Thermal atomic layer etching (ALE) of CoO was demonstrated using sequential exposures of acetylacetone (Hacac) and ozone (O₃). During the surface reactions, Hacac can remove CoO according to: CoO + 2Hacac → Co(acac)₂ + H₂O. Ozone was employed to eliminate carbon residue resulting from Hacac adsorption. In situ spectroscopic ellipsometry observed a linear decrease in CoO film thickness versus Hacac and O₃ exposures with an etch rate of 0.43 Å/cycle at 250 °C. The surface of the CoO film was also observed to undergo changes in oxidation state and crystal structure with each reactant exposure. Ex situ grazing incidence X-ray diffraction (GIXRD) studies revealed that the initial h-CoO thin films were oxidized to c-Co₃O₄ by O₃. Subsequently, the GIXRD analysis showed that the c-Co₃O₄ thin films were reduced to c-CoO by Hacac. X-ray photoelectron spectroscopy investigations confirmed the oxidation state of the various cobalt oxides. Quadrupole mass spectrometry measurements observed Co(acac)₂ etch products during Hacac exposures on Co₃O₄ and CoO powder. Atomic force microscopy measurements also monitored a reduction in surface roughness during CoO ALE. These studies reveal that alternating changes in oxidation state and crystal structure occur during the sequential Hacac and O₃ exposures that define CoO thermal ALE.

_{使用乙酰丙酮 (Hacac) 和臭氧 (O 3} )的连续暴露演示了 CoO 的热原子层蚀刻 (ALE) 。在表面反应过程中，Hacac可以按照以下公式去除CoO：CoO + 2Hacac→Co(acac) ₂  + H ₂ O。使用臭氧来消除Hacac吸附产生的碳残留物。原位光谱椭圆光度法观察到，与 Hacac 和 O ₃暴露相比，CoO 薄膜厚度呈线性下降，蚀刻速率为 0.43 Å/周期，温度为 250 °C。还观察到 CoO 薄膜的表面随着每次反应物的暴露而发生氧化态和晶体结构的变化。易地掠入射X射线衍射(GIXRD)研究表明，最初的h-CoO薄膜被O _{3氧化成c-Co 3} O ₄。随后，GIXRD分析表明c-Co ₃ O ₄薄膜被Hacac还原为c-CoO。X 射线光电子能谱研究证实了各种钴氧化物的氧化态。四极杆质谱测量在 Co ₃ O ₄暴露于 Hacac 期间观察到 Co(acac) _{2蚀刻产物}和CoO粉末。原子力显微镜测量还监测到 CoO ALE 期间表面粗糙度的降低。这些研究表明，在定义 CoO 热 ALE 的连续 Hacac 和 O ₃暴露过程中，氧化态和晶体结构会发生交替变化。