This paper documents an experimental study to compare the behavior of bis-͑3-sodiumsulfopropyl͒ disulfide ͑SPS͒-Clpolyethylene glycol ͑PEG͒ and 3-mercaptopropanesulfonic acid sodium salt ͑MPSA͒-Cl-PEG additive systems during copper electrodeposition. These systems are analogous to those used industrially to plate copper lines onto integrated circuits. Galvanostatic experiments show that in the absence of chloride ion, either SPS or MPSA added to the plating solution inhibited copper deposition. Upon the addition of Cl − , a rapid transition from inhibition to acceleration was observed for both additives, illustrating the critical role played by the chloride ion in these systems. Potentiostatic experiments performed for the Cl-PEG-SPS and Cl-PEG-MPSA additive systems show that the potential dependency of the Cl-PEG-SPS system was much stronger than that of the MPSA-Cl-PEG system. Differences between the SPS and MPSA additive systems suggest that acceleration may occur through an MPSA pathway. Finally, results with chemical compounds similar to MPSA indicate that the thiol group is associated with inhibition and that a synergistic accelerating relationship exists between the sulfonate group and chloride, presumably due to complex formation.

This paper documents an experimental investigation of additive behavior in acidic copper plating solutions containing chloride ions, polyethylene glycol ͑PEG͒, and bis-͑3-sodiumsulfopropyl disulfide͒ ͑SPS͒. These solutions represent a simplified model of solutions used industrially for electroplating copper interconnects. Experiments were conducted with use of a rotating disk electrode under both galvanostatic and potentiostatic conditions and the transient behavior was observed. Linear sweep voltammetry was also performed. A transition time for the system to reach steady state was observed under both galvanostatic and potentiostatic conditions and found to be a strong function of SPS concentration. Superfilling is made possible by the existence of a long transition time that permits establishment of a significant rate difference between the top and bottom of the cavity. Experimental results provide evidence for slow adsorption and desorption of the accelerator and SPS incorporation into the deposit. Linear sweep voltammetry indicates that behavior of the accelerator is potential dependent. The same mechanism used to explain superfilling can be applied to explain the leveling/brightening of copper surfaces in these solutions.

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We describe the preparation of homogeneous olefin-terminated monolayers on scribed silicon made from 1,9-decadiene, and mixed monolayers with varying degrees of olefin termination prepared from 1,9-decadiene and 1-decene or 1-octene, and their subsequent reactions with bromine, osmium tetroxide, dicholorocarbene, and Grubbs' catalyst. Each of these reagents contains a heteroatom, which allows straightforward monitoring of the surface reactions by X-ray photoelectron spectroscopy (XPS). Surface reactions of mixed monolayers made from 1,9-decadiene and 1-octene are consistently more efficient than surface reactions of mixed monolayers made from 1,9-decadiene and 1-decene, presumably because of steric effects. After chemisorbtion of Grubbs' catalyst, ring-opening metathesis polymerization (ROMP) of norbornene is demonstrated. The kinetics of Grubbs' catalyst adsorption and of polynorbornene growth is monitored by XPS and time-of-flight secondary ion mass spectrometry (ToF-SIMS). A principal components analysis (PCA) of the ToF-SIMS data is presented. Autoscaling is shown to be a relatively ineffective preprocessing method for this data. Polynorbornene features on patterned substrates effectively resist and direct the electroless deposition of copper.