A Thermal Model for Carbon Nanotube Interconnects.

Area of Science:

• Materials Science
• Electrical Engineering
• Semiconductor Physics

Background:

• Carbon nanotube (CNT) interconnects are crucial for advanced very large scale integration (VLSI) circuits.
• Understanding thermal effects like Joule heating is essential for predicting device performance and reliability.
• Existing current transport models require enhancement to incorporate thermal influences.

Purpose of the Study:

• To investigate the effects of Joule heating on CNT interconnects.
• To incorporate Joule heating-influenced scattering into a theoretical current transport model.
• To analyze the impact of Joule heating on CNT resistance and scattering parameters.

Main Methods:

• Development of a theoretical model incorporating Joule heating.
• Simulation of current transport in CNT interconnects.
• Analysis of scattering parameters (S12) for varying conditions.

Main Results:

• The theoretical model successfully explains resistance breakdown in CNTs due to Joule heating, limiting current density.
• For a 1 µm single-wall CNT, Joule heating reduces the 3 dB frequency in the S12 parameter from 1 THz to approximately 120 GHz.
• Scattering parameters are found to be highly sensitive to CNT length but minimally affected by bias voltage.

Conclusions:

• Joule heating is a critical factor limiting the performance of CNT interconnects in VLSI.
• The developed model provides a framework for understanding and predicting thermal breakdown in CNTs.
• Device length is a dominant factor influencing scattering characteristics, necessitating careful design considerations.