The 3D nanostructure growth evaluations by the real-time current monitoring on focused-ion-beam chemical vapor deposition

In this study, we examined the potential of real-time monitoring for the detection of structural defects such as deposits on substrates formed during the three-dimensional (3D) nano- and micro-structure fabrication by focused-ion-beam chemical vapor deposition (FIB-CVD). We evaluated the changes in the real-time current in the substrate during the 3D nanostructure growth. The results indicated that the substrate current does not depend on the vertical growth height. We evaluated the changes in the secondary electron (SE) current during vertical and lateral growth of nanostructures also evaluated. The dynamic profile of the substrate current agreed with that of the SE current. In addition, we found that an increase in the substrate current was caused by the formation of structural defects such as deposits on the substrate. This result implied that the increase in the substrate current was caused by a change in the positional relationship between the growth edge of nanostructures and the Ga⁺ FIB. These results indicate that detection and prevention of structural defects in the 3D nanostructure fabrication can be achieved by integrating a current-feedback function into the 3D computer-pattern generator.