11 July 2011

RoseStreet demos first long-wavelength LED based on InGaN-on-Si

RoseStreet Labs (RSL) of Phoenix, AZ, USA, a privately held supplier of products and services for the renewable energy and semiconductor markets, has announced what it claims is the first demonstration of a long-wavelength LED device using silicon wafers, which have a substantial cost advantage over the more traditional sapphire or silicon carbide (SiC) substrates typically used in LED fabrication. The device complements the firm’s proprietary thin-film indium gallium nitride (InGaN) on silicon technology for high-efficiency photovoltaic applications and power devices. 

RSL notes that green and longer-wavelength LEDs have been sought by both science and industry for an extensive period of time because they would fill a high-value gap in the rapidly growing LED market for lighting and illumination where energy efficiency, low cost and miniaturization are critical product characteristics. “Green LED’s have been elusive due to material challenges of producing a high-efficiency device in the green region and the longer wavelengths of the spectrum,” says chief technology officer Wladek Walukiewicz. Efficient long-wavelength LEDs are essential milestones in the roadmap for solid-state lighting (SSL), LED backlighting and next-generation display technology.

Also, green or longer-wavelength nitride-based LEDs are very challenging to fabricate compared with UV and blue LEDs due to decreasing quantum efficiencies, and have remained a tough milestone for the LED industry. However, RSL’s longer-wavelength devices are fabricated using commercial-scale deposition tools at its Nitride Research Center in Phoenix.

RSL plans to eventually package the green and longer-wavelength LEDs through sister company FlipChip International LLC (FCI), a supplier of wafer bumping, wafer-scale packaging and flip-chip products and services. FCI has extensive experience in packaging semiconductor power devices at its manufacturing locations globally, and plans to provide a proprietary packaging solution for the LED devices.

RSL has also demonstrated initial tunability of the technology to multi-color and white-light spectrums. The firm says that the device shows great promise due to its potential for high intensity, low energy consumption, and a roadmap to very low commercial cost. RSL believes that the technology could be commercialized in 2–3 years, with migration to 200mm silicon substrates.

Tags: RoseStreet LEDs InGaN

Visit: www.rosestreetlabs.com