silicon oxide deposited by chemical vapor deposition is added the total height of the actuation is defined by the thickness of the spacer layer 65 having an upper surface level 64 a the next step is illustrated in fig1 showing the pattering of the spacer layer 65 using standard photolithographic processing and etching methods to define the channel 67 where the active region of the mechanical device 100 will be located the standoff layer 60 is then patterned using photolithographic processing and etching methods to produce silicon nitride standoffs 61 as illustrated in fig1 although not illustrated these patterns can consist of pedestals or lines the standoffs 61 act as mechanical stops for the actuation of the device and the upper surface of the standoffs 61 is surface 54 a to allow the additional layers atop the existing structure a conformal sacrificial layer 66 of polycrystalline silicon is deposited to a thickness greater than the separation of surfaces 54 a and 64 a as illustrated in fig1 the deposited sacrificial layer 66 shows a conform recess 68 a in the area of the channel 67 which is located beneath the deposited sacrificial layer 66 the next step as illustrated in fig1 is the removal of the sacrificial layer 66 from the device 100 completely except an area beyond the channel 67 the selective removal of the sacrificial layer 12 is carried out by an appropriate patterning process which is for example followed by an etching step the removal of the sacrificial layer 66 exposes a top surface 64 of the spacer layer 65 how much material of a remaining sacrificial layer 66 a extends beyond the area.