High-Performance Complementary Transistors and Medium-Scale Integrated Circuits Based on Carbon Nanotube Thin Films.

Area of Science:

• Materials Science
• Nanotechnology
• Electronics Engineering

Background:

• Solution-derived carbon nanotube (CNT) network films offer potential for wafer-scale fabrication of field-effect transistors (FETs) and integrated circuits (ICs).
• Achieving high-performance, stable complementary metal-oxide semiconductor (CMOS) FETs with high yield on CNT films remains a significant challenge, hindering IC development.

Purpose of the Study:

• To develop a doping-free fabrication process for CMOS FETs utilizing solution-processed CNT network films.
• To control FET polarity by selective carrier injection using scandium (Sc) or palladium (Pd) source/drain contacts.
• To demonstrate the feasibility of fabricating complex integrated circuits with high yield and performance.

Main Methods:

• Fabrication of top-gated CMOS FETs using solution-processed CNT network films.
• Utilizing Sc or Pd as source/drain contacts to achieve doping-free polarity control.
• Characterization of FET performance, symmetry, scalability, and construction of various CMOS integrated circuits.

Main Results:

• Fabricated CMOS FETs exhibited high symmetry between n- and p-type device characteristics.
• Demonstrated high-performance uniformity and excellent scalability down to a 1 μm gate length.
• Successfully constructed various CMOS ICs, including logic gates, sequential circuits, and arithmetic units, with rail-to-rail outputs.

Conclusions:

• The developed doping-free process enables high-performance, stable, and scalable CMOS FETs on CNT network films.
• The technology facilitates the construction of complex CMOS integrated circuits with high yield, as evidenced by 100% yield in 4-bit full adders.
• This advancement holds significant potential for the development of medium-scale integrated circuits based on CNT network films.