoparticle (NP) production from silane is used as a model system to investigate the nucleation process. Although the mechanisms responsible for silicon NP nucleation and growth have been studied, it is unclear how controllable system parameters (e.g., pressure, system geometry, and gas composition) can be used to inhibit or promote NP formation. For example, the transport of reactive silane species is expected to significantly affect the feed fraction of silane required to nucleate silicon NP (the nucleation onset fraction) due to losses at the reactor walls. In this work, NP mass density was determined as a function of system pressure, gas composition, and reactor diameter for a tubular flow-through radiofrequency plasma using Ar/H2/He/SiH4gas mixtures. A quartz crystal microbalance impactor was developed to measure the total aerosol mass density downstream of the plasma and thereby identify the nucleation onset and its dependence on process parameters. A reaction mechanism was developed and incorporated into a global plasma chemistry model to better understand the nucleation onset and NP growth.