Scanning tunneling microscopy-based on-machine measurement for diamond fly cutting of micro-structured surfaces

This paper presents a new on-machine measuring system based on scanning tunneling microscope principle, in order to meet the demand for precision form control of fabricated micro-structures. It is compactly established and mounted on a diamond turning machine, capable of on-machine measuring microstructures with steep slopes and size of tens of micrometers, which remains a challenge task to accomplish undistorted measurement even for general off-line metrological methods. Fly cutting with V-tip fly-cutter was first applied in two directions with interval angle of 60 to form the crossed micro V-grooves, and then efficient on-machine measurement was carried out to characterize the machined surface form without ending the proceeding of the subsequent fabrication. By depth compensation of fly cutting in 120 direction through feedback of on-machine measured results, the surface of rectangular pyramid array with diamond-shaped feature was successfully generated. Experimental results demonstrate that the proposed measuring system is of significance in the fabrication process, owing to its efficient on-machine characterization capability for generating accurate micro-structured surfaces. (C) 2015 Elsevier Inc. All rights reserved.