Electron holographic study of the effect of contact resistance of connected nanowires on resistivity measurement

Nanowires were formed on a tungsten tip and on an edge of a metal substrate by electron beam induced deposition (EBID), and were made to come in contact with each other in a specially designed transmission electron microscope (TEM) sample holder to perform the measurement of the resistivity of the nanowires. The resistivity of the contacted nanowires was very high (>0.01 Ωm) immediately after making contact. During the resistivity measurement, potential distribution around the contacted nanowires was observed by electron holography, and it was revealed that electric field concentrated on the contact point. It was due to the insulative character of the contact. The irradiation of an intense electron beam decreased such high contact resistance, and electron holographic observation showed that the electric field distribution became uniform.