Design and modeling of self-aligned nano-imprinted sub-micrometer pentacene-based organic thin-film transistors

Sub-micrometer channel length (0.5 m) organic thin-film transistors (OTFTs) are demonstrated using a process flow combining nano-imprint lithography (NIL) and self-alignment (SA). A dedicated test structure was designed and samples were fabricated on 4-in. plastic foils using a p-type sublimated small molecule (pentacene) as semiconductor. Field-effect mobilities, in saturation, between 0.1 and 1 cm2/Vs were obtained not only for the supermicron OTFTs but also for the submicron OTFTs. Those devices were used to select a model based on the "TFT Generic Charge Drift model" which works well for a broad range of channel lengths including the submicron OTFTs. We show that these OTFTs can be accurately modeled, thus giving access to complex circuit simulations and design.