| AVS 61st International Symposium & Exhibition | |
| Thin Film | Monday Sessions |
| Session TF+PS-MoM |
| Session: | Atmospheric, Roll-to-Roll and other Manufacturing Advances in ALD |
| Presenter: | Charles Dezelah, Picosun USA, LLC |
| Authors: | C. Dezelah, Picosun USA, LLC T. Hirvikorpi, Picosun Oy, Finland R. Laine, Picosun Oy, Finland W.-M. Li, Picosun Oy, Finland M. Vähä-Nissi, VTT Technical Research Centre of Finland E. Salo, VTT Technical Research Centre of Finland V. Kilpi, Picosun Oy, Finland S. Lindfors, Picosun Oy, Finland J. Vartiainen, VTT Technical Research Centre of Finland E. Kenttä, VTT Technical Research Centre of Finland J. Nikkola, VTT Technical Research Centre of Finland A. Harlin, VTT Technical Research Centre of Finland J. Kostamo, Picosun Oy, Finland |
| Correspondent: | Click to Email |
Atomic layer deposited (ALD) Al2O3 has proven to be effective in enhancing the moisture and gas barrier properties of various plastic films and coatings [1-3]. The key challenge in several applications is to find a flexible, reliable, and cost efficient means to protect sensitive goods from ambient atmosphere. In this presentation we describe the first deposition trials on plastic films with a new PICOSUN™ roll-to-roll (R2R) chamber. This study demonstrated that a thin Al2O3 layer deposited with this continuous process enhances the barrier performance of these materials with results similar to those obtained in a non-R2R batch processing module.
Silicon wafers, cellophane, polylactic acid, and polyimide film substrates were coated with Al2O3 at 100 °C using both a batch PICOSUN™ reactor and a test setup for a R2R ALD fit to the same reactor. The precursors were trimethyl aluminum and H2O, and 500 deposition cycles were used. The Al2O3 deposited samples were characterized for their barrier and surface characteristics. The deposition rate of Al2O3 on silicon wafer was similar for the batch and the R2R ALD processes. The results from the oxygen transmission rate (OTR) and water vapor transmission rate (WVTR) measurements in 50 % relative humidity and 23 °C were compared between samples across substrate types and deposition modes. It was found that the R2R chamber provided barrier performance was comparable to traditional batch deposition in several cases, and considerably enhanced relative to uncoated substrates.
The initial mechanical properties of the polymeric substrate were found to be crucial for the barrier properties. For example, an Al2O3 coating fabricated on cellophane film was less sensitive to mechanical stresses, and the barrier values obtained were similar to those obtained with batch process for the same substrate. FTIR analyses detected Al2O3 covered surfaces after the R2R ALD. AFM images for the batch and R2R produced samples that were quite similar. The relative polarities of surface energy for Al2O3 deposited with R2R ALD on all three films were lower than for the batch samples. This indicates some differences in the thin film growth. Implications for manufacturability and scalability will also be discussed.
References:
1. P.F. Carcia, R.S. McLean, M.H. Reilly, M.D. Groner, et al., Appl. Phys. Lett. 89 (2006) 031915.
2. T. Hirvikorpi, M. Vähä-Nissi, T. Mustonen, E. Iiskola, et al., Thin Solid Films 518 (2010) 2654.
3 T. Hirvikorpi, M. Vähä-Nissi, A. Harlin, M. Karppinen, Thin Solid Films 518 (2010) 5463.