Interface structure and preferred orientation of Ag/Si(111) revealed by X-ray diffraction

We studied buried interface structures of Ag/Si(lll)root 3-Ag and Ag/Si(lll)-(7 x 7) samples using grazing incidence X-ray diffraction with synchrotron radiation. We also measured the crystal orientation of the Ag overlayers of the samples. Of the numerous root 3 structures, only boron-induced root 3 structure has been detected in buried interfaces. We studied the buried interface superstructure of Ag(26 nm thick)/Si(lll)root 3-Ag, and detected a root 3 fractional order reflection peak. This means that the root 3 structure remained at the interface. (Our results for the crystal orientation of the Ag overlayers of Ag/Si(lll)root 3-Ag showed that Ag{110}, Ag{100} and Ag{111} planes were grown on the surface. By measuring several samples prepared at various substrate temperatures, (290-370 K), we found a strong correlation between the appearance of interface root 3 structure and the growth of the Ag{110} plane. In contrast, our results for the crystal orientation of the Ag overlayers of Ag(26 nm thick)/Si(lll)-(7 x 7) showed that only the Ag{111} plane was grown on the surface.