US Patent 9640445 Methods of fabricating switched-capacitor DC-to-DC converters

A method of fabricating a switched-capacitor converter includes providing a semiconductor layer having a top surface and a bottom surface, forming switching elements on the top surface of the semiconductor layer, forming a first insulation layer and first interconnection patterns on the switching elements, forming a second insulation layer over the first insulation layer and the first interconnection patterns, forming a second interconnection pattern over the second insulation layer, forming a third insulation layer over the second insulation layer and the second interconnection pattern, forming third interconnection patterns and a lower interconnection pattern over the bottom surface of the semiconductor layer, forming a capacitor over the lower interconnection pattern, forming a fourth insulation layer over the bottom surface of the semiconductor layer to expose an upper electrode pattern of the capacitor, forming a fifth insulation layer covering the capacitor, and forming pads in the fifth insulation layer.