Aligned Carbon Nanotube FETs With High Transconductance and Low Subthreshold Swing

Aligned carbon nanotubes (A-CNTs) with high semiconducting purity have been demonstrated to construct field effect transistors (FETs) with high performance including high on-state current (I<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ON</sub>) and transconductance (g<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</sub>) owing to the high carrier mobility. However, the reported high-performance A-CNT FETs always suffer high subthreshold swing (SS) and drain off-state current (I<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">OFF</sub>). In this work, we report A-CNT FETs with both of high performance and necessary low off-state current through improving the structure and fabrication process. The FETs with 100 nm gate length present an I<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ON</sub> above 2 mA/μm, a peak g<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</sub> of 1.37 mS/μm, simultaneously a SS below 100 mV/decade and an I<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">OFF</sub> of 100 nA/μm. The comprehensive excellent on- and off-state performance of our A-CNT FET demonstrates comparable performance to the 65 nm node silicon PMOS FETs.