Strong field charge transport in MIS structures based on low-K carbon films

Abstract Low dielectric constant (low- K ) materials deposited by PECVD are very promising because of they have electrical properties comparable to SiO 2 . Previously, we have reported on preparation of amorphous carbon films (a-C:H) with K =2.1, ρ =10 14 Ω −1 cm −1 and on the correlation between their structure and electronic properties. In this work we report an investigation on carrier transport in high electric field in low- K carbon films. The films were deposited by low frequency (LF)-PECVD at a substrate temperature T s =350 °C on glass `Corning-1737' for optical measurements and on Si wafer to form MIS structure for electrical measurements with Al or Ti top electrodes. Isothermal annealing in argon at a temperature T a =400 °C was conducted in order to test the thermal stability and the effect on the electrical and optic properties of the films. We observed that under high field applied the charge transport is controlled by Schottky mechanism related to the interfaces rather than bulk properties of the films. The behavior of I ( U ) at high field with temperature was also in agreement with the Schottky mechanism for charge transport.