Patent ID: 7657995

Claim:
A method of fabricating a micro-electromechanical system (MEMS) switch on a substrate comprising: forming at least one depletion area within said substrate, followed by blanket depositing an etch stop layer on said substrate; depositing a first metallization layer on said substrate, followed by a first dielectric layer, and patterning said first metallization layer having a first portion of metal within said at least one depletion area and a second portion thereof outside said depletion area, and patterning said first dielectric layer, leaving dielectric only on top of said metal within said depletion area, forming in said first metallization layer: a) bases for hinge posts, b) lower electrodes and c) lower interconnect wiring; depositing and planarizing a second dielectric layer deposited thereon, forming conductive vias in areas where interconnects are expected, said vias becoming a first portion of said hinge posts; depositing a second dielectric layer on a second metallization layer followed by patterning to form: a) said lower electrodes, b) links to upper electrodes to be formed thereafter, c) a rigid movable conductive plate with holding rings on opposing edges of said rigid movable conductive plate, and d) a second portion of said hinge posts; depositing a third dielectric layer thereon followed by patterning to form conductive vias in areas where interconnects form a third portion of said hinges, and interconnect wiring to provide links to said upper electrodes to be formed thereafter; depositing a fourth dielectric layer, followed by depositing a third metallization layer thereon, and patterning to form a) upper hinge caps, b) said upper electrodes, and c) upper interconnect wiring; and depositing a fifth dielectric serving as a hard mask, and opening a cavity down to said etch stop layer to allow said rigid movable conductive plate to move freely.