Substrate Update: It’s All About Patterning & Large Diameter Wafers

yole_developpement_logoMarket research firm Yole Developpement recently published a new report on front-end manufacturing trends for LEDs. Their latest report gives us some very good news about the sapphire market. Semiconductor Today reported on Yole’s analysis. Here are some big take-aways:

  • There is increased demand for larger-diameter sapphire wafers, with big players (such as LG, Sharp or Osram) moving to 6” wafers and Taiwanese players moving to 4” wafers.
  • LED chip makers demand more patterned sapphire substrates (PSS). PSS are now mainstream in the market with an 87% share as of Q1 2014.
  • While some companies (such as Soraa and Toshiba) have begun mass production of gallium nitride-on-silicon (GaN-on-Si) and GaN-on-GaN LEDs, market penetration of these alternative substrates will depend on future improvements in terms of performance and cost.  Without these improvements, alternative substrates will not be able to fully compete with sapphire-based LEDs.

What does this mean for sapphire makers? LED chip manufacturers are looking to gain production efficiencies, lower costs, and increase performance for their LEDs.  As the adoption for LED lighting increases, they need to make more and better performing LEDs. 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. 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 as compared to two-inch wafers.

What does PSS offer? First, PSS helps improve epitaxial growth by promoting growth of the GaN in parallel to the substrate surface. This 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.

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. Already a pioneer in the development of large diameter sapphire substrates, Rubicon Technology has developed capabilities for large diameter PSS making it possible to manufacture 6-inch and even 8-inch PSS. Rubicon is already gaining traction in the PSS market.  The company recently reported in their Q1 2014 earnings call that they received their first order for PSS and have samples out to more than a dozen LED chip manufacturers.

For more information about the report from Yole, visit http://www.i-micronews.com/reports/LED-Front-End-Manufacturing-Trends-report/14/433

For Further Reading

Semiconductor Today, Substrates shaping trends in LED front-end manufacturing, http://www.semiconductor-today.com/news_items/2014/APR/YOLE_300414.shtml

Clearlysapphire.com, Larger Wafers, Larger Yield – The Numbers Behind Large Diameter Sapphire Wafers and Yield, http://blog.clearlysapphire.com/?p=435

Clearlysapphire.com, Large Diameter Patterned Sapphire Substrates Explained, http://blog.clearlysapphire.com/?p=582

Clearlysapphire.com, Sapphire Substrates for LED: The Big Move Toward 6″ Has Already Started, http://blog.clearlysapphire.com/?p=37

Large Diameter Patterned Sapphire Substrates Explained

Rubicon Technology offers large diameter PSS in a range range of shapes including cone, dome and pyramid as well as custom.

Rubicon Technology offers large diameter PSS in a range of shapes including cone, dome and pyramid and range of orientations.

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

Rubicon Announces Large Diameter Patterned Sapphire Substrates

PSS with dome shape

PSS with dome shape

 

This week, Rubicon Technology announced the launch of the first commercial line of large diameter patterned sapphire substrates (PSS) in four-inch through eight-inch diameters.  The new product line provides LED chip manufacturers with a ready-made source of large diameter PSS to serve the needs of the rapidly growing LED general lighting industry.

This is doubly important since patterning helps improve both epitaxial growth and light extraction for each chip and enhances a chipmaker’s throughput and efficiency.  Rubicon announced that they have fully customizable sub-micron patterning capability with tight dimensional tolerances, within ±0.1 µm.  Rubicon offers LED chip manufacturers more usable area to maximize the number of chips per wafer due to an edge exclusion zone as small as 1 mm.  Rubicon’s patterning is available in a range of shapes including cone, dome and pyramid, and in a range of orientations.  Further customization of geometry, pattern and orientation is available too.  You can find a brochure about it on Rubicon’s web site here.

Rubicon’s president and CEO Raja Parvez pointed out the importance of large diameter patterned sapphire substrates in a news release.  “As LED-based general lighting gains worldwide adoption, large-diameter patterned sapphire substrates will become necessary to meet the demands of the rapidly growing lighting market.”

Parvez added that the company developed an unmatched technology platform that is vertically integrated from raw material through crystal growth, large diameter polished wafers, and now custom PSS in 4”, 6” and 8” diameters.  According to Parvez, vertical integration enables Rubicon to produce progressively larger sapphire products while providing customers with exceptional quality, cost control, reliability, and consistency.

For Further Reading

Rubicon Technology, Rubicon Technology Launches First Commercial Line of Large Diameter Patterned Sapphire Substrates for the LED Industry, http://bit.ly/1itVMHq

Clearlysapphire.com, LED Lighting Spotlight: Patterned Sapphire Substrates, http://blog.clearlysapphire.com/?p=390

 

Sapphire – Quality Matters, Part 2: Transmission Quality

Recently, Novus Light Today published an article by Dr. Jonathan Levine, Director of Technical Business Development at Rubicon Technology, about sapphire quality.  His article shares a thorough review of the measures of sapphire quality for optical-grade applications.  Last week, we looked at the first two metrics, chemical analysis and X-ray rocking curves.  This week, we’ll look at transmission quality.

