New photopatternable polyimide and programmable nonvolatile memory performances

Abstract

We report the first photopatternable, nonvolatile memory consisting of high-temperature polyimide (PI), poly (hexafluoroisopropylidenediphthalimide-4-cinnamoyloxytri-phenylamine) (6F-HTPA-CI), and we demonstrate the successful fabrication and programmable operation of 'write-read-erase' memory devices based on nanoscale thin films of 6F-HTPA-CI. The PI thin film enables scalable fine patternability, providing lines and spaces with excellent pattern fidelity. Isolated individual memory devices were successfully fabricated on a bottom electrode via a sequential process of coating, photopatterning, top electrode deposition, developing, rinsing and drying. The 6F-HTPA-CI cells exhibited excellent nonvolatile memory performances in three different modes (unipolar permanent, unipolar flash and bipolar flash memories), regardless of photo-exposure doses. The switching-ON (writing) voltage was in the range of +/- 1.5 to +/- 2.0 V, and the switching-OFF (erasing) voltage was in the range of +/- 0.3 to +/- 0.8 V; these voltages are quite low, indicating that power consumption by the devices during operation is low. The ON/OFF current ratio of the devices was in the range of 10(4)-10(9). Overall, the photopatternable PI 6F-HTPA-CI opens up the possibility of low-cost mass production of high-performance, high-speed, energy-efficient, permanent or rewritable high-density nonvolatile polymer memory devices suitable for future advanced electronics in highly integrated systems.