Capacitance measurements have been used to localize the position of semiconductor band edges before and during the early stages of electrodeposition of various metals on n-GaAs and n-InP. Energy diagrams of the contact during film formation indicate a close relation between the movements of band edges of the semiconductor and the mechanism of electrochemical deposition. Results yield information regarding electron transfer during nucleation. It seems that surface states are involved as mediators. An example illustrates the fundamental importance of the early stages of electron transfer for the final properties of the interface. A method using a double pulse is used successfully to overcome this difficulty in the case of InP.