Growth modulation of atomic layer deposition of HfO₂ by combinations of H₂O and O₃ reactants

Abstract

Two counter reactants, H2O and O3, were individually employed, as well as in combination with consecutive exposure by H2O–O3 and O3–H2O. The film growth behaviors and properties differed when the sequence of exposure of the substrate to the reactants was varied.

Rational Molecular Design for Non-aqueous Atomic Layer Deposition of Zinc Oxide

“…However, due to high reactivity of the oxygen-containing reactants, it has been difficult to apply ZnO ALD onto chemically sensitive substrate materials. For example, ZnO can be used as a charge transport layer in photovoltaic cells; however, for hybrid organic–inorganic perovskites, usage of water during ALD may irreversibly damage the substrate and degrade the device performance. , The reactants may also oxidize the surface of the substrate to form an interfacial oxide, which can cause leakage current and degrade device performance. , In general, the ALD growth behavior and the physicochemical properties of the resulting oxide films are highly dependent to the type of the oxygen source. ,− The oxygen vacancies on the ZnO thin film in the ALD process can be controlled by changing oxygen reactants, which can directly affect the electrical properties of the thin films . Therefore, it is desirable to develop novel alternative reactants with controllable reactivity in order to expand ZnO ALD to various wider applications.…”