Tuesday, March 10, 2015

Spatial ALD at low temperature for flexible electronics encapsulation using a BENEQ R2R

A recent paper on Spatial ALD at low temperature for flexible electronics encapsulation using a BENEQ R2R system at Advanced Surface Technology Research Laboratory Team (ASTRaL), Laboratory of Green Chemistry, Lappeenranta University of Technology, Finland. Thanks Henrik Pedersen for finding this one!

Philipp S. Maydannik, Alexander Plyushch, Mika Sillanpää, and David C. Cameron

Water and oxygen were compared as oxidizing agents for the Al2O3 atomic layer deposition process using spatial atomic layer deposition reactor. The influence of the precursor dose on the deposition rate and refractive index, which was used as a proxy for film density, was measured as a function of residence time, defined as the time which the moving substrate spent within one precursor gas zone. The effect of temperature on the growth characteristics was also measured. The water-based process gave faster deposition rates and higher refractive indices but the ozone process allowed deposition to take place at lower temperatures while still maintaining good film quality. In general, processes based on both oxidation chemistries were able to produce excellent moisture barrier films with water vapor transmission rate levels of 10−4 g/m2 day measured at 38 °C and 90% of relative humidity on polyethylene naphthalate substrates. However, the best result of <5 × 10−5 was obtained at 100 °C process temperature with water as precursor.

Schematic view of modified SALD TFS200R reactor with drum and N2 and precursor inlet, and exhaust ports. J. Vac. Sci. Technol. A 33, 031603 (2015); http://dx.doi.org/10.1116/1.49140

Close up inside the drum of the Beneq TFS 200R, which is  designed for research in Roll-to-Roll atomic layer deposition (ALD) and other forms of continuous ALD (CALD). (www.beneq.com)

Information from BENEQ.com: In the TFS 200R, the flexible substrate is fixed on a rotating cylinder within the reaction chamber. The cylinder itself is surrounded by a number of linear nozzles, each creating an isolated gas region over the full width of the substrate. As the cylinder is rotated, the substrate passes through different gas regions and is coated.

The Beneq TFS 200R, with its robust and modular structure, is designed to meet both industrial standards and the flexibility requirements of research today. Precursor containers are conveniently small, and they can be easily changed. Depending on the process needs, the TFS 200R can be equipped with up to 2 heated sources, type HS 80 and/or HS 180. Additionally, the system can be equipped with up to 8 gas lines and up to 4 liquid sources.