IBM moving to replace
silicon with carbon nanotubes in computer chips
The company said it has
greatly increased the number of carbon nanotubes that can be accurately placed
on a single chip
By Jay Alabaster
October 29, 2012 02:16 AM
ET
IDG News Service - IBM has
hit a milestone in its quest to come up with a successor to silicon computer
chips.
The company said Sunday
its research into semiconductors based on carbon nanotubes, or CNTs, has
yielded a new method to accurately place them on wafers in large numbers. The
technology is viewed as one way to keep shrinking chip sizes once current
silicon-based technology hits its limit.
IBM said it has developed
a way to place over 10,000 transistors made from CNTs on a single chip, two
magnitudes higher than previously possible. While still far below the density
of commercial silicon-based chips -- current models in desktop computers can
have over a billion transistors -- the company hailed it as a breakthrough on
the path to using the technology in real-world computing.
The company made the
announcement to mark the publication of an article detailing the research in
the journal Nature Nanotechnology.
Intel's latest processors
are built using silicon transistors with 22-nanometer technology, and simpler
NAND flash storage chips have been demonstrated using "1X" technology
somewhere below that, but modern manufacturing is nearing its physical limits.
Intel has predicted it will produce chips using sizes in the single digits
within the next decade.
The march toward
ever-smaller transistors has produced chips that use less power and can run
faster, but can also be made at lower cost, as more can be crammed onto a
single wafer. The increasing number of transistors on a given amount of silicon
was famously predicted by Gordon Moore, co-founder of Intel, who predicted they
would double steadily over time.
Carbon nanotubes,
tube-shaped carbon molecules, can also be used as transistors in circuits, and
at dimensions of less than 10 nanometers. They are smaller and can potentially
carry higher currents than silicon, but are difficult to manipulate at large
densities.
Unlike traditional chips,
in which silicon transistors are etched into circuit patterns, making chips
using CNTs involves placing them onto a wafer with high accuracy. Semiconducting
CNTs also come mixed with metallic CNTs that can produce faulty circuits, and
must be separated before they are used.
IBM said its latest method
solves both issues. The company's researchers mix CNTs into liquid solutions
that is then used to soak specially prepared substrates, with chemical
"trenches" to which the CNTs bond in the correct alignment needed for
electrical circuits. The method also eliminates the non-conducting metallic
CNTs.
The company said the
breakthrough will not yet lead to commercial nano-transistors, but is an
important step along the way.
Before they can challenge
silicon, however, they must also pass an often-overlooked part of Moore's law -
affordability. His law applies to "complexity for minimum component
costs," or what consumers are likely to see in the market.
Comments
Post a Comment