Programmable Permanent Data Storage Characteristics of Nanoscale Thin Films of a Thermally Stable Aromatic Polyimide

Abstract

We have synthesized a new thermally and dimensionally stable polyimide, poly(4,4'-amino(4-hydroxyphenyl)diphenylene hexafluoroisopropylidenediphthalimide) (6F-HTPA PI). 6F-HTPA PI is soluble in organic solvents and is thus easily processed with conventional solution coating techniques to produce good quality nanoscale thin films. Devices fabricated with nanoscale thin PI films with thicknesses less than 77 nm exhibit excellent unipolar write-once-read-many-times (WORM) memory behavior with a high ON/OFF current ratio of up to 10(6), a long retention time and low power consumption, less than +/-3.0 V. Furthermore, these WORM characteristics were found to persist even at high temperatures up to 150 degrees C. The WORM memory behavior was found to be governed by trap-limited space-charge limited conduction and local filament formation. The conduction processes are dominated by hole injection. Thus the hydroxytriphenylamine moieties of the PI polymer might play a key role as hole trapping sites in the observed WORM memory behavior. The properties of 6F-HTPA PI make it a promising material for high-density and very stable programmable permanent data storage devices with low power consumption.

Fully transparent nonvolatile resistive polymer memory

“…The T g and T d of PI-DAn-AnDA are somewhat lower than those of the fully aromatic polyimides previously developed for memory device applications, [15][16][17][18] but high enough to be used in the electronic industry. 19 …”

“…The electronic property of the ITO/polyimide/ITO/glass device depended on thickness of the polyimide film. 19,37 The memory devices with the polyimide film thicker than 50 nm showed no forming process, and when the polyimide films were thinner than 30 nm the devices exhibited short circuit current flow. Therefore the memory devices with 30 to 50 nm thick polyimide film were used for the characterization and evaluation of memory properties.…”

“…, indicating that the Ohmic conduction is dominant. 15,19 As the voltage increased continuously (>0.4 V), the current increased nonlinearly (a slope of 1.45), which can be explained by a trap-controlled space-charge limited conduction (SCLC) mechanism. 15,19 On the other hand, the ON state I-V curve (upper line) can be fit well using the Ohmic conduction model (a slope of 1.00), which was not affected by the direction of current [ Fig.…”

Asymmetric isomerization: an efficient strategy to tune the electrical resistive memory behaviors of functional polyimides containing N-phenylcarbazole moieties

“…4 Since the rst PI memory reported by Ling and coworkers, 5 tremendous attention has been paid to the preparation of novel electroactive PIs [6][7][8][9][10][11][12][13][14][15][16][17][18][19] and different memory behaviors, such as dynamic random access memory (DRAM), 20 static random access memory (SRAM), 21 ash memory, 11 and write once read many times memory (WORM), 13 have been demonstrated.…”

Synthesis and memory performance of a conjugated polymer with an integrated fluorene, carbazole and oxadiazole backbone

“…Basically, WORM memory, a type of nonvolatile memory capable of permanently holding data and being repeatedly read, is desirable for the ultra low cost and permanent storage of digital images, and eliminates the need for the slow, bulky and expensive mechanical drives used in conventional magnetic and optical memories. [13][14][15][30][31][32][33][34][35][36][37][38] …”