Wafer fabrication (48%) and the use phase (27%) are the two dominant factors in the life cycle. Energy use to produce the main structural materials in the chip, aluminum and epoxy, represent a tiny share of the total (.3%). The energy investment in a chip is thus mainly in its complex form rather than its bulk substance. The third point is that the preparation of silicon wafers has a substantial share (10%). Purification of materials thus substantially affects the result.
The estimated mass of fossil fuel and chemical inputs needed to produce and use one 2-g microchip are 1670 and 72 g, respectively. Fossil fuels used in production total 600 times the mass of the final product, indicating that the environmental weight of semiconductors far exceeds their small size. This intensity of use is orders of magnitude larger than that for “traditional” goods, as is indicated in Table 3.