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

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

Made in America – Sapphire for the High Growth LED Market

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.”