Improved Thermal Stability of Ag Thin Films by Organic Subnanolayer at Interface with Silicon Oxide Layer

A subnanometer thick organic molecule layer was prepared on a SiO2/Si substrate using 3-mercaptopropyltrimethoxysilane (MPTMS) possessing a thiol moiety as a feature. 60-nm-thick Ag films were deposited on SiO2/Si substrates with and without the MPTMS layer at the interface and their thermal stabilities were compared. After annealing at 400 °C, Ag thin films with the MPTMS interface layer showed better stability than those without the MPTMS interface layer, as determined from the results of morphological observation. The enhancement is considered to be caused by strong bonding between Ag atoms and the thiol moiety in MPTMS.