| Sponsored
Links |
|
|
|
|
|
Commentary:
GaN on Silicon Gets Real
... Never ones to knock a new technology approach, we've been dutifully covering the GaN on Silicon progress for a decade or so at this point. I can't remember if it was at one of our 2000 or 2001 conferences (CS Outlook) that we listened enthusiastically to the "near production...
Jump down to the full story
| |
Features:
|
|
|
August 6, 2012...Aixtron SE of Aachen, Germany, announced that optical communications company, Finisar Corporation, ordered one AIX 2800G4-TM automated reactor dedicated to the growth of indium phosphide materials for lasers and detectors. According to Aixtron, the new order was placed after the first AIX 2800G4-TM system had been successfully installed and qualified at Finisar’s facility in Allen, Texas, USA. Aixtron says its local support team will install and commission the new reactor in a clean-room at the Finisar plant in Fremont, California targeting later this year.
Charles Roxlo, Ph.D., Vice President and General Manager, Active Devices for Finisar Corporation, says, “There are several key features we look for in an automated MOCVD system, and they are well addressed by Aixtron. The AIX 2800G4-TM reactor provides the best means to create high-performance optical device products that fulfill the necessary requirements of our customers. ”
Dr. Bernd Schulte, Executive Vice President and Chief Operating Officer at Aixtron, added, "Finisar is another prized customer with whom we will enjoy working with in the coming months.”
 |
Foxconn Selects BIPV Solar Modules From Ascent Solar for Zhenzhou City Factory
CompoundSemi News StaffAugust 6, 2012...Ascent Solar Technologies, Inc., a developer of flexible thin-film photovoltaic modules, announced that it has been selected to provide BIPV solar modules in a pilot application at Foxconn’s new factory in Zhenzhou City, Henan Province, China. Foxconn makes some of the worlds most popular electronic devices including: the iPad®, iPhone®, Kindle®, Playstation® and Xbox®.
Ascent solar says its flexible and light weight modules can be integrated seamlessly into the building structure in ways traditional glass-back photo-voltaic technology cannot. The modules will reportedly allow the factory to utilize Ascent Solar's CIGS technology to deliver what Ascent solar says is highest power density available on thin-film plastic substrates.
Ascent Solar’s President and CEO, Victor Lee, said, “We are honored to be selected by Foxconn to provide our lightweight, durable, flexible thin-film solar modules in this new factory. We plan to demonstrate the value of our technology and we hope to build a long term relationship with Foxconn.” Rubicon Orders Multiple Optical Profilers For Sapphire Production
CompoundSemi News StaffAugust 6, 2012...Rubicon Technology has ordered multiple units of the Zeta 300 series optical profiler from Zeta Instruments of San Jose, California USA . Rubicon reportedly plans to use the profilers for inspection and metrology of sapphire substrates to help improve wafer yield and lower costs for their LED customers. The Zeta-300 series is the latest in the company's suite of optical profilers. The series combines patterned sapphire substrate (PSS) metrology and defect review for detailed measurement of PSS structure dimensions as well as wafer defect inspection on the same system.
The Zeta-300 series leverages Zeta’s patented Z-Dot technology that the company says offers high repeatability and accuracy measurement of LED-patterned/etched substrates, photo-resist and stacked structures on transparent surfaces. According to Zeta Instruments, the profilers have one of the best optics and algorithm combinations for rapid and reliable data acquisition and analysis.
The Zeta-380 comes with application-specific software and a companion automated wafer system that enables superior imaging and measurement capabilities compared to laser confocal microscopes. Zeta Instruments says that the Zeta-380 is able to measure and detect defects falling outside the industry certification levels.
