Helium Dependent Technologies

SEMICONDUCTORS – Semiconductor manufacturing will drive demand growth

The second largest application for helium, representing an estimated 19% of demand, is semiconductor chip manufacturing. Helium is used in wafer fabs as a carrier gas in deposition processes, to leak test vacuum systems, as a component of specialty gas blends, for load-lock cooling and for backside wafer cooling. Helium is critical to the wafer manufacturing process and, it is becoming more so, as wafer manufacturing processes become more sophisticated. Linx-Consulting, a consultancy that provides electronic materials insight to the semiconductor industry, explains that “vertical scaling” of semiconductor manufacturing processes to increase chip capacity (think of going from a parking lot to a parking deck) requires more of the deposition steps and vacuum steps that require helium. For that reason, new “state of the art” wafer fabs are more helium intensive than fabs using less advanced technology.

Semiconductor manufacturing is expected to grow at double-digit rates at least through the first half of the 2020’s and is expected to surpass MRI as the leading sector for helium demand by 2023.

“Over 100 gases are used in semiconductor manufacturing today, primarily in dry etch processes (dielectric, conductor and polysilicon etching), chemical vapor deposition (both dielectric and metal deposition), diffusion and ion implantation. Helium has in recent years been very much in the spotlight for its growing role in the electronics business and, likewise, the significance of the electronics market as a key end-user for helium.”

Excerpt from “Spotlight on Specialty Gases” Gas World April 14 2022
Rob Cockerill  Editor

MAGNETIC RESONANCE IMAGING (MRI) – Largest user of Helium

The largest single application is the use of liquid helium to cool the superconducting magnets that are utilized in MRI scanners to the
temperatures at which they lose their resistance to electricity. This application represents around 22% of global demand for helium. Between
2,000 – 4,000 liters of liquid helium are usually required to initially cool the magnets down to superconducting temperatures and, thereafter,
the liquid helium must be replenished periodically as it boils off to the atmosphere.

There are over 50,000 MRI scanners installed worldwide and new scanners are being installed at the rate of approximately 5,000 machines per
year (many of these are replacements of older units, so the installed base is growing by less than 5,000 units per year).

AEROSPACE

Increasing quantities of helium are used by the aerospace industry to purge and pressurize tanks and rocket engines that utilize liquid
hydrogen fuel systems. Helium may also be used for some rocket engines that rely on liquid oxygen fuel. Typically, large quantities of helium
are required prior to launches at the launch facility. Additional significant quantities of gaseous helium may be required for the testing of
rocket engines.

Helium is utilised in these applications because it is inert and it remains in gaseous form at liquid hydrogen temperatures due to its extremely
low boiling point.

FIBRE OPTIC CABLE

Gaseous helium is utilised in the manufacturing of fibre optic cable primarily for cooling during the pre-form manufacturing process as well
as in the draw towers where the pre-forms are melted and cooled rapidly to form the actual optical fibre. It is not essential to utilise helium in
the draw towers, but using helium enables you to pour the fibre at a faster rate than you are able to if you use nitrogen for cooling.

SPECIALIST WELDING

12% of helium is used as a shielding gas in plasma arc welding and metal arc welding. Using helium as a component of the welding gas mixture
results in higher quality and more reliable welds of titanium, aluminum, stainless steel and other high-value, high-reliability applications.