Ensuring Uninterrupted Power for Semiconductor Manufacturing Facilities

Semiconductor manufacturing is among the most electrically demanding industrial processes in the world. As device geometries continue to shrink and process complexity increases, even millisecond-scale power disturbances can interrupt critical fabrication steps, compromise yield, and result in substantial production losses. Consequently, modern fabs require more than backup power—they require continuous, conditioned, and disturbance-free power that preserves process integrity under all operating conditions. 

Conventional power architectures based on static UPS systems, battery banks, harmonic filters, and standby diesel generators often achieve continuity through multiple independent subsystems, introducing greater complexity in protection coordination, maintenance, lifecycle management, and facility infrastructure. 

This whitepaper examines the evolving power quality requirements of semiconductor manufacturing, reviews the industry standards governing electrical performance, and analyses the behaviour of semiconductor tools under real-world power disturbances. It further explains how the mtu Kinetic PowerPack combines kinetic energy storage, synchronous machine, and integrated power conditioning into a single electro-mechanical platform capable of delivering stable, sinusoidal power while simplifying electrical system design, enhancing operational reliability, and supporting the long-term resilience of semiconductor fabrication facilities. 

Advanced semiconductor fabs run processes at nanometer geometries, with extreme demands on repeatability and stability. The electrical environment is now as critical as cleanroom classification or process chemistry. Micro-cuts lasting just a few milliseconds [2] can stop wafer-handling robots mid-travel, break a vacuum, and force scrap of high-value wafers. 

Semiconductor tools combine precision drives, radio frequency power systems, lasers, vacuum pumps, and metrology subsystems. Their internal power electronics react almost instantly to deviations in voltage, frequency, or waveform purity. They are designed to work within tight bands of clean power, not to operate under unconditioned power [3]. 

In this environment, “power availability” alone is not enough. Fabs need continuous, conditioned, sinusoidal power with: 

• No micro-cuts during any grid event 
• Voltage held within a narrow band 
• Minimal harmonic distortion 
• Short-circuit strength [4] 

The mtu Kinetic PowerPack has been engineered to address these requirements by delivering uninterrupted, conditioned, alternator-generated sinusoidal power while minimizing disturbance propagation. 

(In a modern fab, even a minor power disturbance can propagate through critical process steps, resulting in yield loss, production downtime, and significant financial impact.) 

Power disturbances can originate from the utility grid or from within the fab itself. High-inrush loads, capacitor switching, and internal faults all propagate across shared buses. When such events reach critical tools, the result is often an immediate halt in production, followed by lengthy recovery and requalification [8]. With wafer values and tool hourly costs escalating, every event translates into a direct hit on yield and on-time delivery [10]. 

Static UPS systems generate output through high-frequency inverter stages. While proven in many industries, inverter-based power can introduce switching harmonics and place limits on fault-current capability and inrush performance [6]. For semiconductor tools, this can create a subtle but important mismatch between what the power system delivers and what the tools expect. 

The mtu Kinetic PowerPack uses a synchronous machine and mechanical kinetic energy accumulator to produce a pure sinusoidal waveform at the alternator terminals. Harmonics from upstream or downstream are significantly reduced by the combination of high-impedance choke and low-impedance synchronous machine [11]. This creates a naturally “stiff” electrical environment, well suited to the precision and speed demanded by semiconductor equipment. 

Semiconductor fabrication is a multi-stage, highly controlled manufacturing sequence in which integrated circuits are built layer by layer on a silicon wafer. The process involves repeated cycles of material formation, pattern transfer, modification, and removal, often performed dozens of times to achieve the final device structure. 

Each step is tightly linked to the next. Any deviation or interruption at one stage can propagate through subsequent steps, affecting device performance and overall yield. 

A single process tool in a fab may include servo drives, RF generators, vacuum systems, lasers, and temperature-controlled subsystems. These loads are not only sensitive to disturbances, but they also generate disturbances themselves. High-frequency switching devices, rectifiers, and VFDs draw nonlinear currents, leading to harmonic distortion and voltage flicker on shared buses [6]. 

