Overcoming the Resistance Penalty in Large-Bandgap Carbon Nanotube Electronics via Synergistic Interfacial Engineering.

High-pressure carbon monoxide (HiPCO) carbon nanotubes (CNTs) offer superior ION/IOFF ratios due to their larger bandgap (EG), yet they suffer from high series resistance limiting drive currents. Here, we demonstrate a synergistic dual-engineering strategy to simultaneously minimize channel and contact resistance in top-gate HiPCO CNT field-effect transistors (FETs). A 200 °C forming gas annealing (FGA) process effectively scavenges organic residues, reducing the intrinsic channel resistance to 318 Ω·μm for specific 50 nm gate-length devices. Furthermore, localized p-type contact doping using contact-defined self-aligned MoOx nanoparticles deposited selectively within the source/drain windows reduces the effective Schottky barrier height from 233 meV to 66 meV. Optimized HiPCO CNTFETs exhibit a record-high on-current density of 2.5 mA/μm at VDS = -0.5 V while maintaining excellent off-state suppression. Our devices outperform existing benchmarks and exceed the IRDS 2039 conductance projections by 4×. This synergistic approach provides a robust pathway for high-performance, low-power carbon-based nanoelectronics.