Patent ID: 6718605
Filing Date: 2004-04-13
Classification: G01P,Y10T

Abstract:
In a method for making a high-sensitivity, microelectromechanical capacitive accelerometer including a proof mass having a thickness along an input axis of the accelerometer and first and second conductive electrodes from a single semiconductor wafer having a predetermined thickness, the improvement comprising:depositing first and second planar layers on a single-side of the wafer, the planar layers being relatively thin along the input axis; stiffening the first and second planar layers to form the first and second conductive electrodes, respectively, which are stiff so as to resist bending movement along the input axis; and forming substantially uniform, first and second narrow gaps between the first conductive electrode and the proof mass and between the second conductive electrode and the first conductive electrode, respectively, wherein the first electrode is suspended above the proof mass and wherein the second electrode is supported on the proof mass to move therewith relative to the first electrode and wherein the thickness of the proof mass is at least one order of magnitude greater than either the thickness of the first planar layer or the thickness of the second planar layer.