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Performance
of 50 Completed ATP Projects
Status
Report - Number 2
NIST SP 950-2
Chapter
4 - Electronics, Computer Hardware & Communications
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Vitesse
Semiconductor Corporation
Gallium Arsenide: a Faster Alternative to Silicon
for Microprocessors and Telecommunications Applications
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| Nearly
all integrated circuits (ICs) are manufactured on a substrate of silicon.
The silicon chip has provided the base on which IC technology has
advanced. But silicon has its limits. Electrons pass through GaAs
about five times faster than through silicon, suggesting potential
for achieving higher processing speeds from ICs fabricated from GaAs.
In the 1970s and 1980s, research efforts were undertaken to develop
gallium arsenide (GaAs) as an alternative material for fabricating
integrated circuits. |
COMPOSITE
PERFORMANCE SCORE
(Based on a four star rating.)
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Barriers to Use of
GaAs-based ICs
Despite their speed advantage, GaAs-based ICs, developed in the 1980s,
did not find widespread commercial use. One barrier to their use was price.
GaAs cost as much as 10 times more than silicon in the early years. The
wafers from which GaAs chips are made were difficult to produce without
a high level of defects. And, they were difficult to produce at all. More
recently, this cost barrier has been significantly reduced as wafer suppliers
and chip producers have perfected manufacturing techniques.
Another barrier to
widespread commercial use of GaAs-based ICs was their high power consumption.
Unlike silicon ICs, which consume power only while performing processing
tasks, GaAs ICs consume power even when they are not in operation. The
use of GaAs as a substrate for ICs had been pioneered for military applications,
namely in microproccessors for supercomputing. Military users were willing
and able to pay the considerable premium for GaAs-based chips in return
for superior processing speed. Commercial users, however, saw the high
power requirements as an unacceptable obstacle.
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| Vitesse’s
ability to fabricate chip's on 6" wafers in it's new plant, (instead
of 4" wafers) more than doubles the number of intergrated circuits
that can be fabricated on each wafer and increases the efficiency
of production. |
The high power requirements
placed limits on the exploitation of the inherent speed advantage of GaAs.
More wiring was needed to transmit more power to the chip, crowding out
the wiring needed to transmit the input and output signals; thus fewer
transistors could fit on the same chip. So constrained, GaAs technology
had to employ several chips to equal the capacity of a single silicon
chip, causing much of the speed advantage of GaAs to be lost in the time
delays between chips.
The ability of GaAs
to compete with silicon for use in ICs was contingent on design innovations
that allow the particular advantages of GaAs to be exploited effectively.
The years of accumulated design and manufacturing process refinements,
however, had been devoted to silicon-based ICs, not GaAs-based ICs.
Vitesse Proposes GaAs
Design Innovations
Vitesse Semiconductor
Corporation, at that time a small company, proposed a project for GaAs
innovations in ATP’s 1993 General Competition. ATP made an award
of $2 million to Vitesse for a 33-month project, later extended to the
maximum allowable period of three-years. Vitesse contributed $4.6 million,
bringing total project costs to $6.6 million.
The company, located
in Camarillo, California, has become a world leader in the design, development,
and manufacture of GaAs ICs. It pioneered the development of Very Large
Scale Integration (VLSI) in GaAs, and also pioneered the adaptation of
proven state-of-the-art silicon chip manufacturing equipment to the production
of GaAs chips to reduce their cost and improve reliability.
Project Goals and Early Results
The project’s first objective was to shrink the size of and reduce
power consumption of GaAs-based ICs by creating a supermicroprocessor.
By replacing multiple chips with a single-chip supermicroprocessor, transfer
delays would be eliminated and the speed advantage of GaAs fully realized.
Two secondary objectives were to use the improved GaAs ICs in communications
applications and automatic testing equipment (ATE).
The research started
with the development of electrical and process models to help determine
the optimal design of GaAs ICs that would exploit their speed advantage.
With the insights provided by these simulations, Vitesse created a library
of basic IC components that permitted the construction of a demonstration
vehicle to test design performance. The initial demonstration vehicle
was a microprocessor, which, in turn, was to be used to test designs of
the supermicroprocessor.
