Silanna UV to Present New UV-C LED Manufacturing Technology at ICNS-14, Japan

News Highlights

• New UV-C LEDs allow more effective disinfection
• Silanna to present details at key Nitride Semiconductor conference
• Silanna executive to make presentation on manufacturing process
• Technology is safer with longer lifetime at lower power
• Patented GaN/AlN SPSL nanostructure manufacturing tech
• Silanna UV-C LEDs achieve 236 nm 18 mW at 1 Amp

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Silanna UV to Present New UV-C LED Manufacturing Technology at ICNS-14, Japan

New Sub-240nm LEDS Are Safe, Effective, Power-Efficient, and Durable

Brisbane, Australia, 2^nd November, 2023 – Silanna UV will reveal details of its unique new Far UVC LED manufacturing technology at the 14th International Conference on Nitride Semiconductors (ICNS-14) in Fukuoka, Japan from November 12 to 17, 2023. This technology is a significant advance in safe, effective, low-maintenance and low-power disinfection processes for air, water, surfaces and other applications.

Jessica Chai, Silanna’s molecular beam epitaxy (MBE) Process Manager will give a talk at the conference in 15:15-15:30 Tuesday 14^th November 2023 at Room “Navis C”.  Jessica will explain the Si-doping characteristics of the GaN/AlN SPSL (short period superlattice) nanostructures used in Silanna UV’s innovative far UVC LEDs. She will also present test results to illustrate the characteristics and benefits of the manufacturing technology.

A Revolution in Contactless Sanitization

Far UV-C LEDs are now acknowledged as a groundbreaking method of safe and effective contactless disinfection. Sub-240nm LEDs are of particular interest, because light below 240 nm inactivates pathogens while being safer in inhabited environments, compared to longer UVC wavelengths.

The traditional bulk AlGaN methods of producing high-Al AlGaN for far UV-C wavelengths suffer from multiple challenges. Silanna UV’s unique, patented III-Nitride SPSL technology overcomes these challenges. The company has successfully demonstrated sub-240nm far UV-C LEDs that achieve 236 nm 18 mW at 1 Amp on a flip-chip device.

More details of Silanna’s Far UVC LEDs at: https://silannauv.com/products

About Silanna UV

The Silanna Group is an Australian semiconductor manufacturer established in 2006. Privately funded since being acquired from Peregrine Semiconductor in 2008, Silanna UV is an ISO 9001:2015 certified solution provider for UV-C LED manufacturing. Based in Brisbane, Australia, Silanna UV provides far UV-C light sources for water quality sensors, gas sensors, disinfection, and HPLC (High-performance liquid chromatography) applications. Silanna UV’s innovative approach allows UV LED technology to push toward shorter wavelengths, from 230nm to 265nm, including deep UV-C and far UV-C ranges. The company holds unique epitaxy technology and holds patents related to UV LED technology. With its unique UV LED technology, Silanna UV strives to create new possibilities by pushing UV wavelength boundaries to the limit. To learn more, please visit http://www.silannauv.com/

ニュースハイライト

• 新しいUV-C LEDにより、より効果的な殺菌が可能に
• Silannaは窒化物半導体の主要会議で詳細を発表予定
• Silanna社エグゼクティブが製造プロセスに関するプレゼンテーションを実施
• 低電力で長寿命、より安全な技術
• 特許取得済みのGaN/AlN SPSLナノ構造製造技術
• Silanna UV-C LEDは1Aで236nm 18mWを達成

Silanna UVが日本で行われるICNS-14にて新しいUV-C LED製造技術を発表

新しい240nm 以下のLEDSは安全で効果的、かつ省電力、耐久性に優れている

オーストラリア、ブリスベン、2023年11月2日 - SilannaUVは、2023年11月12日から17日まで福岡で開催される第14回窒化物半導体国際会議（ICNS-14）で、独自の新しい遠UVC LED製造技術の詳細を発表する。この技術は、空気、水、表面、その他の用途において、安全で効果的、低メンテナンスかつ低電力の殺菌プロセスを大きく前進させるものである。

Silannaの分子線エピタキシー(MBE)プロセスマネージャーであるジェシカ・チャイ(Jessica Chai)が、2023年11月14日(火)15:15-15:30、ルーム "Navis C "にて講演を行う予定だ。 ジェシカは、Silanna UVの革新的な遠紫外線（Far UV-C）LEDに使用されているGaN/AlN SPSL（短周期超格子）ナノ構造のSiドーピング特性について説明する。また、この製造技術の特性と利点を示すテスト結果も紹介する。

非接触型除菌の革命

遠紫外線（Far UV-C）LEDは現在、安全で効果的な非接触消毒の画期的な方法として認められている。240nm以下の光は病原体を不活性化する一方で、人の住環境ではUVCの長波長に比べてより安全であるため、240nm以下のLEDは特に注目されている。

遠紫外線（Far UV-C）波長用の高Al AlGaNを製造する従来のバルクAlGaN法はさまざまな課題に悩まされているが、Silanna UVの独特かつ特許取得済みのIII-窒化物SPSL技術はこれらの課題を克服している。同社はフリップチップデバイスで236nm 18mW、1Aを達成する240nm以下の遠紫外線（Far UV-C） LEDの実証に成功している。

