Growth of Thin Iron Oxide Films on Si(100) by MOCVD

Abstract

The deposition of thin iron oxide films on Si͑100͒ by metallorganic chemical vapor deposition at 55 mbar was systematically studied as a function of temperature between 673 and 1023 K. Ferrocene and oxygen were used as precursors. The growth rate was measured as a function of temperature and the films were characterized by X-ray diffraction ͑XRD͒, Auger electron spectroscopy, energy dispersive X-ray analysis, and scanning electron microscopy. The change from the kinetically controlled regime to the transport controlled regime occurs near 750 K. At similar temperatures, a phase change of the deposited material was observed. Films prepared at temperatures higher than 823 K show the structure of ␣-Fe 2 O 3 , whereas deposition at lower temperature leads to the growth of ␣-Fe 2 O 3 and other oxide phases. The XRD pattern of these films can be explained by the coexistence of different iron oxide phases, namely ␣-Fe 2 O 3 , ␥-Fe 2 O 3 , and/or ␤-Fe 2 O 3 .

Low-Pressure Metallorganic Chemical Vapor Deposition of Fe[sub 2]O[sub 3] Thin Films on Si(100) Using n-Butylferrocene and Oxygen

“…Pflitsch et al obtained an activation energy of about 75 kJ/mol from iron oxide deposition experiments using ferrocene. 38 The growth rates in the second regime ͑i.e., higher than 500°C͒ were almost temperature-independent. This indicated that the deposition in this regime is mass transfer controlled.…”

“…19 Pflitsch et al observed growth rates ranging from 35 to 120 nm/min using ferrocene and oxygen at a pressure of 55 mbar and temperature in the range of 400-750°C. 38 They studied the temperature dependence of film growth and reported three growth regimes: ͑i͒ below 450°C the rate was in the surface reaction-controlled regime, ͑ii͒ between 450 and 600°C the rate was in the diffusion-controlled regime, and ͑iii͒ above 600°C the growth rate decreased. Deposition rates in the present study using n-butylferrocene and oxygen range from about 4 nm/min at 400°C ͑in the kinetics-controlled regime͒ to 50 nm/min at temperatures above 500°C ͑in the mass transfer-controlled regime͒.…”

“…Among metallocenes, only Fe͑C 5 H 5 ͒ 2 has been reported for MOCVD applications. 38 Though it had several advantages over the other precursors mentioned earlier, being a solid precursor it required a fluidized bed evaporator for its delivery to the reactor.…”

Thermodynamic analysis of growth of iron oxide films by MOCVD using tris(t-butyl-3-oxo-butanoato)iron(III) as precursor

“…As one of the most powerful techniques suitable for the formation of stoichiometric and microstructured thin films (Park et al 2006), chemical vapour deposition has been employed for fabrication of iron oxide thin films from different precursors (Shalini et al 2003 and the references therein;Mathur et al 2006;Park et al 2006;Pflitsch et al 2006;Lee et al 2007). The overall motivation for the present work has been to conduct analytical studies to provide stability windows in the CVD process employing metalorganic precursors, corresponding to the experimental realization of specific iron oxide phases.…”

Selective growth of iron oxide thin films using the combined method of metal-organic chemical vapor deposition and microcontact printing

“…2 Because of difference for application depending on their chemical composition and structure, it is important to control their shape. Many oxide materials have been used extensively in the form of thin films because the applications involve microdevices that require materials fabricated on micron or submicron scales.…”