Large Scale Complementary Integrated Circuits Based on Organic Transistors

Organic and polymer based thin-film transistors have been proposed for a number of applications such as displays and radio-frequency (RF) identification tags. The principal motivating factors for the use of organic transistors are the lower cost and simpler packaging as well as demonstrated compatibility with flexible substrates. In digital circuits, such as those used in RF tags, minimal power dissipation and stability against transistor parameter variation are crucial. As in silicon technology, the use of complementary logic for organics should result in reduced power dissipation, improved noise margins, and greater stability of circuit operation. Complementary inverters and ring oscillators based on organic semiconductors have been already reported. We have now realized integration scales of up to 864 transistors/circuit and 0.5-1 kHz operation in clocked sequential complementary circuits. This demonstration establishes for the first time that n-channel and p-channel organic transistors can be combined to yield logic circuits of adequate complexity and scale.