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Two digital printing methods for the fabrication of active matrix thin-film transistor (AM-TFT) backplanes for displays are described. A process using printed resists layers, referred to as digital lithography, was used to fabricate arrays of hydrogenated amorphous silicon TFTs. TFTs were also fabricated using a combination of digital lithography to pattern metals and inkjet printing to pattern and deposit a polymeric semiconducting layer. The relative performance of amorphous silicon and polymer TFTs were evaluated. The utility of digital lithographic processing was demonstrated by the fabrication of prototype reflective displays using electrophoretic media. [ABSTRACT FROM AUTHOR]

Organic thin-film transistors were fabricated by direct patterning of solution-processable semiconductors consisting of either poly(9,9[sup ′]-dioctyl-fluorene-co-bithiophene) or a regioregular poly(thiophene). Acoustic ink-jet printing was used to deposit the polymeric semiconductor onto patterned metal source-drain contacts. Printed and spin coated transistors performed identically. The regioregular poly(thiophene) exhibited a mobility of 0.1 cm[sup 2] V[sup –1] s[sup -1], on-off current ratios of ∼10[sup 6] and low threshold voltage. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]

A jet-printed digital-lithographic method, in place of conventional photolithography, was used to fabricate 64 × 64 pixel (300 µm pitch) matrix addressing thin-film transistor (TFT) arrays. The average hydrogenated amorphous silicon TFT device within an array had a threshold voltage of ∼3.5 V, carrier mobility of 0.7 cm²/V·s, subthreshold slope of 0.76 V/decade, and an on/off ratio of 10[sup 8]. [ABSTRACT FROM AUTHOR]