Method of etching a dielectric layer

Abstract

A method of etching a dielectric layer includes providing a substrate, which includes a dielectric layer and a metal layer, performing a first etching process on the metal layer, and performing a second etching process on the dielectric layer to form a opening in the dielectric layer. The first etching process and the second etching process are in-situ carried out in the same reaction chamber without a vent. Since the first and second etching processes are not performed in different reaction chambers respectively, the cycle time can therefore be improved in the present invention. Because the first and second etching processes are performed without a vent, the substrate is protected from the pollution existing in surrounding.

1 . A method of etching a dielectric layer, comprising:
 providing a substrate, the substrate comprising a base layer, a dielectric layer and a metal layer, the dielectric layer and the metal layer being disposed above the base layer;   performing a first etching process on the metal layer to turn the metal layer into a patterned metal layer; and   performing a second etching process on the dielectric layer to form at least one opening in the dielectric layer, wherein the first etching process and the second etching process are performed in a same reaction chamber.   
     
     
         2 . The method of  claim 1 , wherein the metal layer comprises titanium nitride (TiN). 
     
     
         3 . The method of  claim 1 , wherein the second etching process utilizes the patterned metal layer as an etching mask to etch the dielectric layer. 
     
     
         4 . The method of  claim 3 , wherein the opening of the dielectric layer comprises a trench, a via hole or an opening of a dual damascene structure. 
     
     
         5 . The method of  claim 4 , further comprising a step of forming a patterned photoresist on the metal layer, wherein the first etching process utilizes the patterned photoresist as an etching mask to etch the metal layer. 
     
     
         6 . The method of  claim 5 , further comprising a step of forming a first cap layer on the metal layer before forming the patterned photoresist. 
     
     
         7 . The method of  claim 6 , further comprising a step of forming a bottom anti-reflection coating layer (BARC layer) on the first cap layer before forming the patterned photoresist, wherein the patterned photoresist exposes parts of the BARC layer. 
     
     
         8 . The method of  claim 7 , further comprising a step of etching the BARC layer and the first cap layer by utilizing the patterned photoresist as an etching mask after forming the patterned photoresist. 
     
     
         9 . The method of  claim 5 , wherein the substrate further comprises a second cap layer disposed between the dielectric layer and the metal layer. 
     
     
         10 . The method of  claim 9 , wherein the second etching process utilizes the patterned metal layer as an etching mask to etch the first cap layer and the dielectric layer. 
     
     
         11 . The method of  claim 1 , wherein the opening of the dielectric layer comprises a contact hole. 
     
     
         12 . The method of  claim 11 , further comprising a step of forming a patterned photoresist on the metal layer, wherein the first etching process utilizes the patterned photoresist as an etching mask to etch the metal layer. 
     
     
         13 . The method of  claim 12 , further comprising a step of forming a bottom anti-reflection coating layer (BARC layer) on the metal layer before forming the patterned photoresist, wherein the patterned photoresist exposes parts of the BARC layer. 
     
     
         14 . The method of  claim 13 , further comprising a step of etching the BARC layer by utilizing the patterned photoresist as an etching mask after forming the patterned photoresist. 
     
     
         15 . The method of  claim 11 , wherein the dielectric layer comprises an inter-level dielectric layer. 
     
     
         16 . The method of  claim 1 , wherein the first etching process and the second etching process comprises a plasma etching process. 
     
     
         17 . The method of  claim 1 , wherein the first etching process comprises sulfur hexafluoride gas or chlorine gas. 
     
     
         18 . The method of  claim 1 , wherein the reaction chamber comprises a protecting layer disposed on an inner surface of the reaction chamber. 
     
     
         19 . The method of  claim 18 , wherein the protecting layer comprises silicon carbide or yttrium oxide compounds. 
     
     
         20 . The method of  claim 1 , wherein the substrate is kept in the reaction chamber during a period between the first etching process and the second etching process.