Investigation of copper deposition in the presence of benzotriazole

Abstract

The effect of benzotriazole (BTA) on copper electroplating for ultra large-scale integrated circuits interconnection was investigated. BTA exhibited both strong suppressing and brightening effects by modifying the nucleation and growth steps. Electroplating in the presence of BTA followed a random deposition mechanism rather than a selective or preferential deposition mechanism. As a result, the crystal orientation intensity and mean aggregates size of the electroplated copper with BTA were much smaller than those of BTA-free, which resulted in an increase in resistivity. The increased resistivity of the electroplated copper in the presence of BTA was recovered to approximately 2 muOmega-cm through annealing at 400 degreesC in a nitrogen atmosphere by grain growth and recrystallization. The amounts of carbon and nitrogen impurities from the BTA were below the detection limit of Auger electron spectroscopy. (C) 2002 Elsevier Science B.V. All rights reserved.