Interconnection for monolithically integrated stacked devices and methods of forming thereof

A method of forming a monolithic integrated device, comprising:

• providing a second device over a first device comprising an interconnect and an interlevel dielectric layer surrounding the interconnect, the interconnect comprising a contact pad or a top metal of the first device,
• wherein the second device comprises a first conductive element, and a second conductive element arranged over the first conductive element;
• forming a via opening extending through the first conductive element and the second conductive element of the second device to the interconnect of the first device, wherein the via opening through the first conductive element has a first via width and the via opening through the second conductive element has a second via width wider than the first via width;
• and
• forming a via contact in the via opening to contact the first conductive element, the second conductive element, and the interconnect of the first device;
• wherein the via contact electrically connects the first conductive element and the second conductive element of the second device to the interconnect of the first device.