NOVELTY - Forming thin film semiconductor (70) involves depositing on substrate (28), thin film of n-channel organic semiconductor material with N,N'-di(arylalkyl)-substituted-naphthalene tetracarboxylic diimide compound having optionally substituted carbocyclic aromatic ring attached to each imide nitrogen via divalent hydrocarbon, so that material exhibits field effect electron mobility of greater than 0.01 cm2/Vs; forming spaced apart source and drain electrodes (20, 30) separated by and electrically connected with the film; and forming gate electrode (44) spaced apart from material.    USE - Forming thin film semiconductor device particularly thin film transistors which is used in an integrated circuit (claimed), and other devices (including more complex circuits (e.g. shift registers), logic circuits, smart cards, memory devices, radio-frequency identification tags, backplanes for active matrix displays, active-matrix displays (e.g. liquid crystal or organic light emitting diode), solar cells, ring oscillators and complementary circuits (such as inverter circuits); and in an active matrix display. The transistor used as part of voltage hold circuitry of a pixel of the display.    ADVANTAGE - The films are capable of exhibiting, in the film form, the highest reported field-effect electron mobility, up to 5 cm2/Vs for known n-type compounds. Such semiconductor films are also capable of providing device on/off ratios of at least 105. Advantageously, an n-channel semiconductor film used in the present transistor device does not necessarily require, for obtaining high mobilities, prior treatment of the first and second contact connected to the film. The compounds used in the present method possess significant volatility so that vapor phase deposition, where desired, is available to apply the n-channel semiconductor films to a substrate in an organic tin film transistor. The organic semiconductor materials, when used in the form of an n-channel film, exhibits high performance under inert conditions without the need for special chemical underlayers.    DETAILED DESCRIPTION - Fabricating a thin film semiconductor device (70) involves not necessarily in the following order, depositing onto a substrate (28), a thin film of n-channel organic semiconductor material that comprises an N,N'-di(arylalkyl)-substituted-naphthalene tetracarboxylic diimide compound having optionally substituted carbocyclic aromatic ring system attached to each imide nitrogen atom through a divalent hydrocarbon group, where substituents, if any, on each carbocyclic aromatic ring system are electron donating organic groups, such that the organic semiconductor material exhibits a field effect electron mobility that is greater than 0.01 cm2/Vs; forming a spaced apart source electrode (20) and drain electrode (30), where both are separated by, and electrically connected with, the n-channel semiconductor film; and forming a gate electrode (44) spaced apart from the organic semiconductor material. The compound is deposited on the substrate by sublimation and the substrate has a temperature of not greater than 100 degrees C during deposition. The substrate is flexible.    DESCRIPTION OF DRAWING(S) - The figure shows a cross-sectional view of a typical organic thin film transistor having a top contact configuration.    Source electrode (20)    Substrate (28)    Drain electrode (30)    Gate electrode (44)    Gate dielectric (56)    Semiconductor (70)