The Role of Nitrogen Gas in Semiconductor Manufacturing

The Role of Nitrogen Gas in Semiconductor Manufacturing

Semiconductor manufacturing relies heavily on high-purity gases like nitrogen gas to create controlled environments. Maintaining the proper oxygen levels is critical in preserving production quality, as any oxygen contamination can result in defects and failures. PureAire’s Oxygen Monitors measure and help regulate oxygen levels in semiconductor manufacturing operations for safety and efficiency throughout production.

Nitrogen is a high-purity gas used throughout semiconductor manufacturing processes. Its inert nature prevents undesired chemical reactions during critical manufacturing stages, ensuring that the integrated circuits and silicon wafers remain intact.

Key roles of nitrogen gas include:

1. Purging and Blanketing: Maintains an oxygen-free environment to prevent oxidation.
2. Cooling: Efficiently cools down semiconductor equipment and materials.
3. As a Carrier Gas: Transports chemical vapors in deposition processes for uniform thin film layers up to 50,000 cubic meters of nitrogen per hour.

Oxygen Contamination in Semiconductor Manufacturing

Semiconductor manufacturers must monitor oxygen levels, as even a trace amount of oxygen can ruin the integrity of the manufactured components. Oxygen contamination can lead to increased device failure rates due to oxidation issues, affecting the reliability and longevity of semiconductor equipment.

Impact on Film Deposition Quality

In processes such as film deposition and spin coating techniques, oxygen can severely impact the quality due to:

• Oxidation: Oxygen reacts with various materials, forming undesirable oxides that compromise the structural integrity of thin films.
• Uniformity: Maintaining uniform thin film layers becomes challenging when oxygen contaminants are present, leading to defects and inconsistencies in semiconductor products.

The Importance of Monitoring Oxygen Levels: PureAire’s 10+ Year Oxygen Sensors

Measuring oxygen levels is crucial in semiconductor fabs to protect product integrity and prioritize personnel safety. Semiconductor manufacturing processes are highly susceptible to oxygen contamination, making accurate and dependable monitoring systems essential. PureAire Oxygen Monitors continuously measure oxygen levels to protect employee safety and ensure product integrity.

Key Features of PureAire’s 10+ Year O2 Sensors:

1. Longevity: Unlike other oxygen sensors, which need frequent replacements, PureAire’s sensors can last over 10 years. PureAire’s long-life oxygen sensors significantly reduce maintenance expenses and production downtime.
2. Accuracy: PureAire sensors accurately measure oxygen levels, ensuring that semiconductor environments stay within the ideal range. If oxygen levels change, the monitor’s built-in visual and audible alarms will be triggered, alerting personnel to evacuate and take corrective action. Accuracy is crucial in measuring oxygen levels to help preserve the integrity of manufacturing processes.
3. Durability: PureAire’s O2 sensors are built for harsh industrial conditions, making them ideal for use in challenging environments. The sensors perform accurately in the demanding settings found in semiconductor fabs.
4. Easy Integration: PureAire O2 sensors integrate seamlessly into existing systems, enhancing operational efficiency without requiring extensive modifications.

Why Choose PureAire O2 Sensors to Monitor Oxygen in Semiconductor Manufacturing?

1. Safety: O2 sensors detect oxygen-deficient environments by continuously measuring oxygen levels and alerting personnel before jeopardizing employee health.
2. Product Integrity: PureAire’s O2 sensors help prevent oxidation and device failures by monitoring oxygen levels and alerting personnel to take corrective action.
3. Efficiency: Long-lasting sensors mean fewer interruptions in production, leading to higher throughput and better product quality control.
4. Cost-effectiveness: Reduced need for sensor replacements translates to significant cost savings over time.

Incorporating PureAire’s 10+ year O2 Sensors into semiconductor manufacturing processes provides long-lasting, accurate oxygen monitoring, safeguarding the product’s quality and ensuring a safe working environment.

Nitrogen is an essential gas used to displace oxygen and prevent oxidation during semiconductor manufacturing, protecting the quality and reliability of the final product.

Semiconductor industry professionals who must constantly monitor oxygen levels will appreciate all the key features of PureAire’s Oxygen Monitors, which will help them achieve long-term safety and efficiency in their facilities. By utilizing PureAire’s Oxygen Monitors, semiconductor manufacturers can mitigate these risks.

