1:30 PM - 1:45 PM
[17p-D519-1] Surface-state Conduction of Si Measured by Two-probe Scanning Tunneling Microscopy
Keywords:scanning tunneling microscopy, surface-state conduction, semiconductor
In the pursuit of exploratory devices that are composed of a few atoms or molecules, there is great need for characterization of extremely small one- and two-dimensional structures. In order to assess the electrical conduction properties lateral to the surface, two-probe (2P-) and four-probe (4P-) scanning tunneling microscope (STM) has been developed. The measurement of conductance with 4P-STM is generally preferred over 2P-STM as it can eliminate the uncertainty in the probe-to-surface contact resistance. However, if we can solve the issue of the high resistive contact resistance with 2P configuration, we would be able to measure surface-state conduction with the minimum number of probes, reducing arduous tasks in this field. In this study, we will discuss the refinement of 2P-STM for surface-state conduction measurements by Ohmic contact between probe and surface. We also utilized STM lithography to create electronically isolated regions from the otherwise surface area, finding that we can measure their conduction properties correctly by the Ohmic 2P-STM. Since the probe-to-probe distance can be reduced down to 30 nm, the present method will be useful in a wide range of fields of material sciences.