Corporate Environmental Report

Pollution

Air emissions: phase out all CLASS 1 ODS by the end of 1996. Contribute where we can to the reduction of greenhouse and acid rain generating gases.

By the end of July 1993, all Class 1 Ozone Depleting Substances were eliminated from production processes and by end 1997 all large refrigeration units (chillers) were replaced with more efficient, economical and environmental-friendly equipment. Also, since February of 1998, no site retains fire-fighting systems which rely on environmentally harmful halons.

These actions required an investment of some $20 million.
The final step, now in progress, is to phase out all the remaining Class 1 ODS still present in some small equipment as well as in the air conditioning system in a newly acquired building in Phoenix, Arizona.

Manufacturing sites emit pollutants such as acids, alkalis, solvents to the air. At most ST manufacturing facilities, site scrubbers have been installed to abate these emissions. All scrubbers are equipped with variable frequency drives to conserve energy and to maintain a standard exhaust pressure for the fab equipment.

In addition to several optimization of processes such as the reduction of isopropyl alcohol usage and upgrade of IPA dryers, the Company has installed equipment to cut the emission of Volatile Organic Compounds (VOC) and toxic vapors at several sites. At Carrollton in Texas, this equipment has reduced solvent emissions by 80-90% and 90 tons of vapors are now destroyed each year.

Significant further investments in this area are planned across the corporation. Also in Carrollton, the highly advanced Fourier Transform Infrared Spectroscopy (FTIR) for real time, continuous emission testing from stacks has been installed. Its instrumentation provides chemical detection at concentrations as low as 5 parts per billion. All of these projects are intended to verify the proper operation of all air abatement equipment. The project cost for a typical site is in the region of $K80.

The semiconductor industry currently emits fluorocarbons (CF4, C2F6, CHF3, C3F8), nitrogen trifluoride (NF3), and sulfur hexafluoride (SF6) from its manufacturing process. These gases (collectively referred to as perfluorinated compounds (PFC) are used in two important steps of semiconductor manufacture: plasma etching of thin films and cleaning Chemical Vapor Deposition.

Due to their high global warming potential and long atmospheric lifetimes, PFC are now included in the Kyoto Protocol framework and emission reduction goals have been established by country.

ST Microelectronics is highly committed to the reduction of PFC emissions. Under an international voluntary agreement, promoted by the US Environmental Protection Agency (EPA), ST has agreed to reduce the use of PFC. The European Electronic Components Manufacturers Association (EECA) task force, led by ST, is working to establish a similar program in Europe. In 1997 ST signed a Memorandum of Agreement committing to the reduction of PFC emissions and to share PFC data and technical information with other semiconductor companies operating in Europe.

ST is also involved in other working groups such as the PFC leadership group in the United States and in SEMATECH international programs. The Company participates in the World Semiconductor Council EHS task force where PFC issues are addressed by the industry as a whole. The World Semiconductor Council's challenging common goal of reducing PFC emissions by 10% in absolute quantity with 1995 as a base year is fully supported by ST.

The Company is working closely with equipment and gas suppliers to establish a consistent PFC reduction roadmap. In the technologies investigated, priority is given to proactive solutions : process optimization through less usage of gases; better gas utilization during the process; reduction of process time; retrofits of equipment. Focus is also on the search for alternative chemistries, rather than the systematic utilization of emissions abatement techniques.

Some highlights in ST sites are :

At the R1 facility in Agrate, Italy, a 50% PFC emission reduction has been demonstrated through a very promising dielectric etching process optimization program.

A partnership between the R1 facility at Agrate, LAM Research and Bari University was signed in 1997 for the testing of new PFC substitutes in the etching processes.

PFC abatement systems with good Destruction Removal Efficiency (DRE >95%) are installed in several plants - Rancho Bernardo, Crolles, Agrate, for example.

Optimized C3F8 recipes have been implemented in Catania in Italy and Carrollton in the United States, bringing a reduction of 40% in the emissions versus previous recipes using C2F6.

At Crolles, in France, NF3 with dedicated fluor abatement devices are used for replacing C2F6 gas. (NF3 has a better utilization rate in the process chamber).

Water emission: meet the standards of the most restrictive community in which we operate, at all sites, for waste water discharge.

All sites have invested in waste water treatment plants and with significant increases in production, these have been upgraded in order to maintain the water parameters within the stringent corporate limits. Subject to the tight Italian waste water discharge limit of 6 milligrams of fluorides per liter, the Agrate site in Italy upgraded the existing waste water plant at a cost of about $1 million and installed a second plant to further reduce the fluorides. Fluoride concentrations in water are now about three milligrams per liter, substantially below the legal limit of six milligrams.

The limit of six milligrams of fluoride per liter has been adopted by ST as the corporate standard the world over.

At Rousset, in France, a new Waste Water Treatment Plant (WWTP) shared by other manufacuring sites in the industrial park, guarantees the following :

Noise: meet a "noise to neighbors" at any point on our property perimeter less than 60 dB(A) for all sites, from end 1995.

The Decalogue limits the noise emissions from all sites to 60 dB(A) at the perimeter. Noise may be generated by nitrogen plants, cooling towers, air compressors, scrubbers or other operations. At each site, noise is measured periodically at strategic points around its perimeter.

The ST site in Rennes, France, for example's is surrounded by housing estates. Silencers were introduced at critical points on the epitaxy scrubbers and since October 1997 noise levels are kept at a 48dB(A) level. Other sites not meeting the 60 dB(A) noise level limit have taken a similar approach.

At Rancho Bernardo in California, sound attenuation walls were installed at two strategic locations - the new nitrogen plant and scrubber. The noise level at the site is now close to 54 dB(A) on average at the site perimeters.