FAQs (Frequently Asked Questions)

Is nitrogen used in semiconductors?

Nitrogen gas displaces oxygen from a working environment and prevents oxidation during the semiconductor manufacturing processes, ensuring the quality and reliability of the final product. Displacing or removing oxygen from certain semiconductor processes is necessary to remove contamination from the end products. Even trace amounts of oxygen can lead to production failures.

Is nitrogen used in electronics?

Nitrogen is an inert, oxygen-depleting gas utilized during electronics production. Maintaining proper oxygen levels is essential for ensuring high-quality semiconductor production, as oxygen contamination can lead to increased device failure rates and impact film deposition quality.

What are the various roles of nitrogen gas at different stages of the semiconductor manufacturing process?

Nitrogen gas displaces oxygen, prevents oxidation, and ensures the purity of gases at different stages of semiconductor processes. For example, it purges residual oxygen from channels and pipes, machines, and tools, protecting the production of integrated circuits and silicon wafers. During the deposition stage, nitrogen is used to create thin, contaminant-free film layers. Nitrogen gas ensures that the deposition occurs in a clean, controlled environment, free from impurities that could compromise the quality and performance of the final semiconductor product.

Why is effective oxygen monitoring crucial in semiconductor fabs?

Effective oxygen monitoring is crucial in semiconductor fabs that use nitrogen or other oxygen-depleting gases to remove oxygen from production processes, such as the deposition of uniform film layers. Oxygen displacement, while necessary for semiconductor production, is a safety hazard if gas leaks occur in areas where employees are present.

Why is nitrogen gas used for purging?

Purging with nitrogen removes moisture, chemical contaminants, and any remaining oxygen from piping and tubing, resulting in defect-free, high-quality products.

Can nitrogen be used as a carrier gas?

Nitrogen is a carrier gas that transports chemical vapors in deposition processes for uniform thin film layers up to 50,000 cubic meters of nitrogen per hour. Oxygen contamination poses risks such as increased device failure rates due to oxidation issues and impacts on film deposition quality.

Gas Monitor for Wastewater Facilities and Anaerobic Digesters

 

Anaerobic Digestion Process

Oxygen monitoring is an essential safety and process control measure in facilities that utilize anaerobic digesters. Although the digestion process occurs in an oxygen-free environment, it is important to monitor the surrounding areas to ensure oxygen levels are appropriate for both safety and operational efficiency. The anaerobic digestion process is a multi-stage process which includes:

• Hydrolysis: During hydrolysis, enzymes break down complex organic molecules such as carbohydrates, fats, and proteins into simpler molecules such as sugars, fatty acids, and amino acids.
• Acidogenesis: Acidogenic bacteria further break down the simple molecules produced in hydrolysis into volatile fatty acids, alcohols, hydrogen, and carbon dioxide.
• Acetogenesis: During this stage, products arising from fermentation, namely volatile fatty acids and alcohols, convert into hydrogen, carbon dioxide, and acetic acid.
• Methanogenesis: Methanogenic archaea convert acetic acid, hydrogen, and carbon dioxide into methane and water. This stage is crucial for biomethane production.

Surrounding Areas for Safety

Oxygen monitoring safeguards workers and maintains system safety in areas where gas displacement or oxygen contamination may occur.

• Confined Spaces:
  Best practices include monitoring O2 levels with oxygen detectors, such as PureAire O2 Deficiency Monitors, to ensure safe working conditions, entry points, maintenance areas, and surrounding chambers. Oxygen-deficient environments, caused by displacement from methane or carbon dioxide, pose a risk of asphyxiation.
• Headspace Monitoring:
  Fixed oxygen monitors continuously measure oxygen levels in digesters’ headspaces to confirm they are minimal. This reduces the risk of explosive conditions when methane is present.
• Gas Storage and Handling:
  Oxygen analyzers, like PureAire Oxygen Monitors, detect the presence of oxygen, which may cause contamination in biogas storage tanks and pipelines. This contamination compromises gas purity and increases the risk of fire or explosion.

Maintenance and Purge Systems

• During Maintenance:
  Digesters produce a variety of harmful gases including but not limited to methane, carbon dioxide, and hydrogen sulfide.  Personnel need to be vigilant when digesters are emptied or cleaned; using oxygen monitors ensures the internal atmosphere is free from dangerous gases and safe for entry.
• Ventilation Checks:
  Oxygen levels are monitored during the purging process to confirm adequate ventilation.

