Early stage oxynitridation process of Si(001) surface by NO gas: Reactive molecular dynamics simulation study

Journal Article · Mon Mar 28 00:00:00 EDT 2016 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4944707· OSTI ID:22594531

Cao, Haining; Kim, Seungchul; Lee, Kwang-Ryeol ^[1]; Srivastava, Pooja; Choi, Keunsu ^[1]

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1. Computational Science Research Center, Korea Institute of Science and Technology, 5, Hwarangno 14-gil, Seongbuk-gu, Seoul 02792 (Korea, Republic of)

Initial stage of oxynitridation process of Si substrate is of crucial importance in fabricating the ultrathin gate dielectric layer of high quality in advanced MOSFET devices. The oxynitridation reaction on a relaxed Si(001) surface is investigated via reactive molecular dynamics (MD) simulation. A total of 1120 events of a single nitric oxide (NO) molecule reaction at temperatures ranging from 300 to 1000 K are statistically analyzed. The observed reaction kinetics are consistent with the previous experimental or calculation results, which show the viability of the reactive MD technique to study the NO dissociation reaction on Si. We suggest the reaction pathway for NO dissociation that is characterized by the inter-dimer bridge of a NO molecule as the intermediate state prior to NO dissociation. Although the energy of the inter-dimer bridge is higher than that of the intra-dimer one, our suggestion is supported by the ab initio nudged elastic band calculations showing that the energy barrier for the inter-dimer bridge formation is much lower. The growth mechanism of an ultrathin Si oxynitride layer is also investigated via consecutive NO reactions simulation. The simulation reveals the mechanism of self-limiting reaction at low temperature and the time evolution of the depth profile of N and O atoms depending on the process temperature, which would guide to optimize the oxynitridation process condition.

• OSTI ID: 22594531
• Journal Information: Journal of Applied Physics, Vol. 119, Issue 12; Other Information: (c) 2016 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
COMPUTERIZED SIMULATION
DEPTH
DIELECTRIC MATERIALS
DIMERS
DISSOCIATION
INTERMEDIATE STATE
LAYERS
MOLECULAR DYNAMICS METHOD
MOLECULES
MOSFET
NITRIC OXIDE
REACTION KINETICS
SILICON NITRIDES
SUBSTRATES
SURFACES
TEMPERATURE RANGE 0065-0273 K
VIABILITY