Semiconductor tools typically exhibit: 

• High inrush current during pump starts, stage accelerations, and chamber ignition 
• Sensitivity to even brief voltage sags or interruptions [1] 
• Intolerance to waveform distortion affecting precision analog and RF systems [5] 

This dual characteristic, being highly sensitive to disturbances while simultaneously generating electrical disturbances, demands a power system capable of both conditioning incoming power and isolating tool-generated disturbances [7]. 

Different process modules impose different electrical requirements: 

• Lithography stages depend on smooth torque from drives and stable voltage for lasers and optics [9]. 
• Etch tool requires stable RF matching; voltage dips can instantly destabilize plasma [3]. 
• CMP tools rely on consistent motor torque for planarization uniformity. 
• Metrology tools are sensitive to noise and waveform distortion that can corrupt measurements [5]. 

Many fabs therefore adopt internal standards tighter than SEMI F47 or typical industrial guidelines, effectively creating “fab grade” power specifications [1] [9]. 

The mtu Kinetic PowerPack naturally aligns with such requirements because its synchronous machine and choke arrangement maintain waveform quality, voltage stability, and harmonic performance without the need for separate banks of filters or voltage stabilizer [12]. 

On a shared distribution bus, the startup of one high-inrush tool can disturb neighboring tools. Static UPS systems may reach electronic limits or bypass mode when exposed to repeated large inrush or fault currents [6]. 

mtu Kinetic PowerPack, by contrast, offers strong mechanical stiffness. The synchronous machine delivers short-term peak current capability while the choke limits fault-current contribution to a predictable multiple of rated current i.e. 2.5 to 3 times the rated current of synchronous machine [11]. This balance allows selective tripping of faults while maintaining acceptable voltage on the critical side. 

The semiconductor industry uses SEMI standards to align tool design, fab infrastructure, and expected power quality. Two documents are especially relevant: 

• SEMI F47 defines minimum voltage sag immunity for semiconductor tools [1]. 
• SEMI E6 addresses facility power quality for semiconductor manufacturing equipment [2]. 

SEMI F47 sets the expectation that tools should remain operational through defined sag depths for specified durations. However, many fabs treat these as minimums and aim for conditions where sags are effectively not seen at the tool terminals at all [7]. 

The semiconductor industry uses SEMI standards to align not only tool behavior but also facility infrastructure and power delivery conditions. SEMI E6 provides guidance on how the electrical distribution system within a fab should be designed to deliver stable and high-quality power. SEMI E6 addresses power quality from a facility perspective, focusing on minimizing disturbances before they reach sensitive semiconductor tools. 

SEMI E6 emphasizes that many power quality disturbances originate within the fab itself, including high inrush loads, switching events, and internal faults. These disturbances can propagate across shared electrical systems if not properly managed. 

As a result, semiconductor facilities are designed not only to comply with external standards but also to maintain a controlled electrical environment where disturbances are minimized and isolated. 

Together, SEMI F47 and SEMI E6 establish a complementary framework: 

• SEMI F47 defines the minimum disturbance tolerance of equipment  
• SEMI E6 defines the responsibility of the facility to deliver stable power  

In practice, leading fabs operate beyond both, aiming to ensure that voltage disturbances and interruptions are effectively not seen at the tool terminals. 

IEC standards such as IEC 61000-4-11 and IEC 61000-4-34 define test methods for voltage dips and short interruptions for equipment, including large industrial loads [3]. IEC standards on electromagnetic compatibility frame acceptable disturbance levels and emission limits. 

IEEE standards complement this picture: 

• IEEE 519 sets harmonic limits for power systems, important for nonlinear fab loads [6]. 
• IEEE 1159 defines terminology and techniques for monitoring power quality events [5]. 

Semiconductor fabs must operate within this combined SEMI–IEC–IEEE framework, ensuring both compliance and long-term robustness of tool performance [8]. 

The steady-state output voltage regulation of a mtu Kinetic PowerPack unit is ± 1%, both in conditioning mode and in independent mode.  

