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

Emerging Markets for Sapphire, Part 1 — SoS

SoS improves performance and integration for RF circuits found in smart phones.

While LED is the largest market for sapphire, there are several other emerging markets that take advantage of the physical attributes of sapphire.  We’ll take a look at these emerging markets over the next month or so.   We will begin with Silicon on Sapphire (SoS) for the RFIC market.

SoS is a part of the Silicon on Insulator (SOI) family of CMOS (Complementary metal–oxide–semiconductor) technology for making integrated circuits.  SoS improves performance and integration for RF circuits.  The holy grail of the wireless industry has been finding a better way to optimize power consumption and real estate utilization in mobile phones.  One application for SoS technology is the production of RF chips used in the antenna switch in smart phones.  These SoS chips are significantly smaller and use less power than chips traditionally used for this application.  As a result, chips produced using SoS technology are rapidly gaining market share in the mobile phone industry.

Peregrine Semiconductor is a pioneer in SoS and holds much of the industry’s IP in SoS.  In an interview with EE Times in 2011, Dr. Ronald E. Reedy, Peregrine co-founder said, “SoS is the first and most successful form of SOI focused entirely on improving performance and integration for RF circuits. We saw the emerging need for such a technology when commercial wireless communications started taking off in the early 1990s.”

What makes sapphire so good for SoS? Peregrine summarized it in a paper on the history on SoS. Sapphire and silicon have a unique way of lining up together at an atomic level because of oxygen atoms.  The scientific explanation is that the r-plane of sapphire has oxygen atoms spaced at a distance that is close to the spacing of the atoms in the (100) plane of a silicon crystal.  The spacing delivers unique insulating properties when the silicon is layered on top of the sapphire wafer.  This was discovered by researchers at Boeing in 1963.  Researchers at RCA continued the development of SoS technology into the mid-1970s and continue to process them for space applications.

Technological barriers leading to defects held SoS back from commercial applications until just recently.  Peregrine has been able to overcome these hurdles at just the right time as the wireless industry needs the insulating and power saving benefits of SoS for the latest generations of smart phones.  You’ll find more coverage of the emerging market in posts to come.

For Further Reading:

Electronics Weekly, Peregrine: Single chip phone RF is possible http://www.electronicsweekly.com/Articles/14/02/2012/52966/peregrine-single-chip-phone-rf-is-possible.htm

EE Times, What’s up with silicon on sapphire?, http://www.eetimes.com/design/microwave-rf-design/4216449/What-s-up-with-silicon-on-sapphire-

Peregrine Semiconductor Corporation, The History of Silicon on Sapphire, www.psemi.com/articles/History_SOS_73-0020-02.pdf

Clearlysapphire.com, http://www.clearlysapphire.com/SoS_RFIC.html