Method and system for mems devices with dual damascene formed electrodes

Abstract

Methods and systems for MEMS devices with dual damascene formed electrodes is disclosed and may include forming first and second dielectric layers on a semiconductor substrate that includes a conductive layer at least partially covered by the first dielectric layer; removing a portion of the second dielectric layer; forming vias through the second dielectric layer and at least a portion of the second dielectric layer, where the via extends to the conductive layer; forming electrodes by filling the vias and a volume that is the removed portion of the second dielectric layer with a first metal; and coupling a micro-electro-mechanical systems (MEMS) substrate to the semiconductor substrate. A third dielectric layer may be formed between the first and second dielectric layers. A metal pad may be formed on at least one electrode by depositing a second metal on the electrode and removing portions of the second metal, which may be aluminum.

What is claimed is: 
     
         1 . A microelectromechanical system (MEMS) device comprising:
 a complementary metal oxide semiconductor (CMOS) substrate comprising:
 a conductive layer; 
 a first dielectric layer covering at least a portion of the conductive layer; 
 a second dielectric layer above the first dielectric layer; 
 a dual damascene electrode comprising a single metal layer on a top surface of the second dielectric layer and extending through the second dielectric layer and a portion of the first dielectric layer to the conductive layer; and 
 a metal pad above the second dielectric layer; 
   a MEMS substrate coupled to the CMOS substrate via the metal pad, the MEMS substrate comprising standoffs extending from a first surface of the MEMS substrate; and   a MEMS cover coupled to a second surface of the MEMS substrate opposite to the first surface.   
     
     
         2 . The MEMS device of  claim 1 , wherein a metal pad is on at least one electrode. 
     
     
         3 . The MEMS device of  claim 2 , wherein the MEMS substrate is electrically coupled to the CMOS substrate via the metal pad. 
     
     
         4 . The MEMS device of  claim 1 , wherein the MEMS substrate is electrically coupled to the CMOS substrate via the at least one electrode and the conductive layer. 
     
     
         5 . A microelectromechanical system (MEMS) device comprising:
 a complementary metal oxide semiconductor (CMOS) substrate comprising:
 a conductive layer; 
 a first dielectric layer covering at least a portion of the conductive layer; 
 a second dielectric layer above the first dielectric layer; 
 a dual damascene electrode comprising a single metal layer on a top surface of the second dielectric layer and extending through the second dielectric layer and a portion of the first dielectric layer to the conductive layer; and 
 a cavity in the first and second dielectric layers extending to the conductive layer; 
   a MEMS substrate coupled to the CMOS substrate via the conductive layer; and   a MEMS cover coupled to the MEMS substrate on a surface opposite to a surface of the MEMS substrate coupled to the CMOS substrate.   
     
     
         6 . The MEMS device of  claim 5 , wherein the MEMS substrate is electrically coupled to the metal layer.