화학공학소재연구정보센터
Journal of the Electrochemical Society, Vol.154, No.8, D369-D375, 2007
Cleaning of soldered silicon surface after alkaline etching and contamination with lead impurities
Lead impurities were deposited on a Si surface after the chemical etching and cleaning processes were evaluated by measuring the work function on a silicon chip having a mesa-type structure. Ultraviolet-ray photoelectron analysis in the air and Maxwell stress microscope analysis were utilized for this evaluation. The values of work function on the Si surface are influenced by the cleaning technique employed. A low work function corresponds to Pb impurities observed by scanning electron microscopy. The electrochemical behavior of lead was investigated using the electrochemical quartz crystal microbalance (EQCM) technique on Au electrodes in alkaline aqueous solutions. The interface mass of an Au electrode modified with a Pb monolayer decreases significantly due to the oxidation and dissolution of Pb in the range of 0.25-0.6 V. A thin film of Pb deposited on the electrode easily oxidizes and dissolves in the range of 0.25-1.0 V. (c) 2007 The Electrochemical Society.