This is especially noteworthy in conditioning mode, as this ± 1% regulation is achieved while the utility voltage can vary by ± 10%. Indeed, the output voltage is “isolated” from the utility voltage by the choke; it is directly controlled by the synchronous machine and a digital voltage controller.  

The critical load is thus supplied by a clean, perfectly controlled source, isolated from all the disturbances (voltage sags, unbalances and harmonics) that can be present on the utility voltage. 

In conditioning mode, the mains supply the active power to the critical load, while the alternator operates as a synchronous condenser and supplies the reactive power.  

Upon a mains failure, the mtu Kinetic PowerPack disconnects from the mains and becomes the only source of power. As the alternator was already providing the reactive power, it is only subject to a mainly resistive load step, with a limited impact on the output voltage.  

Under such event, the output voltage remains within a window of ±5% of the nominal voltage. 

The fault current contribution of mtu Kinetic PowerPack unit to a short circuit on the utility side is limited by the impedance of the choke, typically to three times the rated current of the unit. This limited fault current contribution, combined with the low impedance of the synchronous generator, prevents a significant voltage drop on the critical load side.  

In addition, specially designed tapped chokes will compensate the voltage drop at the output of the synchronous generator, further improving the voltage regulation on the load side.  

The voltage drop in case of upstream short-circuit is typically 10% and never exceeds 20%, even in the worst conditions. Besides this, the fault detection scheme and the disconnection from the utility are extremely fast, allowing a quick recovery within the ±5% window, typically in less than 100ms. 

The case of a short circuit at the critical load is considered here for the sake of completeness, since the output voltage sag mainly depends on:  

• the total fault impedance, itself depending on the fault location, 
• the total clearing time of the breaker that will isolate the faulty portion of the circuit.  

Compatibility with the SEMI F47 requirements for such event depends on the application and the site configuration. Nevertheless, the low impedance of the synchronous generator allows a high current inrush, with limited voltage drop compared to gen-set and static UPS solutions.  

A formal Short Circuit Coordination Study must be performed on the total site installation. 

mtu Kinetic PowerPack supports compliance in several ways: 

• Synchronous machine (alternator) - generated sinusoidal output supports low harmonic distortion at the point of common coupling (PCC) [11]. 
• Voltage is regulated tightly, even during upstream disturbances, helping keep effective sag levels at tools above SEMI F47 thresholds [1]. 
• The choke and synchronous machine (alternator) combination limit fault currents while maintaining voltage stiffness, simplifying protection coordination [11]. 

Rather than relying on layers of static UPS units, filters, capacitor banks, and voltage stabilizers, the mtu Kinetic PowerPack delivers power quality aligned to these guidelines [12]. 

For fabs, uninterrupted power is essential, but uninterrupted bad power is still a problem. Voltage fluctuations, micro-cuts, harmonic distortion, and poor power factors all degrade tool performance and shorten equipment life [5]. 

A typical conventional architecture might include: 

• Static UPS systems with rectifier–inverter stages 
• Large battery banks 
• Capacitor banks for power factor improvement 
• Harmonic filters 
• Voltage stabilizers or sag compensators 
• Diesel generators 

Each device adds space, complexity, and maintenance requirements. mtu Kinetic PowerPack consolidates key functions—uninterrupted supply, sag immunity, power factor correction, and harmonic mitigation—into a single system [12]. 

Static UPS systems with large battery rooms bring significant HVAC requirements. Batteries and high-power electronics need controlled temperatures and often dedicated cooling. This HVAC load runs 24/7, adding to operating expenditure and to the energy intensity of the fab’s power infrastructure [10]. 

mtu Kinetic PowerPack avoids these large battery rooms and associated cooling systems. The electro-mechanical components are robust over a wide temperature range and do not require air-conditioning in the same way batteries do. The reduction in HVAC capacity directly translates into lower energy bills and freed-up space that can be used for production or future expansions [12]. 

The resulting reduction in HVAC infrastructure and floor space allows greater flexibility for future production expansion. 

