MECHANIC STUDY OF COPPER DEPOSITION ONTO GOLD SURFACES BY SCALING ANDSPECTRAL-ANALYSIS OF IN-SITU ATOMIC-FORCE MICROSCOPIC IMAGES

Copper electrodeposition rom three acidic solutions containing (i) no additive, (ii) 100 mu M benzotriazole, and (iii) 100 mu M thiourea was studied by in situ atomic force microscopy. The electrodeposited surf aces were analyzed on three levels: (i) qualitatively during in situ m onitoring of morphology evolution, (ii) quantitatively by scaling anal ysis of electrodeposited surface roughness during the course of deposi tion, and (iii) by modeling the spectral power density of the surface shape evolution. Major differences in deposit morphology were found be tween the three electrolytic solutions. All three levels of analysis g ave consistent interpretations of morphology evolution. Deposition fro m additive-free solutions leads to rough surface textures due to rough ening originating from surface diffusion. Addition of benzotriazole ac ts to smooth the deposit by diminishing surface diffusion. Deposits gr own from thiourea-containing solutions exhibit formation of three-dime nsional islands atop initially flat plates, reflecting a two-stage gro wth mechanism.