The Design And Manufacturing Of Micro-plasma Source In Micro Mass Spectrometer For Gas Samples

In recent years, because of the Micro Mass Spectrometer's portability and efficiency, researchers have paid more attention on it. As the key part of the Micro Mass Spectrometer, plasma source has also been concerned with. And some researches have been reported, but most of them are independent of the Micro Mass Spectrometer, not for combination of the Micro Mass Spectrometer.This thesis presents the design of an integrated plasma source. We first review a variety of Micro Mass Spectrometry, and then a Micro Mass Spectrometer's structure based on MEMS is analyzed in detail. Considering the compatibility and stability of the above Micro Mass Spectrometer using silicon based on planar structure, capacitive coupled plasma excitation is selected. Then we choose the power source of microwave frequency, and select metal micro strip line as the transmission lines and the discharge electrodes. Especially we focus on the impedance matching of the discharge circuit. Furthermore, the design and manufacturing of discharge circuits based on ceramic high frequency printed circuit boards are completed of which the lengths of the discharge gaps are 150μm and 500μm. At last the above discharge circuits are tested in vacuum environment to generate high-density plasma in short term within small volume.During the experiment we found that it is essential to generate stable plasma in two steps when the strength of the electric field between the discharge gaps is smaller than MV. We first generate instantaneous gas discharge between the discharge gaps with the external electric ignition, and then maintain the plasma with the help of the low-power microwave power source. In order to be compatible with the Micro Mass Spectrometer, on the basis of the above discharge circuits, we design and manufacture the structure of metal micro strip line on borosilicate glass for the first time.