Semiconductor manufacturing is not considered a major contributor to global warming, but our operations do directly and indirectly emit greenhouse gases (GHGs). The three main contributors to our carbon footprint are emissions from purchased electricity, PerfluoroCarbons (PFCs) and heat-transfer fluids (HTFs).
We measure our carbon footprint according to the GHG Protocol: a set of internationally recognized standards for quantifying and reporting GHG emissions. We report on all three of the categories defined by the GHG Protocol: Scope 1 (direct emissions), Scope 2 (indirect emissions, owned) and Scope 3 (business travel and product transportation).
The GHG Protocol defines Scope 1 emissions as direct emissions from company-owned and controlled resources, including stationary combustion (fuels, heating sources) and process emissions (from onsite manufacturing).
Our Scope 1 emissions include PFCs, HTFs, emissions from the consumption of fossil fuels and emissions of Kyoto gases, including Nitrous Oxide (N2O) and Sulfur Hexafluoride (SF6).
At present, there are no viable alternatives for the PFCs used to etch integrated circuitry onto silicon wafers and to clean the internal chambers of deposition equipment.
Both our normalized and absolute PFC emissions have decreased from a 2010 baseline. This reduction is significant because we produce increasingly complex products that involve many more manufacturing steps that use PFCs. Installing the most up-to-date abatement technology and upgrading existing process tools each year has resulted in continuous year-on-year reduction of PFC emissions.
HTFs are used in manufacturing processes and device testing to maintain a particular temperature. The majority of HTFs are used to test hermetically sealed radio frequency (RF) products while the remainder are used in manufacturing processes.
We use fossil fuel, in the form of natural gas, to heat and control humidity in our clean rooms. Our use of natural gas depends strongly on both the external temperature and internal production activity of the manufacturing facilities.
N2O is used at several points in our manufacturing process, including chemical vapor deposition of silicon dioxide and doped or undoped silicon oxynitride, diffusion, rapid thermal processing and chamber seasoning.
For several years now, we have been installing the most up-to-date abatement technology and upgrading existing process tools. As a result, we have seen a continuous year-on-year reduction in N2O emissions.
The GHG Protocol defines Scope 2 emissions as indirect emissions from the generation of purchased energy, supplied by a utility provider. We use market-based calculations for CO2, which represent actual emission data from energy providers.
We have decreased our Scope 2 emissions even though our current products are more complex and require additional manufacturing steps, meaning they require more electricity to manufacture and test. Furthermore, over the last decade, the footprint of each device on the wafer has continued to shrink, increasing the number of devices per wafer and reducing the total number of wafers needed. Due to the nature of our manufacturing processes, the normalized Scope 2 emissions has increased in recent years.
The GHG Protocol defines Scope 3 emissions as indirect emissions, not included in Scope 2, that occur in the value chain of the reporting company. Our Scope 3 emissions include business travel and product transport and are measured as CO2 equivalents (CO2e).
Our Non-Greenhouse Gas Emissions of atmospheric pollutants, which include nitrogen oxides (NOx), sulfur oxides (SOx) and volatile organic compounds (VOCs), mostly come from our manufacturing process, but some come from our boilers and the use of chemicals, such as solvents in the photolithography process.
In 2020, NOx emissions decreased by 57%, SOx by 40% and VOC by 15% from a 2010 baseline.