The microelectronic industry has been engaged for a long time in measures to reduce its impacts on the environment, regarding all the life cycle phases of its products. For the manufacturing sites, the logical follow-ups to the implementation of pollutions treatment systems are their anticipation. The eco-design of microelectronic technologies, that is the integration of environmental parameters in their development process, enables to meet this objective. The aim of our research work is to environmentally characterize the microelectronic manufacturing processes to propose tools and methods for their designers. Therefore, we modeled a microelectronic technology, and we matched environmental impacts with its inputs and outputs. This allows us to suggest environmental indicators for the R&D, which are adapted to a microelectronic development and manufacturing site.