SUBSTRATE AND SURFACE MICROMACHINED NICKEL STRUCTURES BY ELECTROLESS PLATING PROCESS

Development of effective microelect romechanical systems (MEMS) requires integration of silicon micromechanical structures with suitable on-chip electronics for the appropriate actuation and detection mechanism. One of the limiting factor for the development of miniature MEMS is the incompatibility between silicon micromachining processes and Integrated circuit (IC) fabrication technology. In this thesis, a novel, low-temperature process of electroless plating is proposed as a candidate technology for producing micromechanical structures for MEMS applications. Electroless plating is characterized by selective reduction of metal ions at the surface of a catalytic substrate surface. Continuous deposition is achieved through the catalytic action of the metal deposit itself via autocatalysis. One of the main advantage of electroless plating is that it does not require connection to an electrical source for the plating process. This feature and the low temperature process makes the technology very attractive and compatible with standard commercial CMOS process. Electroless plating process has been studied and characterized for the fabrication of nickel micromechanical structures. Two types of micromachining processes, namely, substrate and surface mieromachining processes have been demonstrated. The electroless plating process, characterization results and the fabricated micromechanical + structures have been presented in this thesis.