Emission Trajectory Calculation of Ions from the Shave-off Cross Section for Realization of 3D Shave-off Method

Abstract

Secondary ion mass spectrometry can analyze all elements and has high versatility. In our laboratory, we have established a method of sputtering the whole sample from the side by using partial primary beam called Shave-off method, which increases spatial resolution and eliminates an effect originated by surface roughness. Furthermore, designing the ion optics that can enlarge and converge the emitted secondary ions from the cross section of the micro sample on the detector, high-precision three-dimensional distribution data with surface resolution of several nanometer level and depth direction resolution of several tens of nanometer level can be obtained at high speed. However, the secondary ions trajectory and the ion aberration caused by the lens in the Shave-off condition have not been verified. In this study, we have constructed a simulation of calculating the trajectory of emitted ions from the Shave-off cross section. It is expected that the simulation will be of great help and powerful tool for future development.

Angular Distribution of Sputtered Particles in Shave-off Section Processing with SDTrimSP

“…In our previous report [8], the sample depth locational information that appeared on the detector depended on the initial energy and the angular distribution of secondary ions. In particular, the angle distribution critically affected the detection position of the secondary ions, and it is the most critical and essential element for the development of the 3D shave-off method development.…”

Simulation of Secondary Ion Position on the Detector for Three-dimensional Shave-off Method

“…Through the previous studies, the introduced magnification lens system had verified that the secondary ions were enlarged only in the depth direction (Z axis) and converged on the Mattuach-Herzog type mass analyzer in the SIMS [6]. As the simulation results, the secondary ions sputtered from a micrometer-sized sample were magnified to a millimeter size at the detector and had 1.4 μm of the Z-axial resolution [7].…”

“…The design and setting of the 3D shave-off SIMS system in the SIMION program are shown in Figure 4. The workbench of the 3D shave-off SIMS system was described in more detail on previous studies [6,7].…”