Atomic scale flattening of organosilane self-assembled monolayer and patterned tin hydroxide thin films

We have succeeded in fabricating an atomic flattening surface of organosilane self-assembled monolayers (SAMs) on a Si substrate. In the present process, the octadecyltrichlorosilane (OTS) compound was selected as the starting material for the SAM. The OTS–SAM was formed by the reaction between the OTS molecules and the substrates, which were hydrogen terminated Si(001) (H:Si) and silica covered on Si(001) (SiO2/Si), at room temperature in a N2 atmosphere. The formation rate of the OTS–SAM onto H:Si was smaller than that on SiO2/Si. Interestingly, the hydrophobicity of the OTS–SAM was observed to increase the amount formed on H:Si in comparison with that on SiO2/Si. The photo reactivity of the SAMs formed on each substrate was also investigated by using ultraviolet (UV) irradiation in ambient air. Tin hydroxide thin films were site-selectively deposited on the patterned OTS–SAM/Si substrate in order to clarify the cleavage of the OTS–SAM by the UV irradiation.