Semiconductor Fabs: Chipping Away at Wasted Energy
Semiconductor technologies have been transforming our lives ever since the development of the first mass-market transistor in the 1940s. In some surprising ways, they have also revolutionized the relationship between production and energy consumption.
While global demand for semiconductors reached an all-time high in 2018 — with more than one trillion units shipped, profit margins are shrinking. The Semiconductor Industry Association (SIA) has announced that revenue, which hit 13.4% in 2018, is predicted to fall to 8.0% in 2020.
As margins tighten, energy efficiency is the key to success.
The semiconductor industry is both technology and energy intense – accounting for 1.3% – 2% of the total US electricity consumption in the manufacturing sector. Utility bills of $1 – $2 million per month are common. According to recent McKinsey research, large semiconductor fabrication plants (fabs) consume as much as 100 megawatt-hours of energy every hour – more than many automotive plants or oil refineries. When comparing weight per weight (of product), the amount of energy and chemicals required for semiconductors is 630 times the weight of the chip. Compare this to a 2:1 ratio needed to manufacture a car!
Why is energy consumption so high?
During the 1960s, Intel’s co-founder, Gordon Moore, observed that semiconductor performance doubles every 18 months, Since then, “Moore’s Law” defines an industry driven to lower production costs and increase production speed. Better, faster, cheaper is the paradigm of every semiconductor manufacturer. Here’s the problem: as is the case in many organizations, engineers and finance teams have different priorities. Engineers tend to focus on gains in percentage yield — frequently overlooking the connection between yield and cost. Finance teams are, naturally, driven to reduce overhead costs and improve profitability. As such, both front-end fabs and back-end manufacturers tended to focus efficiency efforts on equipment yield, material consumption, and labor costs. Energy efficiency simply didn’t become a high priority for most semiconductor plants until recently. Despite the fact that energy costs represent anywhere from 5% to 30% of a fab’s operating costs, many firms assumed that high utility bills were simply the cost of doing business.
How is the energy consumed in a fab?
Facility Infrastructure: As technology evolves, companies rush to bring the latest products to market. Smaller feature sizes require cleaner manufacturing environments, increasing the energy used by HVAC systems (air movement and filtering). On average, the energy consumed to run facility systems (HVAC systems, nitrogen plants, lighting, and water treatment components) accounts for approximately 60% of the total energy consumption.
Manufacturing/Process Tools: Naturally, energy is needed to operate the manufacturing equipment/process tools. This accounts for approximately 35% – 45% of a fab’s energy consumption:
- Increased chip complexity requires more layers on each chip which, in turn, require more process steps and more direct manufacturing energy.
- Shifting from batch to single wafer processing has tended to increase energy consumption.
The case for increased efficiency:
Increased competition, tighter margins, ongoing pressure to improve productivity and rising energy costs — combined with a new emphasis on corporate environmental performance/reduced energy and materials consumption — is impacting the industry. Semiconductor companies are, accordingly, under both financial and political pressure to reduce consumption.
McKinsey’s research suggests that facility and energy system upgrades can reduce energy costs by 30% for most fabs. Efficiency upgrades should include:
- Benchmarking energy use. A fab energy audit can provide real-time benchmarking of energy use, waste, and areas of improvement. The audit should include a thorough analysis of every area within the facility — documenting specific occupant and performance requirements.
- Upgraded Building Automation Systems (BAS) provide centralized control of a fab’s ventilation, heating, air conditioning, fans, and pumps. They provide access to information on equipment performance and utility metering, reducing energy consumption while improving operations, margins, and growth.
- HVAC systems represent about 30% of the electric load of a typical semiconductor fab. They can be upgraded to run more efficiently, boost air quality and improve occupant comfort. Adequate monitoring and analysis of clean room HVAC system performance will help to maintain a high-efficiency operation. Adding metering equipment can provide effective HVAC system analysis, tracking system performance and diagnosing any operational concerns.
- Lights should be converted from energy-draining incandescent and fluorescent bulbs to LEDs. Upgrading lighting is a highly effective way to reduce utility and operating costs while improving employee productivity and safety. Lighting system controls should be installed to optimize lighting run-time and reduce maintenance requirements. Even if the lighting doesn’t account for a large share of the fab’s operating budget, every dollar saved can help the bottom line.
- Pumps and heat exchangers can be shared between process chambers, improving energy consumption and reducing greenhouse gas emissions.
- Waste heat from chillers can be used to heat water and/or the facility itself.
- Energy measurement and verification programs drive continual facility improvements by monitoring equipment and performance to ensure systems are working at optimum levels. They are especially useful for companies with multiple fabs in different locations across the U.S.
The rationale for improving energy efficiency in fabs goes well beyond reduced energy consumption and costs. Since downtime anywhere in a fab is disastrously expensive, the reliability of all equipment is critical. Reduced wear and tear on components such as filters, fans, pumps, and motors increases facility reliability.
And, finally, semiconductor manufacturers are always looking to build new plants that can accommodate the technology needed to design and manufacture the most advanced products. Cutting operating costs by upgrading energy systems and infrastructure can provide firms with the capital needed to fund next-generation plants.
All of these efficiency upgrades can, of course, be completed using SmartWatt’s Efficiency-as-a-Service Program, using their guaranteed energy savings to cover all project costs and saving their capital to invest in the latest tool technology or new plant.
Now’s the time to act
The ability to reduce annual energy costs by 20 – 30% not only increases a company’s profit margin, but it also provides a solid competitive advantage.
So, while energy efficiency hasn’t been a key priority in the past, increased competition and shrinking profit margins have many leading semiconductor manufacturers reexamining their approach to energy management. Intel, for example, has initiated a number of efficiency measures, reducing energy consumption by 3.2 billion kWh and saving $340 million in energy costs.
New programs, such as SmartWatt’s Efficiency-as-a-Service, make it possible for semiconductor companies to achieve their efficiency goals across all fabs with no upfront capital expense. There’s simply no reason to delay!