Reducing metal contamination of silicon wafer, comprises contacting the wafer with liquid medium, which comprises compounds that bind the metal contamination in complexes, and applying electrical voltage to the wafer

摘要

The method of reducing metal contamination of a silicon wafer, comprises: contacting the wafer with a liquid medium, which comprises compounds that bind the metal contaminations in complexes, complex-forming acids or salts or chelators; and applying an electrical voltage to the wafer, which is connected as anode. The liquid medium acts as an electrode for the deposition of metal contamination. The electrical contacting of the wafer is performed by transport rollers and a carrier in which the wafer is contacted itself with the liquid medium. The method of reducing metal contamination of a silicon wafer, comprises: contacting the wafer with a liquid medium, which comprises compounds that bind the metal contaminations in complexes, complex-forming acids or salts or chelators; and applying an electrical voltage to the wafer, which is connected as anode. The liquid medium acts as an electrode for the deposition of metal contamination. The electrical contacting of the wafer is performed by transport rollers and a carrier in which the wafer is contacted itself with the liquid medium. The transport rollers transport the wafer through the liquid medium. The wafer is simultaneously illuminated to increase a conductivity of the wafer. A magnetic field and an ultrasound act on the liquid medium and the wafer. The magnetic field is variable in time. The method is performed in combination with wet chemical steps of etching, cleaning or flushing during the processing of the silicon wafer. The liquid medium is an etching-, texturing-, cleaning- or flushing medium.