Printed, short-channel, top-gate carbon nanotube thin-film transistors on flexible plastic film

Abstract

We fabricated sub-10-µm-class short-channel, top-gate carbon nanotube thin-film transistors using a flexographic printing technique, which is a high-speed printing technique that uses a flexible polymer plate. This device fabrication process is completely photolithography-free and vacuum-free as a result of the printing technique. The printing resolution was improved by using micro-flexo plates fabricated by a microprocessing technique. The fabricated device, with a channel length of 9.5 µm, exhibited a high on-current of 0.94 mA/mm. Hysteresis was suppressed by introducing a top-gate structure.

Formulation of Sol–Gel Derived Bismuth Silicate Dielectric Ink for Flexible Electronics Applications

“…One of the added advantage of printed technology compared to the photolithography driven conventional electronics is its rather simplicity in the fabrication 1 . Within short time since the last decade, printed electronics has made rapid strides both in low and high performance domains like flexible displays, smart labels, decorative paints 2 , antennas 3 , RFIDs 3 , fuel cells 4 , sensors 5,6 , solar cells 7 , thin film transistors (TFT) 8,9 , multilayer ceramic capacitors (MLCC) 10 etc. Different techniques such as screen printing, ink jet printing and gravure printing are commonly adopted for imprinting conducting, semiconducting and dielectric ink onto various substrates 11 .…”

Inkjet Printing of High Performance Transistors with Micron Order Chemically Set Gaps

“…In theory this yields a gap where the width is limited by the resolution of the printer. Given that a printer like the Dimatix has a resolution of 10–30 µm depending on drop volume 13 , this provides a small gap, but by no means a short channel compared to photolithographic methods in a CMOS foundry 4 , 5 .…”

“…One of the more difficult ones is the feature size, which is currently limited to ~30 microns using traditional inkjet methods 2 . Several different methodologies have been developed for working around these limitations, such as imprinting 3 or flexographic printing 4 . While these methodologies allow for micron order feature sizes 5 , they require lithographically defined patterns/masks, minimizing the unique flexibility that inkjet printing allows.…”

“…For printed technology to satisfy the current day requirements and become sustainable in the future, channel lengths under 1 μm are required. Several different methodologies have been developed for working around the fundamental printed channel length limitations, such as imprinting 7 , 8 and flexographic printing 4 . While these methodologies allow for micron order feature sizes 4 , they still require lithographically defined patterns/masks, minimizing the unique flexibility and low cost options that printing allows.…”

“…Several different methodologies have been developed for working around the fundamental printed channel length limitations, such as imprinting 7 , 8 and flexographic printing 4 . While these methodologies allow for micron order feature sizes 4 , they still require lithographically defined patterns/masks, minimizing the unique flexibility and low cost options that printing allows. Recently, a print-and-drag (PND) method was demonstrated to provide 2–13 μm channels 9 , and another process relying on mechanically splitting a printing metal pad by dragging a probe tip across to produce channels in the range of 200 nm–600 nm was demonstrated 9 , however, these methods are not scalable or compatible with additive manufacturing processes.…”