Methods for forming an integrated device using CMOS processing with wafer bonding. In an embodiment, a method is disclosed that includes defining an integrated circuit function using a front-end substrate having one or more active devices and a back-end substrate having connections formed in metal layers in dielectric material, wherein the back-end substrate is free from active devices; manufacturing the front-end substrate in a first semiconductor process; more or less simultaneously, manufacturing the back-end substrate in a second semiconductor process; physically contacting bonding surfaces of the front-end substrate and the back-end substrate; and performing wafer bonding to form bonds between the front-end and back-end substrates to form an integrated circuit. Additional methods are disclosed.