In the paper MEMS-type microsystems working in vacuum conditions are described. All the benefits and drawbacks of vacuum generated in microcavities are discussed. Different methods are used to produce vacuum in microcavity of MEMS. Some bonding techniques, sacrificial layer method or getter materials are presented. It is concluded that the best solution would be to invent some kind of vacuum micropump integrated with MEMS structure. Few types of already existing vacuum micropumps are shown, but they are not able to generate high vacuum. As the most promising candidate for miniaturization an orbitron pump was selected. The working principle and novel concepts of its construction are described. The most important part of the micropump, used for gas ionization, is a field-emission electron source. Results of a research on a lateral electron source with gold emissive layer for integration with a micropump are presented.
Vabond Project, "Long-term stability of vacuum-encapsulated MEMS devices using eutectic wafer bonding" http://www.ist-world.org
T. Tsuchiya, Y. Kageyama, H. Funabashi, and J. Sakata, "Polysilicon vibrating gyroscope vacuum-encapsulated in an on-chip micro chamber", Sensors and Actuators A 90, 49-55 (2003).
I. Kleps, A. Angelescu, N. Samfirescu, A. Gil, and A. Correia, "Study of porous silicon, silicon carbide and DLC coated field emitters for pressure sensor application", Solid-State Electronics 45, 997-1001 (2001).
S. Miller and M. Desmulliez, "MEMS ultra low leak detection methods: a review", Sensor Review 29 (4), 339-344 (2009).
S. J. Randolph, M. D. Hale, M. A. Guillorn, P. D. Rack, and M. L. Simpsonet, "A microfabrication process for a vacuum-encapsulated microchamber", Microelectronic Engineering 77, 412-419 (2005).