“We have evaluated many tools for the production environment and the Zeta 300™ series, delivers the best combination of speed and accuracy for precision metrology applications,” said Raja M. Parvez, president and CEO of Rubicon Technology. UT Austin Scientists Develop Smallest Semiconductor Laser
CompoundSemi News StaffJuly 30, 2012...At the University of Texas at Austin, physicists collaborated with researchers in Taiwan and China to develop what they claim is the world's smallest semiconductor laser. The development was reported in this week's Science. Applications such as ultrafast computer chips; highly sensitive biosensors for disease detection diagnosis and treatement, and next-generation communications require semiconductor lasers that are faster, smaller and use less energy.
The device is constructed of a gallium nitride nanorod that is partially filled with indium gallium nitride. When fired, the nanolaser emits a green light, but the laser is too small to be visible to the naked eye. The ultralow-threshold nanolaser has a single nanorod placed on a thin silver film (28 nm thick). The resonant electromagnetic field is concentrated at the 5-nm-thick silicon dioxide gap layer sandwiched by the semiconductor nanorod and the atomically smooth silver film. Physics graduate student Charlotte Sanders designed and built a special MBE system to to create the smooth silver thin film needed for the laser.
“We have developed a nanolaser device that operates well below the 3-D diffraction limit,” said Chih-Kang “Ken” Shih, professor of physics at The University of Texas at Austin. “We believe our research could have a large impact on nanoscale technologies.”
“Size mismatches between electronics and photonics have been a huge barrier to realize on-chip optical communications and computing systems,” said Shangjr Gwo, professor at National Tsing Hua University in Taiwan and a former doctoral student of Shih’s. Plessey Gets Aixtron Crius II-XL Reactor for GaN-on-Silicon HB LED Production
LIGHTimes News StaffJuly 30, 2012...Plessey Semiconductors took delivery of an Aixtron CRIUS® II-XL reactor in a 7x6-inch wafer configuration. The reactor is the first part of a multi-million pound investment in an HB LED production line. The systems in the new production line will use Plessey's MaGIC™ (MAnufactured on Gan ICs) technology of GaN on 6-inch silicon substrates to produce the HB LEDs at Plessey's Plymouth facility.
Neil Harper, Plessey's HB LED Product Line Director, said, "We use a much thinner GaN layer at only 2.5µm compared to 6-8µm in other GaN on Si technologies. This means less deposition time so that we can do multiple production cycles in the reactor in 24 hours to achieve higher throughputs and lower costs."
The first samples producing the correct wavelength output from Plessey's 6-inch IC production line are being produced. Plessey notes that it is using standard, 6-inch silicon substrate, which offers significant cost reductions of about 80% compared to the current technologies using Silicon Carbide or Sapphire that are both expensive and hard to scale up. Plessey intends to move to 8-inch substrates for even greater cost savings. The company claims that typical MAGIC HB LEDs are yielding at 95% with over 14,000 1 sq. mm 1 Watt MAGIC HB LEDs per 6-inch wafer.
Barry Dennington, Plessey's COO, added, "MaGIC and EPIC are two unique, disruptive technologies that are instrumental in our plan to rapidly grow Plessey into a major electronics company producing smart lighting solutions." Siemens Looks to Spin Off Osram Instead of IPOJuly 30, 2012...Instead of a previously talked about IPO for Osram, Siemens announced plans to spin off the company. Osram ram includes: Osram Opto Semiconductors, the optoelectronics subsidiary of Osram, that manufactures optoelectronic semiconductor components including LEDs and high power laser diodes. The new plans came after the company missed analyst estimates of Euro 1.32 billion, due to an accounting charge relating to Osram. Also Siemens reported that new orders were down 23 percent in Q3 2012 compared to Q3 of last year.
Siemens CEO Peter Loscher said,
“Since market conditions continue to be volatile for an IPO, we have decided to pursue a spin-off to our shareholders as the most probable part of divestiture.”
Loscher noted that demand from China was slowing and said he doesn't expect recovery until 2013 or later.
“Our focus above all is on increasing our productivity and efficiency,” he added. Toshiba to Start Mass Production of GaN on Silicon White LEDs
LIGHTimes News StaffJuly 26, 2012...
