Characterization of physical vapor deposited and patterned thin films for roll-to-roll flexible passive and active electronic devices

In the last decade flexible electronics have become a burgeoning field of electronics research. The adjective "flexible"relates to bendability, conformal shaping, or elasticity. Current flexible electronics applications include solar cells, sensors and medical devices. Future advancements are anticipated in the areas of displays, electronic textiles, X-ray sensor arrays, lighting, and electronic skin. Traditional tools for electronic microfabrication have utilized discrete rigid substrates such as glass or silicon wafers. New toolsets will need to be developed to take advantage of the mechanical properties of flexible substrates, including their ability to be roll-to-roll (R2R) processed. Several novel R2R manufacturing tools have been applied in this dissertation work to enable fabrication of electronic devices directly on unsupported flexible substrates.;Characterization of flexible polymer substrates such as polyethylene naphthalate (PEN), polyethylene terephthalate (PET) and polyimide (PI) as well as flexible glass and stainless steel have identified candidates for direct R2R fabrication of devices. Single layer deposition processes of ITO, SiOx, Al, SixNy, a-Si:H and Si have been designed and characterized for use in single layer passive devices and complex multilayer active devices. R2R photolithography processes have been developed and utilized in single and multi-layer patterning along with etch processes for the aforementioned films. During the first attempts at fabrication of amorphous silicon thin film transistors on R2R PEN substrates important steps have been identified to facilitate the fabrication process in the future.;Thin film stress introduced during the deposition of these layers can lead to several problems with flexible substrates, including substrate curvature, film cracking and film delamination. Through work that involved thin films of greater than 1 micron thickness deposited on 36 micron thick substrates, an understanding of process conditions and its effect on film stress was gained.