Patent ID: 8105498

Claim:
A method for fabricating micromachined structures, comprising the steps of: providing a substrate; forming a fourth dielectric layer on the substrate; forming a first metal layer on the fourth dielectric layer; forming a first dielectric layer on the first metal layer, wherein the first dielectric layer has a first via; forming a second metal layer on the first dielectric layer; forming a second dielectric layer on the second metal layer, wherein the second dielectric layer has a second via; forming a third metal layer on the second dielectric layer; forming a third dielectric layer on the third metal layer, wherein the third dielectric layer has a third via; forming a fourth metal layer on the third dielectric layer; forming a passivation layer on the fourth metal layer; forming an etching window in the passivation layer; pouring an etching solution into the etching window, wherein the etching solution will flow through the first, second and third vias to conduct a wet etching process; removing the etching solution; removing the passivation layer; and etching the substrate to form a micromachined structure.