High Energy Density Capacitor By Plasma-Treated ALD BaTiO3 Thin Films

Atomic layer deposition (ALD) is a modified chemical vapor (CVD) deposition tool, which is suitable for depositing high quality thin films or locally modifying the surface properties. Due to its advantages such as conformality, low pin-hole density, and the easiness of composition/doping control, ALD can used for engineering wide variety of thin film devices.

Crystallizing and densifying thin films to increase their relative permittivities are critical issues in fabricating high information density dynamic random access memory (DRAM) capacitors. The high process temperature (> 600 ° C) is usually necessary for thin film crystallization and densification, which could be detrimental to other components of DRAM. In this manuscript, we report a simple and novel method to simultaneously increase the dielectric constant and decrease the leakage current density of atomic layer deposited BaTiO₃ thin films using post-deposition remote oxygen plasma treatment while keeping the process temperature low (250 °C). The dielectric constant increases from 53 (as-deposited) to 122 (plasma-treated) and the leakage current density decreases by one order of magnitude. The dielectric constant of the plasma-treated BaTiO₃ film is one of the highest values ever reported for ultra-thin (5 nm thick) films. We ascribe such improvements to the crystallization and densification of the film induced by high-energy ion bombardments on the film surface during the plasma treatment. We think that plasma-induced crystallization presented in this work may have an immediate impact on fabricating and manufacturing DRAM capacitors due to its simplicity and compatibility with industrial standard thin film processes [1].

Acknowledgment 

             We thank Manufacturing Technology Center, Samsung Electronics for financial support

References

[1] J. An, et al., ACS Appl. Mater. Inter. 6 (13), pp 10656–10660 (2014)