Micromotor Fabrication by Surface Micromachining Technique.

Abstract

From the last decade MEMS has emerged as one of the major area of interest, not only in India but also in the globe. This is basically due to its wide application in various field including Bio-Engineering, Automotive system (transducers, accelerometers), manufacturing and fabrication etc. MEMS is an approach that conveys the advantages of miniaturization, multiple components and microelectronics, to design and to construct integrated electromechanical systems.This paper is a high level discussion of surface micromachining and its applications amongst many such as sensors, actuators and micro motor etc. Micro fabrication can be done by the various techniques such as Lithography, Bulk micromachining, LIGA and surface micromachining. Surface micromachining enables the fabrication of complex multicomponent integrated micromechanical structures that would not be possible with other methods. This technique encases specific structural parts of a device in layers of a sacrificial material during fabrication process. In other methods even small misalignment between mask and structure can pose a problem. Further all other processes are subtractive micromachining processes but surface micromachining is an additive micro structuring technology.In the present work, fabrication of micro motor by using surface micromachining technique is explained. One of the major advantage of surface micromachining is to fabricate quite small structural heights typically 2-5 µm and seldom exceeds 20 µm. The small structural height also allows for much lateral dimensions compared to other micromachining techniques. Though micromachining of micro motor is a complex process with different micro fabrication techniques, surface micromachining excels through this.