A New Cleaning Solution for Metallic Impurities on the Silicon Wafer Surface

Tsugio SHIMONO  Mikio TSUJI  

IEICE TRANSACTIONS on Electronics   Vol.E75-C   No.7   pp.812-815
Publication Date: 1992/07/25
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on Ultra Clean Technology)
silicon wafer,  matallic impurity,  cleaning technology,  cleaning solution,  

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A new cleaning solution (FPM; HF-H2O2-H2O) was investigated in order to remove effectively metallic impurities on the silicon wafer surface. The removability of metallic impurities on the wafer surface and the concentrations of metallic impurities adsorbed on the wafer surface from each contaminated cleaning solution were compared between FPM and conventional cleaning solutions, such as HPM (HCl-H2O2-H2O), SPM (H2SO4-H2O2), DHF (HF-H2O) and APM (NH4OH-H2O2-H2O). This new cleaning solution had higher removability of metallic impurities than conventional ones. Adsorption of some kinds of metallic impurities onto the wafer surface was a serious problem for conventional cleaning solutions. This problem was solved by the use of FPM. FPM was important not only as a cleaning solution for metallic impurities, but also as an etchant. Furthemore, this new cleaning solution made possible to construct a simple cleaning system, because the concentrations of HF and H2O2 are good to be less than 1% for each, and it can be used at room temperature.