Atomic layer epitaxy of copper: an ab initio investigation of the CuClrH process 2 II. Reaction energies

Reaction energies for different reaction pathways in the CuClrH2 process occurring in the gas phase as well as on a Cu 111.surface have been calculated using Density Functional Theory. All reactions, occurring in the gas phase as well as in the solidrvapour interface where gaseous atomic hydrogen was used as reducing agent, were highly exothermic with reaction energies between approximately y200 and y300 kJ moly1. When molecular hydrogen was used, the reactions were endothermic. A gas phase reaction had a reaction energy of about 100 kJ moly1, whereas for reactions between adsorbed CuCl and gaseous H2, this value decreased to between 32 and 64 kJ moly1 depending on reaction pathway. This was slightly lower than for surface reactions between CuCl and hydrogen where the reaction energies varied between 53 and 88 kJ moly1. q1999 Elsevier Science B.V. All rights reserved