We all have them in our phones: MEMS (Micro Electric Mechanical Systems). Inertial MEMS, for instance, are the tiny accelerometers and gyroscopes in our smart phones. They make playing games on the phone more fun and help us finding the next pizza restaurant. To do that, they measure our movements by recognizing rotation and acceleration. MEMS are really tiny, i.e. in the micro-meter (µm) size regime. You need special microscopes to see their set up in detail, e.g. a scanning electron microscope. However, people are trying to make them even smaller. Why? Well, there are many reasons and of course one of them is the cost. If the devices were smaller, the production cost would also decrease.
The MEMS accelerator and the gyroscope are two of the most important examples of the growing zoo of MEMS. Therefore, we will take them as examples in our discussion on what limits the shrinkage of MEMS? To give an overview, we will first consider some general aspects of dimension scaling. Then we will proceed to more specific aspects which limit the area shrinkage of an inertial MEMS.