Current Conduction Mechanism for Non-volatile Memory Fabricated with Conductive Polymer Embedded Au Nanocrystals
- PDF / 835,423 Bytes
- 5 Pages / 612 x 792 pts (letter) Page_size
- 104 Downloads / 201 Views
1071-F09-18
Current Conduction Mechanism for Non-volatile Memory Fabricated with Conductive Polymer Embedded Au Nanocrystals Jong Dae Lee, Hyun Min Seung, Byeong Il Han, Gon-Sub Lee, and Jea-gun Park Electrical & Computer Engineering, Hanyang University, Nano SOI Process Laboratary, Room #101, HIT, Hanyang University 17 Haengdang-dong, Seoungdang-gu, Seoul, 133-791, Korea, Republic of ABSTRACT Molecular memory is an expected next-generation, nonvolatile memory because it demonstrates the characteristic of a bi-stable switch and has a 45-nm initial feature, an up to 10ns access and store time, and low-cost, flexible, and simple fabrication. Several types of molecular devices have been reported, such as simple and low molecular organic devices and polymer devices. However, fabricating this device is complex because the Ni1-xFx crystals are embedded in the polyimide layer as a floating gate in the flash memory after defining the source and drain regions. We report the memory effects, based on the electrical bistability of the materials, in organic molecules. A bistable phenomenon was observed in a poly(Nvinylcarbazole) (PVK) layer, which contained a high density of Au nanocrystals and was sandwiched between Al electrodes without source and drain regions. The memory phenomenon in this device was based on the electrical bistability of the material, which has two resistance states. Nonvolatile memory devices that use discrete nanocrystals as charge storage sites and exhibit bistability have also been reported. We discuss the current conduction mechanism for nonvolatile memory devices. INTRODUCTION Organic nonvolatile memory devices have been investigated as candidates for nextgeneration nonvolatile memory because of their low-cost, flexible, and simple fabrication [1-5]. The memory phenomenon in these devices is based on the electrical bistability of the material, which has two resistance states [6]. We report on this phenomenon in the organic molecules and polymer nonvolatile memory device. A bistable phenomenon was observed in the poly(Nvinylcarbazole) (PVK) layer, which contained a high density of Au nanocrystals and was sandwiched between Al electrodes. This device showed good nonvolatile memory characteristics. We suggest that the current conduction mechanism for nonvolatile memory fabricated with conductive polymer embedded Au nanocrystals clearly follows space-chargelimited current (SCLC) for a low conductivity state, thermionic field emission for electron charge (writing) or discharge (erasing), and F-N tunneling after erasing. EXPERIMENT A 600-nm HDPCVD film was deposited on an SC1-cleaned p-type silicon substrate. A solvent (chloroform) was used to dissolve the PVK. The weight percent was varied by altering the viscosity and thickness of the PVK film. An 80-nm bottom Al electrode was thermally evaporated at a 10-4-Pa chamber pressure and a 5-Å/s evaporation rate using a shadow mask. The first PVK layer was deposited by spin coating with a 2000-rpm rotation velocity for 99 s and then baking at 120°C for 2 min to
Data Loading...
