In a metallization system of a semiconductor device, a transition via may be provided with an increased degree of tapering by modifying a corresponding etch sequence. For example, the resist mask for forming the via opening may be eroded once or several times in order to increase the lateral size of the corresponding mask opening. Due to the pronounced degree of tapering, enhanced deposition conditions may be accomplished during the subsequent electrochemical deposition process for commonly filling the via opening and a wide trench connected thereto.