Gas Diffusion Barriers Prepared by Spatial Atmospheric Pressure Plasma Enhanced ALD

• Published in: ACS applied materials & interfaces Vol. 9; no. 4; pp. 4171 - 4176
• Main Authors: Hoffmann, Lukas, Theirich, Detlef, Pack, Sven, Kocak, Firat, Schlamm, Daniel, Hasselmann, Tim, Fahl, Henry, Räupke, André, Gargouri, Hassan, Riedl, Thomas
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 01.02.2017
• Subjects: atomic layer deposition; spatial ALD; aluminum oxide; plasma enhanced ALD; atmospheric pressure; gas diffusion barriers; roll-to-roll
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.6b13380

In this work, we report on aluminum oxide (Al2O3) gas permeation barriers prepared by spatial ALD (SALD) at atmospheric pressure. We compare the growth characteristics and layer properties using trimethylaluminum (TMA) in combination with an Ar/O2 remote atmospheric pressure plasma for different substrate velocities and different temperatures. The resulting Al2O3 films show ultralow water vapor transmission rates (WVTR) on the order of 10–6 gm–2d–1. In notable contrast, plasma based layers already show good barrier properties at low deposition temperatures (75 °C), while water based processes require a growth temperature above 100 °C to achieve equally low WVTRs. The activation energy for the water permeation mechanism was determined to be 62 kJ/mol.