Effect of oxidant sources on carbon-related impurities in ALD-Al₂O₃ for solid-state devices

In this study, we investigated the effect of oxidant sources on carbon-related impurities in atomic layer deposited (ALD)-Al2O3 by focusing on the plasma-induced decomposition of -CH3 groups which is attributed to ALD precursor. We found that C-O bonds were detected in ALD-Al2O3 using O-2 plasma instead of the C-H bonds which is attributed to the -CH3 groups of trimethylaluminum. It is considered that the decomposition of -CH3 groups was enhanced by O-2 plasma, and C-O residue was generated. We concluded that the decomposition of -CH3 groups by oxidant sources must be suppressed to reduce the carbon-related impurities in ALD-Al2O3. (c) 2023 The Japan Society of Applied Physics