Generation methods for high pressure plasmas to be operated in wide parameter ranges and their applications.

可在大气压范围内操作的等离子体源对于各种表面处理技术的应用非常感兴趣。因此，在较大面积或体积上实现稳定辉光放电的方法受到了热烈的研究。本课题的研究目标是开发一种能够在大气压范围内稳定工作的等离子体源，并具有较高的等离子体密度，首先设计了一种新型的等离子体源，它具有平面排列的微等离子体集成结构，属于介质阻挡放电（DBD）方案。然后，它的特性进行了研究，与传统的平行板系统的比较。在此基础上，我们发展了一种利用波长为1.08 μm的激光吸收技术对亚稳态He^*（2^3S_1）原子进行定量测量的方法。我们还发展了一种利用毫米波段微波透射特性测量等离子体密度的独特方法，不仅测量了He等离子体的电子密度，而且测量了N_2和空气等离子体的电子密度。诊断结果表明，在工作电压较低、稳定范围较宽的情况下，新型等离子体源获得的等离子体密度比传统源高一个数量级。结果表明，在大气条件下，稀释剂和源气体的流量强烈影响沉积速率和均匀性。我们试图通过使用气流模拟工具来优化沉积条件，以实现更好的结果。

Plasma sources which can be operated at atmospheric pressure range are of much interest for applications to various surface treatment technologies. Therefore, the methods for realizing stable glow discharges over larger areas or volumes have been investigated enthusiastically. The aim of our research is to develop a new plasma source which can be operated stably in a wide pressure range including the atmospheric pressure with higher plasma density.In the first step, we have designed a new type of plasma source with an integrated structure of microplasmas arranged in a plane, which is categorized as a dielectric barrier discharge (DBD) scheme. Then, its characteristics have been investigated in a comparison with a conventional parallel-plate system. On the way, we developed a method for the quantitative measurement of metastable He^*(2^3S_1) atoms by using a laser absorption technique at the wavelength of 1.08 μm. We developed also a unique method for the measurement of plasma density with the transmittance characteristics of microwaves of mm-range, by which the electron densities were measured not only in He plasmas but also in N_2 and air plasmas. As the results of those diagnostics, it has been clarified that the plasma density obtained in our new plasma source is higher than that in a conventional source by about an order of magnitude even though the operating voltage is much smaller and also the stability range is wider.In the second step, the source has been applied to the chemical vapor deposition of SiO_2 films by using TEOS as the source material. It turned out that the flows of the diluent and source gases strongly influence the deposition rate and the uniformity under the atmospheric condition. We are trying to optimize the deposition condition by using a simulation tool for the gas flow to realize better results.