A method for significantly increasing the growth rates (GRs) of high-k oxide thin films grown via plasma-enhanced atomic layer deposition (PE-ALD) by enhancing the plasma density through the addition of Ar gas to the O2 plasma oxidant was developed. This approach led to improvements of ∼60% in the saturation GRs of PE-ALD ZrO2, HfO2, and SiO2. Furthermore, despite the significantly higher GR enabled by PE-ALD, the mechanical and dielectric properties of the PE-ALD oxide films were similar or even superior to those of films grown via the conventional O2 plasma process. Optical emission spectroscopy analyses in conjunction with theoretical calculation of the electron energy distribution function revealed that adding Ar gas to the O2 plasma increased the density of high-energy electrons, thereby generating more O2 plasma species, such as ions and radicals, which played a key role in improving the GRs and the properties of the films. This promising approach is expected to facilitate the high-volume manufacturing of films via PE-ALD, especially for use as gate insulators in thin-film transistor-based devices in the display industry.
Bibliographical noteFunding Information:
This work was supported by the Materials and Components Technology Development Program of MOTIE/KEIT [10080642, Development on precursors for carbon/halogen-free thin film and their delivery system for high-k/metal gate application]. It was also supported by a National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIP) (no. NRF-2017R1C1B5076821).
Copyright © 2018 American Chemical Society.
All Science Journal Classification (ASJC) codes
- Materials Science(all)