OFETs with sub-100 nm channel length fabricated by wafer-scale NIL and comprehensive DC and AC characterizations

• 4-Inch wafer-scale OFET matrices with min. 88 nm channel lengths were fabricated by NIL.
• Polymer working mold avoids the damage of the master wafer.
• OFETs with shorter channels obtain larger Id and higher effective charge mobility.
• Performances of OFETs with submicron channels depend seriously on contact behavior.
• OFETs’ dynamic gm and AC response speed scales proportionally to L−1.

Solution processed poly(3-hexylthiophene) organic field effect transistors with channel lengths down to 88 nm were fabricated by thermal nanoimprint lithography with 4-inch wafer-scale molds. Polymer based working templates avoided the damage of the high-valuable silicon master wafer during the imprint process caused by the high pressure at high temperature. This technique realized an improved throughput compared to chip-scale nanoimprint techniques reported in our previous works. It can be applied to produce large-area OFETs matrices used e.g. in display backplanes. The DC and AC response of OFETs with different channel dimensions were characterized including the transfer and output characteristics, short channel effects, effective charge carrier mobility, the frequency dependent transconductance, and the switching speed limits. Finally, the achievements as well as the therefrom induced limitations by downscaling OFETs channel lengths were summarized.

Figure optionsDownload as PowerPoint slide