Carbon nanotube complementary logic with low-temperature processed end-bonded metal contacts

CNT-based complementary logic using low-temperature processed end-boned metal contacts are demonstrated. This new form of end-bonded contact is made by carbon dissolution into metal contacts with high carbon solubility (e.g., Ni and Co), which requires only low annealing temperature (400-600 °C). As-fabricated end-bonded Ni contacts serve as robust p-type contacts to CNTs and perform better than standard Pd side-bonded contacts at scaled dimensions. In addition, stable NFETs are converted from PFETs using Al2O3 as an n-type physicochemical doping layer. CMOS inverters are further built with end-bonded contacts for both PFETs and NFETs, featuring the smallest contact size thus far for CNT inverters. These new findings could pave the way to realizing CNT-based scalable CMOS technology.