Integrated Isothermal Atomic Layer Deposition/Atomic Layer Etching Supercycles for Area-Selective Deposition of TiO2

New approaches for area-selective deposition (ASD) are becoming critical for advanced semiconductor patterning. Atomic layer deposition (ALD) and atomic layer etching (ALE), that is, “inverse ALD”, are considered important for ASD, but to date, direct integration of ALD and ALE for ASD has not been reported. This work demonstrates that self-limiting thermally driven ALE, using WF6 and BCl3, can be directly coupled with self-limiting thermal ALD, using TiCl4 and H2O, in a single isothermal reactor at temperature 0.9, nearly a 10× improvement over previous reports of inherent TiO2 ASD. After ALD/ALE (=30/5) 14 supercycles at 170 °C, X-ray photoelectron spectroscopy da...