【作者】 武洪臣；

【导师】 马腾才；

【作者基本信息】 大连理工大学 ， 等离子体物理， 2009， 博士

【摘要】 本文从分析等离子体浸没离子注入技术（Plasma Immersion Ion Implantation,PIII）目前存在的改性不均匀及改性层较薄的问题入手,针对等离子体动态鞘层诊断、提高等离子体密度、改进偏压方式等关键技术,提出相应的解决方案并开展了初步工艺探索。为该技术的推广与实际工程应用奠定基础。绪论部分主要回顾等离子体浸没注入技术的发展历程,并简要分析工程上材料改性对等离子体技术的实际要求。由此引出本文所针对的关键问题及研究工作安排。改性不均匀及改性层较薄是浸没注入目前比较突出的两个主要问题。本文围绕这两个问题开展了动态鞘层检测、微波等离子体源改进、脉冲直流复合偏压及保形增强沉积工艺探索等工作。第二章介绍PIII过程中高压鞘层演化特点,举例说明目前典型理论模型与实际问题的差别以及现有实验检测方法的对比。不同理论模型对同一问题的模拟结果仍然存在较大出入,且很少涉及鞘层的恢复过程。现有检测方法大多利用小探针移动方式来获取不同位置的鞘层信号。此类方法不易获得鞘层演化的整体信息及时间过渡特征。第三章提出长探针对动态鞘层演化的测量方法及基本原理。利用此方法用对“静态”磁控溅射等离子体以及脉冲阴极弧“流动”金属等离子体的鞘层进行了测量。经与理论值初步对比,结果认为是合理的。同时发现,在快速流动的金属等离子体中,基体的上、中、下游的鞘层行为有着很大的区别。上游及侧面鞘层对高压脉冲响应迅速,但下游明显地存在着时间延迟现象,而且鞘层尺寸按上、中、下游的次序依次增大。侧面鞘层实测值与理论值的偏差最小,吻合程度最好。根据鞘层检测结果,第四章对微波ECR等离子体源与高压电源进行改进,以期提高等离子体密度（缩小鞘层尺寸达到保形注入）及实现复合偏压（增加改性层厚度）。采用谐振腔内部添加铁芯的措施,使得微波放电区进一步向工艺区靠近,测量数据显示工艺区的平均等离子体密度由6.67×10⁹提高到了2.12×10¹⁰cm^-3。这样既延长了微波等离子体源的工作寿命,又保持了工艺区的等离子体密度,将有助于增加处理工艺的均匀性。针对浸没注入及增强沉积的复合工艺,利用电感、电容元件对交、直流电的不同特性,将负高压脉冲与直流偏压复合在一起,在浸没方式下实现混合注入与沉积。第五章以TiN涂层为例,进行复杂形面（杯形件）的保形增强沉积工艺探索与动态混合沉积试验。结果显示,在实验条件下,5μs的脉冲宽度可获得较好的均匀性。当杯形件口径接近2倍鞘层尺寸且深度不大于口径的2/3时,用20kV、5μs的高压脉冲可以实现内壁的注入与强化,对底部强化作用偏弱。同时,当脉冲高压参数选择适当时,复合偏压可使涂层硬度与结合力同时得到提高。利用脉冲阴极弧等离子体,在0-90°的范围内测量了基体偏压对Cu、Ti等元素的附着系数的影响。实验发现一定入射能量下（＞50eV）Cu元素在入射角60°附近有最小（为0）的附着系数。该结果与文献上的理论模拟取得了很好的一致。而基体偏压可明显改善最小附着系数为0的现象,有利于涂层沉积。更多还原

【Abstract】 The present dissertation analyses the problems such as nonuniformity and thinner modification layer existing in Plasma Immersion Ion Implantation （PIII）. Aiming at these problems, some ideas are proposed to improve the dynamic sheath measurement, increase plasma density, and modifythe substrate biasing. Establish a basic support of this technology’s application in industry.The first chapter mainly reminds the development process of PIII and describe the surface modification demands on plasma technology, and then educe the problems that limited the technology and the arrangements of the dissertation. Aiming at the limitations, the research works including dynamic sheath measurement, modifying the ECR plasma souece and the high voltage pulas souce have been finished. The conformal enhanced deposition process is explored.The second chapter makes an intrpduction of the PIII sheath features. Illustrate the defferirnts between fifferent models for a certion problem. Although various theoretical models and simulations were developed to explain the sheath behavior, experimental results are still considered more reliable for guiding the practical process. Most of the methods to measure the sheath reported up to now are putting several small probes at different positions or moving the probes to different positions. The whole data of sheath expansion and recovery during a high voltage pulse usually can’t be obtained in such conditions because one cannot move the probe continuously nor put probes at every position.To measure the whole information of a sheath, a method and its principle of using a long probe is proposed in the third chapter. Using the long probe, the sheaths in "static" magnetron sputtering and the "flowing" pulsed cathodic arc plasma are measured. The results can be believed reasonable after comparision with the theoretic values. It is found that there are big differences between the sheaths induced in upstream, side and the downstream of the substrate in the fast flow plasma. In upstream and side, almost no time delay between the sheath and the HVP . But there is apparent response delay for the downstream sheath after the HVP passed. The sheath thickness is increased in the sequence of upstream, side and the downstream. But the agreement between measured side sheath and theoretic value is the best one. In the fourth chapter some modifations have been done related to the plasma source according to the sheath measurement result. An iron core is put inside the cavity and make the discharge zone moving closer to the process area. The density in the process area is increased from 6.67×10⁹ to 2.12×10¹⁰cm^-3. So the lifetime of the couple window is elongated and higher plasma density is kept. Also, HVP and DC bias are composed together by using the features of inductance and capacitance. Thus the implantation, deposition or dynamic mixing deposition can be realized in one vacuum period.Finally, the conformal implantation and deposition process is explored by "cup" shape holder with TiN coating. Under the test condition, the results show that when the pulse width is 5μs the uniformity is better and it is difficult to implant or enhance the bottom when the cup diameter less than 2 times sheath size and the cup depth greater than the 2/3 diameter. But when proper HVP parameters are choosed the bound strength and hardness of the coating can be increased.The sticking probabilities of deposition particles in different incident angle（0-90o ） are measuered in cathodic arc plasma with Cu and Ti elements. It is found that the substrate bias has more effect to the sticking probability in the flowing plasma. It can change the phenominon of 0 sticking probability at certain incident angle（for Cu is 60°）.更多还原