AVS 52nd International Symposium
    MEMS and NEMS Tuesday Sessions
       Session MN-TuM

Paper MN-TuM9
A Fully Integrated Micro Plasma Electron Source in Silicon

Tuesday, November 1, 2005, 11:00 am, Room 207

Session: Micro and Nano Fabrication Techniques for MEMS & NEMS
Presenter: E. Wapelhorst, Hamburg University of Technology, Germany
Authors: E. Wapelhorst, Hamburg University of Technology, Germany
J.P. Hauschild, Hamburg University of Technology, Germany
J. Müller, Hamburg University of Technology, Germany
Correspondent: Click to Email
This paper presents the concept and the fabrication of a novel, fully integrated electron and UV light source using a micro plasma. The electron source is primarily developed for use in a micro mass spectrometer. This novel system is fabricated using standard processes in silicon e.g. DRIE based on the working principle of a micro plasma ion source as shown in.@footnote 1@ Furthermore, the RF-efficiency is increased by direct RF coupling through vias. An application of this type of electron source for ionization purposes in a micro mass spectrometer has been presented in,@footnote 2@ which uses the concept of.@footnote 1@ The electron source consists of three units: The filament, the plasma chamber, and the electron accelerator. The pressure in the plasma chamber is set to 100 Pa. To ignite a stable RF plasma in the chamber, a current pulse is driven through the filament to free electrons while the RF signal is directly applied to the RF coupler. After ignition the filament is switched off. By applying a voltage between the extraction grid and the acceleration grid electrons can be extracted from the plasma and accelerated to a defined kinetic energy. Due to its shape, the acceleration area has a focusing effect on the electron beam. The pressure in the acceleration area is less than 1 Pa. The two described pressure regimes are installed by the extraction grid which acts as pressure aperture. The system emits an electron beam with adjustable and defined energy, e.g. a 100µA beam and an electron energy of 70eV. Benefits of the system are the high electron current, small dimensions (diameter of the plasma chamber is less than 1mm), the low gas and power consumption, uncritical vacuum requirements because of the small size, and the adjustable electron energy. @FootnoteText@ @footnote 1@ Plasmagestuezte Ionenquelle in Mikrosystemtechnik fuer den Einsatz in einem MMS, P.Siebert, TUHH, 2001@footnote 2@ A Micro Mass Spectrometer, G.Petzold et al. MicroTAS, 2001.