UK-based Oxford Instruments, which provides process technology equipment for the manufacturing of high-brightness light-emitting diodes (HBLEDs), says that its systems are being used to facilitate the introduction of ultraviolet (UV) LEDs being utilized in water purification systems to bring safe drinking water to remote places.
Oxford Instruments' PlasmaPro1000 Stratum plasma-enhanced chemical vapour deposition (PECVD) tool is used for depositing dielectric materials essential to the manufacture of UV LEDs, for which the film quality, batch size and throughput are suited. The systems can produce the thicker passivation layers that UV LEDs need to operate reliably at high powers while maintaining film quality and low cost of ownership. The batch size of up to 14 x 4" wafers is enabled by the chamber design, which ensures that each wafer within the batch achieves the same amount of high-specification film deposition, says the firm. Also, fast plasma clean of the chamber is automatically controlled through optical emission spectroscopy (OES), helping to realise maximum yield and uptime.
"UV LEDs have several advantages over traditional UV light sources," notes Dr Mark Dineen, optoelectronics product manager at Oxford Instruments Plasma Technology (OIPT). "They operate at low DC power, meaning that they can be powered from a solar energy source. Combined with the fact that they are lighter and more robust than the traditional sources, this makes them ideally suited for use in remote, off-grid locations where clean water supplies are limited or non-existent," he adds.
"UV LEDs are also tuned to the optimum wavelength for the removal of bacteria, making them significantly more effective in purifying water than traditional light sources," Dineen continues. "Lastly, UV LEDs do not contain mercury, an essential component part of traditional UV lamps. Consequently there is a significant reduction in the environmental impact risk, through both accidental contamination and the need for recycling when comparing UV LEDs and traditional UV lamps."
