Scanning probes in nanostructure fabrication

Abstract

Scanning probes have enabled modern nanoscience and are still the backbone of today's nanotechnology. Within the technological development of AFM systems, the cantilever evolved from a simple passive deflection element to a complex microelectromechanical system through integration of functional groups, such as piezoresistive detection sensors and bimaterial based actuators. Herein, the authors show actual trends and developments of miniaturization efforts of both types of cantilevers, passive and active. The results go toward the reduction of dimensions. For example, the authors have fabricated passive cantilever with a width of 4 μm, a length of 6 μm and thickness of 50–100 nm, showing one order of magnitude lower noise levels. By using active cantilevers, direct patterning on calixarene is demonstrated employing a direct, development-less phenomena triggered by tip emitted low energy (<50 eV) electrons. The scanning probes are not only applied for lithography, but also for imaging and probing of the surface before and immediately after scanning probe patterning. In summary, piezoresistive probes are comparable to passive probes using optical read-out. They are able to routinely obtain atomic step resolution at a low thermal noise floor. The active cantilever technology offers a compact, integrated system suited for integration into a table-top scanning probe nanolithography tool.