STMicroelectronics Sets World Record for Silicon Light Emission; Breakthrough Technology Opens Road to Commercial Products With Integrated Optical Processing.

Business Editors & High-Tech Writers

GENEVA--(BUSINESS WIRE)--Oct. 28, 2002

STMicroelectronics (NYSE: STM), the world's third largest semiconductor manufacturer, has announced details of a ground-breaking technology that allows silicon-based light emitters to match the efficiency of traditional light-emitting compound semiconductor materials such as gallium arsenide (GaAs).

The new technology opens up many potential applications in which optical and electrical functions are combined on a single silicon chip. This was not previously possible because although silicon is ideal for building memories, microprocessors and other complex circuits, it could not be made to act as an efficient light emitter.

"The ability to combine optical and electronic processing on the same chip presents enormous opportunities for ST to be the first to develop many new types of semiconductor products, especially as the technology is compatible with existing volume production process flows and equipment. ST has already identified a number of promising applications and key manufacturing issues have already been solved so that the technology can be rapidly moved into production," said GianGuido Rizzotto, Director, Corporate Technology R&D, STMicroelectronics.

ST's new silicon-based light emitting technology sets a world record for efficiency. It is based on an innovative structure in which ions of rare-earth metals such as erbium or cerium are implanted in a layer of Silicon Rich Oxide (SRO), i.e. silicon dioxide enriched with silicon nanocrystals of 1-2nm diameter. "The quantum efficiencies achieved are about 100 times better than has previously been possible with silicon and are, for the first time, comparable to those obtained from GaAs and other compound semiconductors traditionally are used to make Light-Emitting Diodes," said Salvo Coffa, manager of the team responsible for the breakthrough. The frequency of the emitted light depends on the choice of rare-earth dopant and ST has patented key techniques for implanting the rare-earth ions into the silicon.

The new technology was developed in Catania, Sicily, by researchers from ST's Corporate Technology R&D Organization, which was established to explore and industrialize new technologies resulting from the convergence of microelectronics, physics, chemistry and biology, leveraging ST's deep understanding of microelectronics technology and its worldwide network of blue-chip academic and industrial partners. The process was developed using the same pilot line that ST uses to develop new MOSFET and bipolar devices. This has allowed the Company to accelerate the transfer from proof-of-concept experiments to prototype development and industrialization.

One of the first applications of the new technology is to build power control devices in which the control circuitry is electrically isolated from the power switching transistors. Currently, electrical isolation, which is mandatory in many applications for safety reasons, can only be achieved by using external devices such as relays, transformers or discrete optocouplers, all of which involve additional cost, power consumption or bulk.

ST has patented a novel structure in which two circuits, built on the same chip but electrically separated from each other by insulating silicon dioxide, communicate via optical signals using integrated silicon light emitters and detectors. These devices will have numerous important applications, including motor control, power supplies, solid-state relays and similar applications where the power circuit needs to handle much higher voltages than the control circuit. Engineering samples will be available by the end of 2002.

In the longer term, ST is investigating integrated optical data-transmission systems for use in advanced CMOS circuits where clock signals are distributed through the chip at the speed of light, as well as low-cost integrated devices for Dense Wavelength Division Multiplexing (DWDM) fiber-optic communication.

About STMicroelectronics

STMicroelectronics, the world's third largest semiconductor company, is a global leader in developing and delivering semiconductor solutions across the spectrum of microelectronics applications. An unrivalled combination of silicon and system expertise, manufacturing strength, Intellectual Property (IP) portfolio and strategic partners positions the Company at the forefront of System-on-Chip (SoC) technology and its products play a key role in enabling today's convergence markets. The Company's shares are traded on the New York Stock Exchange, on Euronext Paris and on the Milan Stock Exchange. In 2001, the Company's net revenues were $6.36 billion and net earnings were $257.1 million. Further information on ST can be found at www.st.com.