Market Changes Compel
Reorientation of Project
Unexpectedly, Vitesse was forced to abandon its supermicroprocessor objective
at the end of the first year of the project. Although the supercomputer
and workstation markets for GaAs supermicroprocessors appeared to be a
reasonable target at the time of the project’s proposal and selection,
subsequently the market for supercomputers steeply declined. The decline
was due in part to the collapse of government and aerospace demand for
supercomputers. Early in the project, Convex Computers, the only supercomputer
producer using GaAs-based microprocessors (and Vitesse’s only customer
in this application) suffered serious losses. Convex Computers had accounted
for half of Vitesse’s revenues.
Vitesse confronted
a large investment risk in entering the high-performance microprocessor
market. Higher performance microprocessors are split between two competing
standards: complex instruction set computers (CISC) and reduced instruction
set computers (RISC). Within these broad classes, many fundamental architectural
differences exist, each with its own specific demands. Vitesse would have
to bet on one. Moreover, Vitesse would have to supply compilers, linkers,
math libraries, and other high-level software to complement any microprocessor
that it chose to make. This would require a daunting investment of up
to $30 million.(1)
The company’s financial condition and the uncertainty characterizing
the direction of the high-performance microprocessor market led Vitesse
to seek alternative opportunities for GaAs technology during the first
year of the project.
Vitesse requested
a change in the project, and ATP agreed to allow a change in focus on
developing and testing GaAs design innovations for use in the development
of wire-line transceivers and ICs for automatic test equipment (ATE).
This use for GaAs IC technology was on the rise. Networks of workstations,
configured to emulate a supercomputer at far less cost, were becoming
increasingly popular, and these workstations, like other local area networks
(LANs), require the use of transceivers for data transmission and error-checking.
There are also many
other applications for transceivers. They are essential in telephone communications
that share large volumes of digital data among various points, such as
central switching offices and cellular transmission sites. Credit card
companies also rely on transceivers for the data links that connect databases
and terminals, ensuring speedy authentication during transactions. Transceivers
will also be an essential component in digital television. Transmission
of digital television signals from television stations to home sets, between
the cameras and the studio, and between the studio and the network facilities
will all require very high-speed links with transceivers at either end.
ATP Flexibility Important
to Company’s Future Success: Funding Supports Critical Shift in Business
Strategy
By accepting Vitesse’s request that it be allowed to shift the project’s
focus for applying the technology rather than stopping the project, ATP
enabled Vitesse to continue the development of GaAs technology following
the business reverses of its main customer. According to Ray Milano of
Vitesse, ATP funding was essential for sustaining its development of GaAs
technology. Accomplishments in the project ultimately allowed the company
to build its position in wire-line transceivers and ICs for automatic
testing equipment.(2)
Design Innovations
Achieved
Vitesse made substantial progress toward the revised project goals. Vitesse
designated the new generation of GaAs IC technology developed from the
project’s design innovations as H-GaAs IV. The H-GaAs IV embodies
a 50 percent decrease in size for equivalent functionality, and requires
just half as much power to deliver the same amount of processing speed.
Memory per chip was increased four-fold.
Higher levels of integration
and reduced power consumption made possible by project-related design
innovations have allowed Vitesse to provide GaAs-based ICs with clear
advantages over traditional silicon-based ICs, both
for transceivers and ICs for automatic testing equipment (ATE).
Project Innovations
Embodied in Transceivers and ATE Equipment
The old technology for ATE employed multiple, linked silicon ICs to perform
the same task as one H-GaAs IV IC. The greater number of connections required
to link the silicon ICs with the IC to be tested, the greater space they
took up, the power consumed, and the amount of heat generated caused ATE
producers to be very receptive to Vitesse’s H-GaAs IV. Virtually
all ATE makers, including Intel, have purchased GaAs chips from Vitesse.
Every Pentium microprocessor built has been tested by ATE using Vitesse
ICs.
Overall, the chief
commercial application of H-GaAs IV-based IC technology has been for transceivers
used in telecommunications and data communications. Customers include
telecommunication equipment makers such as Lucent Technologies, Alcatel,
and Ericsson.
