Ashing apparatus, ashing methods, and methods for manufacturing semiconductor devices

Abstract

A method for manufacturing a semiconductor device in accordance with an embodiment of the present invention includes a step of forming a TiN film 2 on an underlying film 1 ; a step of coating a photoresist film on the TiN film 2 , and exposing and developing the photoresist film; a step of etching the TiN film 2 using the photoresist film 4 a as a mask, by using an etching apparatus that etches an Al alloy film; a step of introducing a mixed gas containing O 2 gas and N 2 gas adjacent to the photoresist film, and plasmatizing the gas to thereby ash the photoresist film, and a step of introducing H 2 O gas adjacent to the TiN film, and plasmatizing the gas to thereby ash foreign matter on the TiN film.

What is claimed:  
     
         1 . An ashing method that ashes a photoresist film on a body to be processed in which a TiN film is etched using the photoresist film as a mask, the method comprising: 
 disposing a body to be processed in an ashing chamber;    a first step of introducing a first ashing gas adjacent to the body to be processed, and forming a plasma in the first ashing gas and ashing the photoresist film; and    a second step of introducing H 2 O gas adjacent to the body to be processed, and forming a plasma in the H 2 O gas and ashing foreign matter, if present, on the body to be processed.    
     
     
         2 . An ashing method according to  claim 1 , wherein the first ashing gas comprises O 2  gas and N 2  gas.  
     
     
         3 . An ashing method according to  claim 1 , wherein the body to be processed includes a TiN film formed over an underlying film, a BARC formed on the TiN film, and a photoresist film formed on the BARC film.  
     
     
         4 . An ashing method according to  claim 3 , wherein, when the photoresist film and the BARC are ashed, before ashing in the first step, the body to be processed is maintained for 5 seconds to 7 seconds on a stage that is controlled to be at an elevated temperature in order to adjust and stabilize a pressure inside the ashing chamber.  
     
     
         5 . A method for manufacturing a semiconductor device, the method comprising: 
 a first step of forming a TiN film on an underlying film;    a second step of coating a photoresist film on the TiN film, and exposing and developing the photoresist film;    a third step of etching the TiN film using the photoresist film as a mask, by using an etching apparatus that etches an Al alloy film;    a fourth step of introducing a mixed gas containing O 2  gas and N 2  gas adjacent to the photoresist film, and forming a plasma in the gas and ashing the photoresist film; and    a fifth step of introducing H 2 O gas adjacent to the TiN film, and forming a plasma in the gas and ashing foreign matter, if present, on the TiN film.    
     
     
         6 . A method for manufacturing a semiconductor device according to  claim 5 , wherein there is no break in vacuum during and between the third step and the fourth step.  
     
     
         7 . A method for manufacturing a semiconductor device, the method comprising: 
 a first step of forming a TiN film on an underlying film;    a second step of forming a BARC on the TiN film;    a third step of coating a photoresist film on the BARC, and exposing and developing the photoresist film;    a fourth step of etching the BARC and the TiN film using the photoresist film as a mask, by using an etching apparatus that etches an Al alloy film;    a fifth step of introducing a mixed gas containing O 2  gas and N 2  gas adjacent to the photoresist film, and forming a plasma in the gas and ashing the photoresist film and the BARC; and    a sixth step of introducing H 2 O gas adjacent to the TiN film, and forming a plasma in the gas and ashing foreign matter, if present, on the TiN film.    
     
     
         8 . A method for manufacturing a semiconductor device according to  claim 7 , further comprising a step, between the fourth step and the fifth step, of maintaining the body to be processed for 5 seconds to 7 seconds on a stage that is controlled to be at an elevated temperature in order to adjust and stabilize a pressure inside the ashing chamber.  
     
     
         9 . A method as in  claim 1 , further comprising before the first step, maintaining the body to be processed for 5 seconds to 7 seconds at an increased temperature.  
     
     
         10 . A method as in  claim 7 , wherein the increased temperature is about 250° C.  
     
     
         11 . A method for manufacturing a semiconductor device according to  claim 5 , further comprising the step, between the fourth step and the fifth step, of maintaining the body to be processed at an increased temperature for 5 seconds to 7 seconds on a stage inside the ashing chamber.  
     
     
         12 . An ashing method that ashes a photoresist film on a body to be processed in which a conducting layer has been etched using the photoresist film as a mask, the method comprising: 
 introducing a first gas into the chamber, forming a plasma in the first gas and ashing the photoresist film on the body; and    introducing a second gas comprising H 2 O gas into the chamber, forming a plasma in the second gas and ashing foreign matter, if present, on the body;    wherein the first gas has a composition different from that of the second gas.    
     
     
         13 . A process for processing a body in which a conducting film has been etched using the photoresist film as a mask, the process comprising: 
 providing a body having a photoresist film thereon in a chamber;    introducing a first ashing gas to the chamber, forming a plasma in the chamber with the first ashing gas therein, and ashing the photoresist film;    stopping the introducing a first ashing gas to the chamber; and    introducing a second ashing gas comprising H 2 O into the chamber and forming a plasma in the chamber with the second ashing gas comprising H 2 O gas therein.    
     
     
         14 . A process as in  claim 13 , wherein the stopping the introducing a first ashing gas to the chamber is carried out prior to the introducing a second ashing gas comprising H 2 O to the chamber.  
     
     
         15 . A process as in  claim 14 , wherein the first ashing gas includes O 2  gas and N 2  gas.  
     
     
         16 . A process as in  claim 15 , wherein the second ashing gas consists of H 2 O.  
     
     
         17 . A process as in  claim 13 , wherein the first ashing gas consists of O 2  gas and N 2  gas, and the second ashing gas consists of H 2 O.