The Nucleation and Epitaxial Growth of Au and Ag on Thin Silicon Studied With a Scanning Transmission Electron Microscope

Abstract

ABSTRACTAn UHV Scanning Transmission Electron Microscope (STEM) has been used to study the nucleation and epitaxial growth of Au and Ag deposited at room temperature on H-passivated thin silicon (111) and (100) substrates. Direct observations of the initial stages of overlayer growth were made using bright field (BF) and annular dark field (ADF) imaging modes. Gold was found to grow on silicon in a quasi-continuous layer mode, while 3D island growth with density as high as 4×1012/cm2 was observed in Ag/Si systems. Electron diffraction studies reveal a good epitaxial relationship for Ag films grown both on silicon (111) and (100) substrates. Diffraction also indicates that Au (111) grows on the silicon (111) surface but the grains may be azimuthally rotated.