Toshiba Corporation of Japan, announced plans to start mass production of white LEDs on a production line that the company will construct in the 200mm wafer facility at Kaga Toshiba Electronics Corporation, a production base for discrete products in northern Japan. Mass production will start from October 2012. Toshiba reportedly is applying GaN-on-Silicon technology to the development of white LEDs.
Since January 2012, Toshiba has collaborated with Bridgelux Inc. of Livermore, California USA, on GaN-on-Silicon technology for LEDs. Then, in May the companies announced a record 614mW output 1.1mm square blue-emitting LED operating at 350 mA and less than 3.1V. Content continues for LIGHTimes SecondPage members... Our news features are reported
by the CompoundSemi News staff writers.
For submissions or content suggestions, you can contact us using
editor -at - compoundsemi.com
For more information and to reserve promotion space contact
Info7 -at - compoundsemi.com
or call +1 (512) 257-9888
|
|
|
|
|
|
Commentary & Perspective...
GaN on Silicon Gets Real
Tom Griffiths - PublisherJuly 26, 2012...Never ones to knock a new technology approach, we've been dutifully covering
the GaN on Silicon progress for a decade or so at this point. I can't remember
if it was at one of our 2000 or 2001 conferences (CS Outlook) that we listened
enthusiastically to the "near production availability" of GaN-on-Si
substrates from Motorola (before they had Freescaled). Cheaper, easier to handle,
processes move to standard silicon-type platforms, and since the wafers were
smaller than state-of-the-art, those production platforms were likely older
and already amortized making the cheaper even cheaper. Cool. Followed by, pretty
much, nothing...
As time passed, it seemed we'd hear about more amazing progress in GaN-on-silicon
about every two years, with a blip from a university or other research house.
But each time it appeared to be a little over-hyped, as a decent lab result
failed to translate into a production-ready solution. However, that's how technical
innovation (as well as fame and fortune) often progresses. The "overnight"
successes are often decades in the making, as hard workers take two steps forward,
and somewhere between 1 and 3 steps back, but as long as that average is less
then two back, it creates progress. And progress builds on progress.
What it means for lighting... Before we dive down into some LED material/technology
kind of detail, it should be noted that GaN-on-silicon LEDs won't be likely
to supersede existing technologies. As far as the luminaire and lamp designers
would be concerned, what they will be looking at is a richer variety of price-performance
choices that could be enabled by lowered manufacturing costs for the GaN-on-Si
based solutions. That will first hinge on actual high volume production, which
may still be a while away. Toshiba, for example, announced this week that they
were going into mass production on GaN-on-Si for white LEDs, but somewhat confusingly
noted their progress in "milliwatts of output power" which is not
the typical way of quoting white LED performance (that's the single-color metric),
and that it would start in October on a new production line they are building
for it. While only a few months away, that's still a lot time for things to
happen, so wait and see is still the order of the day. When we do get GaN-on-silicon
LEDs in mass production, they also likely won't be running at the same peak
efficiencies as we see from the existing technologies, and efficiency is still
a big part of the game here, since more lumens per watt generally lets you pack
more lumens into a given amount of space. While we have plenty of space to produce
a streetlight that is plenty bright enough at 100 lumens per watt, things get
a bit more squeezy when we look at an A-lamp or worse, an MR. Lots of lumens
per square millimeter are required, and more lumens per watt usually correlates.
GaN-on-Si will be good for some things, but not likely for everything. "Traditional"
LED costs also continue to fall, and manufacturing efficiencies are increasing,
so I don't believe that one "winner" can be forecast, except for the
designers and buyers who will have more types of technology competing for their
business, and more competition is better when it comes to driving down costs.
