Large-scale complementary carbon nanotube integrated circuits for harsh radiation environments.

Area of Science:

• Materials Science
• Electrical Engineering
• Nanotechnology

Background:

• Silicon integrated circuits require complex hardening for radiation environments, causing performance issues.
• Carbon nanotubes (CNTs) possess inherent properties suitable for high-performance, radiation-tolerant electronics.
• Fabrication challenges have limited the development of macroelectronic devices using CNT field-effect transistors (CNTFETs).

Purpose of the Study:

• To demonstrate the fabrication of radiation-tolerant complementary CNTFETs for macroelectronic applications.
• To evaluate the performance of CNTFET-based logic gates and ring oscillators under radiation exposure.
• To assess the potential of CNTFETs as a replacement for silicon-based transistors in radiation-intensive environments.

Main Methods:

• Fabrication of radiation-tolerant, highly symmetric, and uniform CMOS building blocks using CNTFETs.
• Implementation of various logic gates (inverters, NAND, XOR) and ring oscillators (ROs) with different stages (5, 11, 501).
• Irradiation of fabricated devices up to 6 Mrad(Si) to test radiation tolerance.

Main Results:

• All fabricated CNTFET devices maintained rail-to-rail outputs after irradiation up to 6 Mrad(Si).
• A 501-stage ring oscillator, comprising 1004 CNTFETs, exhibited minimal delay variation (10.3 ± 0.8 ns).
• Demonstrated the radiation tolerance of large-scale CNTFET circuits.

Conclusions:

• Large-scale complementary CNTFETs are radiation-tolerant and maintain stable operation.
• CNTFETs show significant potential to replace silicon-based field-effect transistors in radiation-heavy applications.
• This work paves the way for advanced electronics in harsh environments.