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2
Volume 54. No. 8
August 2025
ISSN 2632 573X
Editorial
Environmental concerns with semiconductor manufacturing
You may have heard that semiconductor manufacturing (including
for devices like solar panels) uses large amounts of fresh water. If
this wastewater is not properly treated, it can become contaminated
with the acids and other chemicals used during processing.
The good news is that many of these devices are manufactured in
China, where environmental controls have improved significantly in
recent years. Air pollution levels have dropped dramatically, and it’s
reasonable to assume that water pollution is also being addressed.
I’m far from a chemophobe; my usual retort when someone
complains that something “contains chemicals” is that we are
made of chemicals. But there’s one group of chemicals used in
semiconductor manufacturing that does raise serious concern: perand polyfluoroalkyl substances (PFAS).
There are two major problems with this group: they are highly toxic,
with studies showing dramatically increased risks of certain cancers
at concentrations as low as a few parts per billion (ppb); and they
are extremely persistent. In the environment, they do not break
down; at least not easily and, in many cases, not at all.
In fact, so many PFAS have been released into the environment
(mainly from Teflon production and their use in firefighting foams)
that they’ve contaminated water supplies worldwide. Once absorbed
by the body, they tend to accumulate, as natural metabolic processes
cannot break them down or flush them out.
In semiconductor manufacturing, PFAS are primarily used as
surfactants in photoresists and anti-reflective coatings (ARCs).
They help control surface tension, improve coating uniformity and
enhance pattern resolution. PFAS are also used in plasma etching,
post-etch cleaning, and resist stripping, where they aid in wetting
fine features and preventing contamination or watermarking.
In addition, fluoropolymers (a PFAS subclass) are used as non-stick,
chemically resistant coatings on process tools, wafer carriers, valves,
pipes, and gaskets – where resistance to strong acids, solvents, and
heat is critical.
Given their toxicity and near-infinite persistence, I hope safer
alternatives to PFAS can be developed and adopted soon. If their
use is unavoidable, strict measures must be in place to prevent
environmental release, with effective recycling or degradation
methods applied after use.
Nicholas Vinen, Electron Publishing (Australia)*
Publisher & Editor,
Practical Electronics Magazine
* a division of Silicon Chip Publications Pty Ltd.
Practical Electronics | August | 2025
