Industrial aspects of GaN/SiC blue light emitting diodes in Europe

The market of optoelectronic devices is continuously growing. Especially th e development of hyper bright visible light emitting diodes (LEDs) leads in to new applications such as automotive, signs and illumination. To serve th ese markets, low cost production processes have to be developed. The spectr al region of blue and green is realized using GaN based devices. Such devic es suffer from the availability of high quality substrates such as SiC or;s apphire. Due to its conductivity, SiC is at Siemens AG the substrate of cho ice, even though it is quite expensive. On top of that, process control pla ys an important role for GaInN. Since there are lots of new. unsolved physi cal properties of this material, it becomes very important to overcome proc ess related difficulties. One of the main problems is wavelength stability for different operation currents. As can be shown, there are possibilities to overcome these types of problems. (C) 1999 Elsevier Science S.A. All rig hts reserved.