| 摘要 |
PURPOSE:To make it possible to analyze depth accurately at a high speed and to save man-hours in analysis, by alternately projecting ions having different electronegativities at low energy, and sputtering the surface of a sample with third ions at high energy. CONSTITUTION:In the depth distribution measurement of elements using secondary ion mass analyzer, at first, an S doped GaAs epitaxial layer 51 is formed on a Cr doped GaAs substrate 50. On the surface of this ample, an O2<+> ion beam 1 having high electronegativity is projected as first ions at very low energy. The ions are physically adsorbed, and an O2 adsorbed layer 11 is formed on the surface of the sample. Then, a Cs<+> ion beam 2 having low electronegativity is projected as second ions at very low energy, and a Cs adsorbed layer 21 is formed. An N<+> ion beam 3 having medium electronegativity between the adsorbed layers 11 and 21 is projected as third ions at high energy. With the surface being sputtered an etched, Cr<+> 41 and S<-> 42, which are emitted from the surface of the sample, are analyzed through a mass analyzer, and the signals are outputted to a detector. These steps are repeated, and the depth distribution of the secondary ions is obtained. |
