Growth and Density Time Dependence of Electroless Cu Films Deposited onto Au Using Cu-EDTA-HCHO Bath

摘要

This article reports on the growth and density time dependence of electroless copper films deposited onto smooth gold surfaces as the fundamental background for studies of electroless copper morphology. Al/Au/Ti/Si(100) substrates were immersed in an alkaline electroless copper bath (0.04 M CuSO_4, 0.08 M ethylenediaminetetraacetic acid (EDTA), 0.004-0.24 M HCHO, 0.0004 M 2,2'-dipridyl) in order to obtain plated continuous films. Changing the HCHO concentration in the range of 0.04-0.24 M, both deposition rate and volumetric density rapidly increase followed by a slow increase tending to saturatation. Based on the mixed potential theory, a consistent explanation for this behavior is proposed.