硬X線光電子分光による酸化膜の評価

Study of oxide film with the hard X-ray photoelectron spectroscopy

小畠 雅明  ; 小林 啓介*

Kobata, Masaaki; Kobayashi, Keisuke*

大きな検出深さを持つ硬X線光電子分光装置を利用した界面反応領域の深さ方向分析手法、及びこれを活用した金属電極/絶縁膜/半導体ゲートスタック構造などの多層構造に埋もれた界面の化学結合状態と電子状態について紹介する。

We report the applications of a hard X-ray photoelectron spectroscopy to the characterization of SiO/Si(001)systems. Large escape depth of high-energy photoelectron enables us to probe buried layers and their interfaces in multilayer structures. Estimation of SiO overlayer thicknesses up to 25 nm by angle resolved XPS was possible in SiO/Si(001) samples. Determination of the thickness profile of a wedged shape SiO buried layer was successfully done in Ir (8 nm)/HfO (2.2 nm)/thickness graded-SiO (0-10 nm) / Si (100). The Si 1s core level showed a SiO thickness dependent shift, which was ascribed to fixed charge at the SiO-Si interface. Energy distribution of interface states at ultrathin thermal oxide/Si(100) interfaces were determined by Si 1 core level shift by applying gate bias in metal-oxide-semiconductor (MOS) structure with 5 nm Au gate electrodes.