Younghee Lee, Jaime Dumont, S. George
Apr 26, 2016
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Influential Citations
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Journal
Chemistry of Materials
Abstract
Trimethylaluminum (TMA, Al(CH3)3) was used as the metal precursor, together with HF, for the atomic layer etching (ALE) of Al2O3 using sequential, self-limiting thermal reactions. Al2O3 ALE using TMA demonstrates that other metal precursors, in addition to Sn(acac)2, can be employed for Al2O3 ALE. The use of TMA for Al2O3 ALE is especially interesting because TMA can also be used for Al2O3 atomic layer deposition (ALD). Quartz crystal microbalance (QCM) experiments monitored Al2O3 ALE at temperatures from 250 to 325 °C. The Al2O3 ALE was linear versus the number of HF and TMA reaction cycles. The QCM studies showed that the sequential HF and TMA reactions were self-limiting versus reactant exposure. The Al2O3 etching rates increased at higher temperatures. The QCM analysis measured mass change per cycle (MCPC) values that varied from −4.2 ng/(cm2 cycle) at 250 °C to −23.3 ng/(cm2 cycle) at 325 °C. These MCPCs correspond to Al2O3 etch rates from 0.14 A/cycle at 250 °C to 0.75 A/cycle at 325 °C. X-ray refle...