Success in these markets allowed Vitesse to build a major new chip fabrication
plant. This plant will fabricate chips on six-inch wafers. Heretofore,
GaAs ICs have been fabricated on four-inch wafers. The shift to six-inch
wafers will more than double the number of ICs that can be fabricated
on each wafer, dramatically increasing the efficiency of GaAs IC production.
Producers and Customers
Benefit from Lower Costs, New Capabilities
H-GaAs IV-based ICs offer a superior alternative to silicon-based transceivers.
Because just one IC must be purchased, and because the Vitesse transceiver
consumes less power than the set of silicon ICs, total system cost is
substantially less.
H-GaAs IV IC technology
has been instrumental in meeting the needs of ATE producers and their
customers. The ICs used in ATE must be faster than the ICs to be tested.
Silicon technology was running up against technical limits. H-GaAs IV
IC technology has allowed ATE producers to overcome the technological
bottleneck and produce equipment with the capability to test increasingly
fast ICs.
Increased levels of
integration and reduced power consumption made possible by project-related
design innovations in GaAs-based IC technology have enabled Vitesse to
provide substantial cost and performance advantages over silicon ICs,
both for transceivers and for ICs used in automatic testing equipment.
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Project
Highlights
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PROJECT:
To achieve design innovations needed to exploit the speed and power
advantage of GaAs, a substrate material for fabricating high-performance
integrated circuits (ICs) for use in microprocessors, transceivers,
and ICs used in automatic testing equipment.
Duration: 3/01/94 – 12/31/96
ATP Number: 93-01-0124
FUNDING (in
thousands):
| ATP |
$2,000
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30%
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| Company |
4,634
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70%
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| Total |
$6.634
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ACCOMPLISHMENTS:
Initial applications of GaAs design innovations in the development
of a supermicroprocessor for use in supercomputers and workstations
were abandoned due to market uncertainty. Vitesse refocused its
efforts on the development of GaAs design innovations for transceivers
used in telecom-munications and data communications, and for ICs
used in automatic test equipment. Project accomplishments included:
- 400 percent
increase in memory per chip;
- 50 percent
decrease in size of an IC for equivalent functionality;
- 50 percent
reduction in power consumption;
- GaAs design
innovations commercialized as H-GaAs IV-based technology in transceivers
and ATE;
- construction
of a new, more efficient chip fabrication plant to fabricate GaAs
chips on six inch wafers instead of four inch wafers;
- disseminated
the technology through articles in the Electronic Engineering
Times, Computer Design Magazine, Lightwave, and Semiconductor
FabTech; and
- enabled ATE
producers to be able to test increasingly fast ICs.
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COMMERCIALIZATION
STATUS:
The design innovations in GaAs have been commercialized in the form
of H-GaAs IV–based IC technology. It is being applied to transceivers
for use in telecommunications and data communications, which now
account for approximately 80 percent of Vitesse's revenues. H-GaAs
IV–based ICs are also used in automated test equipment (ATE),
accounting for the remaining 20 percent of Vitesse’s revenues.
Virtually all ATE makers have purchased H-GaAs IV–based ICs
from Vitesse. Every Intel Pentium microprocessor built has been
tested by ATE using Vitesse ICs. Success in these markets has allowed
Vitesse to build a new and more efficient chip fabrication plant.
OUTLOOK:
H-GaAs IV IC technology has enabled Vitesse to produce transceivers
and chips for automated testing equipment that offer substantially
lower system costs than silicon IC sets previously used. H-GaAs
IV IC technology has allowed ATE producers to overcome the technological
limits of silicon IC technology to be able to test increasingly
faster ICs. The project has reduced or eliminated major barriers
limiting the use of GaAs, and the company has taken the technical
advances achieved in the project into commercialization. The outlook
appears strong.
Composite
Performance Score:
COMPANY:
Vitesse Semiconductor Corporation
741 Calle Plano
Camarillo, CA 93012
Contact:
Mr. Ira Deyhimy
Phone: 805-388-7511
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____________________
1. This estimate was developed in discussions between
Vitesse and Compaq, a prospective customer and development partner.
2. In-person
communication between Phil Perconti, ATP, and Ray Milano, Vitesse, March
1999.
Return to Table
of Contents or go to next section.
Date created: April
2002
Last updated:
April 12, 2005
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