Four-probe measurements with a three-probe scanning tunneling microscope.
We present an ultrahigh vacuum (UHV) three-probe scanning tunneling microscope in which each probe is capable of atomic resolution. A UHV JEOL scanning electron microscope aids in the placement of the probes on the sample. The machine also has a field ion microscope to clean, atomically image, and shape the probe tips. The machine uses bare conductive samples and tips with a homebuilt set of pliers for heating and loading. Automated feedback controlled tip-surface contacts allow for electrical stability and reproducibility while also greatly reducing tip and surface damage due to contact formation. The ability to register inter-tip position by imaging of a single surface feature by multiple tips is demonstrated. Four-probe material characterization is achieved by deploying two tips as fixed current probes and the third tip as a movable voltage probe.
National Institute for Nanotechnology, National Research Council of Canada, Edmonton, Alberta T6G 2M9, Canada.
Mark
M
Salomons
National Institute for Nanotechnology, National Research Council of Canada, Edmonton, Alberta T6G 2M9, Canada.
Bruno V C
BV
Martins
National Institute for Nanotechnology, National Research Council of Canada, Edmonton, Alberta T6G 2M9, Canada.
Janik
J
Zikovsky
National Institute for Nanotechnology, National Research Council of Canada, Edmonton, Alberta T6G 2M9, Canada.
Robert A
RA
Wolkow