Micro electromechanical switch having self-aligned spacers

A method of forming a micro-electromechanical switch (MEMS) comprising the steps of:

• a) depositing a first dielectric layer on a substrate, said first dielectric layer having a plurality of conductive interconnect lines formed therein;
• b) wet etching metal to form trenches on the boundaries of said conductive interconnect lines;
• c) depositing a second dielectric layer through which conductive vias are formed, said conductive vias contacting at least one of said plurality of conductive interconnect lines and replicating the trench topographies to the top surface of said second dielectric layer and filling with metal said replicated trench topographies;
• d) forming a cavity that is etched-out from said second dielectric layer and having said metal trench topographies selectively inhibit etching the dielectric underneath the metal trench topographies to form self-aligned spacers;
• e) filling said cavity with sacrificial material and planarizing said sacrificial material;
• and
• f) depositing a third dielectric layer to form a conductive beam with said conductive vias contacting said conductive beam.