- LTP Takes Interactive Architectural LED Lighting to New Heights for Barratt London – LEDs Magazine: Lighting Technology Projects has completed work on another energy-efficient architectural LED lighting scheme. The Tower, which is the centerpiece of Barratt London’s new regeneration project, is a 27-story residential building which overlooks West London’s ‘Golden Mile’. The installment is comprised of 53 horizontal rows going up the ‘spine’ or the building, each containing six LED lights that are programmed to operate fully automatically.
- Lower-Cost LEDs Offer Some Competition to Compact Fluorescent Lights – The New York Times: LEDs have long been more expensive than CFLs, but with costs beginning to level and consumer demand is starting to shift, experts say that demand for compact fluorescents will continue to dwindle, while demand will continue to rise for LEDs.
- Strategies Unlimited Reports Global Packaged LED Market to Reach $22B by 2019 – LEDs Magazine: Strategies Unlimited recently released a report investigating the global packaged LED market. The total packaged LED market grew 7.6 percent in 2014 to reach overall revenue of $15.6 billion. Lighting made up 34 percent of total revenue, which is almost the same as display backlighting and mobile applications combined, and is expected to reach 45 percent of total revenue by 2019.
- Materials Innovations Help LEDs Turn On – Photonics Spectra: Innovations in sapphire manufacturing is helping cut cost and boosting performance for LEDs. While there are other suitable substrate choices for LEDs, the majority of LEDs today are using sapphire. Rubicon Technology’s CEO, Bill Weissman discusses how the industry shift towards large diameter wafers minimizes edge loss and how patterning of substrates is increasing light extraction.
While LED chip manufacturers have been using patterned sapphire substrates (PSS) for years, there’s growing interest in large diameter PSS. Recently, Rubicon Technology announced the commercial availability of large diameter PSS. During their latest earnings call, they indicated that they’ve received interest from 7 major LED chip manufacturers for 4- and 6-inch large diameter PSS. Why the interest from LED chip manufacturers?
First, PSS helps improve epitaxial growth by promoting growth of the GaN in parallel to the substrate surface. This also helps reduce the number of dislocations, called the dislocation density, which can degrade performance of an LED. Secondly, patterning can help extract as much as 30 percent more light from an LED. This is particularly advantageous for high brightness LEDs (HB LEDs) that are used in LED lighting applications.
Second, the evolution of patterning large diameter substrates brings economical advantages to LED chip manufacturers, especially those anticipating demand from the LED lighting market. Large diameter sapphire wafers help LED chip manufacturers cut costs by enabling more throughput for each run of the MOCVD reactor. This helps chip manufacturers make better use of the reactor “real estate” and decreases the cost per unit of area processed because of the curvature of the larger wafer. The outer curvature of a 6-inch wafer is less, enabling greater use of the surface area than the tighter curvature of a 2-inch wafer resulting in less edge loss. Larger diameter wafers also provide post-MOCVD efficiencies. Depending on the type of MOCVD reactor used, LED chip manufacturers using six-inch wafer platforms may achieve up to 48% greater usable area per reactor run compared with two-inch wafers. These efficiency gains become very compelling when manufacturers want to ramp up LED chip production to support greater volumes of LEDs for light bulbs.
Finally, LED chip manufacturers have been buying smaller 2-inch and 4-inch PSS from outside suppliers for years. The next step in the evolution in the market is the migration to large diameter PSS for the reasons we mention above. While some LED chip manufacturers will have specialized patterning needs and the resources to keep the work in-house, others will not. Some LED chip manufacturers may not have the expertise and equipment to move to large diameter PSS, so having a ready, trusted supplier will prove handy.
