a Microwave-Driven Excimer Lamp and its Applications

A microwave-driven excimer lamp has many applications in industry and scientific research for several reasons: First, the microwave-driven excimer lamp is a high efficiency, incoherent photon source. The energetic VUV-UV and Visible -to-Infrared photons produced inside the lamp can initiate and enhance a variety of chemical, physical or biological processes. Thus either as a photon source or as a driving force, the lamp can be used in many fields, such as lighting, laser discharge, plasma processing, diamond thin film growth, photovoltaic cell, etc. Second, the microwave discharge is an electrodeless discharge, thus contamination resulting from impurities contained in electrode materials can be avoided. This is a very important advantage for a spectroscopic light source and for plasma-assisted chemical processing. Third, the microwave resonator has high cavity efficiency (the ratio of the absorbed power by the plasma to the incident microwave power). By choosing certain coupling methods and precisely adjusting impedance matching, it is possible to couple 90% of the microwave energy into the plasma load. Finally, the lamp can be used for any microwave plasma-assisted process system. Basically, it has the same principle and almost same structure as a plasma lamp. Thus, through the study of a plasma lamp, the theory and design methods for any plasma process system are also obtained. The work that has been done in this dissertation includes the following: (1) Five excimer lamps (four cylindrical and one elliptical) were designed and built, and the corresponding microwave system was set up. In addition, ten related papers were published. (2) A new and more general theoretical lamp model, which includes the influence of the quartz tube, was developed in this research. Under special conditions, its results can be simplified into the results of former researchers (such as B. Agdur and B. Enander, 1961; M. L. Passow et al., 1991) and classical model. Thus, this model is effective and more general.