Method of patterning dielectric

Abstract

A method of patterning a dielectric layer. On a substrate having a metal wiring layer formed thereon, a dielectric layer and a masking layer are formed. A cap insulation layer is formed on the masking layer before patterning the dielectric layer. In addition, a dual damasecence process is used for patterning the dielectric layer.

What is claimed is:  
     
         1 . A method of patterning a dielectric layer, wherein a substrate having a metal wiring layer formed thereon is provided, comprising: 
 forming a dielectric layer on the metal wiring layer;    forming a masking layer on the dielectric layer;    forming and patterning a cap insulation layer to form an opening on the masking layer, the opening is aligned with the metal wiring layer;    etching the masking layer and the dielectric layer, so that the opening is deepened and the metal wiring layer is exposed; and    a conductive layer is formed over the substrate to fill the opening.    
     
     
         2 . The method according to    claim 1   , wherein the conductive layer is further polished to form a plug within the opening.  
     
     
         3 . The method according to    claim 2   , wherein the conductive layer is polished by chemical-mechanical polishing.  
     
     
         4 . The method according to    claim 1   , wherein the dielectric layer includes low k dielectric layer.  
     
     
         5 . The method according to    claim 1   , wherein the dielectric layer includes organic polymer.  
     
     
         6 . The method according to    claim 1   , wherein the dielectric layer includes xylene plastic.  
     
     
         7 . The method according to    claim 1   , wherein the masking layer includes a silicon oxide layer.  
     
     
         8 . The method according to    claim 1   , wherein the cap insulation layer includes a silicon nitride layer.  
     
     
         9 . The method according to    claim 8   , wherein the masking layer and the dielectric layer are etched by plasma containing oxygen.  
     
     
         10 . A method of patterning a dielectric layer, wherein a substrate having a metal wiring layer formed thereon is provided, comprising: 
 forming a first dielectric layer on the metal wiring layer;    forming a first masking layer on the first dielectric layer, and a first cap insulation layer on the first masking layer;    forming a first opening aligned with the metal wiring layer by etching the first cap insulation layer, so that the underlying first masking layer is exposed;    etching the exposed first masking layer to expose the first dielectric layer;    forming a second dielectric layer, a second masking layer and a second cap insulation over the substrate in sequence;    forming a second opening by etching the second cap insulation, so that the second masking layer is open within the second opening;    etching the exposed second masking layer and the underlying second dielectric layer, and etching the first dielectric by using the second cap insulation layer as a mask until the metal wiring layer is exposed; and    forming a conductive layer over the substrate.    
     
     
         11 . The method according to    claim 10   , wherein the conductive layer is further polished to form a plug within the opening.  
     
     
         12 . The method according to    claim 10   , wherein the conductive layer is polished by chemical-mechanical polishing.  
     
     
         13 . The method according to    claim 10   , wherein the first dielectric layer includes low dielectric layer.  
     
     
         14 . The method according to    claim 10   , wherein the first dielectric layer includes organic polymer.  
     
     
         15 . The method according to    claim 10   , wherein the first dielectric layer includes xylene plastic.  
     
     
         16 . The method according to    claim 10   , wherein the first masking layer includes a silicon oxide layer.  
     
     
         17 . The method according to    claim 10   , wherein the first cap insulation layer includes a silicon nitride layer.  
     
     
         18 . The method according to    claim 10   , wherein the first masking layer and the first dielectric layer are etched by plasma containing oxygen.  
     
     
         19 . The method according to    claim 10   , wherein the second dielectric layer includes low k dielectric layer.  
     
     
         20 . The method according to    claim 10   , wherein the second dielectric layer includes organic polymer.  
     
     
         21 . The method according to    claim 10   , wherein the second dielectric layer includes xylene plastic.  
     
     
         22 . The method according to    claim 10   , wherein the second masking layer includes a silicon oxide layer.  
     
     
         23 . The method according to    claim 10   , wherein the second cap insulation layer includes a silicon nitride layer.  
     
     
         24 . The method according to    claim 10   , wherein the second masking layer and the second dielectric layer are etched by plasma containing oxygen.