OTS-Templated Cobalt Deposition Using Co<sub>2</sub>(CO)<sub>8</sub> Precursor

Abstract

We have investigated selective deposition of Co thin films on the OTS-patterned glass surface by using μ-CP(Micro-Contact Printing) coupled with MOCVD(Metal Organic Chemical Vapor Deposition) method with Co2(CO)8 as a Co precursor. Co thin films in the thickness of 5-180 nm has been selectively formed on the glass surface in the presence of the OTS(Octadecyltrichlrosilane) monolayer at the temperatures 60-90, at the pressure of 0.03-0.6 Torr. The self-assembled OTS monolayer on the surface passivates the surface hydroxyl(-OH), adsorption sites for Co precursors, and thus significantly increases the induction period to nucleate Co metals on the OTS monolayer, compared with on the bare glass. Lowering the temperature and the processing pressure is likely to increase the difference in the induction period for the two substrate surfaces and thus improves the selectivity. About 180 nm-thick Co thin film was selectively formed on the OTS-patterned glass at 70, however, lowering the temperature to 60 decreased the thickness, which is attributed to the reduced growth rate of Co at the lower temperature. The Co thin films deposited at 60-90 and at 0.03-0.6 Torr have the resistivities of 10-20 μ4-cm and are free of contamination. Consequently, the low temperature process for the selective deposition of Co in the presence of the OTS monolayer can be utilized for a variety of applications including flexible electronics and semiconductor devices.