Metallization process for manufacturing semiconductor devices and system used in same

Abstract

A metallization process for manufacturing semiconductor devices and a system that uses the same that minimizes corrosion failures in aluminum patterns. The process for the metal pattern formation is carried out by loading a semiconductor wafer into an etching chamber, the semiconductor wafer having a photoresist pattern formed over a metal material layer, stabilizing the environment in the etching chamber, main-etching the metal material layer to the etch-end point by using the photoresist pattern as an etch mask while supplying etching gas containing chlorine (Cl 2 ) into the etching chamber, over-etching the metal material layer for a certain period of time over the etch-end point so as to form metal patterns, purging the etching chamber after the over-etching step, and unloading the wafer from the etching chamber. The pressure in the transfer module is optimized, and the load lock chamber is continuously purged.

What is claimed is:  
     
         1 . A metallization process for manufacturing semiconductor devices, comprising the steps of: 
 a) loading a semiconductor wafer into an etching chamber, the semiconductor wafer having a photoresist pattern formed over a metal material layer to be etched;    b) stabilizing the environment in the etching chamber;    c) main-etching the metal material layer to an etch-end point by using the photoresist pattern as an etch mask while supplying etching gas containing chlorine into the etching chamber;    d) over-etching the metal material layer over the etch-end point for a certain period of time to form a metal pattern;    e) purging the etching chamber after the over-etching; and    f) unloading the wafer from the etching chamber.    
     
     
         2 . The metallization process of  claim 1 , wherein the metal material layer to be etched contains aluminum.  
     
     
         3 . The metallization process of  claim 2 , wherein the etching gas contains boron chloride and chlorine.  
     
     
         4 . The metallization process of  claim 1 , wherein a titanium nitride capping layer is further formed between the metal material layer and the photoresist pattern.  
     
     
         5 . The metallization process of  claim 1 , wherein the purging step is performed by supplying purified nitrogen gas into the etching chamber.  
     
     
         6 . A metallization process for manufacturing semiconductor devices, comprising the steps of: 
 a) loading a semiconductor wafer into a load lock chamber, the semiconductor wafer having a photoresist pattern formed over a metal material layer to be etched;    b) pumping and purging the load lock chamber so as to maintain a certain level of vacuum therein;    c) transferring the semiconductor wafer from the load lock chamber into an etching chamber via a transfer module, the transfer module being maintained at a certain level of vacuum and being purged;    d) etching the metal material layer by using the photoresist pattern as an etch mask while supplying etching gas containing chlorine to form a metal pattern;    e) purging the etching chamber after the etching step;    f) transferring the wafer from the etching chamber into an ashing chamber via the transfer module, the transfer module being maintained at a certain level of vacuum;    g) performing an ashing process on the metal pattern in the ashing chamber; and    h) transferring the wafer from the ashing chamber into the load lock chamber via the transfer module, the load lock chamber being continuously purged and the transfer module being maintained at a certain level of vacuum.    
     
     
         7 . The metallization process of  claim 6 , wherein the metal material layer contains aluminum.  
     
     
         8 . The metallization process of  claim 7 , wherein the etching gas includes boron chloride and chlorine.  
     
     
         9 . The metallization process of  claim 6 , wherein the pressure in the load lock chamber and the transfer module is maintained higher than that in the etching chamber and the ashing chamber, in order to prevent the gas remaining in the etching chamber and the ashing chamber from flowing back into the load lock chamber and the transfer module.  
     
     
         10 . The metallization process of  claim 9 , wherein the pressure in the transfer module is set by connecting an RGA-QMS (Residual Gas Analyzer-Quadrupole Mass Spectrometer) to the load lock chamber and analyzing the movements of impurities in the load lock chamber while changing the pressure in the transfer module.  
     
     
         11 . The metallization process of  claim 9 , wherein the pressure in the etching chamber is from 50 to 300 mTorr, and the pressure in the load lock chamber and the transfer module is maintained at a level higher than 300 mtorr.  
     
     
         12 . The metallization process of  claim 11 , wherein the pressure in the etching chamber is from about 50 to 300 mTorr, and the pressure in the transfer module is set at about 450 mTorr.  
     
     
         13 . The metallization process of  claim 6 , wherein the ashing process comprises a strip process for removing the photoresist pattern remaining on the metal pattern and a passivation process for removing chlorine components remaining on the side walls of the metal pattern, both of the processes being carried out at least one time.  
     
     
         14 . The metallization process of  claim 6 , wherein the step of etching the metal material layer further comprises the steps of: 
 a) stabilizing the environment in the etching chamber;    b) main-etching the metal material layer to an etch-end point by using the photoresist pattern as an etch mask while supplying etching gas containing chlorine into the etching chamber; and    c) over-etching the metal material layer over the etch-end point for a certain period of time so as to form the metal pattern.    
     
     
         15 . The metallization process of  claim 6 , wherein the load lock chamber, the transfer module, and the etching chamber are purged by supplying purified nitrogen gas.  
     
     
         16 . The metallization process of  claim 6 , further comprising the step of aligning the flat zone of the wafer prior to the step of transferring the wafer from the load lock chamber into the etching chamber via the transfer module, the transfer module being maintained at a certain level of pressure and being purged.  
     
     
         17 . The metallization process of  claim 6 , wherein the wafer unloaded from the ashing chamber is cooled in a cooling chamber before the wafer is transferred into the load lock chamber.  
     
     
         18 . A system for forming matal patterns in a semiconductor device comprising: a transfer module having a robot for transferring wafers therein, the transfer module being continuously purged under a certain level of vacuum; 
 a load lock chamber connected to the transfer module via a first slit valve, the load lock chamber being continuously purged under a certain level of vacuum after the wafer is supplied therein;    an etching chamber connected to the transfer module via a second slit valve, an etching process for metal pattern formation being carried out therein by using a photoresist pattern as an etch mask; and    an ashing chamber connected to the transfer module via a third slit valve, an ashing process for removing the photoresist pattern and the etching by-products being carried out therein.    
     
     
         19 . The system of  claim 18 , wherein the transfer module and the load lock chamber are purged by using a single purge gas supply line.  
     
     
         20 . The system of  claim 18 , wherein an etching gas supply line for supplying etching gas containing chlorine is provided for the etching chamber.  
     
     
         21 . The system of  claim 18 , wherein a water vapor supply line and an oxygen supply line are provided for the ashing chamber.  
     
     
         22 . The system of  claim 18 , wherein an RGA-QMS is connected to the load lock chamber for monitoring the movement of the impurities in the gas remaining in the load lock chamber.  
     
     
         23 . The system of  claim 18 , further comprising a flat-zone aligner for aligning the flat zone of the wafer before the wafer is transferred from the load lock chamber into the etching chamber via the transfer module.  
     
     
         24 . The system of  claim 18 , wherein the pressure in the load lock chamber and the transfer module is maintained higher than that in the etching chamber and the ashing chamber, in order to prevent the gas remaining in the etching chamber and the ashing chamber from flowing back into the load lock chamber and the transfer module.  
     
     
         25 . The system of  claim 24 , wherein the pressure in the etching chamber is from 50 to 300 mTorr, and the pressure in the load lock chamber and the transfer module is maintained at a level higher than 300 mTorr.  
     
     
         26 . The system of  claim 25 , wherein the pressure in the etching chamber is from about 50 to 300 mTorr, and the pressure in the transfer module is set at about 450 mTorr.  
     
     
         27 . The system of  claim 18 , wherein the etching chamber is purged with purified nitrogen gas after the etching process is carried out.