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Voltage sags are an incredibly disruptive power quality issue facing semiconductor manufacturing. They are the power quality disturbance with the highest economic losses for commercial, microgrid and industrial networks. These sudden voltage drops impact equipment operation and lead to losses and downtime. Manufacturers use standards like SEMI F47 to protect their equipment and maintain production.
What Is SEMI F47?
SEMI 47 is an industry standard developed by Semiconductor Equipment and Materials International (SEMI). It establishes minimum voltage sag immunity requirements for semiconductor manufacturing. Manufacturers can use it to define how long and how deep equipment must tolerate voltage drops without malfunctioning or shutting down. A voltage sag immunity baseline helps prevent operational disruptions.
Sag events are modeled on real-world conditions caused by large motor starts, utility faults and switching events. In high-density semiconductor fabs, even the smallest disruptions can affect production runs. Establishing a standard maintains quality for the entire industry.
SEMI F47 has primary and secondary focuses. The primary focus covers critical tools such as:
- Dry and wet etch systems
- Metrology and automated test systems
- Film deposition
- Photolithography equipment
- Chemical mechanical polishing tools
- Ion implant equipment
- Thermal processing tools
The secondary focus applies to key subsystems and components such as:
- Robotics and communication systems
- Power supplies and chillers
- Adjustable speed drives and vacuum pumps
- Radio frequency (RF) generators and alternating current (AC) contactors
Any subsystem powered through the tool's mainframe and impacted by the Emergency Machine Off system is considered in scope. The goal is to guard the entire system, not just the mainframe, against voltage issues.
What Is SEMI F47 Compliance?
SEMI F47 compliance is how well your semiconductor tools meet the guidelines developed by SEMI. While governments do not require them, they are industry-agreed-upon standards. After SEMI F47's development and implementation, the industry saw widespread improvements. When introduced, SEMI F47-compliant wafer manufacturing plants were expected to save $2.6 to $3.4 million annually. At the same time, 71% of semiconductor manufacturers in the United States and Germany said SEMI F47 compliance was now standard for their new equipment.
SEMI F47 combined expert knowledge and testing to create a high-quality standard that protects businesses without driving up equipment costs. Semiconductor equipment that follows SEMI F47 standards is compliant, and manufacturers will look for products that meet these standards. It has become the bare minimum for many operations.
How SEMI F47 Compares to Other Standards
While multiple standards address power quality, SEMI F47 stands out due to its focus and higher standards. Other standards include:
- IEC 61000-4-11 defines general testing methods for voltage dips and shows equipment interruptions. It is the testing foundation for SEMI F47, but does not establish set performance thresholds.
- IEC 610000-4-34 extends IEC 610000-4-11 to other equipment but only establishes test methodology.
- IEEE 1668 is a broad guide for voltage tolerance in critical systems, but it is not semiconductor-specific.
Compared to these, SEMI F47:
- Specifically discusses semiconductor manufacturing tools.
- Sets pass/fail limits based on sag depth and duration.
- Considers survivability and operational continuity. Tools must handle the event without outside intervention.
SEMI F47 compliance is often mandatory in procurement contracts, with noncompliance risking penalties.
Key Requirements of SEMI F47
Receiving SEMI F47 certification involves meeting standards for voltage sag tolerance, equipment testing and documentation. Failing to satisfy these requirements means semiconductor tools do not pass SEMI F47 standards.
Voltage Sag Tolerance Levels
The revised SEMI F47-0706 requires equipment to withstand:
- 50% sag for 0.2 seconds.
- 70% sag for 0.5 seconds.
- 80% sag for 1 second.
Tools may fall short of these levels due to resetting, locking up or triggering alarms. Equipment must meet these levels to avoid lost product and downtime.
Equipment Testing and Certification
Testing for SEMI F47 compliance requires controlled lab environments and voltage sag simulators. Many companies use third-party labs to test their tools, and larger manufacturers might have in-house capabilities. However, semiconductor fabs looking to purchase tools might require these operations to have their results verified by a third party. This practice helps avoid biased results.
Documentation and Reporting
After testing, suppliers provide customers with compliance certificates and detailed test reports. These documents support industry traceability and confirm equipment performs as intended.
Why SEMI F47 Compliance Is Critical for Semiconductor Manufacturers
Semiconductor plants must protect against frequent voltage sags. Even a sag lasting a few cycles can interrupt tools and trigger a reset, which requires operator intervention, diagnostic tests and system recovery efforts. Here are some of the benefits of SEMI F47 compliance for your operation:
1. Enhances Equipment Reliability
Brief dips in AC voltage can cause sensitive semiconductor tools to malfunction, reset or shut down. SEMI F47 compliance confirms that your semiconductor tools can handle expected voltage dips easily. Reliable tools reduce downtime and simplify management.
2. Improves Production Efficiency
Semiconductor fabs need equipment to operate at peak efficiency to meet their production goals. Every second of downtime is a second they are not meeting production metrics. SEMI F47 requirements minimize voltage sag impact, which translates to fewer interruptions. Operations can process more wafers per day and use their assets more efficiently.
3. Protects Product Quality
If voltage sags during critical moments like etching or lithography, it can compromise wafer quality. Since SEMI F47-compliant tools address voltage issues, you protect product quality. Semiconductor fabs see more consistent yields and fewer reworks or scrapped pieces.
4. Increases Customer Base
SEMI F47 has become an industry standard, and many clients require or look for SEMI F47 compliance when choosing vendors. Proving your products' quality expands your customer base and accesses global markets.
5. Promotes Operational Resilience
SEMI F47 goes beyond an obligation — it is a practice investment in protecting manufacturing. Compliant equipment is better equipped to handle power changes, improving your facility's resilience. You will work more easily through utility and regional grid issues. More reliable equipment makes it easier to meet expanding production and automation demands.
How to Achieve SEMI F47 Compliance
Establishing products as SEMI F47 compliant means investing in equipment upgrades and testing. You can retrofit older equipment or design new tools that meet SEMI standards. If you want better-performing semiconductor manufacturing tools, these steps can help you get started:
Assessing Current Equipment
The first step toward SEMI F47 compliance is evaluating your current equipment. Measure voltage sag data using power quality analyzers. You can also partner with third-party labs to test equipment under worst-case scenarios. These assessments identify weak points and make prioritizing upgrades easier.
Upgrading and Retrofitting Equipment
Once you have isolated equipment concerns, it is time to upgrade or retrofit your semiconductor tools. Look at installing uninterruptible power supplies or ride-through capacitors. Many original equipment manufacturers (OEMs) will offer support for upgrading. Invest in new equipment that will pass SEMI F47 standards.
Working with Suppliers and Partners
The semiconductor industry wants everyone along the chain to stay safe. Investing in communal compliance raises the industry's standards and makes clients feel more confident. Talk to component suppliers, OEMs and system integrators to confirm product and supplier certifications, integrate compliant systems and check test reports.
Explore SEMI F47-Compliant Semiconductor Equipment Options
Astrodyne TDI delivers high-reliability power and EMI/RF filter solutions that semiconductor OEMs depend on to meet industry standards like SEMI F47. We engineer our products for critical environments, helping you minimize downtime.
While larger suppliers offer limited, off-the-shelf options, Astrodyne TDI can customize EMI/RF filters and power supplies to your exact specifications. We will collaborate with your team to shorten design cycles, support system integration and scale with your timelines. We bring certified facilities and widespread industry experience to the table. Choose Astrodyne TDI and enjoy unmatched technical support and engineering.