Semiconductor sites are planned for long-term capacity growth. When power infrastructure is fragmented across many devices, expansion planning becomes more complex. There are more systems to maintain, more spare parts to stock, and greater coordination required for any upgrade [8]. 

mtu Kinetic PowerPack reduces the equipment count by eliminating the need for separate static UPS, batteries for energy storage, capacitor banks, voltage stabilizers, and harmonic filters at the protected bus. This reduction simplifies maintenance strategies and improves overall system reliability for the facility [12]. 

Battery-based energy storage is a core element of conventional static UPS architectures. While effective for short-duration backup, batteries introduce lifecycle, operational, and safety challenges that are particularly relevant in semiconductor fabrication environments. 

Battery performance gradually degrades over time due to ageing, temperature exposure, and operating conditions. This results in progressive derating of available capacity and reduced backup reliability. To maintain performance, batteries typically require replacement every 3 to 5 years, leading to recurring capital expenditure and planned maintenance interventions. 

In addition, battery systems require continuous monitoring, periodic testing, and controlled environmental conditions. Dedicated HVAC systems are often necessary to maintain temperature within acceptable limits, adding to operational complexity and energy consumption. 

From a safety perspective, large-scale battery installations introduce fire and thermal runaway risks. Standards such as NFPA 855 define requirements for installation, ventilation, fire protection, and system segregation. Compliance with these requirements increases space utilization and infrastructure cost within the facility. 

In semiconductor fabs, where reliability, space efficiency, and operational stability are critical, these factors collectively add complexity to power system design. 

The mtu Kinetic PowerPack avoids these constraints by eliminating battery-based storage and using a kinetic energy accumulator for providing power backup, reducing maintenance, HVAC dependency, and safety-related infrastructure requirements. 

The mtu Kinetic PowerPack is built around a common rotating main shaft. Key elements on this shaft include a synchronous machine, kinetic energy accumulator, and an electromagnetic clutch connecting the diesel engine. A high-impedance choke connects to the electrical path to the utility side [12]. 

During normal operation, the synchronous machine works as a synchronous condenser / motor, drawing power from the grid and conditioning it for the critical load.  The kinetic energy accumulator is maintained at its rated speed. During a grid failure, the same synchronous machine transitions to alternator mode, first using stored kinetic energy and then engine power. 

The synchronous machine performs two roles: 

• As a synchronous condenser/motor, it helps eliminate harmonic distortion and improves the voltage profile and power factor while driving the shaft during utility availability. 
• As an alternator, it delivers a clean, sinusoidal output to the load during grid interruptions, drawing initial energy from the kinetic energy accumulator and then from the diesel engine. 

The kinetic energy accumulator is a rotating mass, mounted on main shaft via roller bearings, running close to 3000 rpm. It stores kinetic energy while the grid is present. When the mains fail, it instantly releases this energy to the main shaft, ensuring uninterrupted power at the alternator terminals while the engine starts and takes over the load. 

The charging of the accumulator is efficient. Once it reaches rated speed, it only compensates for small losses. 

The diesel engine will be at standstill condition during conditioning mode, with the electromagnetic clutch disengaged. When a power failure is detected, a start command is given from Control Panel to start the diesel engine. The electromagnetic clutch will start engaging with diesel engine after some time and helps engine to accelerate faster, to reach rated speed. Once at 1500 rpm, the engine takes over the mechanical load, and the accumulator begins recharging to its rated speed. 

In conditioning mode, utility supply is available, the diesel engine is stopped, and the clutch is open. The synchronous machine operates as a synchronous condenser / motor, keeping the kinetic energy accumulator at its rated speed and conditioning the incoming power.  

The result is a clean, sinusoidal voltage profile at the critical load bus, with an improved power factor and reduced harmonic distortion—without separate capacitor banks or harmonic filters. 

When a utility failure occurs, input breaker opens to isolate the grid. Output breaker remain closed. The kinetic energy accumulator immediately discharges through the synchronous machine, which now acts as an alternator. Power at the critical bus remains continuous; there is no interruption or transfer delay. 

