Microstructure and through-film electrical characteristics of vertically aligned amorphous carbon films

The microstructure and electrical properties of in-situ annealed carbon films is studied in this paper. In-situ annealing (150 °C to 600 °C) was done during the deposition of carbon films with −300 V substrate bias. Transmission electron microscopy and two points electrical probing studies were performed and the deduced transition for vertical orientated graphitic planes occurs at temperatures above 400 °C. The microstructure of the films strongly depends on the deposition temperature of the films (room temperature, 400 °C and 600 °C). Electrical conductivity of the film strongly depends on texturing due to the formation of preferred orientation in the vertical direction. The vertically orientated carbon (VOC) sheet provides effective nanochannels for electron transport, thus significantly improves the electrical properties of the annealed film.

Research highlights
► Microstructure and electrical properties of in-situ annealed carbon films are being studied.
► Annealing temperatures of 150°C-600°C were used with -300V substrate bias.
► Transition from amorphous carbon to vertical orientated graphitic planes occurs above 400°C.
► Electrical conductivity strongly depends on the formation of preferred orientation in the vertical direction.
► Vertically orientated carbon (VOC) sheet provides effective nanochannels for electron transport thereby improves the electrical properties.