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 CuSO4, 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. (c) 2005 The Electrochemical Society.