Memory Cards News - Australia

Latest news and reviews on flash memory cards.

Tuesday, December 21, 2004

Flash Memory Capacity Increases while Size Shrinks

Scientists at Infineon Technologies AG, Germany, have built the world's smallest non-volatile flash memory cell. The new memory cell measures just 20 nanometers - approximately 5,000 times thinner than a human hair.

Given that all manufacturing-related challenges - including that of lithography - can be resolved, the new development would make nonvolatile memory chips with a capacity of 32 Gbit possible within a few years. That is eight times the capacity of what is currently available in the market.

Nonvolatile flash memories are becoming increasingly popular as mass storage media for devices such as digital cameras, camcorders and USB sticks. The most advanced nonvolatile flash memory devices available today can permanently store one or two bits of information per memory cell without a supply voltage.

Such memories have a feature size of around 90 nanometers, and shrinking this feature size using typical techniques to half that size has posed many problems because of nanoscale physical effects. In particular, fabricating 20 nanometer-sized flash memory cells has been considered almost impossible because these physical effects would make the memory cells extremely unreliable.

The Infineon researchers created a three-dimensional structure with a fin for the transistor that acts as the heart of the memory cell. The geometry minimizes unwanted effects and improves electrostatic control compared to today's flat transistors.

Called a FinFET (Fin Field Effect Transistor), the Infineon device stores the electrons that carry the information in a nitride layer that lies electrically isolated between the silicon fin and the gate electrode. 8 nanometers thin, the fin is controlled by the 20 nanometer-wide gate electrode.

According to Infineon the FinFET is extremely durable and possesses excellent electrical characteristics. For example, the most advanced memories on the market today need approximately 1,000 electrons in order to reliably remember one bit. The new Infineon memory cell uses only 100 electrons; an additional 100 electrons stores a second bit in the same transistor. 100 electrons roughly correspond to the number of electrons in a single gold atom.

Details about the new flash memory were presented at a post-deadline paper at the IEEE’s International Electron Devices Meeting in San Francisco yesterday.

0 Comments:

Post a Comment

<< Home