Levine writes that the quality of a sapphire is determined by how closely the grown crystal matches the ideal structure with respect to the arrangement of atoms within the lattice, dislocations, defects, and stress.  Root causes for these problems often originate from insufficient purity of the starting material and the growth process itself.

Sapphire exhibits excellent transmission in the ultraviolet (UV) to the mid-infrared (IR) range (~200 – 5000 nm).   According to Levine, conditions within the sapphire growth furnace can induce subtle interactions between the molten sapphire and the growth environment.  These interactions can produce bubbles, dislocations and other stresses that could impact optical performance.   Levine says that carefully controlling the growth environment produces sapphire that maintains excellent transmission at 200 nm through the mid-IR wavelengths.  He illustrates the impact of furnace interactions by comparing Rubicon’s ES-2 sapphire with another commercial sapphire maker’s crystal produced using a different growth method in the figure below.  From the image in the post, you can see a sharp absorption peak at 200 nm for sapphire produced by the commercial maker that is absent in sapphire grown by Rubicon.

Optical transmission of sapphire depicting a sharp absorption peak at 200 nm for sapphire produced by a commercial producer that is absent in sapphire grown by Rubicon.  Inset: Optical transmission for Rubicon sapphire from the visible to mid-IR range approaching 90% due to the high quality of the material.

Optical transmission of sapphire depicting a sharp absorption peak at 200 nm for sapphire produced by a commercial producer that is absent in sapphire grown by Rubicon. Inset: Optical transmission for Rubicon sapphire from the visible to mid-IR range approaching 90% due to the high quality of the material.

For Further Reading

Novus Light Today, Optical-Grade Sapphire, Where Quality Matters, http://www.novuslight.com/optical-grade-sapphire-where-quality-matters_N1596.html#sthash.giGipxT1.dpuf

Alternative Substrates – Dimming the Hype

Two-inch, Four-inch and Six-inch Sapphire Wafers

Two-inch, Four-inch and Six-inch Sapphire Wafers

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

How Do They Do It? From Sapphire to LED Infographic

You’ve heard a lot about LEDs, but did you know that a tiny piece of sapphire – the pure, colorless industrial variety, not the blue gemstone – is in more than 80% of LEDs? Sapphire is the foundation for the LED chip, just as silicon is for a computer chip.  Rubicon Technology has put together an infographic that describes the sapphire manufacturing process and where sapphire is found in an LED. The bottom of the infographic features examples of products that feature LEDs for lighting. Click on the infographic below to see it larger.

Infographic for Post

 

 

 

 

 

Link to: http://www.rubicontechnology.com/sites/default/files/From%20Sapphire%20to%20LED%20Infographic.pdf

Larger Wafers, Larger Yield – The Numbers Behind Large Diameter Sapphire Wafers and Yield

rubicon-waferyield-540x720-3Today, 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=

Top 9 Things You Didn’t Know about LEDs

Philips Luxeon LED

Philips Luxeon LED

Recently, the Department of Energy published a list of the Top 8 Things You Didn’t Know about LEDs. We’d like to share the list, and add one more for our Clearlysapphire blog post this week.

9.  Sapphire is the base material for more than 80% of LEDs, just like silicon is the base material for computer chips.

8. A light-emitting diode, or LED, is a type of solid-state lighting that uses a semiconductor to convert electricity into light. Today’s LED bulbs can be six-seven times more energy efficient than conventional incandescent lights and cut energy use by more than 80 percent.

7. Good-quality LED bulbs can have a useful life of 25,000 hours or more — meaning they can last more than 25 times longer than traditional light bulbs. That is a life of more than three years if run 24 hours a day, seven days a week.

6. Unlike incandescent bulbs — which release 90 percent of their energy as heat — LEDs use energy far more efficiently with little wasted heat.

5. From traffic lights and vehicle brake lights to TVs and display cases, LEDs are used in a wide range of applications because of their unique characteristics, which include compact size, ease of maintenance, resistance to breakage, and the ability to focus the light in a single direction instead of having it go every which way.

4. LEDs contain no mercury, and a recent Energy Department study determined that LEDs have a much smaller environmental impact than incandescent bulbs. They also have an edge over compact fluorescent lights (CFLs) that’s expected to grow over the next few years as LED technology continues its steady improvement.

3. Since the Energy Department started funding solid-state lighting R&D in 2000, these projects have received 58 patents. Some of the most successful projects include developing new ways to use materials, extract more light, and solve the underlying technical challenges. Most recently, the Energy Department announced five new projects that will focus on cutting costs by improving manufacturing equipment and processes.

