ALD Simulations

Bimolecular Reaction Mechanism in the Amido Complex-Based Atomic Layer Deposition of HfO2

“…In reality, however, the fact that the precursors are provided to the surface in the gas rather than the liquid phase and the involvement of the surface in the chemical reaction imply that the chemistry of the growth process is considerably more complex than what the proposed reaction schemes assume, and knowledge about the exact surface chemical processes is very limited. − In consequence, it is difficult to control undesirable side reactions and to improve the quality of the grown films in a deliberate fashion. Conventional surface science methods provide an avenue toward an improved understanding, but they are typically hampered by being limited to high-vacuum environments.…”

First-Principles Mechanistic Study of the Initial Growth of SrO by Atomic Layer Deposition on TiO2-Terminated SrTiO3 (001)

“…Moreover, the continued scaling requires deposition of high-quality thin conformal dielectric films with atomic scale thickness control over the increasingly complex three-dimensional device structures . SrTiO 3 and BaTiO 3 perovskites exhibit high dielectric constant and have lattice constants ( a = 3.91 and 3.99 Å, respectively) that match fairly well with the (001) surface atomic spacing of Si ( d = 3.84 Å) and Ge ( d = 3.99 Å), making them particularly attractive for investigations. , Their bulk and surface properties have been rather extensively studied both experimentally − and theoretically. − In early studies, molecular beam epitaxy was predominantly used to grow epitaxial SrTiO 3 and BaTiO 3 thin films on Si (001) and Ge (001) substrates, respectively. , As aforementioned, however, chemical routes are needed for depositing uniform and conformal thin films required by the semiconductor industry . About two decades ago, deposition of conformal SrTiO 3 thin films by ALD at 325 °C was demonstrated using strontium bis­(cyclopentadienyl) [Sr­(Cp) 2 ] and titanium tetraisopropoxide as Sr and Ti precursors, respectively, and water as an oxidant. , After annealing in air at 500 °C, the deposited SrTiO 3 films were found to have measured permittivity values of around 180 .…”