Hideki Matsunaga

Determination of impurities in strontium titanate ceramics by inductively coupled plasma mass spectrometry

The determination of impurities in SrTiO3 by ICPMS was investigated. The sample was decomposed with hydrochloric and hydrofluoric acids in a PTFE pressure vessel. The internal standard method using Au was selected to eliminate an ion count suppression by the Sr and Ti matrix. Impurities at sub μg/ml level in SrTiO3 were determined. The detection limits were in the range of 0.008 to 0.01 μg/g.

Evaluation of Ultratrace Metallic Impurities in Thin Copper Layers, Barrier Metals and Silicon Wafers for Copper Metallization Technology

An analytical method for the determination of ultratrace concentrations of metals in several semiconductor-related materials for copper metallization technology such as thin Cu layers, barrier metals and silicon wafers has been developed. Using this method, the concentration of Cu impurities in Si wafers resulting from diffusion of Cu from Cu metallization layers through barrier layers of TiN, TiSiN, or WSiN was found to be less than 1012 atoms/cm3.