Determination of ultratrace metallic impurities in silicon wafers by acid vapor decomposition/electrothermal vapolization ICP-MS

摘要

A method of acid vapor decomposition for determining ultratrace impurities in silicon wafers was developed. Ultratrace concentrations of Cr, Fe, Ni and Cu in an etching solution were determined by electrothermal vaporization ICP-MS (ETV/ICP-MS). (NH_4)_2SiF_6 was formed on a silicon surface by the acid vapor decomposition of HF/HNO_3. After a decomposition process, (NH_4)_2 SiF_6 was dissolved by 5ml of water.