The tech part... In the most basic sense, the problem everyone was trying
to solve is pretty simple. Gallium nitride, with its combinations and derivatives,
which support the LEDs in the bluish end of the spectrum, as well as high-frequency,
high power transmission types of technology as well as blue laser, is not "lattice
compatible" with silicon. The whole game of building a wafer that becomes
the foundation of a semiconductor device is that you want to blend the right
materials as evenly and defect-free as possible. Pure GaN would be a great starting
point for all of these devices, but "growing" a pure GaN substrate
is not easy and is devilishly expensive. Sometimes it's worth it, if you're
just trying to get a few thousand dollar transistors off of it, but in most
cases, you want more devices, and you want them cheaper, so GaN needs to be
"deposited" on top of something else. That something else (sapphire
most commonly, along with silicon carbide (SiC) and now silicon, has a different
crystal structure than the GaN, so if you just squirted some GaN layers onto
it, the GaN part would end up with a bunch of cracks or other features that
would lead to dead or prematurely dying devices. The solution is to add a "buffer-layer"
between the starting substrate and the GaN layers. Buffers can be either a mix
of materials or a series of layer steps that can act as a transition between
the substrate's crystal structure and the GaN's structure. A typical buffer
description could be something like is found in Taiwan National Cheng-Kung University's
2006 patent 7,014,710 that reads "...characterized in that a buffer layer
of SiCN [silicon carbon nitride] is grown to avoid lattice mismatch which appears
when Gallium Nitride is grown directly on silicon substrate". Note that
the buffer blends things that appear above and below it, silicon at one end
and a nitride at the other. While the buffer thing is "simple" as
a problem, it's not "easy" to solve, since you don't have the dynamics
of the crystal structure, but the fact that the melting point that allows you
to "spray" a composition onto one material may be a thermal stress
point for the other material, and once they are layered, they may heat or cool
at different rates, like that bi-metal strip that makes incandescent Christmas
lights blink... bending not good in this case.
So folks are figuring it out... Bridgelux was the first to set off the
latest round of "we're gonna make it work and change the face of the LED
industry" and went with a chips-all-in attitude when describing the future
of their LED technology. In a March
2011 story (scroll down a bit when you get there), they announced 135 lm/W
result for a 4700K GaN-on-silicon LED that was a result of "quietly dedicated
GaN-on-silicon team" that had been operating for the previous 5 years.
As we've seen, we never know til we see chips on the market, but "all of
sudden", we're hearing a lot more about GaN on silicon than ever before.
In a January 2012 news release, Osram Opto Semiconductors,
a company not known for brash "lab results" claims, announced that
their own GaN-on-Si program had chips in the pilot stage. With similar timing,
Cree, who bases their LEDs on silicon carbide rather than sapphire, began a
concerted effort to message on what they see as inherent advantages to that
approach, essentially, "GaN-on-SiC produces more efficient, more reliable
LEDs, and always will". It begs the question of "why now?" when
they've been in the sapphire vs. SiC trenches for a decade, and have simply
messaged on their results, which are consistently good. But if someone if they
were trying to counter an up and coming approach that is going to be making
a lot of noise in the near future, their "re-emphasized" message is
exactly the one I'd recommend. Validation that GaN-on-SiC might finally be a
commercial threat?
In this week's news, GaN-on-Si was riding a wave as: A) Toshiba
announced they where kicking into full volume production as a result of
"collaboration" first
announced in May with Bridgelux for GaN-on-Si LED technology; B) Aixtron
announced the launch of their AIX G5+ 5x200 mm GaN-on-Si technology package
for its AIX G5 Planetary Reactor® platform; C) Azzuro
Semiconductors announced it had received 2.6 million Euro grant from the
government of Saxony (Germany) for a 200 mm LED and Power Semiconductor GaN-on-Si-wafer
development program which; D) which was followed by a mildly head-scratching
Veeco
announcement the next day that it had sold them a TurboDisc® K465i™
MOCVD system to do 150mm GaN on Si work (so is that the precursor to their 200mm
work, or will we see Azzuro "spreading the love" with an upcoming
AIX G5+ 200mm purchase?). Sounds like we're getting close... If you have news or
views to share about the compound semiconductor, LED or solid
state lighting industries
contact our Publisher, Tom Griffiths
His direct tel in Austin is +1-512-257-9888
|
|
