Introduction
Yield optimization is one of the most critical yet challenging tasks to ensure to achieve goals in manufacturing, particularly when it comes to semiconductor fabrication. While recent advances in equipment effectiveness have led directly to sustainable yield improvements, many facilities still struggle to optimize processes to achieve a competitive advantage.
For fabs, where the quality of gas used in a process is intrinsically tied to yield, the gas purifier is an integral part of the equipment. If gases introduce a single contaminate during production, or trace contaminates remain in process piping or bleed through face seal fittings, there can be wide-sweeping ramifications for production quality and system integrity. In ultra high purity applications which require purity down to parts per billion (PPB), that means gas purity and yield must go hand in hand.
As such, fabs and high purity manufacturers should consider the purity of their gas from end to end, taking into account the essential elements required to optimize output. In this eBook, we will explore the core considerations for upholding purity and maximizing yield throughout production.
3.3 Percent
of silicon wafers are scrapped during production each day.
Removing Contaminates at the Right Level
At its core, a purifier’s role is to remove trace impurities from process gases to ensure contaminates do not impact production. Doing so requires gas purification technology that can remove impurities down to the parts per million (PPM), parts per billion (PPB), or parts per trillion (PPT) level. If a single contaminate remains, it can prove disastrous for output.
Explore the scale of one part per billion purification in the video to the right.
Handling the Purification of Needed Gas Volumes
Different facilities require different volumes of pure gas to power applications. Ensuring pure yields therefore requires gas purification technology optimized to operate at various flow rates and configurations, with purifier options breaking down into three categories: point-of-use, micro-bulk, and bulk purifiers.
Point-of-Use: Low Flow Rate
0.1 to 100 standard liters per minute
Resides at the point of use for a single application (e.g. process tool).
Micro-Bulk: Moderate Flow Rate
100 to 500 standard liters per minute
Resides in either the laboratory or equipment chase area to serve multiple tools.
Bulk Purifiers: High Flow Rate
30 to >5000 normal cubic meters per hour
Resides outside the fab or factory. Can be configured in a protected, but not thermally controlled enclosure.
Selecting the Right Purifier Type
Once a manufacturer or fab has identified the volume of gas required, the next essential element to consider is the type of purifier. When selecting a gas purifier, there are three main types: getter, catalyst, and adsorber. Each purifier can be used in isolation or in a series with others based on gas stream, level of impurities, and outlet impurity required. For instance, getter purifiers operate at the ultra high purity level, making them the purifier of choice for UHP applications such as semiconductor fabrication.
Did you know?
Catalyst technologies are commonly used in U.S. automobiles in order to convert gases from combustion processes into more environmentally friendly gases.
Minimizing Potential Leakage
Purifiers rarely include on-board continuous purity analysis capabilities, meaning it is challenging to identify failures until production compromise occurs. To ensure pure yields, it is critical that components are fitted in such a way that they prevent leakage. While welding every component and plumbing section together would provide the highest level of assurance against contaminates, it would also drastically increase maintenance costs when replacing components or spent purifier vessels. To maintain greater flexibility, high purity face seal fittings should be utilized when removing or servicing purifiers.
A face seal fittings’ toroidal seal ring is machine and electropolished to a surface roughness of .25 micrometers. For comparison, a human hair is ~90 micrometers, or 360 times the width of a .25 micrometer scratch.
Upholding Safety in the Process
Gas purification oftentimes relies on utilizing highly reactive media which can react exothermically when exposed to particular contaminates—in some cases causing elevated temperatures capable of melting stainless steel. For instance, if percentage-level amounts of oxygen pass through activated nickel, exothermic reactions could reach over 1000° C. Such results can be localized to the analyzer, tool, or lab, but in cases where they were coupled with an on-site air separation plant, these events can shut down an entire manufacturing facility for months—not to mention risk operator health and safety. As such, an essential element of gas purity is facilities’ ability to reliably and precisely deliver process gases without introducing trace contaminants.
Gas types are often categorized into three buckets of varying purity—industrial grade, high purity (HP) and ultra high purity (UHP)—with “N” used to signify the number of 9s present.
Achieving Pure Yields with ARM Purification
Pure gases ensure pure yields. They are necessary to maximize the volume and quality of your output for significant cost and performance gains. That is why ARM Purification offers the technology, services, and support required to uphold your most stringent gas purity demands. With three lines of purifiers capable of operating at a variety of flow rates, temperatures, and pressure levels—for a wide range of gas types—we can readily support diverse high and ultra high purity requirements.
We combine this expertise with our parent company Applied Energy Systems (AES)’ proven history delivering SEMI S2-certified gas delivery systems to Tier 1 companies around the world. Together we ensure quality throughout your system—from the purifier that removes contaminates to the process piping that brings the gas to its point of use—is optimized so you can be confident in the quality of your output.
ARM Purification Purifies
Over 65 Gas Types
spanning inert, corrosive, fluorinated, and hydride gas categories.
Point-of-Use Purifiers
Low flow rate, highly precise purifiers serving single applications.
Micro-Bulk Purifiers
Moderate flow rate purification systems serving multiple tools and applications.
Bulk Purifiers
Large flow rate, permanently installed purifiers delivering gases facility-wide.
Achieving Pure Yields with ARM Purification
Along with our core purifiers, ARM Purification offers an arsenal of value-added services to ensure gas purity never impacts production yield.
Purifier Regeneration
ARM Purification restores spent purifier vessels to full-life operation through heated regeneration.
Gas Analysis
We offer portable analytical services to test gas quality for trace impurities down to the PPT level.
Asset Evaluation
When considering an asset replacement, we assess system and component health and provide recommendations for replacement or servicing.
Technology Refresh
As systems age, ARM Purification offers asset control and instrumentation updates to extend the useful lifecycle of purifiers.
Asset Disposal
At end of life, ARM Purification will ensure proper disposal, neutralizing remaining media and disposing of materials.
Purifier Training
ARM Purification offers flexible on-site and remote training to demonstrate proper purifier operation and maintenance.
Ready to maximize your production volumes and ensure the highest quality output?
Visit armpurification.com to speak to an ARM Purification expert about the role pure gas plays in your application.
