2004 年 25 巻 3 号 p. 157-162
Observation of ultrathin silicon nitride surfaces by using ultrahigh vacuum scanning tunneling microscopy (STM) and atomic force microscopy (AFM) was performed. The ultrathin silicon nitride was prepared on Si(111) and (001) surfaces by novel thermal nitridation method using N2/H2 gas mixture at 780−1100oC. On Si(111) surface, the STM and AFM images show clear step-and-terrace structure and well-ordered atomic arrangement showing 8/3×8/3 superstructure. On Si(001), atomic arrangement showing 2×2 superstructure was observed on the surface. The structural models were proposed for these observed surface superstructures.