AMD Future High-Speed Transistors

AMD provided additional details on its next-generation, silicon-on-insulator (SOI) transistor design for use in microprocessors. AMD’s transistor design uses three gates and is geared for the 45-nm node, although the circuit can be scaled down to 20-nm and below. The transistor is not dependent upon the use of high-k gate dielectric materials, which have been shown to have negative effects on some aspects of transistor performance. The transistor will make use of AMD’s next-generation, fully-depleted SOI, metal gates based on nickel-silicide, and what it calls “locally strained channel” technology.


At the 2003 IEEE International Electron Devices Meeting (IEDM)
in Washington, DC, AMD provided additional detail on its revolutionary
next-generation silicon-on-insulator (SOI) transistor design, while also
providing new information on its successful use of SOI technologies in its
current microprocessors.

“This next-generation SOI transistor uniquely incorporates
several of AMD’s most significant innovations into a single design. It is an
important achievement, part of critical research that allows AMD to continue to
meet our customers’ needs for low power and high performance — today and in the
future,” said Craig Sander, VP of process technology development at AMD.

Towards a Complete 45 Nanometer (nm) Solution

AMD’s new transistor is expected to offer a high-confidence
solution to many of the most critical challenges the semiconductor industry
expects to face at the 45 nm technology generation (or “node”). A nanometer is a
billionth of a meter.

“Each time you shrink transistors in a new technology generation, it presents
additional challenges. Reducing electrical leakage when the transistor is off is
one challenge, but equally important is maximizing electrical flow when the
transistor is on,” said Ming-Ren Lin, AMD Fellow. “While research from other
companies often addresses these challenges individually, AMD’s approach is to
address all of them as an integrated whole.”

Currently, the International Technology Roadmap for Semiconductors forecasts
that transistor gates, the primary parts of transistors that turn the flow of
electricity on and off, will need to be as small as 20 nm in order to achieve
performance projections for the 45 nm generation. Today, minimum gate lengths in
the highest-performance microprocessors from AMD are approximately 50 nm.

“Aggressively shrinking the size of transistor gates is fundamental to
ever-increasing transistor performance, and this trend shows no sign of
abating,” added Lin. “To maintain this pace of innovation, it is imperative that
leading-edge manufacturers incorporate innovative transistor structures such as
AMD has done here.”

Unique Multi-Gate Design

AMD’s new transistor design uses three gates, instead of one
as in today’s transistors, and incorporates several innovations that allow for
continued transistor gate scaling down to 20 nm and below, while providing
increased speed and decreased electrical leakage. Further, AMD’s transistor is
not dependent upon the use of so-called “high-k” gate dielectric materials,
which have been shown to have negative effects on some aspects of transistor
performance.

“We have taken a structural approach that utilizes conventional materials in new
ways to provide a demonstrated solution at the 20 nm gate dimension. This is the
kind of innovation required to drive technology advancement well into the next
decade,” stated Lin.

AMD research technologies used in the new multi-gate design include:

Fully depleted SOI (FDSOI): The next generation of silicon-on-insulator (SOI)
technology that increases the performance and power-saving benefits of today’s
SOI.
Metal gates: Gates made from nickel-silicide, rather than polysilicon as they
are today, in order to improve electrical flow while reducing unwanted leakage.

Locally strained channel: A revolutionary way of combining advanced materials in
a geometry that naturally “strains” the atoms within the transistor’s electrical
path so electricity can flow more fully.
AMD’s approach has resulted in transistors that demonstrate record-setting
performance with dramatically reduced current leakage. For further technical
details on AMD’s multi-gate research presented at the conference, visit
www.amd.com/IEDM03_triple.

Extending the Benefits of SOI

AMD’s next-generation SOI research builds upon the company’s
current successes using SOI in a high-volume manufacturing environment within
AMD Fab 30. AMD detailed these successes at IEDM as well, giving in-depth
information on the SOI technologies used in AMD64 processors to increase product
performance while reducing power requirements.

“SOI is a key contributor to the AMD Opteron™ processor delivering leading-edge
32-bit and 64-bit performance, while minimizing power consumption,” stated
Sander. “Lower power means less heat. For enterprise IT staffs, less heat can be
a major factor in reducing total cost of ownership and helping to ensure
reliability.”

AMD also provided information for the first time on its leadership in
introducing what are known as “low-k” dielectric materials for improved circuit
performance. These low-k materials are used to insulate the copper interconnect
lines that conduct electrical signals across the chip and reduce the energy that
is needed to propagate these signals. AMD was a leader in the introduction of
low-k materials into a high-volume manufacturing environment, starting with its
130 nm process in AMD Fab 30.

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