For Further Reading
ClearlySapphire, LED Lighting Spotlight: Patterned Sapphire Substrates http://blog.clearlysapphire.com/?p=390
Semiconductor Today, Patterned sapphire for nitride enhancements, http://www.semiconductor-today.com/features/SemiconductorToday_SeptOct_PatternedSapphire.pdf
Compound Semiconductor, New Wet Process For LEDs On Patterned Sapphire Boosts Efficiency, http://www.compoundsemiconductor.net/csc/news-details.php?cat=news&id=19734296
Compound Semiconductor, Rubicon Orders Multiple Profilers For Sapphire Production, http://www.compoundsemiconductor.net/csc/news-details.php?cat=news&id=19735318
Clearlysapphire.com, Larger Wafers, Larger Yield – The Numbers Behind Large Diameter Sapphire Wafers and Yield, http://blog.clearlysapphire.com/?p=435
Clearlysapphire.com continues to follow the growth of LED lighting as well as sapphire and alternative substrates. This week, we’ll focus on a new report from Yole Developpement, a research firm that covers LEDs and the semiconductor industry. Yole recently reported that the packaged LED market will grow from $13.9 billion in 2013 to $16 billion by 2018, driven mainly by general lighting and completed by display applications. The report, Status of the LED Industry, details how LED-based general lighting has surpassed all other applications, representing nearly 39 percent of total revenue of packaged LEDs In 2012.
Costs need to continue to drop to keep LED-based lighting’s momentum in the general lighting market according to the report’s author, Pars Mukish, market and technology analyst, LED for Yole Developpement. He commented, “Cost represents the main barrier LEDs must overcome to fully compete with incumbent technologies. Since 2010, the price of packaged LEDs have sharply decreased, which has had the consequence of decreasing the price of LED-based lighting products.”
Mukish notes that in order to maintain growth, the industry needs to continue reducing pricing. He pointed out that while LED still has some potential for cost reduction, widespread adoption will require manufacturers to reduce costs on all components of the system such as drivers, heat sink, and PCB.
Yole also updates their reporting on the use of alternative substrates in the LED market. This situation hasn’t changed since we last covered alternatives in these posts: Clearlysapphire.com, Alternative Substrates – Dimming the Hype, http://blog.clearlysapphire.com/?p=496 and Clearlysapphire.com, Alternative Substrates for LEDs, http://blog.clearlysapphire.com/?p=293.
According to Yole, companies working on alternatives such as silicon and GaN still face major obstacles. Mukish says the benefit of GaN-on-silicon LEDs depends on decreasing manufacturing cost by using cheaper 8 inch silicon substrates that can leverage fully depreciated and highly automated CMOS fabs. However, he maintains that GaN-on-silicon LEDs still suffer from low manufacturing yields and full compatibility with CMOS fab still needs to be achieved. He added that GaN-on-GaN LEDs benefit from a lower defect density in the epitaxial layers, allowing the device to be driven at higher current levels and to use a lower number of LED devices per system. However, he said that GaN-on-GaN LEDs suffer from low GaN substrate availability and high costs.
For Further Reading
iMicronews, Sample, State of LED Industry, SLI report, http://www.i-micronews.com/upload/Rapports/SLI%20Sample.pdf
Compound Semiconductor, Yole: Inexpensive LED Solutions Pushing Adoption In General Lighting, http://www.compoundsemiconductor.net/csc/detail-news/id/19736834/name/Yole:-Inexpensive-LED-solutions-pushing-adoption-in-general-lighting.html
Novus Light Today, Yole Releases Status of LED Industry Report, http://www.novuslight.com/yole-releases-status-of-led-industry-report_N1675.html
Today, more than 80% of LEDs are made based on sapphire wafers. Recently, Lux Research published a report, Dimming the Hype: GaN-on-Si Fails to Outshine Sapphire by 2020, about the state of alternative substrates. In LED production, sapphire is used as the substrate onto which the chemicals that will become the emitting layer of the LED are deposited as a vapor. With the LED lighting market expected to grow to $80 billion, Lux Research expects the substrate market to grow to $4 billion in 2020 making it a highly attractive market. Lux expects sapphire to continue to dominate the substrate market.
“Silicon is already widely used for electronics, and some LED die manufacturers are hoping to take advantage of silicon substrates,” said Pallavi Madakasira, Lux Research Analyst and lead author of the Lux report. She explained that GaN-on-Si presents technical challenges such as cracking and a lattice mismatch that reduces the performance of LEDs based on the alternative substrate.
In an interview with Compound Semiconductor, Madakasira spoke about LEDs based on silicon substrates. She doesn’t buy the argument that GaN-on-silicon makers can save on costs. She says that even if they use fully depreciated CMOS equipment, the process of depositing complex buffer layers onto silicon prior to GaN deposition to overcome GaN and silicon lattice mismatches, adds time and cost to a manufacturing line.
