Infineon scales Flash memory cells to 20 nm

San Francisco (CA) - Scientists at semiconductor company Infineon said that it has built the world’s smallest Flash memory cell. Measuring just 20 nm, the cell is about 5000 times thinner than a human hair.

Despite its introduction dates more than 16 years back, Flash memory today experiences growing popularity, not just because growing memory needs in compact portable audio players and digital cameras but most recently also because of the convenience of USB memory sticks. The technology, currently manufactured in 170 nm to 90 nm production processes, however faces threats from new non-volatile memory technologies such as MRAM being developed as potential successors.

Continued scaling of Flash is critical to increase performance and capacity of the devices. Intel announced in September that it just has started a program to move Flash to a 65 nm production process, but that "visibility" beyond 32 nm and 20 nm was "limited". Scaling challenges include a decreasing reliability of the chips.

Infineon’s announcement can be seen as sign that the industry is confident about scaling Flash and defending the memory’s position as popular storage technologies beyond the year 2008. Because of its lower production cost, Flask is likely to continue its dominance in the market, until a natural barrier of scaling opportunities is reached and the industry will have to shift to reinvent production processes.

Infineon believes that the achievement will make mass-market memory chips with 32 Gbit capacity a reality within a few years, if "manufacturing-related challenges - including that of the lithography - can be resolved".

The company said that it was able to scale to 20 nm by creating a "unique three-dimensional structure with a fin for the transistor that acts as the heart of the memory cell". The special geometry minimizes unwanted effects and significantly improves electrostatic control compared to today’s flat transistors.

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