Bell Labs researchers claim gate oxides could hit six atom level

Apr 17, 2000 --- Researchers at Lucent Technologies' Bell Labs say they have evidence that the insulating layer used in transistors could be reduced to fewer than six atoms.

Previously, researchers have suggested that nine to 10 atoms would be the thinnest insulating layer possible for practical chips; current chips average 12 atoms thick. Ashraful Alam and his Bell Labs colleagues claim the intrinsic reliability limit is fewer than six atoms, or 1.5 nanometers.

To obtain their reliability results, the researchers first studied how thicker gate oxide layers withstood high voltages over many days and developed computer models to simulate those results. Applying the same physics-based models, they showed that a transistor with a 1.5-nanometer gate oxide operating at three volts for several hours would be comparable to a similar transistor operating at one volt for 10 years.

Using conventional manufacturing techniques, Bell Labs researchers made the ultra-thin gate oxides by growing atomic layers that were exceptionally uniform and smooth, then tested the reliability of the transistors to support their findings.

The researchers presented their results last week at the International Reliability Physics Symposium in San Jose.