A study of preferred orientations in gold/silica/silicon interfaces

Abstract

The interfacial structure of Au (metal) on Si(100), Si(111) and SiO2 (non-metal) substrates are studied owing to their immense use in the microelectronic industry. The interface study is important for understanding the structure-property relationships in materials. -- The final orientation distribution of metallic crystalline films grown on these amorphous/crystalline, amorphous substrates namely Au/SiO2 /Si(100); Au/SiO2 /Si(111); Au/SiO2 is strongly influenced by preferred orientations. Preferred orientations can be due to atomic mismatch, interface defects, anisotropy in crystal nucleation, growth rates, kinetics, etc. Geometric models have tried to explain the phenomena occurring at the interface to some extent. -- The orientation of Au{111}, close-packed planes was found to be of low energy as the annealing temperature was increased, also a greater numbers of Au peaks of higher intensity were observed, implying more rotation of Au particles into preferred orientations of low energy. Orientations were observed to be influenced by Silicon substrates across native oxide of 20--35 Å; this suggests the effect of long range ordering via interfacial layer. The XRD/Pole figures, SEM/EDS and AFM were the tools used to characterize the prepared samples. The average crystallite size was determined by various methods on stage III samples and it was found to be fairly consistent.