Electrical behavior of ALD-molybdenum films in the thin-film limit

Test structures were designed and fabricated to investigate the electrical properties of ultra-thin molybdenum films obtained by atomic layer deposition. The films were incorporated in conventional Van der Pauw and circular transmission line method test structures to explore the effect of film thickness on the resistivity, temperature coefficient of resistance, contact resistivity, and external electric field applied. The resistivity was shown to depend strongly on film thickness, while the temperature coefficient of resistance changed from positive to negative, indicating a change in the dominant conduction mechanism. A modest field effect was observed for the films in their thickness limit.