Stacks of chips, one on top of the other, will power the next
generation of superfast PCs, IBM has announced.
Laying chips vertically, instead of side by side, reduces the
distance data has to travel by 1,000 times, making the chips faster
and more efficient.
Big blue has said that it will start producing the compact silicon
sandwiches in 2008.
Chip manufacturer Intel has previously announced that it is also
developing similar vertical chip technology.
Last year, the firm unveiled a chip with 80 processing cores and
capable of more than a trillion calculations per second (teraflops)
that used vertical stacking technology.
Other firms, such as Tru-Si, have also developed techniques for
creating 3D stacked chips.
High rise
Today most chips are laid out side-by-side, connected by wires.
The new technique involves placing chips directly on top of each
other, connected by tungsten filled pipes, etched through the
silicon.
These "through-silicon vias" (TSV), as they are known, eliminate the
need for wires, increasing the speed at which information can flow
between chips.
It has taken researchers at IBM a decade to refine the precise
technique for mass producing the multi-storey chips.
"This allows us to move 3D chips from the 'lab to the fab' across a
range of applications," said Lisa Su, vice president, semiconductor
research and development center at IBM.
The first application will be in wireless communications chips. Using
TSV will increase the efficiency of the chips by up to 40%, the firm
says.
Speed boost
IBM is also exploring use of the technique in their multi-core chips.
As more and more cores are added to chips it becomes increasingly
difficult to deliver uniform power to each one. By stacking them
vertically and reducing the length of the connections between them,
IBM hopes to overcome this problem,
Using these high-rise multi-core chips should also increase processor
speeds and reduce power consumption.
Advantages like these also make 3D chips attractive for use in
supercomputers.
IBM says it is developing the technology for use in the current
fastest supercomputer in the world, Blue Gene/L.
The ultra powerful number cruncher, installed at the US Department of
Energy's Lawrence Livermore National Laboratory (LLNL) is already
capable of 280.6 trillions calculations per second.
The 3D stacked chips would allow a "new generation of
supercomputers", IBM said.
The first chips will be available by the end of 2007 with full scale
production expected to begin i n2008.
