Shave-off method has been proven its efficacy for highly precise depth profiling in secondary ion mass spectrometry (SIMS) analysis. The unique technique, shave-off method has distinctive cross-sectional shape after scanning compared with raster scan method. We investigated the cross sectional shape of three different height tungsten samples using focused ion beam scanning electron microscopes (FIB-SEM) and transmission electron microscope (TEM). Though it is a simple cross-sectional shape, the analysis results enable the investigation of an angle between primary ion beam and sample surface, and sputtering yield.

In our previous studies, some approaches have been taken to get three-dimensional (3D) image for both inorganic and organic materials using FIB-ToF-SIMS technique. Of these, shave-off cross-sectioning and metal-assisted shave-off processes were predominant. In the present study, a further approach has been taken to get a 3D image through developing 3D shave-off cross-sectioning method for the generation of secondary ions. Currently used shave-off cross-sectioning method is able to provide 2D image on X-Z plane and that can be improved into 3D by using resistive anode detector through changing the optical transportation system of the secondary ions. Installation of cylindrical lens along Z-axis shows 1000 times magnification of the real image on the detector. For investigation of angular distribution of secondary ions, shape and/or angle of the shave-off cross-sectioning areas, using W-wires as model samples, was evaluated. Shave-off method exhibited the formation of a certain shape of the sample surface with 87º angle. The peak angle of the generated secondary ions was ~45º for 87º tilted samples (Si-wafer and Al-foil) and the observed secondary ion images were 2D by using a resistive anode detector. No significant change in angular distribution of the secondary ions was observed from highly roughness (Al-foil) and almost flat surfaces (Si-wafer).