The Measurement Of Dynamic Sheath With Long Probe And The Exploring Of Conformal Enhanced Deposition Process

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°).