| 摘要 |
PURPOSE: To find the edge position of a thin film accurately by detecting intrinsic secondary ion generated from a base material, finding secondary ion intensity distribution which is not affected by sputtering particles caused by convergence ion beam, and based on it, setting constant threshold level. CONSTITUTION: When scanning with ion beams along the cross section of a sample, silicon ions are detected out of a base 1 as secondary ions, and through the silicon ion from the base material 1 is detected, silicon ions from a thin film 2 is not detected. Near the edge boundary 3 of the thin film 2, sputtering particles from the base material are hard to stick to the thin film 2, so the secondary ion intensity distribution faithfully reflecting the edge boundary 3 of the thin film 2, is obtained. For finding the edge boundary from the secondary ion intensity distribution, half of the maximum value of the secondary ion intensity is set as threshold level 4, and an edge position 5 is decided where the threshold level 4 is cut. |
