Method of etching a multi-layer

Abstract

A method of etching a multi-layer is provided. The multi-layer includes an aluminum layer disposed on a semiconductor substrate and an anti-reflection coating layer disposed on the aluminum layer. The method includes: performing a first etching process to etch the anti-reflection coating layer by providing a first etching gas, wherein the first etching gas includes a chlorine-containing substance; then performing a second etching process to etch the aluminum layer by providing a second etching gas, wherein the second etching gas does not include a chlorine-containing compound.

1 . A method of etching a multi-layer, the multi-layer comprising an aluminum layer disposed on a semiconductor substrate and an anti-reflection coating (ARC) layer disposed on the aluminum layer, the method comprising:
 performing a first etching process to etch the ARC layer by providing a first etching gas, wherein the first etching gas comprises a chlorine-containing substance; and   performing a second etching process to etch the aluminum layer by providing a second etching gas, wherein the second etching gas does not comprise a chlorine-containing compound.   
     
     
         2 . The method as in  claim 1 , wherein the chlorine-containing compound comprises BCl 3 . 
     
     
         3 . The method as in  claim 1 , wherein the second etching gas comprises chlorine gas. 
     
     
         4 . The method as in  claim 1 , wherein the first etching gas comprises chlorine gas and BCl 3 . 
     
     
         5 . The method as in  claim 1 , wherein the first etching gas comprises chlorine gas. 
     
     
         6 . The method as in  claim 1 , wherein the first etching process further comprises providing a first passivation gas. 
     
     
         7 . The method as in  claim 6 , wherein the first passivation gas comprises hydrocarbon. 
     
     
         8 . The method as in  claim 6 , wherein the first passivation gas comprises ethylene (C 2 H 4 ). 
     
     
         9 . The method as in  claim 1 , wherein the second etching process further comprises providing a second passivation gas. 
     
     
         10 . The method as in  claim 9 , wherein the second passivation gas comprises hydrocarbon. 
     
     
         11 . The method as in  claim 9 , wherein the second passivation gas comprises ethylene. 
     
     
         12 . The method as in  claim 6 , wherein the first etching process is performed under a condition as follows: a pressure between 12 and 18 mTorr, a RF power between 1200 and 1600 W, a bias power between 250 W and 350 W, a period between 120 and 180 seconds, a flow rate of the first etching gas between 150 and 210 sccm and a flow rate of the first passivation gas between 120 and 180 sccm. 
     
     
         13 . The method as in  claim 9 , wherein the second etching process is performed under a condition as follows: a pressure between 8 and 12 mTorr, a RF power between 1300 and 1700 W, a bias power between 250 W and 350 W, a flow rate of the second etching gas between 120 and 180 sccm and a flow rate of the second passivation gas between 120 and 180 sccm. 
     
     
         14 . A method of anisotropically etching an aluminum layer, comprising: providing an etching gas to etch the aluminum layer, wherein the etching gas comprises a chlorine-containing substance, but does not comprise a chlorine-containing compound. 
     
     
         15 . The method as in  claim 14 , wherein the chlorine-containing compound comprises BCl 3 . 
     
     
         16 . The method as in  claim 14 , wherein the etching gas comprises chlorine gas. 
     
     
         17 . The method as in  claim 14 , further comprising providing a passivation gas. 
     
     
         18 . The method as in  claim 17 , wherein the passivation gas comprises hydrocarbon. 
     
     
         19 . The method as in  claim 17 , wherein the passivation gas comprises ethylene. 
     
     
         20 . The method as in  claim 17 , wherein the etching process is performed under a condition as follows: a pressure between 8 and 12 mTorr, a RF power between 1300 and 1700 W, a bias power between 250 W and 350 W, a flow rate of the etching gas between 120 and 180 sccm and a flow rate of the passivation gas between 120 and 180 sccm.