Micromechanical Thin-Film Characterization

Microelectromechanical systems (MEMS) can be regarded as advanced film-based devices. Although the dimensions of a MEMS are in the range of micrometers to millimeters, due to low mass and contact area the interaction of the micro parts is confined to the upper monolayers of the material. To achieve a good performance as well as a long lifetime it is necessary to control the adsorbate coverage of the micro parts. Besides the tools of surface science (XPS, HREELS, AES, …) a precise characterization of the adsorbate film with respect to mechanical properties (adhesion, friction, mechanically induced desorption) is required. Those needs are met with a new generation of test equipment comprising of sensors and actuators, thus, rendering the instruments also a MEMS. Force sensing devices made of glass are introduced to measure ultra low deflections caused by the interaction of the micro parts via the adsorbate layer. The devices combine precisely etched glass structures (bending beams,) with fiber optics.