Low-temperature thermal atomic layer deposition of beryllium oxide films using discrete feeding methods

• BeO deposition using the discrete feeding method (DFM) enables low-temperature DF-ThALD. • This is the first study investigating the temperature-dependent behavior of films grown by DF-ThALD. • At 150 °C, BeO films grown by DF-ThALD exhibit a leakage current density of 3.69 × 10⁻⁶ A/cm² at −1 MV/cm. We demonstrate a new approach for Beryllium Oxide (BeO) film deposition using a discrete feeding method (DFM) to achieve low-temperature thermal atomic layer deposition (ThALD). Typically, BeO film deposition using ThALD at low temperatures leads to a low density and high carbon impurities, which degrade the electrical properties. To overcome this issue, the DFM was applied to successfully deposit BeO films at 150 °C, resulting in a significant improvement in the electrical performance compared to that obtained with the conventional ThALD process. Although previous studies on the DFM have focused on improving the growth properties of thin films and demonstrating the advantages of the method, this is the first study to investigate the temperature-dependent behavior of films grown using the DFM in ALD. At 150 °C, the film density of BeO grown by discrete feeding thermal ALD (DF-ThALD) was 2.95 g/cm 3 , which is higher than that of films grown by the conventional ThALD process. The leakage current density was reduced to 3.7 × 10⁻⁶ A/cm 2 at -1 MV/cm, representing a reduction of approximately five orders of magnitude. Hence, the results of this study highlight the effectiveness of the DFM in improving the quality of BeO films in low-temperature ThALD processes.