Novel Interface Structures between Ultrathin Oxynitride and Si(001) Studied by X-Ray Diffraction

概要

論文の詳細を見る
For ultrathin oxynitride layers 2.4 nm thick, X-ray crystal truncation rod (CTR) scattering is conducted to investigate the interface structures between oxynitride and Si(001). (004) and (202)CTRs showed that the [amorphous oxide]/Si(001) interface is hardly varied by NO-nitrided oxynitridation. On the other hand, (111)CTR indicated that epitaxial oxide crystallites in the matrix of amorphous oxide layer are significantly affected by nitrogen: It is very likely that nitrogen atoms at the interface are captured by these crystallites after their migration on the interface. As interstitial atoms, the adsorbed nitrogen makes the crystallites amorphous. Such an annihilation of the crystallites should be responsible for the high performance of oxynitride as gate oxides. Further oxynitridation where the nitrogen concentration reaches 4 at.% showed a distinct variation in (111)CTR, indicating the creation of a novel structural order at the interface. Such a structural order is likely to be nucleated by the excessively concentrated nitrogen. A close relationship between the novel structural order and degradation of the over-oxynitrided layers is strongly suggested.
Published by the Japan Society of Applied Physics through the Institute of Pure and Applied Physicsの論文
2003-12-15