The semiconductor industry is a high tech leader and, perhaps because of stringent demands placed on manufacturing to minimize particle counts and contamination, is considered a clean industry. An extensive processing science has been developed to reliably produce nanometer scale devices over large areas, but a small percentage of the materials and resources used in manufacturing end up in the finished device. An opportunity exits to reduce the environmental burden of manufacturing by understanding the fundamentals of the relevant processing science. Research on low environmental impact processes must, however, intersect the aggressive technology development program set by industry, since decisions are made based on device performance and cost. Thin films having low dielectric constants are a performance driver in the interconnect wiring used to link transistors. The next generation of these materials containing manufactured pores filled with air will be needed to achieve dielectric constants below 2.4 for the 32 nm device generation. Pores compromise the structural integrity of thin films and create significant process integration challenges since the pores must be cleaned, free of etching damage, and capped before the deposition of subsequent layers. My group has demonstrated using surface spectroscopy techniques and electrical measurements that low dielectric constant films damaged by patterning were repaired and capped using silylation chemistries introduced using supercritical carbon dioxide (scCO₂). The supercritical fluid penetrates nanometer scale pores without leaving a residue and is easily separated from reaction byproducts, offering the possibility of recycle. Copper interconnect wiring also drives performance, and work on copper surface chemistry has shown that the fluorinated ligand hfacH dissolved in scCO₂ etches cupric oxide (CuO) relative to copper metal. These processes combined with the development of photoresist and particle removal steps using scCO₂ could provide an integrated sequence for building advanced structures and devices that is environmentally sustainable.