At the same time, the diesel engine receives a start signal, accelerates to rated speed, and engages via the electromagnetic clutch.  

Once the engine carries the entire load, the system operates independently from the grid. The accumulator returns to its rated speed, restoring kinetic energy reserve.  

The system will not reconnect the grid until the accumulator is ready for the next grid event and utility conditions meet synchronization criteria. When synchronization is confirmed, the input breaker closes, the clutch disengages, and the system returns to conditioning mode, with the engine cooling down and then stopping automatically. 

In the mtu Kinetic PowerPack, the Kinetic energy accumulator and electromagnetic clutch work as redundant starting system. The system features redundant engine start capabilities, incorporating independent starting systems for the diesel engine to ensure reliability and prevent downtime. 

If the engine does not start via the battery-driven starter motor, the clutch can close and transmit torque from the rotating main shaft to the engine flywheel to reach engine ramp-up speed. This Kinstart functionality is a distinctive reliability feature for mission-critical facilities. This redundant starting capability provides an additional layer of operational resilience for mission-critical facilities. 

The switchover from grid power to mtu Kinetic PowerPack and back to grid is seamless. The synchronous machine changes its operating mode from synchronous condenser to alternator and vice versa without any interruption at the output. This results in continuous waveforms without missing cycles, both during loss of grid and reconnection. 

Because the kinetic energy accumulator rotates continuously, it is sometimes assumed that it must consume power, reducing overall efficiency. In reality, total system efficiency from input to output including, choke losses, alternator losses, and accumulator losses is much better compared to static UPS architecture. 

The diesel engine in the mtu Kinetic PowerPack can operate on 100% HVO (Hydrotreated Vegetable Oil), enabling up to around 90% reduction in lifecycle CO₂ emissions compared to conventional diesel [18]. This allows fabs to combine high electrical resilience with their decarbonization roadmaps. 

The mtu Kinetic PowerPack is both modular and scalable, allowing it to be customized to fit various layouts and requirements. It features customizable containers and enclosures, options for sound attenuation, ventilation systems, as well as complete building installation. Being operational at low and medium voltage, the system supports both single and dual output configurations: single output for continuous power and dual output for separating critical and non-critical loads. This flexibility not only saves space but also optimizes power distribution and electrical discrimination of the installation. 

The mtu Kinetic PowerPack offers competitive total cost of ownership (TCO), especially on power ratings above 1,000 kVA. Its design eliminates the need for batteries, minimizing associated production, recycling and exchange waste and making it an environmentally friendly option. Even in times when the diesel engine is in operation, the environmental impact can be minimized using sustainable diesel fuels, like HVO. Additionally, the mtu Kinetic PowerPack boasts high power density, providing significant space savings compared to static UPS, offering to utilize the free space differently or simply reduce installation investment cost. 

A leading electronics manufacturing facility in India operated on conventional critical power architecture consisting of utility supply, static UPS systems, battery banks, and standby diesel generators. While the system provided backup power, the facility faced challenges in protection coordination due to the varying short-circuit capabilities of the grid, diesel generators, UPS inverters, and bypass paths. 

The available fault current varied significantly depending on the operating mode of the system. Under utility operation, fault levels were high, while during generator operation they were considerably lower. During UPS operation, inverter fault current capability was inherently limited, making fault discrimination more complex. 

As a result, relay coordination studies required significant engineering effort, and downstream fault clearing often depended on transferring faults to the UPS bypass path. This increased system complexity and exposed critical loads to varying electrical conditions during disturbance events. 

As part of a Phase 2 expansion, the facility selected the mtu Kinetic PowerPack to support its growing critical load requirements. The synchronous machine within the mtu Kinetic PowerPack provides consistently high short-circuit capability under both utility-connected and islanded operating modes. This simplified relay coordination by maintaining predictable fault-current levels throughout the system. 

In the event of downstream faults, the alternator provides sufficient fault current to enable selective operation of protective devices without relying on bypass transfers. This allows faults to be isolated quickly while maintaining stable power to healthy sections of the facility. 

