The feasibility of using a thiosulfate-sulfite bath to electrodeposit soft gold for microelectronic applications has been investigated. This bath is stable at near-neutral pH, shows good compatibility with positive photoresists, and does not contain any additives. It was found that the bath produced gold bumps with straight sidewalls, flat top surfaces, and a good reproduction of the resist pattern was achieved. The thickness uniformity, roughness, stress, hardness, adhesion, and shape of the plated structures were found to be compatible with the requirements for a wide range of microelectronic applications, including wafer bumping. (C) 2003 The Electrochemical Society.