jz502542a_si_001.pdf (418.27 kB)
Download file

Use of Mixed CH3–/HC(O)CH2CH2–Si(111) Functionality to Control Interfacial Chemical and Electronic Properties During the Atomic-Layer Deposition of Ultrathin Oxides on Si(111)

Download (418.27 kB)
journal contribution
posted on 17.12.2015, 07:21 by Leslie E. O’Leary, Nicholas C. Strandwitz, Christopher W. Roske, Suyeon Pyo, Bruce S. Brunschwig, Nathan S. Lewis
Silicon surfaces terminated with a mixed monolayer containing both a propyl aldehyde functionality and methyl groups were prepared and used to control the interfacial chemical and electronic properties of Si(111) surfaces during atomic-layer deposition (ALD) of Al2O3 or MnO. Si(111) surfaces functionalized only with the aldehyde moiety exhibited surface recombination velocities, S, of 2500 ± 600 cm s–1 whereas the mixed CH3–/HC­(O)­CH2CH2–Si­(111) surfaces displayed S = 25 ± 7 cm s–1. During the ALD growth of either Al2O3 or MnO, both the HC­(O)­CH2CH2–Si­(111) and CH3–/HC­(O)­CH2CH2–Si­(111) surfaces produced increased metal oxide deposition at low cycle number, relative to H–Si(111) or CH3–Si­(111) surfaces. As detected by X-ray photoelectron spectroscopy after the ALD process, the CH3– and mixed CH3–/HC­(O)­CH2CH2– functionalized Si(111) surfaces exhibited less interfacial SiOx than was observed for ALD of metal oxides on H–Si(111) substrates.