Over the past 20 years, the application of micro electronics technology to the fabrication of mechanical devices has completely changed the research in microsensors and microactuators to develop Micro Electrical Mechanical Systems (or MEMS or Microsystems). At the early stage, the micromachining process was mainly achieved by wet chemical etching such as Potassium Hydroxid (KOH) or Tetra Methyl Ammonium Hydroxid (TMAH). During the last 10 years, the Deep Reactive Ion Etching (DRIE) of Silicon has opened new fields of application in MEMS and device integration. Opposite to the wet anisotropic etching, the DRIE process prevents lateral etching of the Si resulting in highly anisotropic etch profiles at high etch rates and with high aspect ratio. Alcatel Micro Machining Systems rapidly grew to be one of the market leaders in deep plasma etching equipment. Over 200 tools are now in use at major industries and laboratories world-wide such as ESIEE, France. The goal is to be at the forefront of deep etching technology while bringing real benefits to customers. Today, fully integrated Microsystems on a single chip include biological or chemical sensors, movable parts and actuators, micro-fluidics, optics and electronics for the control. A review of the typical etched patterns has been carried out, the features sizes are ranging from large exposed areas for Si microphone to comb structures for 3D high precision inertial sensors to nanofeatures. In fact, an optimisation of the DRIE process by varying process parameters including reactive gas flow, pressure, and ion energy in order to minimize the rippling of the sidewalls usually called ‘scalloping effect’ could even produce well defined nanostructures. The DRIE process coupled with adapted high resolution lithography tools to large surface allows the research community to explore the very innovating and exciting nano-world. J-M. Thevenoud, B. Mercier, T. Bourouina, F. Marty, M. Puech, N. Launay