Silanna社の紫外線（Far UV-C）LEDの詳細はhttps://silannauv.com/productsからご覧いただけます。

Silanna UVについて

Silanna Groupは2006年に設立されたオーストラリアの半導体メーカーです。2008年にペレグリン・セミコンダクター社に買収されて以来、個人出資で設立されたSilanna UVはISO 9001:2015認証を取得したUV-C LED製造のソリューション・プロバイダーです。オーストラリアのブリスベンを拠点とするSilanna UVは、水質センサー、ガスセンサー、殺菌、HPLC（高速液体クロマトグラフィー）アプリケーション向けに遠紫外線（遠UV-C）光源を提供しています。Silanna UVの革新的なアプローチにより、UV LED技術は230nmから265nmの短波長化へと進み、深(deep)UV-Cや遠(far)UV-Cの範囲も含みます。同社は独自のエピタキシー技術を有し、UV LED技術に関する特許を保有しています。独自のUV LED技術により、Silanna UVはUV波長の限界を押し広げ、新たな可能性の創造に努めています。詳細については、http://www.silannauv.com/をご覧ください。

by Wayne Britten

Head to page 50 of the latest Compound Semiconductor Magazine Volume 29 Issue 7 to see their review of Silanna’s Applied Physics Letters SPSL paper!

https://data.angel.digital/pdf/Compound_Semiconductor_Issue_7_2023.pdf

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MBE for far-UV LEDs

150 mm sapphire substrates are a promising platform for high-volume production of far-UVC LEDs via MBE

WHILE MOCVD is the most common growth method for producing far-UV LEDs, MBE also enables high-volume, high-yield production of these devices, says Silanna UV.

This Australian outfit has made more than 10,000 functional devices from a 150 mm GaN-based epiwafer, produced on a sapphire substrate using a Veeco GEN200 MBE tool. Following packaging, these far-UV LEDs produce an output power of 1.7 mW at peak efficiency, and have a lifetime of several thousand hours.

Silanna’s devices are compelling candidates for the optical source for disinfection and sterilisation. Emitting below 240 nm, radiation from these LEDs has minimal penetration beyond the outmost layers of skin, ensuring that exposure poses a reduced cancer risk. In addition, the company’s far-UVC LEDs can be used in sensing and high-performance liquid chromatography.

These far-UVC LEDs are produced on commercial 150 mm sapphire substrates, which are outgassed prior to growth in the Veeco GEN200. 

“The Veeco GEN200 platform is a dual-chamber system, so we are capable of meeting current demand,” says Jordan Nichols, a senior device integration engineer at Silanna, who reveals that the company’s epitaxy facility has been purpose built to expand production capacity as demand grows.

To form the LED’s epistructure, Silanna’s engineers deposit a 400 nm-thick AlN buffer, followed by four different superlattices and then a p-type GaN layer (see Figure). The superlattice for the recombination region is about 80 nm-thick and features 36 periods, with layer widths tuned to meet the target wavelength, which can vary from 229 nm to 240 nm.  

“Devices at shorter wavelengths will have a lower output power,” says Nichols. “We bin our LEDs to assist customers with selecting the appropriate output power and wavelength for their desired application.”

One merit of using a short-period superlattice for the active region is a band structure that promotes transverse electric emission, leading to increased light extraction efficiency. This form of active region also reduces the dopant ionisation energy, thereby reducing resistivity, compared with a conventional quantum well region for a far-UVC LED.

To improve hole injection into the heart of the device, Silanna inserts a chirp superlattice between the p-type GaN layer and the active region. Also acting as an electron-blocking layer, this chirp superlattice prevents electrons from overshooting the recombination region.

Silanna produces LEDs from its epiwafers using standard photolithography and metallisation processes. After forming mesas by dry etching, 

Ti/Al contacts are deposited to form electrical contacts. Following the addition of a standard passivation layer, engineers at the company may undertake optoelectronic measurements at the wafer-level using an integration sphere.

Wafer-level maps of electroluminescence spectra were recorded for more than 10,000 individual LEDs driven at 20 mA. For these devices, emitting at around 233 nm, the standard deviation in peak wavelength for devices in the middle 100 mm of the wafer is just 0.16 nm, and the average optical power 0.2 W.

Nichols his co-workers have produced packaged LEDs by dicing 1 mm by 1 mm devices from epiwafers, thinning the substrate to 275 μm and polishing it, and then flip-chip bonding the die to an AlN ceramic package. These devices delivered a peak wall-plug efficiency of 0.55 percent at 50 mA. Cranking the current up to 1 A caused the output power to climb to 17.4 mW, which is claimed to be the highest radiant flux for a far-UV LED grown on sapphire.

Lifetime tests on 80 packaged devices driven at 20 mA indicate a lifetime of 2,800 hours, based on the time it takes for the radiant flux to decrease to 70 percent of its initial value.  

Goals for the team include realising even higher output powers and longer wavelengths.

REFERENCE

J. Nicholls et al. Appl. Phys Lett. 123 051105 (2023)

by Wayne Britten