22-02-2009, 01:36 AM
1. INTRODUCTION
Imagine a time when your mobile will be your virtual assistant and will need far more than the 8k and 16k memory that it has today, or a world where laptops require gigabytes of memory because of the impact of convergence on the very nature of computing. How much space would your laptop need to carry all that memory capacity? Not much, if Intel's project with Thin Film Electronics ASA (TFE) of Sweden works according to plan. TFE's idea is to use polymer memory modules rather than silicon-based memory modules, and what's more it's going to use architecture that is quite different from silicon-based modules.
While microchip makers continue to wring more and more from silicon, the most dramatic improvements in the electronics industry could come from an entirely different material plastic. Labs around the world are working on integrated circuits, displays for handheld devices and even solar cells that rely on electrically conducting polymersâ€not siliconâ€for cheap and flexible electronic components. Now two of the worldâ„¢s leading chip makers are racing to develop new stock for this plastic microelectronic arsenal: polymer memory. Advanced Micro Devices of Sunnyvale, CA, is working with Coatue, a startup in Woburn, MA, to develop chips that store data in polymers rather than silicon. The technology, according to Coatue CEO Andrew Perlman, could lead to a cheaper and denser alternative to flash memory chipsâ€the type of memory used in digital cameras and MP3 players. Meanwhile, Intel is collaborating with Thin Film Technologies in Linkping, Sweden, on a similar high capacity polymer memory.
2. PRESENT MEMORY TECHNOLOGY SCENARIO
Digital Memory is and has been a close comrade of each and every technical advancement in Information Technology. The current memory technologies have a lot of limitations. DRAM is volatile and difficult to integrate. RAM is high cost and volatile. Flash has slower writes and lesser number of write/erase cycles compared to others. These memory technologies when needed to expand will allow expansion only two dimensional space. Hence area required will be increased. They will not allow stacking of one memory chip over the other. Also the storage capacities are not enough to fulfill the exponentially increasing need. Hence industry is searching for Holy Grail future memory technologies for portable devices such as cell phones, mobile PCâ„¢s etc. Next generation memories are trying a tradeoffs between size and cost .This make them good possibilities for development.
3. NEXT GENERATION MEMORIES
As mentioned earlier microchip makers continue to wring more and more from silicon, large number of memory technologies were emerged. These memory technologies are referred as ËœNext Generation Memoriesâ„¢. Next Generation Memories satisfy all of the good attributes of memory. The most important one among them is their ability to support expansion in three dimensional spaces. Intel, the biggest maker of computer processors, is also the largest maker of flash-memory chips is trying to combine the processing features and space requirements feature and several next generation memories are being studied in this perspective. They include MRAM, FeRAM, Polymer Memory and Ovonics Unified Memory.
Polymer memory is the leading technology among them. It is mainly because of their expansion capability in three dimensional spaces. The following graph also emphasis acceptance of Polymer memory.
Figure1- Memory Technology Comparison
The graph shows a comparison between cost and speed i.e., the Read/Write time. Disk drives are faster but expensive where as semiconductor memory is slower in read/write. Polymer memory lies in an optimum position.
Polymer-based memory modules, as against silicon-based ones, promise to revolutionize the storage space and memory capabilities of chips. Coatueâ„¢s polymer memory cells are about one-quarter the size of conventional silicon cells. And unlike silicon devices, the polymer cells can be stacked that architecture could translate into memory chips with several times the storage capacity of flash memory. By 2004, Coatue hopes to have memory chips on the market that can store 32 gigabits, outperforming flash memory, which should hold about two gigabits by then, to produce a three-dimensional structure.
3.1 The Fundamental Technology of Next Generation Memories- FeRAM
Figure2- Central atom responsible for bistable nature.
The fundamental idea of all these technologies is the bistable nature possible for of the selected material which is due to their difference in behavior of internal dipoles when electric field is applied. And they retain those states until an electric field of opposite nature is applied. FeRAM works on the basis of the bistable nature of the centre atom of selected crystalline material. A voltage is applied upon the crystal which in turn polarizes the internal dipoles up or down. I.e. actually the difference between these states is the difference in conductivity. Non “Linear FeRAM read capacitor, i.e., the crystal unit placed in between two electrodes will remain in the direction polarized(state) by the applied electric field until another field capable of polarizing the crystal™s central atom to another state is applied.
3.1.1 Attributes of FeRAM
¢ The FeRAM memory is non volatile: - The state of the central atom or the direction of polarization remains even if power is made off.
¢ Fast Random Read Access.
¢ Fast write speed.
¢ Destructive read, limited read and write cycles.
¢ Very low power consumption.
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