High-Sensitivity and High-Depth Resolution Auger Depth Profiling Using an Inclined Holder based on Geometric Characteristics of Auger Electron Spectroscopy Apparatus Equipped with Concentric Hemispherical Analyzer

半球型電子分光器を搭載したオージェ電子分光装置では，傾斜ホルダーを用いると装置のジオ メトリー特性との関係からイオン及び一次電子の入射角の自由度が大きくなる.特に試料回転の 回転軸が一次電子の入射方向と一致する場合は，傾斜ホルダーの回転角によってイオン入射角を 設定でき，電子線の入射角は傾斜ホルダーの傾斜角度を選択することでイオン入射角と独立して 任意に決定することができる.そこで，筆者らは電子およびイオンの両方を試料表面から極低角 度で入射できる高傾斜ホルダーを試作し，極低角度電子・イオン入射オージェ深さ方向分析法を 開発した.この計測法により GaAs/AlAs 多層膜の深さ方向分析を行った結果，Al-LVV(68 eV)を 用いた深さ分解能として1.7 nmを達成した.さらに，Si/Geデルタドープ多層薄膜試料を測定し た結果，Ge デルタドープ6層すべてを高感度で検出できることがわかった.この報告では計測法 の原理ならびに得られた高感度，高深さ分解能データを紹介しながら本計測法について解説する.
Application of an inclined holder based on geometric properties of the Auger electron spectroscopy (AES) apparatus equipped with a concentric hemispherical analyzer to AES sputter depth profiling improves the flexibility in setting of the incidence angles of both electrons and ions. In particular, when the incidence direction of the electron beam coincides with the axis of the specimen azimuthal rotation, the incidence angle of ions can be obliquely determined by the rotation angle of the inclined holder and the incidence angle of the electron beam can be set independently by choosing the inclination angle of the inclined holder. Basing on this concept, we developed a 85°-high-angle inclined specimen holder which enabled the specimen surface to be irradiated by both the electron and ion beams at the glancing incidence. We have investigated the high-depth resolution AES sputter depth profiling analysis with the inclined specimen holder. In consequence, the resultant depth resolution for the GaAs/AlAs superlattice was found to be independent of the sputtered depth and the highest depth resolution of 1.7 nm was achieved with the Al-LVV Auger peak. The Auger depth profiles of the Si/Ge multiple delta-doped layers revealed that the Ge mono-layer can be in-depth profiled with high sensitivity and high depth resolution using the inclined specimen holder. In this article, we outline the basic comcept of the high-sensitivity and high-depth resolution AES sputter depth profiling using the inclined specimen holder and its application to the AES depth profiling.