Fabrication of 70 nm channel length polymer organic thin-film transistors using nanoimprint lithography

We report on the fabrication of short-channel polymer organic thin-film transistors (OTFTs) using nanoimprint lithography. Currently, there is significant interest in OTFTs due to their potential application in inexpensive, large-area electronics. However, polymer carrier mobilities are typically poor, and thus to increase the OTFT drive current per unit area, there is a need for short-channel devices. We have fabricated working devices with channel lengths from 1 μm down to 70 nm with high yields. The performance of these devices was studied as the channel length was reduced. We find that drive current density increases as expected, while the on/off current ratio remains ${10}^4.$ However, at short-channel lengths, OTFTs no longer saturate due to space charge limiting current effects.