A MEMS DEVICE INCLUDING A LATERALLY MOVABLE PORTION WIHT PIEZO-RESISTIVE SENSING ELEMENTS AND ELECTROSTATIC ACTUATING ELEMENTS ON TRENCH SIDE WALLS AND METHODS FOR PRODUCING THE SAME

摘要

P-type doped region(s) 25 are formed in the upper surface of an n-type substrate 20. A trench 22 is formed in the substrate (e.g. by DRIE cutting) intersecting with the doped regions and defining a portion 21 of the substrate which is movable in the plane of the substrate relative to the rest of the substrate. Then diffusion of P-type dopant is effected into the trench side-walls to create piezoelectric elements 27 and electrode elements 29 for electrostatic actuation. Owing to the intersection of two doped regions, there are good electrical paths between the electrical elements 27, 29 on the trench side-walls and the previously doped portions on the wafer surface. The trench 22 intersects with insulating elements 28, so that the insulating elements 28 mutually insulate adjacent ones of the electrical elements 27, 29. P-n junctions between the electrical elements 27, 29 and the substrate 20 insulate the electrical elements 27, 29 from the substrate.