Chamber cleaning method using f2 and a process for manufacture of f2 for this method

Abstract

Elemental fluorine is often manufactured electrochemically from a solution of KF in hydrogen fluoride (HF) and contains varying amounts of HF as impurity. The present disclosure relates to a method for chamber cleaning using F 2 containing more than 0.1% by weight and equal to or less than 10% by weight of HF. Surprisingly, such an F 2 is very well suited for the purpose of chamber cleaning.

1 . A method for the cleaning of chambers, the method comprising using F 2  which contains more than 0.01% by weight and less than 10% by weight of HF. 
     
     
         2 . The method of  claim 1  wherein the F 2  contains equal to or more than 1% by weight of HF, and a content of equal to or less than 2% by weight of HF. 
     
     
         3 . The method of  claim 1  wherein the chamber is a CVD chamber. 
     
     
         4 . The method of  claim 1  wherein the chamber is used during the manufacture of a semiconductor, a micro-electromechanical system, TFT (flat panel display) or a solar cell for depositing at least one layer. 
     
     
         5 . The method of  claim 1  wherein F 2  is applied which was obtained in a process comprising the following steps (I) and (II):
 A step (I) comprising 
 A) at least one step of electrolytically producing raw F 2  from HF in the presence of KF 
 B) at least one step of removing particles entrained in the raw F 2  obtained in step A) 
 C) at least one step of filtering any remaining particles out of the F 2  leaving step B) 
 and 
 D) a step of providing F 2  to a buffer tank or a storage tank; 
 and 
 A step (II) wherein F 2  is withdrawn from the buffer tank or storage tank and delivered to a chamber to perform a t least one step of chamber cleaning. 
 
     
     
         6 . The method of  claim 5  wherein the F 2  was obtained in step (I) in a process comprising the following steps:
 A) a step of electrolytically producing raw F 2  from HF in the presence of KF 
 B) a step of removing particles entrained in the raw F 2  obtained in step A) 
 C) a step of filtering any remaining particles out of the F 2  leaving step B) 
 and 
 D) a step of delivering F 2  to a buffer tank or a storage tank. 
 
     
     
         7 . The method of  claim 5  wherein the particle filter of step C) comprises pores having a diameter between 0.01 and 20 μm. 
     
     
         8 . (canceled) 
     
     
         9 . The method of  claim 5  wherein the steps A) to D) are performed on the site of chamber cleaning. 
     
     
         10 . The method of  claim 9  wherein step A) is performed in an electrolyzer, step B) is performed in a static scrubber, step C) is performed using a metallic filter, step D) is performed in a buffer tank or storage tank, and the F 2  leaving step D) is delivered to at least one chamber and used in the chamber in a chamber cleaning step (II), wherein the electrolyzer, the static scrubber, the metallic filter, the buffer tank or storage tank, and the at least one chamber are operably connected. 
     
     
         11 . The method of  claim 10  wherein the pressure of the F 2  in each of the steps B) to D) and (II) is lower than the pressure of F 2  in the preceding step. 
     
     
         12 . The method of  claim 5  wherein the F 2  pressure in step A) is equal to or lower than 1.1 bar (abs). 
     
     
         13 . The method of  claim 11  wherein the F 2  is delivered to the chamber in step (II) at a pressure from equal to or greater than 0.2 bar (abs) to equal to or lower than 0.55 bar (abs). 
     
     
         14 . A process for the manufacture of F 2  which contains more than 0.1% by weight and equal to or less than 10% by weight of HF, the process comprising the following steps:
 A) at least one step of electrolytically producing raw F 2  from HF in the presence of KF   B) at least one step of removing particles entrained in the raw F 2  obtained in step A)   C) at least one step of filtering any remaining particles out of the F 2  leaving step B)   and   D) a step of delivering the F 2  to a buffer tank or a storage tank.   
     
     
         15 . The process of  claim 14  for the manufacture of F 2  which contains more than 0.1% by weight and equal to or less than 2.5% by weight of HF, comprising the following steps:
 A) a step of electrolytically producing raw F 2  from HF in the presence of KF 
 B) a step of removing particles entrained in the raw F 2  obtained in step A) 
 C) a step of filtering any remaining particles out of the F 2  leaving step B) 
 and 
 D) a step of delivering the F 2  to a buffer tank or a storage tank, 
 wherein the F 2  pressure in step A) is equal to or lower than 1.1 bar (abs), the pressure of the F 2  provided to the chamber to be cleaned is from equal to or greater than 0.2 bar (abs) to equal to or lower than 0.55 bar (abs), and wherein the pressure of the F 2  in each of the steps B) to D) is lower than the pressure of F 2  in the preceding step. 
 
     
     
         16 . The method of  claim 11  wherein the F 2  is not subjected to a pressurizing treatment. 
     
     
         17 . The method of  claim 5  wherein the filter used in step C) is cleaned with liquid HF. 
     
     
         18 . The method according to  claim 17  wherein the cleaning HF is recovered and fed to a step of electrolytically producing F 2 . 
     
     
         19 . The process of  claim 15  wherein the F 2  is not subjected to a pressurizing treatment. 
     
     
         20 . The process of  claim 14  wherein the filter used in step C) is cleaned with liquid HF. 
     
     
         21 . The process of  claim 20  wherein the cleaning HF is recovered and fed to a step of electrolytically producing F 2 .