SIMS深さ方向分析における酸素イオン照射によるヒ素の広がり現象の研究

抄録

SIMS is widely used for the process control in the field of LSI manufacture. The reason is that SIMS is the only surface sensitive technique to quantify the low concentration of impurities like Arsenic (As), Boron (B), and Phosphorus (P). The concentration of the impurities would typically be lower than ppb (parts par billion).
In this paper, Arsenic distribution was measured by O₂⁺ beam bombardment for different primary beam energies, incident angles and raster sizes. The sample where the Arsenic ion was implanted into SiO₂ layer was prepared to study the pile-up of Arsenic into the interface of SiO_x/Si. The following two items are the results of this study.
(1) The arsenic distortion heavily increased with both higher beam energy and lower incident angle.
(2) To avoid the As distortion effect, experiments must be done with O₂⁺ primary beam which has the energy lower than 8 keV and incident angle higher than 45°.