Atomic layer deposition of Al2O3 on H-passivated Si. I. Initial surface reaction pathways with H/Si(100)-2×1
- 8 June 2003
- journal article
- research article
- Published by AIP Publishing in The Journal of Chemical Physics
- Vol. 118 (22), 10221-10226
- https://doi.org/10.1063/1.1571513
Abstract
Aluminum oxide grown by atomic layer deposition (ALD) is currently under investigation for use as a high-κ gate dielectric alternative to Cluster calculations employing hybrid density functional theory have been carried out to examine the chemical reaction pathways between the ALD precursors, trimethylaluminum (TMA) and with the H/Si(100)-2×1 surface. Results obtained using and dimer and double dimer clusters to represent the surface active site are in good agreement, providing a consistent view of reaction energetics on the H/Si(100)-2×1 surface. The adsorption energies for TMA and on the surface are calculated to be 0.02 and 0.15 eV, respectively. For the reaction between and the H/Si(100)-2×1 surface, hydroxylation of the surface accompanied by loss of was found to be the preferred pathway having an activation energy and overall reaction enthalpy of 1.60 eV and −0.75 eV, both of which are ⩾0.70 eV lower than the corresponding values for the possible H/D exchange reaction. TMA exposure of the H/Si(100)-2×1 surface favors the deposition of with loss of having a barrier height of 1.30 eV and reaction enthalpy of −0.31 eV, which are 0.10 and 0.40 eV lower than the surface methylation pathway exchange) and 2.64 and 0.45 eV lower in energy than the loss reaction, that results in the deposition of to the surface. Therefore, the dominant reactions identified in this work are those with direct implication in the ALD growth mechanism, leading to the formation of Si–O and Si–Al species on the H/Si(100)-2×1 surface.
Keywords
This publication has 32 references indexed in Scilit:
- Atomic layer deposition (ALD): from precursors to thin film structuresThin Solid Films, 2002
- High-κ gate dielectrics: Current status and materials properties considerationsJournal of Applied Physics, 2001
- Alternative dielectrics to silicon dioxide for memory and logic devicesNature, 2000
- Pushing the LimitsScience, 1999
- The electronic structure at the atomic scale of ultrathin gate oxidesNature, 1999
- Atomic layer epitaxyCurrent Opinion in Solid State and Materials Science, 1998
- Advanced ALE processes of amorphous and polycrystalline filmsApplied Surface Science, 1997
- Thermodynamic stability of binary oxides in contact with siliconJournal of Materials Research, 1996
- The reaction pathway for the growth of alumina on high surface area alumina and in ultrahigh vacuum by a reaction between trimethyl aluminum and waterJournal of Vacuum Science & Technology A, 1991
- Sequential surface chemical reaction limited growth of high quality Al2O3 dielectricsApplied Physics Letters, 1989