Following commissioning, the facility reported: 

• Zero production interruptions attributable to power quality disturbances 
• Improved fault discrimination and protection coordination 
• Elimination of UPS bypass-related concerns on the mtu Kinetic PowerPack protected loads 
• Stable sinusoidal power during both normal and disturbed operating conditions 
• Reduced engineering complexity and lower lifecycle operating costs 

This project demonstrated how the mtu Kinetic PowerPack can simplify protection system design while providing the high-quality, uninterrupted power required by electronics manufacturing and semiconductor facilities. 

Semiconductor fabs and electronics manufacturing units demand the most stringent power conditions of any industrial environment. Disturbances that might be acceptable in other sectors can trigger immediate, high-cost consequences in wafer fabrication. As global fab capacity expands, sites that can guarantee uninterrupted, tightly conditioned, and guideline-aligned power will have a structural advantage. 

The mtu Kinetic PowerPack offers semiconductor manufacturers a unified platform for clean, sinusoidal, and interruption-free power. By combining kinetic energy storage, synchronous generation, harmonic mitigation, power factor improvement, and sag immunity within a single electro-mechanical system, it removes many of the complexity drivers inherent in multi-device static UPS-centered architectures. It reduces HVAC demand, saves space, simplifies maintenance, and strengthens overall reliability—while providing advanced features such as Kinstart and HVO-ready engines. 

For fabs and electronics manufacturing units designing new facilities or upgrading existing ones, mtu Kinetic PowerPack provides a robust foundation for power infrastructure that can keep pace with the precision, availability, and sustainability expectations of modern semiconductor manufacturing. 

1. SEMI, SEMI F47 – Specification for Semiconductor Processing Equipment Voltage Sag Immunity, SEMI International, latest revision 
2. SEMI, SEMI E6 – Guide for Semiconductor Factory Power Distribution, SEMI International. 
3. International Electrotechnical Commission, IEC 61000-4-11: Electromagnetic Compatibility (EMC) – Voltage Dips, Short Interruptions and Voltage Variations, IEC. 
4. International Electrotechnical Commission, IEC 61000-4-34: EMC Testing for Equipment with Rated Current Greater Than 16 A, IEC. 
5. Institute of Electrical and Electronics Engineers, IEEE Std 1159 – Recommended Practice for Monitoring Electric Power Quality, IEEE. 
6. Institute of Electrical and Electronics Engineers, IEEE Std 519 – Recommended Practice and Requirements for Harmonic Control in Electric Power Systems, IEEE. 
7. SEMI, Guidelines for Power Quality in Semiconductor Manufacturing Facilities, SEMI Technical Publications. 
8. Electric Power Research Institute, Power Quality Issues and Solutions for Industrial and High-Tech Manufacturing Facilities, EPRI. 
9. International Technology Roadmap for Semiconductors, Factory Integration and Infrastructure Requirements, ITRS / successor roadmaps.
10. Uptime Institute, Electrical Infrastructure Resilience and Fault Tolerance, Uptime Institute Research. 
11. CIGRE, Power System Disturbances, Short-Circuit Behavior, and Equipment Ride-Through, CIGRE Technical Brochures. 
12. mtu Solutions (mtu Kinetic PowerPack) – Technical Description, Application Guides, internal and technical documentation. 
13. International Energy Agency, Energy Efficiency and Emissions Considerations for Industrial Power Systems, IEA Publications. 
14. SEMI, Global Semiconductor Fab Construction and Capacity Outlook, SEMI World Fab Forecast. 
15. DataPandas — Semiconductor Manufacturing by Country (baseline fab counts, May 2025). Semiconductor Manufacturing By Country 2025 
16. SEMI — World Fab Forecast / press releases (project pipeline, regional projects starting construction 2024–2026 and ongoing forecasts). Eighteen New Semiconductor Fabs to Start Construction in 2025, SEMI Reports | SEMI
17. https://www.mtu-solutions.com/seai/en/sustainability/hvo.html