Ultra-high purity (UHP) gases are the lifeblood of the semiconductor industry. As unprecedented demand and disruptions to global supply chains push up the price of ultra-high pressure gas, new semiconductor design and manufacturing practices are increasing the level of pollution control needed. For semiconductor manufacturers, being able to ensure the purity of UHP gas is more important than ever.

Ultra High Purity (UHP) Gases Are Absolutely Critical in Modern Semiconductor Manufacturing

One of the main applications of UHP gas is inertization: UHP gas is used to provide a protective atmosphere around semiconductor components, thereby protecting them from the harmful effects of moisture, oxygen and other contaminants in the atmosphere. However, inertization is just one of many different functions that gases perform in the semiconductor industry. From primary plasma gases to reactive gases used in etching and annealing, ultra-high pressure gases are used for many different purposes and are essential throughout the semiconductor supply chain.

Some of the “core” gases in the semiconductor industry include nitrogen (used as a general cleaning and inert gas), argon (used as the primary plasma gas in etching and deposition reactions), helium (used as an inert gas with special heat-transfer properties) and hydrogen (plays multiple roles in annealing, deposition, epitaxy and plasma cleaning).

As semiconductor technology has evolved and changed, so have the gases used in the manufacturing process. Today, semiconductor manufacturing plants use a wide range of gases, from noble gases such as krypton and neon to reactive species such as nitrogen trifluoride (NF 3 ) and tungsten hexafluoride (WF 6 ).

Growing demand for purity

Since the invention of the first commercial microchip, the world has witnessed an astonishing near-exponential increase in the performance of semiconductor devices. Over the past five years, one of the surest ways to achieve this kind of performance improvement has been through “size scaling”: reducing key dimensions of existing chip architectures in order to squeeze more transistors into a given space. In addition to this, the development of new chip architectures and the use of cutting-edge materials have produced leaps in device performance.

Today, the critical dimensions of cutting-edge semiconductors are now so small that size scaling is no longer a viable way to improve device performance. Instead, semiconductor researchers are looking for solutions in the form of novel materials and 3D chip architectures.

Decades of tireless redesign mean today’s semiconductor devices are far more powerful than the microchips of old — but they’re also more fragile. The advent of 300mm wafer fabrication technology has increased the level of impurity control required for semiconductor manufacturing. Even the slightest contamination in a manufacturing process (especially rare or inert gases) can lead to catastrophic equipment failure – so gas purity is now more important than ever.

For a typical semiconductor fabrication plant, ultra-high-purity gas is already the largest material expense after silicon itself. These costs are only expected to increase as demand for semiconductors soars to new heights. Events in Europe have caused additional disruption to the tense ultra-high pressure natural gas market. Ukraine is one of the world’s largest exporters of high-purity neon signs; Russia’s invasion means supplies of the rare gas are being constrained. This in turn led to shortages and higher prices of other noble gases such as krypton and xenon.