Variability Study of MWCNT Local Interconnects Considering Defects and Contact Resistances--Part I: Pristine MWCNT

Abstract

In this paper, an enhanced compact model of multiwalled carbon nanotube (MWCNT) interconnects while considering defects and contact resistance is proposed. Based on the atomistic-level simulations, we have found that defect densities impact MWCNT resistance and ultimately their electrical performance. Furthermore, we have computed by atomisticlevel simulations the end-contact resistance between single-wall carbon nanotube (SWCNT) and Palladium (Pd) electrode to mimic the Pd-CNT end-contact resistance of each CNT shell in MWCNT. We have developed an advanced shell-by-shell model to include various parameters such as shell diameter, shell chirality, defects on each shell, and connectivity of each shell to endcontacts. We run Monte Carlo simulations to perform variability studies on each of these parameters to understand the electrical performance variation on MWCNT interconnects. We present simulation results to convey the critical impact of variations. The impact of doping on MWCNT variability in the form of Fermi level shift will be addressed in Part II of this paper.

Mini-Review: Modeling and Performance Analysis of Nanocarbon Interconnects

“…Further, some studies have been conducted to analyze the crosstalk, variability, Joule heating, and electrostatic discharge (ESD) reliability of CNT interconnects [64,[74][75][76][77][78][79][80][81][82][83].…”

Importance of Interconnects: A Technology-System-Level Design Perspective

“…CNTFET inverter structure is based on [7] and MWCNT interconnect ( Fig.1b) are based on [8][9]. The layout design for CNT benchmark is in Fig.…”

“…MWCNT interconnects are introduced at gate-level, and we employ the model of pristine and doped MWCNTs. MWCNT interconnect doping concentration is represented by CNT Fermi-level shift Ef which increases electron density of state (DOS), thus introducing additional conducting channels and further enhancing CNT interconnect conductivity [9]. We consider end-contacts between CNTFET device and MWCNT interconnect with various values to present different metal materials [12][13][14][15][16].…”

“…(a) Illustration of small section of ring oscillator benchmark to demonstrate the circuit-level schematic which is implemented with 1) CNTFET devices and MWCNT interconnects between inverter gates, and 2) 7 nm FinFET devices with Cu interconnects with various aspect ratios. (b) MWCNT interconnect electrical compact model[9].…”

Carbon Nanotube SRAM in 5-nm Technology Node Design, Optimization, and Performance Evaluation—Part II: CNT Interconnect Optimization

“…In addition, doping techniques, such as NO 2 , H 2 SO 4 , SOCL 2 , PtCl 4 , etc., [10]- [15] have been experimentally found to be effective in significantly improving the conductance of CNT interconnects. We use the CNT interconnect models based on compact models proposed in [16] and [17]. For the intra-cell interconnect design, to obtain the best CNT interconnect electrical performance, side-contacts instead of end-contacts [18] are Geometric structure of interconnects (layers 1 to 3) between ground/power lines.…”