Logic Gates Based on Carbon Nanotube Field-Effect Transistors with SiNx Passivation Films

Abstract

We demonstrated logic gates based on complementary carbon nanotube field-effect transistors (CNT-FETs) with SiNx passivation films deposited by catalytic chemical vapor deposition. The carrier type of CNT-FETs was controlled by forming SiNx passivation films. Electrical measurements revealed that the p-type characteristics of CNT-FETs were converted to n-type characteristics after the deposition of SiNx passivation films. Then, the n-type CNT-FETs with SiNx passivation films were reconverted to p-type CNT-FETs by annealing in N2 atmosphere. As a consequence, complementary voltage inverters comprising p- and n-type CNT-FETs with SiNx passivation films were demonstrated on the same SiO2 substrate by conventional photolithography and lift-off techniques. Moreover, the static transfer and dynamic characteristics of the CNT-FET-based inverters were investigated. It was found that a gain of approximately 3 was achieved and that the device was switched properly at frequencies of up to 100 Hz.