標題: Computational study of reaction pathways for the formation of indium nitride from trimethylindium with HN3: Comparison of the reaction with NH3 and that on TiO2 rutile (110) Surface
作者: Tzeng, Yi-Ren
Raghunath, P.
Chen, Szu-Chen
Lin, C.
應用化學系分子科學碩博班
Institute of Molecular science
公開日期: 26-七月-2007
摘要: The reactions of trimethylindium (TMIn) with HN3 and NH3 are relevant to the chemical vapor deposition of indium nitride thin film. The mechanisms and energetics of these reactions in the gas phase have been investigated by density functional theory and ab initio calculations using the CCSD(T)/Lanl2dz//B3LYP/Lanl2dz and CCSD(T)/Lanl2dz//MP2/Lanl2dz methods. The results of both methods are in good agreement for the optimized geometries and relative energies. These results suggest that the reaction with HN3 forms a new stable product, dimethylindiumnitride, CH3-InN-CH3 via another stable In(CH3)(2)N-3 (dimethylindium azide, DMInA) intermediate. DMInA may undergo unimolecular decomposition to form CH3InNCH3 by two main possible pathways: (1) a stepwise decomposition process through N-2 elimination followed by CH3 migration from In to the remaining N atom and (2) a concerted process involving the concurrent CH3 migration and N-2 elimination directly giving N-2 + CH3InNCH3. The reaction of TMIn with NH3 forms a most stable product DMInNH2 following the initial association and CH4-elimination reaction. The required energy barrier for the elimination of the second CH4 molecule from DMInNH2 is 74.2 kcal/mol. Using these reactions, we predict the heats of formation at 0 K for all the products and finally for InN which is 123 +/- 1 kcal/mol predicted by the two methods. The gas-phase reaction of HN3 with TMIn is compared with that occurring on rutile TiO2 (110). The most noticeable difference is the high endothermicity of the gas-phase reaction for InN production (53 kcal/mol) and the contrasting large exothermicity (195 kcal/mol) released by the low-barrier Langmuir-Hinshelwood type processes following the adsorption of TMIn and HN3 on the surface producing a horizontally adsorbed InN(a), Ti-NIn-O(a), and other products, CH4(g) + N-2(g) + 2CH(3)O(a) [J. Phys. Chem. B 2006, 110, 2263].
URI: http://dx.doi.org/10.1021/jp0690345
http://hdl.handle.net/11536/10545
ISSN: 1089-5639
DOI: 10.1021/jp0690345
期刊: JOURNAL OF PHYSICAL CHEMISTRY A
Volume: 111
Issue: 29
起始頁: 6781
結束頁: 6788
顯示於類別:期刊論文


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