In developing a new MEMS device, it is clearly essential for the designer to consider the process flow by which the device can be fabricated during the initial design phase. Failure to do so runs the risk of the final design being impossible to fabricate or simply uneconomical even if fabrication is physically possible. It is therefore necessary for the designer to have some understanding of the basic MEMS fabrication technologies and materials sets at their disposal together with some of the fundamental processing rules . The aim of this chapter is not to provide the reader with detailed information about specific processes, as many excellent reference texts already exist for this purpose, but to provide an overview of microfabrication to allow the designer to make a rule of thumb decision on the feasibility of a particular device.

To this end, a variety of MEMS devices will be examined as case studies of microfabrication. Initially, some simple passive devices will be considered as a means of introducing the basic micromachining technologies by example. Both actuating and sensing device will then by discussed together with their related materials systems. Finally, we will see how these elements can be integrated using a larger process flow to produce complete microsystems.