Local current measurements of an insulating layer using an UHV atomic force microscope in contact mode

Abstract We have used an UHV atomic force microscope operated in a DC-polarized contact mode to measure both the topography and the current distribution of an insulating alumina layer sputter-deposited from an Al 2 O 3 target. With a very good reproducibility, the barrier thickness T 0 as well as the effective barrier height Φ 0 have been measured with a very narrow dispersion ( T 0 =1.8–2 nm, Φ 0 =0.8–1 eV).