Gate oxide may not hit 'brick wall' until after 2005, say Bell Labs researchers
By Semiconductor Business News
Apr 17, 2000 (8:18 AM)
URL: semibiznews.com
MURRAY HILL, N.J. -- The semiconductor industry may be able to shrink transistor feature sizes for at least five more years without hitting a key technical barrier identified in some technology roadmaps, according to researchers at Bell Labs here.
The R&D laboratory of Lucent Technologies Inc. today said a team of researchers has demonstrated that the intrinsic reliability limits of silicon-dioxide insulators in transistors is fewer than six atoms thick--or 1.5 nanometers. Other research groups have found the limit to be 9 to 10 atoms thick, according to Bell Labs.
"Achieving such thin dimensions with the required intrinsic reliability was previously thought to be impossible," said Ashraful Alam, a member of the research team discovering the new limits to scaling transistor silicon-dioxide insulators. Consequently, Bell Labs researchers concluded that the "doomsday" scenario or "brick wall" for the conventional silicon ICs might be delayed until after 2005, instead of the next couple of years.
Today's IC transistors have insulators--gate oxides--of about 12 atoms thick. If silicon dioxide can be scaled to fewer than six atoms in gate oxides, the chip industry will have more time to find a reliable replacement for today's insulating material. This would be good news for Moore's law, which has paced the industry's shrinks for higher performance and device density since the 1970s.
"These results will help us direct our process development efforts to continue advancing integrated circuit performance for demanding wireless and networking applications," said Gregg Higashi, a technical manager at Lucent's Microelectronics Group.
To obtain reliability results, Bell Labs researchers first studied how thicker gate oxide layers withstood high voltages over many days and developed sophisticated computer models to simulate those results. Lucent said the researchers used the same physics-based models to show that a transistor with a 1.5-nanometer gate oxide operating at 3volts for several hours would be comparable to a similar transistor operating at 1 volt for 10 years -- a very strong reliability indicator, according to Lucent.
Bell Labs researchers presented their research results about gate-oxide reliability last week at the International Reliability Physics Symposium in San Jose.
Jim |
