High-Frequency Ballistic Transport Phenomena in Schottky Barrier CNTFETs

The effective-mass Schrödinger equation is solved directly for the wave functions to explore the steady state and the time-dependent quantum-ballistic transport in Schottky barrier carbon nanotube (CNT) field-effect transistors (FETs). The employed contact parameters allow for discontinuities of the effective mass at the metal-CNT interface, and carefully chosen boundary conditions minimize spurious reflections at the simulation domain boundaries. Two-port Y-parameters of a selected device structure are computed and qualitatively explained with the time dependence of coherent quantum-ballistic charge injection. The finite escape times of the charge carriers in an open quantum system are identified for determining the inertial response to high-frequency terminal signals. Since the escape times depend on the shape of the Schottky barriers, the latter contribute to the dynamic behavior of ballistic CNTFETs.