The mechanistic process comparison between a novel slotted injection manifold versus the multiple injection manifold of a low pressure square type atomic layer deposition reactor

Advanced manufacturing techniques have obtained global interest, especially fabricating nanotechnology products. One such technique called atomic layer deposition (ALD) has without doubt manifested itself as an attractive key-enabling nanotechnology that is able to deposit ultrathin, uniform, conformal and pinhole-free nano-films on complex topography. It is utilized in fabrication of superconductors, solar cells, fuel cells, microelectronics, and medical equipment, among other applications. Nonetheless, the ALD process properties and thermal, chemical and flow behaviors are still not well enough understood to provide detailed information, resulting in numerous impasses. In this study, a novel slotted inlet manifold is designed and analyzed in comparison to that of the standard spliced eight-inlet manifold that is currently adopted in a Gemstar 6 reactor. By means of computational fluid dynamics (CFD) the study is centered in observing the impact on the deposition rate due to the different flow patterns of the two ALD reactor designs. The film material of interest is Al2O3 fabricated by the sequential injection of TMA and O3 precursors with argon gas as the purge substance in the ALD reactors. The numerical model adopts the governing laws of the conservation of mass, momentum, energy, species, and kinetic chemical reactions to analyze the behavior in a reactor scale domain. These equations are solved by using the software ANSYS Fluent and ChemkinPro. The end results are validated by available literature.