Separation And Determination Of Chip Copper Interconnects Of High Purity Copper Sulfate

In order to meet the strict demand of IC feature sizes, it is required that the each content of Ag, Al, Ca, Cd, Co, Cr, Fe, K, Mg, Na, Mn, Ni, Pb, Au, Ti in high-purity copper sulfate solution for copper interconnect chip is less than 0.1 ppm.Therefore, it is essential to establish a simple and accurate determination of the impurities.Although the detection limit of the modern instrumental is getting lower and lower.But because of the interference of matrix, it is difficult to analysiz directly. Therefore separation techniques are used to improve the analytical method sensitivily and selectivily.Solid-Phase extraction (SPE) technique combined with different detection techniques has become increasingly popular in trace elements separation and detection. And the choice of solid-Phase adsorbents is the decisive factor that affects analytical sensitivity and selectivity, so, it has still been a heated research field to find new and effective adsorbents nowadays.Carbon nanotubes (CNT) have attracted great attention because of their unique morphologies and surface characteristics. CNTs can be visualized as a sheet of graphite that has been rolled into a tube, which is hollow and with two ends of pentagonal or heptagonal carbon ring. The possible existence of defects makes it modified easily. Due to their curved internal surface, nanotubes show a stronger binding ability for molecules.The hexagonal arrays of carbon atoms in graphene sheets of CNTs surface have a strong interaction with other molecules or atoms, which make CNTs an ideal adsorbent material.CNTs are chosen as adsorbents in this dissertation. They are modified, and used to separate and enrich copper-based in high-purity copper sulfate solution.The trace element impurities are left in the residue solution, which are analysized by inductively coupled plasma atomic emission spectrometry (ICP-OES) at last..The adsorption characteristics of certain trace elements ions on multiwalled carbon nanotubes acidified are studied and the conditions for preconcentration of trace elements are optimized.In an innovative way, CNTs are modified by L-tyrosine.The new formed carbon nanotubes can adsorbe copper selectivity in the high purity copper sulfate.So a new method has been developed for preconcentration.19 trace impurity elements in high-purity copper sulfate solution for copper interconnect chip are determined by inductively coupled plasma-atomic emission spectroscopy (ICP-OES) after preconcentration.In this dissertation, the effect of RF and working gas (including air cooled, auxiliary gas, carrier gas) on the SBR is studied. The right spectral lines are chosen out.The detection method has better advantages of accuracy, precision and rapid. The detection limit of the method is 0.0001-0.024mg/L.The recovery rates were in the rang of 89.6%-100.7% with RSD <5%. The result can meet the requirement of the determination of 19 impurity elements in high-purity copper sulfate solution for copper interconnect chip.