Joined: 16 Mar 2004
|Posted: Thu Dec 21, 2006 2:47 pm Post subject: Nanoscale capacitor feasibility studied
|Nanoscale capacitor feasibility studied
U.S. scientists say they have discovered why the size of capacitors, often the largest components in integrated circuits, can't be cut to nanoscale.
Researchers at the University of California-Santa Barbara say their finding answers a 45-year-old question: Why is the capacitance in thin-film capacitors so much smaller than expected?
Scientists have tried to use high-permittivity materials to achieve more capacitance in a smaller area but nanoscale devices have yielded lower-than-expected capacitance values. Those low values have limited the performance of thin-film capacitors and prevented further device miniaturization.
University of California-Santa Barbara Professor Nicola Spaldin and post-doctoral researcher Massimiliano Stengel used quantum mechanical calculations to prove a so-called "dielectric dead layer" at the metal-insulator interface is responsible for the observed capacitance reduction.
Spaldin and Stengel say the fundamental quantum mechanical properties of the interfaces are the root cause of the problem and show that metals with good screening properties can be used to improve the properties. "Our results provide practical guidelines for minimizing the deleterious effects of the dielectric dead layer in nanoscale devices," they said.
This story was first posted on 13th October 2006