MicroElectroMechanical Systems (MEMS) are the
integration of mechanical elements, sensors, actuators and
electronics on a common substrate using integrated circuit
process sequences [1-6, 9-17]. The electronics are fabricated
using standard IC processing, micromechanical components
are fabricated using compatible ‘micromachining’ processes
that can selectively etch parts of the substrate, or add sections
on to the top surface, leaving free standing structures. A large
market already exists for micromachined sensors. In this case
the microelectronic integrated circuits can be thought of as the
brain of the system and micromechanical section as the ‘arms’
and ‘eyes’ of the system, sensing thermal, biological,
chemical, optical and magnetic phenomena in the
environment. The evolving nature of MEMS means that new
applications are continually being reported. In recent years,
RF and millimetre-wave MEMS have emerged from sensor
based technology, they use the same fabrication techniques
and have become an area of significant interest. MEMS based
RF circuits could have a large impact on handset applications,
because of their inherent small size and good electrical
performance