Apparatus and methods for removing metallic contamination from wafer containers

Abstract

In a method for cleaning for cleaning metallic ion contamination, and especially copper, from wafer containers, the containers are loaded into a cleaning apparatus. The containers are sprayed with a dilute chelating agent solution. The chelating agent solution removes metallic contamination from the containers. The containers are then rinsed with a rinsing liquid, such as deionized water and a surfactant. The containers are then dried, preferably by applying heat and/or hot air movement.

What is claimed:  
     
         1 . A method for removing a metal from a wafer container, comprising the steps of: 
 spraying the container with a solution of a liquid including a metal removing agent;    rinsing the container; and    drying the container.    
     
     
         2 . The method of  claim 1  wherein the metal removing agent comprises a chelating agent.  
     
     
         3 . The method of  claim 2  wherein the concentration of the chelating agent in the solution is 10-100 parts per million.  
     
     
         4 . The method of  claim 3  wherein the concentration of the chelating gent is 20-60 parts per million.  
     
     
         5 . The method of  claim 1  wherein the metal comprises copper.  
     
     
         6 . A method for removing a metal from a wafer container, comprising the steps of: 
 immersing the container at least partially into a bath of a solution including a metal removing agent;    rinsing the container; and    drying the container.    
     
     
         7 . The method of  claim 6  wherein the metal removing agent comprises a chelating agent.  
     
     
         8 . The method of  claim 6  wherein the concentration of the chelating agent in the solution is 10-100 parts per million.  
     
     
         9 . The method of  claim 6  wherein the containers are rinsed by immersing the containers into a bath of a rinsing liquid.  
     
     
         10 . The method of  claim 6  wherein the solution of comprises a chelating agent and de-ionized water.  
     
     
         11 . The method of  claim 1  further comprising the step of spraying the containers with a surfactant solution.  
     
     
         12 . The method of  claim 11  with the liquid including the surfactant solution.  
     
     
         13 . A machine for cleaning a metal from wafer containers, comprising: 
 an enclosure;    a plurality of container holders within the enclosure;    a plurality of spray nozzles within the enclosure;    a de-ionized water source connected to at least some of the spray nozzles; and    a metal removal chemical source, connected to at least one of the spray nozzles.    
     
     
         14 . The machine of  claim 13  wherein the metal removal chemical source comprises a source of chelating agent.  
     
     
         15 . The machine of  claim 14  wherein the spray nozzles include inner spray nozzles positioned within the container, and outer spray nozzles, and with the metal removal chemical source connecting to one or more of the inner and outer spray nozzles.  
     
     
         16 . The machine of  claim 15  further comprising a pump for pumping the metal removal chemical source into a water supply line leading to the one or more inner and outer spray nozzles.  
     
     
         17 . The machine of  claim 15  further comprising a surfactant source connecting to one or more of the spray nozzles.