Although silicon power transistors are inferior to their GaN rivals in many regards, they win hands-down in the metric that matters most: Cost. However, affordable GaN HEMTs are within reach, when production moves to 200 mm GaN-on-silicon epiwafers processed on standard CMOS lines, argues imec’s Brice De Jaeger, Marleen Van Hove and Stefaan Decoutere.
The miniscule scratches and pits found on the surface of SiC substrates spawn yield-killing defects in the epiwafers. It is not possible to pick-up these minor imperfections and track their consequences with conventional light-scattering inspection tools, but this can be done with our detection systems employing confocal optics and differential interferometry, argues Yuji Asakawa from Lasertec Corporation.
The performance of LED light bulbs is impaired when delamination occurs within or between the parts that make up a packaged device. These deficiencies cannot be detected by widely used characterisation techniques such as X-ray and infrared microscopy, but they are exposed with acoustic imaging at very high frequencies, according to Tom Adams, a consultant to Sonoscan.
Returning home in the early 1980s without a job to go to, Ian Neale had a big decision to make about his future. Hindsight shows that he got it right when he decided to launch Hiden Analytical, a highly successful metrology firm that is now celebrating its thirtieth anniversary. Richard Stevenson reports.
Separating the phosphor from the blue-emitting chip is a great way to improve the performance of LED light bulbs, according to Mitch Jansen from Intematix. With this architecture bulbs are brighter, their emission more uniform, and they last far longer, thanks to superior thermal management.
SiC chipmakers from all over the world have been recently releasing SiC products, including high-current diodes and high-voltage MOSFETs and JFETs. Many of these devices, and some of the modules that were built with them, were unveiled at the fourth International SiC Power Electronics Applications Workshop. Enrique Lamoureux reports from this event.
Today’s conventional triple-junction cells seem to offer little room for improvement, with average production efficiencies hovering just below 30 percent. This can be increased by ten percentage points with a switch to six junction cells incorporating two dilute nitride layers, say Simone Missirian, Jeff Allen, Vijit Sabnis and Homan Yuen from Solar Junction.
Vast swings in MOCVD reactor shipments, stagnation in LED sales in the build up to the solid-state lighting revolution and technologies to slash the cost of chips for LED light bulbs featured at euroLED 2012. Richard Stevenson reports.
GaN devices have the potential to capture a billion dollar power market for electrified vehicles. But if they are to be successful, they need to sell for little more than silicon products, have higher threshold voltages than they do today, show no signs of current collapse and deliver very high currents, argue Ming Su and Chingchi Chen from Ford Motor Company.
Researchers have developed a novel, vertical transistor that outperforms typical MOSFETs. Compound Semiconductor talks to the Japanese team behind the device that promises to deliver smaller, faster electronics.
Blue laser diode inventor, Shuji Nakamura, recently unveiled a non-polar violet VCSEL, claiming 'one of the biggest breakthroughs in laser diode technology'. Compound Semiconductor talks to Nakmura and industry colleagues, to find out more.
GaN-on-silicon products will become far more competitive when processing is carried out at fully depreciated 200 mm silicon fabs. This requires the use of very flat wafers, which can be formed through the introduction of rare oxide epi-layers that can also enhance the performance of LEDs, transistors and solar cells, say Michael Lebby, Andrew Clark and Guoying Ding from Translucent.