| AVS 56th International Symposium & Exhibition | |
| Thin Film | Friday Sessions |
| Session TF-FrM |
| Session: | Transparent Electronic Materials and Applications |
| Presenter: | J.M. Walls, Loughborough University, UK |
| Authors: | J.M. Walls, Loughborough University, UK D.R. Gibson, Applied Multilayers Ltd, UK S. Stanley, Applied Multilayers Ltd, UK A.R. Waugh, Applied Multilayers Ltd, UK |
| Correspondent: | Click to Email |
There is an increasing requirement for depositing complex multilayer active coatings on to surfaces of flexible polymer sheet. Applications include thin film photovoltaics, electrochromic coatings and displays. Coating materials include transmitting conducting oxides such as ITO, dielectric metal-oxides, refractory metal-oxides and metal conductors. Coating flexible polymer sheet presents a challenge since it requires a low temperature process that deposits thin films that are spectrally stable but also low in stress to prevent cracking.
This paper describes a flexible reactive sputtering process in which adjacent unbalanced magnetrons are constructed of opposite magnetic polarity. The resulting closed magnetic field maintains a high density reactive plasma. In contrast to previous reactive sputtering strategies, the process does not require an auxiliary ion or plasma source and the associated use of high Voltage ion acceleration. As a result, the deposition energy is optimized and insufficient to cause damage in the growing thin film. The substrate temperature is typically maintained below 100oC without the need for direct cooling. The thin films exhibit bulk optical properties, they are also dense and super-smooth (<1nm rms roughness). The thin films also have typically low compressive stress. The magnetron targets are simple metals and are converted to compound thin films by using the appropriate reactive gas. The deposition process is high rate using pulsed dc power.
This paper provides data derived from a high throughput batch system with a 0.75m diameter drum substrate carrier and eight 1.2m linear magnetrons. The process geometry
is scaleable and adaptable to roll to roll deposition. Examples of both active coatings using on polymer substrates including polycarbonate, PET and Polyimide will be included. Details and examples of a novel final stage metal patterning process will also be presented .