In 2018 our normalized Scope 1 emissions decreased by 26.5% from a 2010 baseline.
Fossil fuels are hydrocarbons, primarily coal, fuel, oil, or natural gas. The burning of
fossil fuels by humans is the largest source of CO2 emissions. Fossil fuels are still the
main source of energy in the global economy.
At NXP, the most commonly used fossil fuel is natural gas, used for heating and humidity
control in our clean rooms. NXP’s use of natural gas depends strongly on both the external
temperature and internal production activity within the manufacturing facilities. Diesel is
also used at NXP for back-up generators.
From 2010 to 2018, our normalized fossil fuel emissions decreased by more than 33%.
PFCs are essential chemicals in today’s semiconductor manufacturing processes. When it
comes to etching integrated circuitry onto silicon wafers, or cleaning the internal
chambers of deposition equipment, there are no alternatives for PFCs. Without them,
semiconductor companies would not be able to produce the complex, high performance ICs that
have become so essential to our daily lives. Nevertheless, PFCs pose a serious dilemma for
every semiconductor company. We have essentially exhausted the two most cost-effective
options for PFC reduction–process optimization and switching to alternative gases.
We recognize the undesirable impact PFCs have on the environment and have joined with
others in the semiconductor industry to seek ways to minimize their use and emissions. For
example, NXP signed the Memorandum of Understanding in the US, and the Memorandum of
Agreement in Europe, to voluntarily reduce the emissions of PFCs. The industry, as a whole,
achieved this target before the 2010 deadline. The European Union has recognized the
semiconductor industry’s proactive approach by granting an exemption to the so-called
F-gases regulation. It is a voluntary agreement. No ban on the use of PFCs for critical
applications has been imposed on the semiconductor industry in Europe. We are, however,
committed to looking for alternatives.
Like the rest of the semiconductor industry, NXP Semiconductors remains strongly devoted to
its proactive management of PFC emissions. We support the New 2010-2020 Global
Semiconductor Industry Voluntary Agreement, including the Best Practice Guidance, which
addresses worldwide emissions from semiconductor manufacturing for the present decade. The
agreement is supported by all members of the World Semiconductor Council (WSC), and covers
the optimization of production processes (so they consume fewer greenhouse gases), the
replacement of greenhouse gases with global warming potential (GWP)-free or lower-GWP
alternatives, and use of the most up-to-date abatement technology.
NXP also has its own goals for the reduction of PFC emissions. We proactively review
Point-Of-Use (POU) abatement when we maintain, replace, or relocate existing fab tools. As
we upgrade existing process tools, we add POU abatement, when feasible. If such POU
abatement is not feasible, we look for measures elsewhere in our factories to compensate
for the emissions. In 2018, the Oak Hill, Chandler, and SSMC labs installed 29 abatement
equipment to further reduce the emissions of PFCs (NF3, CF4, C2F6).
As a global company, we use the Intergovernmental Panel on Climate Change (IPCC) for
calculating our PFC emissions using the Tier 2b methodology. From 2010 to 2018, our
normalized total PFC emissions decreased by 38%, even though many of our products have
become more complex, requiring additional manufacturing steps, and hence more PFCs. In 2018,
we did encounter a slight increase in the normalized PFC emissions from 2017, which is
attributed to the decrease of wafer output and the additional manufacturing steps for
specific layers of the wafer.
In Action: Per fluorocarbons (PFC’s) emissions contribute to 31% of NXP’s total carbon
footprint, so at the end of 2018, the SSMC site added 24 PFC abatement units making
a significant reduction of approximately 40% less annualized emissions, which we
will see in our results in 2019.
Heat-Transfer Fluids (HTFs)
NXP uses HTFs for device testing, for cooling purposes (manufacturing tools, facilities,
and air-conditioning), and in a few cases as a fire suppressant.
During the manufacture of semiconductor devices, HTFs serve as coolants in chillers,
removing excess heat during many manufacturing processes. During semiconductor device
testing, devices are immersed in containers of HTFs, cooled or heated to a desired
temperature to verify their integrity, and exposed to HTFs to prevent overheating during
certain tests. HTFs are also used to attach semiconductor devices to circuit boards via
solder, which may be melted by the vapor of an HTF heated to its boiling point.
Some of the HTFs we use are ozone-depleting substances and, as such, are strictly
controlled. For instance, the European Union has adopted regulation EC No 1005/2009 on
substances that deplete the ozone layer. By order of this regulation, the so-called
“controlled substances” are to be phased out. The phase-out date differs from country to
country. NXP has strict rules in place, regarding all ozone-depleting substances, calling
for their phase-out well before legislation comes into effect.
From 2013 to 2018 our normalized HTF emissions decreased by 24.7%.
In Action: Aligning with the 2020 goal, the Kuala Lumpur site committed to reduce
Heat Transfer Fluid (HTF) emissions, which is used for testing hermetically sealed
HTFs are used to detect pin hole leaks on RF power amplifiers. However, during the
testing there are two steps within the testing procedure that releases HTFs into
the atmosphere, which are due to vapor diffusive loss and fluid drag out. HTFs
contribute to one of the highest emissions of GHG from the Kuala Lumpur site.
To address HTF emission reduction at Kuala Lumpur, a three-phase project was
developed. The first phase was to substitute a high global warming potential HTF
with a lower global warming potential HTF. This substitution of materials reduced
the emissions by 10%. The second phase modified the existing process by minimizing
the surface area of the testing tray to capture more fluid in the vat and reduce
the drag out which resulted in another 20% reduction of emissions. The third phase
is modifying the manual system by designing a semiautomated, closed loop system.
This new system will add additional mechanisms to create 2 zones in which emissions
are now collected instead of emitted. The first zone captures the vaporized solvent
through the cooling process and the second zone recycles the solvent in a closed
loop system by condensation. This will provide an additional 40% emission
Nitrous oxide is a colorless, nonflammable, non-CO2, global-warming gas. It is naturally
present in the atmosphere, as part of the earth’s nitrogen cycle, and comes from a variety
of natural sources. However, human activities, such as agriculture, fossil-fuel combustion,
wastewater management, and industrial processes, are increasing the amount of N2O in the
N2O is used in semiconductor processes, such as the chemical vapor deposition of
silicon dioxide, doped or undoped silicon oxynitride, diffusion, rapid thermal processing, and chamber seasoning.
Emissions from N2O are minor compared to other emissions such as those from
PFCs. From 2010 to 2018 the normalized N2O emission decreased by almost 14%.
However, the absolute N2O emissions have increased due to very specific process-related requirements for technologies requiring N2O.
NOx, SOx, and VOC
Additional emissions are nitrogen oxides (NOx), sulphur oxides (SOx), and volatile organic
compounds (VOC). NOx and SOx are air pollutants that arise from a wide variety of sources
but mainly as a result of combustion. NOx is a term used to refer to nitric oxide (NO) and
nitrogen dioxide (NO2). SOx refers to sulphur dioxide (SO2).
At NXP, predominate NOx and SOx emissions are from the manufacturing processes of
integrated circuits. Minimal NOx and SOx emissions come from our boilers. VOC emissions
result from use of chemicals such as solvents used in the photolithography manufacturing
process. VOCs include isopropyl alcohol (IPA) and other solvents.
From 2010 to 2018, the following normalized emission percentages for NOx, SOx, and VOC are
as follows: NOx decreased by 8%, SOx decreased by 71%, and VOC decreased by 27%. However,
our absolute NOx and VOC have increased slightly due to specific requirements of the wafer
layers and the photolithography processes required in the product mixes.