Specifications

9
maximumpc.com JUL 2011
MAXIMUMPC
Tom
Halfhill
Fast
Forward
FINALLY, THE SEMICONDUCTOR industry is
catching up with Intel. Now, any chip de-
signer can use transistors with high-k metal
gates, which enable higher clock speeds and
lower power consumption. It’s the biggest
advance in transistor technology in 50 years.
Intel announced high-k metal-gate
(HKMG) transistors in 2003 and introduced
them in 2007 with 45nm Penryn proces-
sors. AMD wanted 45nm HKMG, too, but
couldn’t pull it off. The first AMD chip with
HKMG is the Llano Fusion processor, an in-
tegrated CPU/GPU. Llano is manufactured
in a 32nm process and is finally hitting the
market this year.
Now the wait is over. Independent chip
foundries like GlobalFoundries (the AMD
spin-off) and Taiwan Semiconductor Manu-
facturing Corp. (TSMC) are rolling out their
28nm HKMG processes this year. Any chip
designers willing to pay the price can use
HKMG transistors in their new designs.
Test chips and engineering samples are
looking good, so volume production will
ramp up next year. The improved transis-
tors will appear in some consumer prod-
ucts you’ll buy in 2012.
Few of those products will advertise HKMG,
but the benefits will be higher performance
and greater power efficiency. It’s coming in
time for the next wave of smartphones, tab-
lets, and other mobile electronics.
The “k” in high-k is the dielectric con-
stant, a measure of electrical capacitance.
The “gate” determines if the transistor
passes current or not. Since the 1960s, tran-
sistor gates have been made of silicon ma-
terials. As transistors keep shrinking with
each generation of fabrication technology,
the gates keep getting thinner. Now they’re
so thin (only four atoms, in some cases) that
they’re leaking too much current.
Substituting exotic metallic materials
for the silicon increases the gate’s capaci-
tance, so it’s less leaky. Higher capaci-
tance also permits higher drive currents,
which allow higher clock frequencies.
The entire semiconductor industry now
turns on such microscopic differences.
Tom Halfhill was formerly a senior
editor for Byte magazine and is now
an analyst for Microprocessor Report.
HKMG FOR
THE MASSES
Intel Gets 3D
Transistors
New 22nm design due next
year in Ivy Bridge CPUs
Announcing a “revolutionary” break-
through, Intel says its next CPUs
will feature a 3D tri-gate design
that allows it to pack transistors
into less space—and more impor-
tantly, greatly increase perfor-
mance while reducing power con-
sumption.
While today’s CPUs flow power
through a flat surface, the new
3D tri-gate design builds up and
out, much the same way a sky-
scraper does. By building three-
dimensional gates, Intel says it
can dramatically improve transis-
tor performance. The upcoming
22nm tri-gate transistor will, for
example, offer up to a 37 percent
increase in performance over a
32nm planar transistor. The same
tri-gate will also reduce power by
up to 50 percent when the transis-
tor is switched on.
The upshot is that the next-
generation Ivy Bridge CPU (the
sequel to Sandy Bridge) is likely
to offer higher clock speeds while
consuming less power. Or tweaked
for a mobile application, Ivy Bridge
could offer more performance
while consuming less power.
The first Ivy Bridge–based pro-
cessors aren’t expected until the
first half of 2012, and they will go
into desktops, laptops, and serv-
ers. To demonstrate how well the
technology is already running,
though, Intel showed off an Ivy
Bridge–based PC running Windows
7 and Need for Speed via its inte-
grated graphics processor, as well
as a server running SUSE Linux.
Perhaps more importantly, the
3D tri-gate when applied to an
Atom chip could finally put the little
x86 processor on the same power
footing as today’s very popular
ARM chips, which are used in tab-
lets and smartphones. Intel didn’t
reveal details of when Atom would
get the new 3D transistor, but most
expect it by 2013 at the latest. –
GU
Today’s 32nm transistor passes elec-
tricity underneath a gate in a flat plane.
On the right is the new 3D transistor
which increases surface area, lowers
leakage, and increases density.
An electron
microscope image
of Intel’s new 3D
tri-gate transistor
shows the gates
(in green) with
current running
through (in white).