Gap-filling dynamics of several different species of additives for copper electrodeposition was investigated by monitoring the cross section of a partially filled copper profile on the scanning electron microscopy photo. The filling ration ⌬y/⌬x between ''bottom-up'' with ''sidewall shift'' was found to be proportional to the filling power of additives. The adsorption-diffusion model combined with cathode polarization and cyclic voltammetric stripping measurements was employed to explain the attribution of additives in superfilling phenomena. The superfilling dynamics was achieved under behavior of additives providing selective inhibition gradient within the damascene feature. By means of those analyses, we have optimized the appropriate amount of additives and achieved the superfilling performance for 0.15 m vias with aspect ratio 6 by an acid-copper electrolyte with polyethylene glycol, C1 Ϫ , and 2-mercaptopyridine ͑2-MP͒. Due to the additive of 2-MP, chelate formed which enhanced adsorption ability on Cu 0 surface, and the concentration gradient between side-wall shift and bottom-up in the damascene became high enough to attend superfilling electroplating.

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Since this potentially life-threatening adverse effect of daptomycin appears more common than previously reported, clinicians should have a high level of suspicion in any patient with recent daptomycin exposure who presents with pulmonary symptoms. In many cases, this process is highly responsive to prompt initiation of corticosteroid therapy.

The removal selectivity control of aluminum and titanium metal barrier during aluminum chemical mechanical polishing in the Damascene process is known to be critical for surface planarity without metal dishing and dielectric erosion. Unfortunately, the electrochemical behaviors of aluminum and titanium are dissimilar, as one may expect. In this study, in situ electrochemical impedance spectroscopy was carried out to investigate the influences of H 2 O 2 concentration, slurry pH, and metal oxide formation through the passivation on aluminum and titanium. As H 2 O 2 concentration increases, the measured impedance of aluminum and titanium decreases, or the oxidation rates of these two metals are enhanced upon increasing the oxidizer concentration. As the slurry pH increases, the removal rate of polished titanium increases, but it decreases for polished aluminum. The removal rate of titanium was limited to its oxidation rate and aluminum was limited to its oxide dissolution rate.Chemical mechanical polishing ͑CMP͒ has long been recognized as a promising technique for global planarization to delineate metal patterns for submicrometer integrated circuit ͑IC͒ processing. 1-3 Aluminum ͑Al͒ and its alloys have traditionally been used as multilevel interconnects and have emerged as the most important material for such applications. On the other hand, it is well known that titanium ͑Ti͒ is an effective metal barrier. 4 The total process time for Al CMP is also controlled by the removal of the Ti diffusion barrier. Little research has been devoted to the CMP of this barrier film. Since Ti is harder than Al, a lower Ti removal rate is therefore expected.Because Al is soft and easily scratched, polishing on a softer pad has therefore been suggested to avoid severe surface damage, but this technique can produce unwanted pattern geometry effects like metal dishing and interlevel dielectric ͑ILD͒ erosion. 5 Therefore, a two-step CMP process has usually been implemented. For the first step, the overburden Al would be planarized for the step-high reduction, be removed faster and uniformly, and stopped as Ti exposed. For the second step, both Al and Ti outside of trenches would be removed simultaneously and stopped as the ILD exposed. The control of removal selectivity is therefore very critical in the second step. In the ideal case, Al, Ti, or TiN and ILD would be expected to remove at the same rate, or it would result in metal dishing, oxide erosion, and surface nonplanarity. Overpolishing for the complete removal of overburden metals outside of trenches would further induce surface nonplanarity.Kaufman et al. 6 has proposed a desirable removal mechanism for metal CMP which involves the oxidation of metal to form passive surface oxide and dissolution of this metal oxide under polishing stress. No direct metal corrosion to form soluble metallic ions or direct mechanical abrasion on nonoxidized metal substrates would be allowed for CMP, and it would result in the issues of metal corrosion and surface scratching. The formation and di...

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