Madakasira also shared performance data in her report with Compound Semiconductor. She notes that alternative substrates haven’t provided the performance of sapphire. According to Lux, the luminance efficacy of GaN-on-SiC LEDs is 200 Lumens per Watt with GaN-on-sapphire devices coming in at between 150 to 180 Lumens per Watt.
What does this mean? The Lux report concluded that sapphire will remain highly competitive for the rest of the decade. GaN-on-silicon, will snare only 10% market share while GaN-on-silicon carbide will grow to 18% of the market. Where do they fit? Here are Lux’s conclusions:
- Choice and cost of LEDs will determine adoption. Where GaN-on-sapphire is suited to all applications, GaN-on-bulk GaN will be relegated to niche commercial lighting and GaN-on-Si, with unproven performance, will be better suited to cost-sensitive residential applications.
- Four-inch wafers will rule (for now), though six-inch wafers start to come into vogue. Four-inch wafers will peak at 62% market share with $2.1 billion in 2017 sales. Later, the LED industry will move towards 6” epiwafers, which will take a 35% share, equivalent to $1.4 billion, in 2020.
- Technology will advance sapphire substrates. Sapphire substrate manufacturing technology has advanced significantly with specialists such as Rubicon and Monocrystal demonstrating substrates up to 12” in diameter. New methods like hydride vapor phase epitaxy (HVPE) will further improve throughput and cut costs, keeping sapphire highly competitive for the rest of the decade.
For Further Reading
Lux Research, Epi-Wafer Market to Grow to $4 Billion in 2020 as LED Lighting Zooms to $80 Billion, http://www.luxresearchinc.com/news-and-events/press-releases/182.html
Compound Semiconductor, Sapphire Substrates to Lead Future LED Markets, http://www.compoundsemiconductor.net/csc/indepth-details/19736669/Sapphire-substrates-to-lead-future-LED-market.html
Today, more than 80% of LEDs are based on sapphire substrates. For years, two-inch and four-inch diameter sapphire wafers have been the standard for LED production. Now, LED chip manufacturers are looking to migrate to six-inch diameter wafers to increase the yield or the amount of LED chips they can make out of each wafer. This is important as new market opportunities like LED-based general lighting take off, demanding more sapphire.
Rubicon put together an infographic, Larger Wafer, Larger Yield, about the yield from large diameter wafers. You can see it here on Rubicon’s new web site: http://www.rubicontechnology.com/sites/default/files/Rubicon_WaferYield_v3.pdf
Rubicon Technology’s CEO Raja Parvez talked about the benefits of moving to large diameter sapphire wafers in an article, Vertical Integration Streamlines Sapphire Production, in Compound Semiconductor earlier this year.
According to Parvez, LED chip manufacturers look to large diameter sapphire wafers to cut costs. Large diameter sapphire wafers enable more throughput for each run of the MOCVD reactor, making better use of the reactor “real estate” and decreasing the cost per unit of area processed. The outer curvature of the 6 inch wafer is less, enabling greater use of the surface area than a 2 inch wafer resulting in less edge loss. In addition, large wafers provide post-MOCVD efficiencies. Depending on the type of MOCVD reactor used, LED chip manufacturers using six-inch wafer platforms may achieve up to 48% greater usable area per reactor run compared with two-inch wafers. These efficiency gains become very compelling when LED chip production ramps up in large volumes to support a high growth market like general lighting.
For Further Reading
Compound Semiconductor, Vertical Integration Streamlines Sapphire Production http://www.compoundsemiconductor.net/csc/features-details.php?cat=features&id=19736275&key=rubicon%20technology&type=
Over the past several months, there has been some industry chatter about alternative substrates for the production of LEDs. In fact, the dialog has been more heat than light until now if you think about it in terms of a filament in an incandescent light bulb.
Sapphire substrates have been established for quite some time as the base material for LED chips. Today, more than 80% of LEDs are based on sapphire substrates with the remainder based on SiC and a few other materials. But the big question is whether an alternative substrate like silicon or GaN can offer the performance and cost advantages of sapphire.
Last week, market research firm Yole Developpement held a webcast, Alternative Substrates for LED Manufacturing, to examine the alternatives, the technical challenges and the conditions for success. You can access the archive here.
According to Yole analyst Eric Virey, the principal benefit of using Si as an LED substrate would be the ability to leverage larger 8” wafers and use fully depreciated and highly automated CMOS fabs. But “the jury is still out,” he said, “regarding a massive industry transition from sapphire to silicon. At the end of the day, this is a cost game; manufacturing yields are a major cost contributor to LED, and they pose specific challenges to the use of silicon.”
