at inlet and the pumping rate at outlet, in this modeling, we apply a time dependent pressure, 1 Torr+ PTMA/PH2O, as the inlet bound- ary and 0.9 Torr as the outlet boundary. For the precursor pulses, the partial pressure of the applied TMA pulse (PTMA) is set at 15% of the system pressure according to the experiment setting (0.15Torr), while the partial pressure of H2O pulse, PH2O, is set two times larger than that of TMA (0.3 Torr). This is because each TMAmoleculetheoreticallyneedstoreactwithtwoH2Omolecules to form stable film composition R3 and R4 [4]. According to the experiment, the purging process by inert gas takes 10 s between two precursor pulses, where each pulse takes 0.02 s. In the begin- ning of the ALD process, the substrate surface is assumed to be hydroxylated and well prepared after the treatment of the first water vapor pulse, where the initial surface coverage of hydroxyl groups are assumed to be 80% [19,20]. Our modeling study of TMA+ H2O cycling treatment will start from the first TMA pulse in the firstcycle. The surfacereaction ratesare referred fromTravis et al. [13,14], which are calculated based on the equilibrium rela- tionship between the adsorbed adduct and the surface reaction transition states. The related operating parameters are character- ized in Table 1, and the parameter definitions are listed in the nomenclature.