Selective MOCVD of titanium oxide and zirconium oxide thin films using single molecular precursors on Si(1 0 0) substrates

Abstract

Titanium oxide (TiO 2) and zirconium oxide (ZrO 2) thin films have been deposited on modified Si(1 0 0) substrates selectively by metal-organic chemical vapor deposition (MOCVD) method using new single molecular precursor of [M(O i Pr) 2(tbaoac) 2] (M=Ti, Zr; tbaoac=tertiarybutyl-acetoacetate). For changing the characteristic of the Si(1 0 0) surface, micro-contact printing (μCP) method was adapted to make self-assembled monolayers (SAMs) using an octadecyltrichlorosilane (OTS) organic molecule which has –CH 3 terminal group. The single molecular precursors were prepared using metal (Ti, Zr) isopropoxide and tert-butylacetoacetate (tbaoacH) by modifying standard synthetic procedures. Selective depositions of TiO 2 and ZrO 2 were achieved in a home-built horizontal MOCVD reactor in the temperature range of 300–500 °C and deposition pressure of 1×10 −3–3×10 −2 Torr. N 2 gas (5 sccm) was used as a carrier gas during film depositions. TiO 2 and ZrO 2 thin films were able to deposit on the hydrophilic area selectively. The difference in surface characteristics (hydrophobic/hydrophilic) between the OTS SAMs area and the SiO 2 or Si–OH layer on the Si(1 0 0) substrate led to the site-selectivity of oxide thin film growth.