The electronics we rely on, from smart phones to microwaves to thermostats to computer systems in newer cars, wouldn’t exist if not for the silicon-based semiconductor components that make them work.
And those components couldn’t be made if not for the highly complex gas panels, regulators, valves and tubing systems integral to the manufacturing process.
Silane (SiH4) and related gaseous silicon compounds are the building blocks for a wide variety of diodes, transistors and other components found in such products as microprocessors and photovoltaic cells. The systems that transport silanes from safe storage to a chemical vapor deposition (CVD) area must be carefully fabricated, operated and maintained.
Silane delivery system fabrication
Silane’s molecular structure is the same as methane (CH4), a volatile organic compound that burns when sparked. Unlike methane, silane doesn’t need a spark. Once exposed to oxygen, it often combusts. Fabricating, installing, operating and maintaining these systems must be done right, no exceptions.
That’s why the integrity of silane gas delivery systems must be ensured, and it starts during fabrication. These systems are usually fabricated in cleanrooms and typically feature high-quality corrosion-resistant 316L stainless steel.
It’s also often required that delivery tubing be double contained depending on the concentration of the silane (and other gases in specific settings) it transmits. It works like this: The carrier line is fabricated and quality tested to precise specs. Then, a coaxial containment line the next size up from the carrier line is enveloped around the carrier line. Spider inserts ensure no part of the containment line and carrier line touch. The containment line is not finished to the same level of purity as the carrier line, but it plays a crucial role in the protection of nearby equipment and personnel.
Silane combusts when it oxidizes. The result of this intense reaction is energy (which can damage equipment) plus silicon dioxide (SiO2) in the form of fine silica dust. This dust contaminates the tubing it contacts. The damage and contamination caused by silane events result in costly downtime and emergency remediation.
Double containment is crucial to reducing the overall impact of a silane event but will not eliminate the potential improper operation and maintenance of systems due to human error. Get more information on silane safety and accident prevention here.
Silane system operation and maintenance
The importance of proper operation and maintenance of silane delivery systems cannot be overstated.
Process piping and tubing components don’t last forever. Frequent component changeouts are inherent to semiconductor manufacturing. When it happens, systems must be properly purged of the gas.
Proper purging ensures that routine swapping of source gas and system components is done safely. Semiconductor and microelectronic manufacturers should have Standard Operation Procedures in place to guarantee safety when parts are replaced or any time lines are opened to atmosphere for maintenance.
In addition, improper purging can result in the unwanted deposit of purging compounds that will corrupt the silane and the tubing it travels through. Immediate and long-term problems ensue.
In the short term, corrupted silane lines can lead to defective semiconductor components. There’s no room for error here. You’re lucky if the worst that happens is that the problem is caught and you waste costly materials. If the problem isn’t noticed, the defective parts may make their way into manufactured products that won’t work.
In the long term, corrupted silane lines are at risk of corrosion. If the corrosion isn’t caught and rectified right away, lines may fail, upping the risk of a silane event. High Purity Systems maintains ongoing relationships with customers to provide counseling and guidance in the proper maintenance and safe replacement or modification of silane gas delivery systems.
High Purity Systems offers silane system support
High Purity Systems is far more than a fabricator of silane gas delivery systems. We play a close supporting role for our customers, offering guidance for the safe maintenance of existing systems and providing key design assist services when it’s time to expand or renovate.
As your silane gas delivery system partner, we cultivate a broad network of suppliers to secure the raw materials we need quickly. And in the unfortunate event of a failure, our nimble team of skilled cleanroom welders stands ready to take on emergency replacement projects.
Find out more about the advantages of partnering with High Purity Systems and its skilled team of cleanroom welders by reading our guide What to Look For in a Cleanroom Welding Contractor. And if we can help answer any other questions you have as you consider a critical silane system project, let’s talk it over.