摘要 |
At least two thicknesses of dielectric are formed in the fabrication of organic field effect transistors. One thickness is formed in the active regions of the transistor for adjusting the desired threshold of the device. A second thickness is deposited in the field regions of the transistor to electrically isolate the transistors, and reduces leakage current and capacitance. A third dielectric thickness that is thicker than the first thickness but thinner than the second thickness can be used to define transistors having a second threshold voltage. The multiple dielectric thicknesses can be produced by multiple cell sizes of a gravure roll when using gravure printing, multiple cell sizes in an anolox roll in flexography printing, multiple nozzle size and chamber pressure in inkjet printing, or by printing successive layers of a single thickness of dielectric. The method can be employed in top gate, bottom gate top contact, and in bottom gate bottom contact organic transistor structures. |