射频、甚高频磁控溅射沉积硅薄膜的研究

发布时间：2018-05-17 15:54

本文选题：磁控溅射 + 硅薄膜　；参考：《苏州大学》2015年硕士论文

【摘要】：通过选择合适的放电驱动频率,调控离子能量、离子通量、等离子体密度、电子温度,来沉积有不同结构特性的硅薄膜,成为调控薄膜结构与性能的一种有效途径。但是这种通过驱动频率调控硅薄膜结构与性能的技术手段目前主要应用于等离子体增强的化学气相沉积(PECVD)技术,极少在溅射沉积硅薄膜方面获得应用。为了研究溅射驱动频率对磁控溅射沉积硅薄膜的影响,本文采用2MHz、13.56 MHz、27.12MHz和60 MHz驱动的磁控溅射技术开展了硅薄膜的沉积及特性研究。论文主要研究了2MHz、13.56MHz、27.12MHz和60 MHz驱动频率和100-250W的溅射功率对磁控溅射制备硅薄膜的沉积特性、结构及性能的影响。发现射频溅射(13.56MHz、27.12MHz)沉积的薄膜主要呈非晶结构,薄膜表面粗糙度较大,形成薄膜的颗粒尺寸也较大;而低频(2MHz)和甚高频(60MHz)沉积的薄膜主要呈纳米晶结构,薄膜表面粗糙度较小,形成薄膜的颗粒尺寸也较小。为了分析薄膜沉积与结构变化的可能原因,论文采用Langmuir探针、拒斥场能量分析仪研究了溅射沉积硅薄膜时的等离子体特性,发现随着驱动频率的增加,由于体等离子体区和基片鞘层区的等离子体性能受到影响,离子能量和电子温度会增加,而离子通量和等离子体密度会减小。离子通量的减小导致了较低的薄膜沉积速率、较小的颗粒尺寸和平均粗糙度,离子能量的增大增强了吸附原子的扩散,有助于纳米晶硅的形成。因此,硅薄膜的结构随着溅射频率的改变而呈现较大变化。根据甚高频(60MHz)溅射等离子体特性,论文进一步开展了在Ag(111)薄膜基底上甚高频溅射制备类硅烯薄膜的初步探索。因此,采用溅射技术沉积硅薄膜时,溅射频率是影响薄膜沉积与结构特性的重要因素,可以通过溅射频率调控技术来控制硅薄膜的结构。
[Abstract]:By selecting suitable discharge driving frequency, regulating ion energy, ion flux, plasma density and electron temperature, the silicon thin films with different structure characteristics are deposited, which is an effective way to control the structure and properties of the films. However, this technique of controlling the structure and properties of silicon thin films by driving frequency is mainly used in plasma enhanced chemical vapor deposition (PECVD) technology, and is rarely applied in sputtering deposition of silicon thin films. In order to study the effect of sputtering driving frequency on Si thin films deposited by magnetron sputtering, the deposition and characteristics of Si thin films were studied by magnetron sputtering technique driven by 2MHz 13.56MHz and 60 MHz. The effects of driving frequency of 13.56 MHz and 60 MHz and sputtering power of 100-250 W on the deposition characteristics, structure and properties of Si thin films prepared by magnetron sputtering were studied. It was found that the films deposited by RF sputtering (13.56MHz ~ 27.12MHz) were mainly amorphous, the surface roughness of the films was larger, and the grain size of the films formed was larger, while the films deposited at low frequency (2MHz) and VHF (60MHz) were mainly nanocrystalline, and the surface roughness of the films was relatively small. The particle size of the film is also small. In order to analyze the possible causes of deposition and structural changes of thin films, the plasma characteristics of Si films deposited by sputtering are studied by using Langmuir probe and rejection field energy analyzer. It is found that the plasma characteristics increase with the increase of driving frequency. The ion energy and electron temperature will increase and the ion flux and plasma density will decrease because of the influence of the plasma performance in the bulk plasma region and the substrate sheath region. The decrease of ion flux leads to lower deposition rate, smaller particle size and average roughness, and the increase of ion energy enhances the diffusion of adsorbed atoms, which contributes to the formation of nanocrystalline silicon. As a result, the structure of Si thin films changes greatly with the change of sputtering frequency. Based on the plasma characteristics of very high frequency (VHF) 60MHz) sputtering, the preparation of Si-like thin films on the substrates of AgLi _ (111) thin films by VHF sputtering has been investigated in this paper. Therefore, the sputtering frequency is an important factor affecting the deposition and structure of silicon thin films by sputtering technology. The structure of silicon thin films can be controlled by sputtering frequency control technology.
【学位授予单位】：苏州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.2

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