Life-Cycle Assessment of NAND Flash Memory

Solid state drives (SSDs) show potential for environmental benefits over magnetic data storage due to their lower power consumption. To investigate this possibility, a life-cycle assessment (LCA) of NAND flash over five technology generations (150 nm, 120 nm, 90 nm, 65 nm, and 45 nm) is presented to quantify environmental impacts occurring in flash production and to view their trends over time. The inventory of resources and emissions in flash manufacturing, electricity generation, and some chemicals are based on process data, while that of fab infrastructure, water and the remaining chemicals are determined using economic input-output life-cycle assessment (EIO-LCA) or hybrid LCA. Over the past decade, impacts have fallen in all impact categories per gigabyte. Sensitivity analysis shows that the most influential factors over the life-cycle global warming potential (GWP) of flash memory are abatement of perfluorinated compounds and reduction of electricity-related emissions in manufacturing. A limited comparison between the life-cycle energy use and GWP of a 100 GB laptop SSD and hard disk drive shows higher impacts for SSD in many use phase scenarios. This comparison is not indicative for all impact categories, however, and is not conclusive due to differences in boundary and functional unit.