PROBLEM TO BE SOLVED: To provide a method of three-dimensionally integrating elements such as singulated dies or wafers and an integrated structure having connected elements such as singulated dies or wafers.SOLUTION: Either or both of the die and wafer have semiconductor devices formed therein. A first element having a first contact structure is bonded to a second element having a second contact structure. The first and second contact structures can be exposed at bonding and is electrically interconnected as a result of the bonding. A via may be etched and filled after bonding to expose and form an electrical interconnect to interconnect the first and second contact structures and provide electrical access to this interconnect from a surface. Alternatively, the first and/or second contact structures are not exposed at bonding, and a via is etched and filled after bonding to electrically interconnect the first and second contact structures and provide electrical access to the interconnected first and second contact structures.