J. Campi

We have fabricated organic thin-film transistor (OTFT)-driven active matrix liquid crystal displays on flexible polymeric substrates. These small displays have 16×16 pixel polymer-dispersed liquid crystal arrays addressed by pentacene active layer OTFTs. The displays were fabricated using a low-temperature process (<110 °C) on flexible polyethylene naphthalate film and are operated as reflective active matrix displays.

We have fabricated and characterized analog and digital circuits using organic thin-film transistors on polyester film substrates. These are the first reported dynamic results for organic circuits fabricated on polyester substrates. The high-performance pentacene transistors yield circuits with the highest reported clock frequencies for organic circuits.

A systematic study of post-metallization annealing (PMA) effect on the quality of thermal SiO/sub 2/ on p-type 6H- and 4H-SiC has been carried out. A simultaneous quasi-static hi-lo frequency capacitance-voltage method has been employed to measure the total effective oxide charge (N/sub eff/) and interface state density (D/sub it/). To ensure accurate results, D/sub it/ was measured at 350/spl deg/C which, depending on the hole capture cross sections, should enable the measurement of interface states located in the band gap as deep as 1.3-1.5 eV from the valence band edge. The dependence of N/sub eff/ and D/sub it/ on annealing temperature and ambient as well as the effect of thermal and sputtered gate metal on the oxide quality are reported. It is shown that N/sub eff/ values close to the detection limit due to the uncertainty in SiC electron affinities and D/sub it/ values below 1/spl times/10/sup 11/ cm/sup -2//eV deep in the band gap can be reproducibly obtained for both p-type 6H- and 4H-SiC.

We have fabricated the fastest organic circuits on flexible substrates yet reported. These circuits use the small-molecule hydrocarbon pentacene as the active semiconductor material and 75 /spl mu/m thick flexible, transparent, colorless, polyethylene naphthalate (PEN) film as the substrate. Transistor arrays, inverters, ring oscillators, and other circuits with good electrical performance, yield, and uniformity were obtained. A field-effect mobility of 1 cm/sup 2// V-s was extracted from OTFT saturation characteristics, and ring oscillators had minimum propagation delay <40 /spl mu/sec per stage and <50 /spl mu/sec per stage at bias levels below 8 V.

Abstract We have fabricated and demonstrated active‐matrix liquid‐crystal displays using organic thin‐film transistors (OTFTs) on polyester substrates. This is the first reported demonstration of an OTFT active‐matrix liquid‐crystal display, and also the first demonstration of a TFT active‐matrix liquid‐crystal display of any type fabricated on a polyester substrate.