Selective Deposition of Copper with Iodine Assisted Growth of MOCVD on an MPTMS Monolayer Surface at a Low Temperature

Abstract

We have investigated the selective deposition of Cu films on the mercaptopropyltrimethoxysilane-ocatadecyltrichlorosilane (MPTMS-OTS) patterned glass substrate using (hfac)Cu(DMB) and C₂H₅I as precursors at 110°C. The low temperature deposition of Cu without iodine exhibited the difficulties of Cu nucleation on MPTMS with its low Cu growth rate of 22 nm/min and long induction period of approximately 4 min at 110°C. The addition of iodine significantly enhanced the surface diffusion of Cu adatoms on the MPTMS surface and thus led to increased nucleation and growth rate (28 nm/min) at 110°C. With these advantages, we successfully increased the maximum thickness of Cu selectively deposited on the MPTMS patterned lines from 57 nm to 140 nm without selectivity loss by adding iodine to (hfac)Cu(DMB)(3,3-dymethyl-1-butene) at 110°C. Consequently, the low temperature process for the selective deposition of Cu on the MPTMSOTS patterned surface can be utilized for the fabrication of flexible electronics.