Biogas Systems

• Purity Control:
  Oxygen analyzers verify that oxygen levels remain within safe and operational limits in biogas pipelines and upgrading systems. This ensures compliance with safety standards and maximizes energy production efficiency.

Emergency Preparedness

Oxygen monitoring systems, such as PureAire O2 Deficiency Monitors, can detect accidental oxygen ingress into the anaerobic digestion system, alerting operators to potential risks to process stability or safety.

PureAire Oxygen Monitors

PureAire O2 Deficiency Monitors continuously monitor critical areas around anaerobic digesters, ensuring safety and compliance in even the most demanding environments and, in the event of a gas leak and a drop in oxygen to an OSHA action level, will set off an alarm, complete with horns and flashing lights, alerting employees to evacuate the affected area.

Our Monitors offer thorough air monitoring, with no time-consuming maintenance or calibration required. An easy-to-read screen displays current oxygen levels for at-a-glance reading by employees.

PureAire’s durable, non-depleting, long-life zirconium oxide sensor will last for more than 10 years in a normal environment without needing to be replaced.

While oxygen monitoring is not required inside the core anaerobic digesters, it is vital in ensuring safety and operational integrity in surrounding areas and systems. Oxygen monitors help protect workers, maintain biogas quality, and mitigate risks, making them an essential component of anaerobic digestion facilities.

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Air Delivery of Super-Cooled COVID-19 Vaccines

There are several potential COVID-19 vaccines that may soon be available for widespread distribution. In particular, the United Kingdom has recently approved Pfizer’s vaccine, and the U.S. Food and Drug Administration is considering extending Emergency Use Authorization to the Pfizer and Moderna vaccines.

That is certainly promising news, but storage, transportation, and delivery of these potentially game-changing vaccines will be quite challenging, with the CEO of the International Air Transport Association describing the distribution of COVID-19 vaccines as “the largest and most complex logistical exercise ever” undertaken.

It is not just the huge numbers (literally, in the billions of doses) and vast geographic scope (worldwide, requiring delivery to every country on the planet) that make the COVID-19 vaccine distribution task so daunting, but both the Pfizer and Moderna vaccines must be stored and transported in strict climate-controlled environments (reportedly, at some -70 degrees Celsius for Pfizer, and -20 degrees Celsius for Moderna) as integral parts of the vaccines’ “cold chains.”

COVID-19 Vaccine Cold Chain

The U.S. Centers for Disease Control (the “CDC”) describes a cold chain as a temperature-controlled supply chain that includes all vaccine-related equipment and procedures. The vaccine cold chain begins with a cold storage unit at the vaccine manufacturing plant, extends to the transport and delivery of the vaccine (including proper storage at the provider facility), and ends with the administration of the vaccine to the patient. A breakdown in protocols anywhere along the cold chain could reduce the effectiveness of, or even destroy, a vaccine.

Given the extreme cold temperatures required within their cold chains by the Pfizer and Moderna vaccines (and, perhaps, other COVID-19 vaccines that may now be under development by other firms), various companies within the vaccine delivery network (including temperature-controlled container manufacturers, logistics specialists, storage facility operators, commercial airlines, and dry ice producers) have been hard at work for months to meet the challenges associated with safely storing and transporting billions of vaccine doses once, as now appears to be at hand, they finally become available for international distribution.

Creating Super-Cold Environments

Dry ice, which is the common name for solid (i.e., frozen) carbon dioxide, is often used in cold chains to maintain the very cold temperatures required to keep certain vaccines viable. At a temperature of approximately -78.5 degrees Celsius (equating to -109.3 degrees Fahrenheit), dry ice is significantly colder than frozen water (that is, conventional ice), making it ideal for transport and storage of those vaccines which require an extremely cold temperature environment.

Safety precautions are critical when shippers use dry ice in the transportation and storage of vaccines. Unlike conventional ice, dry ice does not melt into a liquid. Instead, dry ice “sublimates” (changes from a solid to a gas state), turning into carbon dioxide gas. In poorly ventilated, confined spaces, such as storage rooms, railway cars, trucks, and cargo holds in airplanes, carbon dioxide can build up, creating a potentially serious health risk to transportation workers, including ground and flight crews.

