Abstract: A MEMS device having a fixed element and a movable element wherein one or the other of the fixed element and the movable element has at least one radially-extended stop or overdeflection limiter. A fixed overlayer plate forms an aperture. The aperture is sized to minimize vignetting and may be beveled on the margin. Overdeflection limitation occurs during deflection before the movable element can impinge on an underlying electrode. The overdeflection limiter may be conveniently placed adjacent a gimbaled hinge.

Abstract: Method for fabricating ultrathin gaps producing ultrashort standoffs in array structures includes sandwiching a patterned device layer between a silicon standoff layer and a silicon support layer, providing that the back surfaces of the respective silicon support layer and the standoff layer are polished to a desired thickness corresponding to the desired standoff height on one side and to at least a minimum height for mechanical strength on the opposing side, as well as to a desired smoothness. Standoffs and mechanical supports are then fabricated by etching to produce voids with the dielectric oxides on both sides of the device layer serving as suitable etch stops. Thereafter, the exposed portions of the oxide layers are removed to release the pattern, and a package layer is mated with the standoff voids to produce a finished device. The standoff layer can be fabricated to counteract curvature.

Abstract: Disclosed is a positioning stage for precisely positioning an object within a limited range of travel (e.g. 100 &mgr;m). By way of example, the stage can be used to position an electron source such as a field emitter in an electron beam microcolumn. The stage includes a block which defines a channel to allow flexure along a first axis. The block also defines another channel to allow flexure along a second axis perpendicular to the first axis. Using actuators in the channels to flex a portion of the block, the object supported by the block can be precisely positioned to a desired location in a horizontal plane defined by the first and second axes.

Abstract: An apparatus for surface inspection and processing of a wafer includes a microcolumn and an associated scanning probe microscope. The microcolumn enables high speed scanning of the wafer at a relatively high resolution, while the scanning probe microscope provides atomic resolution of highly localized areas of the wafer. The microcolumn and scanning probe microscope can be partially fabricated out of the same substrate. Additionally, the microcolumn and scanning probe microscope can be a portion of an array of microcolumns and/or scanning probe microscopes. The apparatus may be used for imaging, lithography and spectroscopy.

Abstract: A field emission source produces a charged particle beam that can be electrostatically aligned with the optical axis. Quadrupole (or higher multipole) centering electrodes approximately centered on the optical axis are placed between the emitter and the extraction electrode. By applying centering potentials of equal amplitude and opposite polarity on opposing elements of the centering electrodes, an electrostatic deflection field is created near the optical axis. The electrostatic deflection field aligns the charged particle beam with the optical axis thereby obviating the need to mechanically align the emitter with the optical axis. A second set of centering electrodes may be used to deflect the charged particle beam back and to ensure that the charged particle beam is parallel with the optical axis. Further, the extraction electrode may be split into a quadrupole arrangement with the extraction and centering potentials superimposed.

Abstract: The present invention is directed to a method for selectively scaling the dimensions of a field emission electron gun. The electron gun includes a field emission tip followed by a dual electrode immersion lens. The lens consists of two planar electrodes separated by a dielectric layer. A well defined circular hole is present at the center of each electrode and the dielectric layer. A high scaling factor is applied to the region consisting of the first electrode and the emission tip, reducing the first electrode thickness and bore diameter and the distance between the tip and first electrode to the micrometer range. A weaker scaling factor is applied to the bore diameter of the second electrode and the spacing between the electrodes such that the second electrode bore diameter and distance between the electrodes are approximately equal and are greater than the first electrode thickness and bore diameter and the distance between the tip and first electrode.