High-Speed Operation of Vertical Type Organic Transistors Utilizing Step-Edge Structures

An organic transistor having a novel structure, step-edge vertical-channel organic field-effect transistor (SVC-OFET), with a short channel length has been fabricated by a low-cost self-alignment process. The short channel is formed in the vertical direction along the side wall of a step-edge structure. The SVC-OFET structure also has an advantage in reducing the parasitic capacitance between the gate and drain electrodes. A short channel and reduced capacitance are important properties for a high-speed operation. The cutoff frequency achieved was approximately 900 kHz, which is a very high value for organic transistors.