Organic contaminant detection of silicon wafers using negative secondary ions induced by cluster ion impacts

クラスターイオン照射による2次負イオンを用いたシリコンウエハー上の有機物汚染の検出

平田 浩一*; 齋藤 勇一; 千葉 敦也; 鳴海 一雅

Hirata, Koichi*; Saito, Yuichi; Chiba, Atsuya; Narumi, Kazumasa

Emission yields of carbon and hydrogenated carbon cluster secondary ions CpHq (p, q) originating from organic contaminants on a silicon wafer are compared between monoatomic (0.5 MeV/atom-C1) and cluster ion (0.5 MeV/atom-C8) impacts using time-of-flight (TOF) secondary ion mass spectrometry. CpHq for the cluster ion impact exhibits the highest emission yield per incident atom among CpHq with the same p number. The highest relative CpHq emission yield for the cluster ion impact reaches and times higher in comparison with those of CpHq and CpHq with the same p number for the impact of the monoatomic ion with the same velocity, respectively. Combination of negative secondary ion TOF measurements with cluster impact ionization is a promising tool for highly sensitive detection of organic-contaminants on silicon wafers.