Certain vaccine manufacturers may elect to ship their vaccines in multi-layered, storage canisters chilled with liquid nitrogen, rather than dry ice. We note that the potential health risks associated with nitrogen leaks are similar to those that may be caused by dry ice sublimation.

Oxygen Deficiency Risks Associated with Super-Cooled Environments

Carbon dioxide (as is nitrogen) is an oxygen-depleting gas that is both odorless and colorless. As such, absent appropriate monitoring, personnel working with the transportation of COVID-19 and other vaccines kept frozen with dry ice or liquid nitrogen likely would be unable to detect if dry ice were to sublimate (causing CO2 levels to rise), or if there were a nitrogen gas leak, and an associated decrease in oxygen.

According to the Occupational Safety and Health Administration (OSHA), an environment in which oxygen levels fall below 19.5 percent is considered an oxygen-deficient atmosphere and should be treated as immediately dangerous to health or life. When there is not enough oxygen in the air, persons working in the affected area may become disoriented, lose consciousness, or even suffocate due to the lack of sufficient oxygen.

FAA Guidance/Increased Air Shipment Capacity/Risk Mitigation

On May 22, 2009, the U.S. Federal Aviation Administration (the “FAA”) issued Advisory Circular No. 91-76A to specifically address the risks associated with the sublimation of dry ice aboard aircraft and, historically, the FAA has permitted even widebody aircraft to carry only relatively small amounts (typically not exceeding 1-1.5 tons per flight) of dry ice in refrigerated and insulated containers.

However, The Wall Street Journal (the “WSJ”) reported on November 29, 2020, that, in order to maintain the ultra-cold temperatures required by Pfizer’s COVID-19 vaccine, United Airlines has recently sought, and obtained, FAA approval to carry up to 15, 000 pounds (7.5 tons) of dry ice per flight. In a December 2, 2020 interview with CNN, Josh Earnest, Chief Communications Officer with United Airlines, noted that the FAA approval will allow United to ship as many as 1.1 million doses of COVID-19 vaccines on each flight of its commercial 777 airplanes.

Notwithstanding the FAA’s relaxation of dry ice weight limits to permit United Airlines to help bring the COVID-19 pandemic under control, it remains focused on risks associated with air shipments of dry ice. In its November 29, 2020 reporting, the WSJ noted that “regulators restrict the amount of dry ice that can be carried on passenger jets because they typically lack the equipment to monitor and mitigate any leaked carbon dioxide.”

Fortunately, by utilizing a top-quality oxygen-deficiency monitor, vaccine storage and transportation personnel, including flight crews, can safely track levels of oxygen and detect (and react to) potentially dangerous low oxygen levels, whether caused by dry ice sublimation or a nitrogen gas leak.

PureAire Monitoring Systems, Inc.

PureAire Monitoring Systems’ Oxygen Deficiency Monitor offers thorough air monitoring, with no time-consuming maintenance or calibration required. A screen displays current oxygen levels, for at-a-glance reading by crew members, who derive peace of mind from the Monitor’s presence and reliable performance.

Built with zirconium oxide sensor cells, to ensure longevity, the Monitor can last, trouble-free for 10 years in normal working conditions.

Our Oxygen Deficiency Monitor does not rely on the partial pressure of oxygen to operate, meaning that the Monitor is not affected by the changing pressure inside an aircraft due to altitude changes. In the event that dry ice begins to sublimate (causing carbon dioxide levels to rise), or if there is a nitrogen leak, and oxygen decreases to unsafe levels, PureAire’s Monitor will set off an alarm, complete with horns and flashing lights, alerting flight personnel to take corrective action.

For over 20 years, PureAire Monitoring Systems has been an industry leader in manufacturing long-lasting, accurate, and reliable Oxygen Deficiency Monitors. We have dedicated ourselves to ensuring the safety and satisfaction of our clients, many of which have very sophisticated operating requirements. We are proud to note that NASA’s SOFIA-Stratospheric Observatory for Infrared Astronomy--a Boeing 747SP aircraft modified to carry a 2.7 meter (106 inch) reflecting telescope--carries onboard a PureAire Oxygen Deficiency Monitor.