Thin film transistors

The specification describes thin film transistor integrated circuits wherein the TFT devices are field effect transistors with inverted structures. The interconnect levels are produced prior to the formation of the transistors. This structure leads to added flexibility in processing. The inverted structure is a result of removing the constraints in traditional semiconductor field effect device manufacture that are imposed by the necessity of starting the device fabrication with the single crystal semiconductor active material. In the inverted structure the active material, preferably an organic semiconductor, is formed last in the fabrication sequence. In a preferred embodiment the inverted TFT devices are formed on a flexible printed circuit substrate.