2. The first visible-spectrum LED was invented by Nick Holonyak, Jr., while working for GE in 1962. Since then, the technology has rapidly advanced and costs have dropped tremendously, making LEDs a viable lighting solution. Between 2011 and 2012, global sales of LED replacement bulbs increased by 22 percent while the cost of a 60-watt equivalent LED bulb fell by nearly 40 percent. By 2030, it’s estimated that LEDs will account for 75 percent of all lighting sales.

1. In 2012, about 49 million LEDs were installed in the U.S. — saving about $675 million in annual energy costs. Switching entirely to LED lights over the next two decades could save the U.S. $250 billion in energy costs, reduce electricity consumption for lighting by nearly 50 percent and avoid 1,800 million metric tons of carbon emissions.

For Further Reading

Department of Energy, Top 8 Things You Didn’t Know about LEDs, http://energy.gov/articles/top-8-things-you-didn-t-know-about-leds

Opportunities for Sapphire: New Applications & Markets Explained

Rubicon Technology announced the publication of Opportunities for Sapphire, a new white paper that examines markets that leverage the highly versatile material, sapphire.  Based on research from IMS Research, the paper takes an in-depth look at the demand for sapphire in key markets including LED, semiconductor and optical.  You can find the white paper on Rubicon’s new web site at http://rubicontechnology.com/resources/papers, but here’s a look at what you’ll find.

Sapphire has emerged as a versatile material in a range of industries for many varied applications.  Sapphire’s inherent physical attributes for durability, light transmission, chemical inertness and thermal insulation make it desirable for a growing list of applications in a range of markets.  The white paper examines the opportunity for the LED market in general lighting, backlighting and display and uses in industries like automotive.  It also explores sapphire applications for optical-grade sapphire windows, lenses and covers as well as semiconductor applications such as silicon-on-sapphire chips in radio frequency integrated circuits (RFICs) for RF antennas, as digitally tunable capacitors (DTCs) and power amplifiers in smart phones and other consumer devices.

According to white paper author Jamie Fox of IMS Research, high quality sapphire delivers great benefits to LED chip manufacturers gearing up for applications like LED-based general lighting.  “Every LED company we spoke to during the research for this paper purchases sapphire and benefits from the superior yields and quality,” writes Fox.  “Substrate demand in 2012 is estimated at 42 million two-inch equivalent wafers (TIE) and expected to grow to 57 million TIE in 2013 according to market research firm Displaybank.  As the lighting market grows into a more significant segment and larger, thicker wafers are utilized, sapphire demand will accelerate.”

“Opportunities for Sapphire” also discusses the role of sapphire in LED production, the emergence of the market for large diameter sapphire wafers and sapphire demand by application.

LED Sapphire Ingot Demand Forecast

LED Sapphire Demand Graphic WPPR

(source: DisplayBank)

 

 

 

 

 

 

 

The market has shown growing demand since 2010 with an expansion of the LED/LCD TV market and the growth of applications such as general lighting.

Green line indicates rate of growth per year

Key:  Demand in thousands of millimeters of two-inch equivalent sapphire

Commercial Sapphire Spotlight – Vertical Integration in Sapphire

Rubicon Family of Sapphire Boules

Last month, Compound Semiconductor Magazine featured a contributed article about Vertical Integration in sapphire production by Raja M. Parvez, President and CEO of Rubicon Technology.  Rubicon has adopted vertical integration to set itself apart from other sapphire companies.  The article details Rubicon’s approach.

Vertical integration isn’t a new concept. It has been around since the 1800s when US Steel tycoon Andrew Carnegie introduced the vertical integration by owning virtually every part of the steel-making value chain from iron ore through steel mills to physically building the railroads.  Later, in the 1920s, Ford Motor Company decided to make the steel for their cars, popularizing the concept further.

According to Rubicon’s president and CEO Raja Parvez, vertical integration holds the key to Rubicon’s cost structure and reliable supply of high-quality products.  This integrated approach influences every step in the growth of sapphire crystals and their processing into wafers. The company’s end-to-end manufacturing capability, with strong intellectual property at each step of the manufacturing process, produces an advantageous cost structure and provides better control of product quality and delivery schedules. Vertical integration is also central to the company’s ability to grow larger and larger sapphire and be the first to market with large-diameter sapphire wafers for the LED and SoS/RFIC markets.  To date, Rubicon has shipped more than 400,000 6-inch wafers.

To read the full article, visit:   http://content.yudu.com/A2360p/CompSemMar13/resources/index.htm?referrerUrl=http%3A%2F%2Fwww.compoundsemiconductor.net%2Fcsc%2Fmagazine.php