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

可在大气压范围内工作的等离子体源在各种表面处理技术中具有重要的应用价值。因此，如何在更大的面积或体积上实现稳定的辉光放电一直是人们研究的热点。本研究的目的是开发一种能够在较宽的气压范围内(包括较高的等离子体密度)稳定工作的新型等离子体源。第一步，我们设计了一种新型的等离子体源，它具有微等离子体在平面上排列的集成结构，被归类为介质阻挡放电(DBD)方案。然后，通过与传统的平行板系统的比较，研究了它的特性。在此过程中，我们发展了一种利用激光吸收技术在1.08μm波长下定量测量亚稳态He^*(2^3S_1)原子的方法，还发展了一种独特的利用毫米波传输特性测量等离子体密度的方法，该方法不仅可以测量He等离子体中的电子密度，而且可以测量N_2和空气等离子体中的电子密度。诊断结果表明，在较小的工作电压和较宽的稳定范围内，新型等离子体源的等离子体密度比传统等离子体源高一个数量级左右。第二步，以正硅酸乙酯为源材料，将其应用于化学气相沉积二氧化硅薄膜。结果表明，在大气条件下，稀释剂和源气体的流量对沉积速率和沉积的均匀性有很大影响。我们试图通过使用气体流动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.