CATANIA, Italy -- At a technical seminar devoted to some of its leading edge R&D and manufacturing activities, STMicroelectronics (NYSE: STM), one of the world's leading manufacturers of semiconductor devices, today disclosed further significant advances it has achieved in the field of light-emitting silicon technology. Among other applications, the enhanced technology will allow ST to enter the market for optocouplers in the near future.

Silicon, the second most common element found on earth, is the material used to fabricate almost all of the integrated circuits ("silicon chips") used in today's electronic equipment such as PCs, mobile phones and set-top boxes. Silicon's ability to act as a detector of light signals has been long known and successfully exploited in technologies such as ST's digital camera chips. However, the physical properties of pure silicon are not conducive to the emission of light and this function has traditionally been accomplished by more expensive compound semiconductor materials formed by combinations of rarer and more expensive elements such as gallium, arsenic and indium.

Last year, ST announced a breakthrough technology that allowed silicon-based devices to emit light with an efficiency that was some two orders of magnitude better than the best previously achieved results with silicon, allowing these devices to reach, for the first time, efficiencies comparable to those of more expensive compound semiconductors while retaining the cost advantages of high-volume silicon technology.

"Since then, ST has made substantial further progress towards turning this pioneering research into both near-term commercial products and potentially disruptive new technologies," said Dr. Salvo Coffa, Research Director of the SST (Soft Computing, Si-optics and post-silicon Technologies) group within ST's Corporate R&D organization.

The results announced by ST in October 2002 already went far beyond the existing state-of-the art in silicon-based light emission, making ST the first semiconductor manufacturer in the world to be in a position to consider the integration of Si-based light emitting technology into products such as optocouplers, for which there is already a substantial world market based on more expensive non-silicon technologies, as well as entirely new types of product that exploit ST's ability to integrate the all three functions of light emission, light waveguides and light detectors on a single silicon chip that can be manufactured at low cost on high-volume production lines.

Already, ST has produced fully working prototypes of a completely silicon-based optocoupler that demonstrate that all-silicon devices can deliver similar performance to that of traditional devices while offering the cost benefits of silicon manufacturing. "Comparing the performance of our first prototypes with that of existing devices and considering the improvements we have already made to the initial technology, we expect to reach the commercial crossover point in around six months," said Coffa.

In fact, Coffa's team has not only increased the external quantum efficiency of its light-emitting devices by a factor 1.5, which already exceeds the quantum efficiency of traditional semiconductor materials, but also increased the maximum emitted power by a factor 50. As a result, ST is now able to produce more than 1mW of emitted light power for each square millimetre of silicon.

"Given that we already know from our current research that it will be possible to increase this performance by at least another order of magnitude, we are on the threshold of opening up entirely new industrial applications in the fields of displays and even solid state illumination. In addition to targeting the large existing market for conventional optocouplers, ST will be aggressively pursuing these novel applications," said Coffa.

STMicroelectronics NV