Fast Flexible Transistors with a Nanotrench Structure.
The simplification of fabrication processes that can define very fine patterns for large-area flexible radio-frequency (RF) applications is very desirable because it is generally very challenging to realize submicron scale patterns on flexible substrates. Conventional nanoscale patterning methods, such as e-beam lithography, cannot be easily applied to such applications. On the other hand, recent advances in nanoimprinting lithography (NIL) may enable the fabrication of large-area nanoelectronics, especially flexible RF electronics with finely defined patterns, thereby significantly broadening RF applications. Here we report a generic strategy for fabricating high-performance flexible Si nanomembrane (NM)-based RF thin-film transistors (TFTs), capable of over 100 GHz operation in theory, with NIL patterned deep-submicron-scale channel lengths. A unique 3-dimensional etched-trench-channel configuration was used to allow for TFT fabrication compatible with flexible substrates. Optimal device parameters were obtained through device simulation to understand the underlying device physics and to enhance device controllability. Experimentally, a record-breaking 38 GHz maximum oscillation frequency fmax value has been successfully demonstrated from TFTs with a 2 μm gate length built with flexible Si NM on plastic substrates.
Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA.
Jung-Hun
JH
Seo
Department of Electrical Engineering and Computer Science, University of Michigan-Ann Arbor, Ann Arbor, MI 48109, USA.
Tao
T
Ling
Department of Biomedical Engineering and Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI 53706, USA.
Shaoqin
S
Gong
Department of Electrical Engineering, University of Texas at Arlington, Arlington, TX 76019, USA.
Weidong
W
Zhou
University of California - Berkeley, Berkeley, CA 94720, USA.
Alice L
AL
Ma
Department of Electrical Engineering and Computer Science, University of Michigan-Ann Arbor, Ann Arbor, MI 48109, USA.
L Jay
LJ
Guo
Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA.
Zhenqiang
Z
Ma