allowed the precise exposure of the photoresist and the precise lithography of the underlying thick polysilicon fig1 shows the achieved lithography on the rough surface of the stress relieved and released thick polysilicon the sog allowed extremely precise lithography of the thick polysilicon without any machining of the surface of the thick polysilicon which remains at its full thickness at all locations this important feature eliminates the undesirable local thickness variation associated with prior art mems fabrication techniques involving photoresist etch back and or chemical mechanical polishing the result is a low cost wide process window and high performance mems fabrication process providing users a forgiving set of design rules for sensors and actuators because the thick suspended rough surface polysilicon has upward microscopic pyramids whose sizes are much smaller than the typical dimensions of the components patterned in the suspended thick polysilicon the novel process can provide reproducible electrostatic actuators since it has much more uniform thickness over the dimensions of these typical components because the random distribution of the surface roughness results in a uniform average thickness of patterned components the vertical electrodes formed by two neighbouring and facing each other deep etched thick polysilicon surfaces over or not local topology result in a parallel plate capacitor of repeatable net surface area and hence repeatable capacitance value since the inter electrode spacing is also achieved by this precise lithography process the novel process can also provide repeatable mechanical elements since the average thickness of deep etched thick polysilicon is not affected by the underlying topology since the surface roughness of the thick polysilicon is increasing with deposited thickness the number of coats of sog can be different from four 4 and is a function of the thickness.