A method includes forming elongate structures on a first substrate, such that the material composition of each elongate structure varies along its length so as to define first and second physically different sections in the elongate structures. First and second physically different devices are then defined in the elongate structures. Alternatively, the first and second physically different sections may be defined in the elongate structures after they have been fabricated. The elongate structures may be encapsulated and transferred to a second substrate. The invention provides an improved method for the formation of a circuit structure that requires first and second physically different devices to be provided on a common substrate. In particular, only one transfer step is necessary.