These challenges range from a lattice mismatch and thermal expansion coefficient mismatch, to melt back and blue light absorption. Sapphire outperforms silicon on all of these factors, and each is having a negative impact on LED chip yields from silicon. Virey commented silicon and/or GaN must meet the performance of sapphire to be successful. To date, that hasn’t happened.
In the meantime, the sapphire substrate manufacturers have made great strides to making large diameter substrates that help LED manufacturers drive down costs and increase yields to support the aggressive cost targets of SSL. For example, Rubicon Technology has shipped more than 230,000 large diameter sapphire wafers with this number growing.
Where are efforts now? Virey mentioned during the webinar that almost all LED manufacturers are exploring alternative substrates, although most are doing so only as a defensive strategy. Toshiba and Bridgelux have been working with silicon as a substrate. In July, the companies announced Toshiba would begin silicon-based LED production in October 2012, but there has been no further word. Plessey Semiconductors and Lattice Power also announced they would enter production in 2012.
LED Magazine reports that silicon-based substrates are “no sure thing” in their latest SSL Technology Update video blog. Associate editor Nicole Pelletier said, “A number of companies plan to ride the incumbent sapphire technology. At The LED Show back in August, LED market leader Nichia said it had investigated and dismissed the possibility of using silicon.”
At the conclusion of the webcast, Virey agreed. “If the technology hurdles are cleared, LED on silicon will be adopted by some LED manufacturers, but not necessarily become the standard.”
For Further Reading
LED Magazine, SSL Technology Update: October 22, 2012, http://ledsmagazine.com/features/9/10/11
Yole Developpement Webinar, Alternative Substrates for LED Manufacturing, http://www.i-micronews.com/consult_webcast.asp?uid=97
Solid State Technology, Beyond sapphire: LED substrates from GaN to ZnO, SiC, and Si, http://www.electroiq.com/articles/sst/2012/05/beyond-sapphire-led-substrates-gan-zno-sic-si.html
Solid State Technology, The demise of sapphire wafers? http://www.electroiq.com/articles/sst/print/vol-55/issue-6/columns/leds/the-demise-of-sapphire-wafers.html
While Google made a splash recently about making the Nexus Q media player in the US, companies all over the US are making key contributions of the economy by manufacturing in America. One of the key building blocks for LEDs is sapphire. Much like silicon is used for computer chips, sapphire is the foundation for an LED chip. Illinois-based Rubicon Technology is one of the world’s leading producers of sapphire ingots, blanks, polished substrates and windows. With more than 80% of the world’s LEDs based on sapphire, Rubicon makes a very important contribution to the market right here in the US.
Rubicon grows large sapphire crystals in sapphire furnaces in its Franklin Park, Batavia and Bensenville, Illinois-crystal growth facilities. The company makes very large sapphire crystals – bulk crystal ranging in size from 30 kg to 85 kg to 200 kg – that are cored and shipped to a Rubicon finishing facility in Malaysia or to directly to finishing customers throughout Asia to make sapphire wafers that and then made into millions of little LED chips. These LED chips are found in everything from smartphones, laptops and tablets, HDTVs, big ad displays, street lights, commercial lighting and even new LED light bulbs.
Why manufacture the sapphire crystals in the US? According to Rubicon, the crystal growth process is a high precision process that uses energy that must be kept constant. Any deviation in the power during the crystal growth process can lead to imperfections in a crystal rendering that crystal unusable.
Based on a decade of Rubicon company experience and decades of semiconductor expertise, Rubicon has custom-built next-generation crystal growth furnaces for their US plants. Rubicon’s innovations have resulted in industry-leading large-diameter sapphire wafers – six inches or more in size versus the commonly made two, three and four inch wafers – that help bring LED chip manufacturers cost efficiencies they can’t achieve with smaller wafers. To date, Rubicon has shipped 230,000 large diameter wafers.
“No other country in the world has reliable, low cost utilities like the US,” said William Weissman, CFO for Rubicon. “We specifically have designed our crystal growth facilities around reliable resources for power and water. The location in the US also allows us to protect our intellectual property inherent in our furnaces and processes in a way that cannot be maintained outside of the country.”