Improved properties of the MEMS-type ion-sorption micropump

Abstract

In this paper, the authors demonstrate how to improve the properties of a recently elaborated microelectromechanical system (MEMS) ion-sorption micropump in order to generate high and ultrahigh vacuum inside MEMS and miniature nanoelectronics devices. This research goal has been achieved by applying mechanisms leading to an increase of the efficiency of a gas ionization process. One of the cathodes of the micropump was covered with different nanomaterials, which have either good field emission properties (carbon nanotubes) or high secondary emission coefficient (nanoporous silicon and magnesium oxide nanopowder). In this way, the number of primary or secondary electrons which collide with gas particles was multiplied. For all of the modified structures a significant increase of a discharge current inside the micropump was observed. In the case of electrodes covered with MgO, it increased about 1000 times. The use of these cathodes may allow to obtain ultrahigh vacuum inside hermetically sealed MEMS structure.