High-purity fluorine gas, the production and use thereof, and a method for monitoring impurities in a fluorine gas

Abstract

An apparatus for producing a fluorine gas, comprising at least one fluorine generating cell, and at least one fluorine generating cell detector for detecting components of products obtained by the fluorine generating cell, wherein at least one of the fluorine generating cells is connected with the fluorine generating cell detector.

1 . An apparatus for producing a fluorine gas, comprising at least one fluorine generating cell, and at least one fluorine generating cell detector for detecting components of products obtained by the fluorine generating cell, wherein at least one of the fluorine generating cells is connected with the fluorine generating cell detector. 
     
     
         2 . The apparatus according to  claim 1 , wherein the fluorine generating cell detector detects impurities presented in the fluorine obtained by the fluorine generating cell. 
     
     
         3 . The apparatus according to  claim 1 , wherein the fluorine generating cell detector comprises:
 (a) a sampler operable to withdraw a sample from the product obtained from the fluorine generating cell;   (b) a scrubber for destroying any fluorine and HF from the sample and producing a gas stream optionally containing impurities;   (c) a means for detecting impurities contained in the gas stream recovered from the scrubber.   
     
     
         4 . The apparatus according to  claim 1 , wherein the fluorine generating cell detector detects CF 4  present in the fluorine obtained by the fluorine generating cell. 
     
     
         5 . The apparatus according to  claim 1 , wherein the fluorine generating cell detector is a UV analyzer. 
     
     
         6 . The apparatus according to  claim 5 , wherein the UV analyzer operates with UV light in a range of 250 to 330 nm. 
     
     
         7 . The apparatus according to  claim 1 , comprising two or more fluorine generating cells wherein each fluorine generating cell is independently connected with the fluorine generating cell detector. 
     
     
         8 . The apparatus according to  claim 1 , further comprising a control means for independently opening or closing said fluorine generating cell. 
     
     
         9 . The apparatus according to  claim 8 , wherein the fluorine generating cell detector is independently connected with the control means respectively. 
     
     
         10 . A method for producing a fluorine gas, comprising providing the apparatus for producing fluorine gas according to  claim 1 , and further comprising electrolysis of a molten compositions comprising KF and HF in the at least one fluorine generating cell to produce the fluorine gas, wherein components of products obtained by the fluorine generating cell are detected by the at least one fluorine generating cell detector. 
     
     
         11 . (canceled) 
     
     
         12 . (canceled) 
     
     
         13 . A process for manufacturing a semiconductor, a photovoltaic cell, or a thin film transistor (TFT), comprising a step (a) wherein fluorine is produced by the method according to  claim 10  and comprising a step (b) selected from the group consisting of:
 feeding the fluorine obtained in step (a) into a semiconductor processing system, a system for processing a photovoltaic cell, or a system for processing a thin film transistor to etch the semiconductor, the photovoltaic cell, or the thin film transistor with elemental fluorine; and 
 feeding the fluorine obtained in step (a) into a process chamber cleaning system to clean a process chamber used during the manufacture of the semiconductor, the photovoltaic cell, or the thin film transistor. 
 
     
     
         14 . (canceled) 
     
     
         15 . (canceled) 
     
     
         16 . The apparatus according to  claim 5  wherein the UV analyzer operates with UV light in a range of from 270 to 290 nm. 
     
     
         17 . The method of  claim 10  wherein the fluorine generating cell detector is a UV spectrometer. 
     
     
         18 . The method of  claim 17  wherein UV absorption between 270 and 290 nm is measured to monitor the increase and decrease of the F 2  concentration. 
     
     
         19 . The method of  claim 18  wherein, after the detection of a decrease of more than 0.1% by volume of the fluorine content, the fluorine generating cell is separated from the production. 
     
     
         20 . The method of  claim 19  further comprising shutting down and repairing the fluorine generating cell when the fluorine content decreases further. 
     
     
         21 . The apparatus of  claim 3  wherein the means for detecting impurities is selected from the group consisting of a gas chromatography (GC) detector, a thermal conductivity detector, a tunable diode laser (TDL) spectrometer, and a Fourier Transform IR (FTIR) detector.