Traceable quantitative analysis of Ag x Cu1-x alloy films by ID ICP-MS, RBS and MEIS

The measurement traceability of Rutherford backscattering spectroscopy (RBS), medium energy ion scattering spectroscopy (MEIS) and isotope dilution inductively coupled plasma mass spectrometry (ID ICP-MS) was compared for the quantitative analysis of alloy thin films. A set of thin Ag x Cu1-x alloy films were selected as a model alloy system for the quantitative analysis of MEIS and ID ICP-MS. Two sets of five Ag x Cu1-x alloy films with different mole fractions were grown on Si (100) wafers by ion beam sputter deposition. The mole fractions of thick Ag x Cu1-x alloy films (100 nm) measured by RBS and ID ICP-MS showed a great agreement within 0.4% difference. The mole fractions of thin Ag x Cu1-x alloy films (10 nm) measured with MEIS and ID ICP-MS also showed a small difference of about 1.0%. As a result, ID ICP-MS, RBS and MEIS can be used to certify the mole fractions of thin alloy reference films. ID ICP-MS is an absolute method for the mole fraction analysis of thin Ag x Cu1-x alloy films. Although the contribution of sample homogeneity was included, the uncertainties of ID ICP-MS results were much smaller than those of RBS and MEIS.