Method and apparatus for performing hydrogen optical emission endpoint detection for photoresist strip and residue removal

Abstract

A method for monitoring and detecting a hydrogen optical emission while performing photoresist stripping and removal of residues from a substrate or a film stack on a substrate.

1 . A method of removing a photoresist layer comprising: 
 positioning a substrate comprising a photoresist layer into a processing chamber;    removing the photoresist layer using a plasma; and    monitoring the plasma for a hydrogen optical emission during the process.    
     
     
         2 . The method of  claim 1  wherein the photoresist layer comprises a hardened crust layer.  
     
     
         3 . The method of  claim 1  wherein the photoresist layer is implanted with an implant species.  
     
     
         4 . The method of  claim 1  wherein the photoresist layer has been exposed to ions.  
     
     
         5 . The method of  claim 1  wherein the photoresist layer has been exposed to an electron beam.  
     
     
         6 . The method of  claim 2  wherein the monitoring step produces a signal having a first level while etching the crust and produces a signal having a second level after the crust has been removed.  
     
     
         7 . The method of  claim 1  wherein the hydrogen optical emission occurs at a wavelength of about 656 nm.  
     
     
         8 . The method of  claim 1  further comprising: 
 monitoring the plasma for an oxygen optical emission while etching.  
 
     
     
         9 . The method of  claim 8  wherein the oxygen optical emission occurs at a wavelength of about 777 nm.  
     
     
         10 . The method of  claim 1  further comprising: 
 stopping the etching upon the hydrogen optical emission obtaining a predetermined level.  
 
     
     
         11 . The method of  claim 8  further comprising: 
 stopping the etching upon either the hydrogen optical emission obtaining a first level or the oxygen optical emission obtaining a second level, or both.  
 
     
     
         12 . The method of  claim 2  further comprising: 
 monitoring the plasma for an oxygen optical emission while etching.  
 
     
     
         13 . The method of  claim 12  wherein the oxygen optical emission monitoring step produces an oxygen optical emission signal having a first level while etching the crust and a second level after the crust is removed.  
     
     
         14 . The method of  claim 13  wherein the oxygen optical emission signal has a third level after the photoresist is removed.  
     
     
         15 . The method of  claim 8  wherein the hydrogen optical emission is correlated with the oxygen optical emission.  
     
     
         16 . A method of etching a photoresist layer comprising: 
 providing a substrate comprising a photoresist layer to a process chamber;    etching the photoresist layer using a plasma; and    monitoring the plasma for both a hydrogen optical emission and an oxygen optical emission while etching.    
     
     
         17 . The method of  claim 16  wherein the photoresist layer comprises a crust.  
     
     
         18 . The method of  claim 16  wherein the photoresist layer is implanted with an implant species.  
     
     
         19 . The method of  claim 16 , wherein the photoresist layer is implanted with at least one of As, B, BF 2 , BF 4 , P, In, Sb or H.  
     
     
         20 . The method of  claim 16  wherein the photoresist layer has been exposed to an ion beam.  
     
     
         21 . The method of  claim 16  wherein the hydrogen optical emission occurs at a wavelength of about 656 nm.  
     
     
         22 . The method of  claim 16  wherein the oxygen optical emission occurs at a wavelength of about 777 nm.  
     
     
         23 . The method of  claim 16  further comprising: 
 stopping the etching upon either the hydrogen optical emission obtaining a first level or the oxygen optical emission obtaining a second level, or both.  
 
     
     
         24 . The method of  claim 16  wherein the oxygen optical emission monitoring step produces an oxygen optical emission signal having a first level while etching the crust and a second level after the crust is removed, and wherein the hydrogen optical emission monitoring step produces a hydrogen optical emission signal having a third level while etching the crust and a fourth level after the crust is removed.  
     
     
         25 . The method of  claim 16  wherein the oxygen optical emission signal has a fifth level after the photoresist is removed.  
     
     
         26 . The method of  claim 16  wherein the hydrogen optical emission is correlated with the oxygen optical emission.