National Research Council of Canada. National Institute for Nanotechnology
National Research Council of Canada. Security and Disruptive Technologies
Chemical sensors; Focused ion beams; Image reconstruction; Quartz; Scanning probe microscopy; Springs (components); AFM; Atomic-resolution imaging; Fabrication technique; Field evaporation; High resonance frequency; Quartz tuning fork; Spring constants; Atomic force microscopy; silicon dioxide; tungsten; atomic force microscopy; electric conductivity; electric field; electrochemistry; evaporation; measurement accuracy; nanotechnology; qPlus sensor; quantitative analysis; sensitivity analysis; sensor; surface property
A new technique for the fabrication of highly sensitive qPlus sensor for atomic force microscopy (AFM) is described. The focused ion beam was used to cut then weld onto a bare quartz tuning fork a sharp micro-tip from an electrochemically etched tungsten wire. The resulting qPlus sensor exhibits high resonance frequency and quality factor allowing increased force gradient sensitivity. Its spring constant can be determined precisely which allows accurate quantitative AFM measurements. The sensor is shown to be very stable and could undergo usual UHV tip cleaning including e-beam and field evaporation as well as in situ STM tip treatment. Preliminary results with STM and AFM atomic resolution imaging at 4.5. K of the silicon Si. (111). -. 7. ×. 7 surface are presented.