Cutting the energy bill

Talk to most people in the semiconductor industry about energy saving and theyll probably think you are a little strange or have nothing else to say. The discussion quickly changes to supposedly more important topics like improving yield, wafer throughput or reducing cost of ownership. Energy conservation is always seen as an issue for those working in facilities or EHS. Is it really the responsibility of others or something we all have to contribute to together?

Everyone agrees that energy conservation is of prime importance to preserve the environment for future generations. However, for most companies the reality is that it receives a very low priority in day-to-day work. So what do we have to do to change these priorities? What are the IC industrys targets and what is the current status of energy conservation in the industry?

In the past many energy conservation measures have been implemented at semiconductor plants especially in facility systems, monitoring and control of supplies, electricity, air, water, UHP, gasses, CDA, and eliminating waste and leakage. Energy efficiency programmes have focused on chiller operation and efficiency, variable speed motors for ventilation, high vacuum pumps, filter clogging detection, etc. While many viable energy conservation measures have been implemented in many fabs worldwide, there are still areas for improvement and future gains could come from the process tools themselves. Today, many equipment suppliers have taken notice of the increased need for more efficient manufacturing tools and they are trying, some successfully and some not, to improve the performance of their products.

Some of the ideas and inventions to reduce the use of energy are now common, including HEPA velocity, frequency controlled pumps, optimizing exhaust air system (fab-side), and lighting management. And new ideas and methods are being shared, such as monitoring systems and mass flow analysis, eco-washers for make-up air system, and optimization of energy use in the planning phase.

While the energy conservation targets of the WSC and the ITRS are the responsibility of fab owners, future energy gains must also come from making the process tools more "energy efficient". End users have two possibilities to improve process tool efficiency.

1) Retrofit machines with energy saving devices or components
Many new generation "energy saving" components are currently available on the market, but the return on investment is often too long. One solution could be to retrofit "energy saving" components as part of a preventative maintenance campaign, thus offsetting the retrofit cost. Examples of retrofits may include the replacement of internal components such as more efficient power supplies, or the replacement of support components such as more efficient vacuum pumps or point-of-use chillers.

2) Invest in new "energy" saving process tools (assuming they really do exist!)
Energy conservation is not usually a main design criteria for process equipment, and is often low on the list of design priorities. The integration of energy saving equipment and subcomponents is often made with an extra cost, although cost of ownership should be lower in the long term. However, there are already a lot of potential solutions available that are not integrated into new equipment. Equipment suppliers must be strongly encouraged to redesign their equipment to reduce energy consumption. This encouragement can begin with the tool purchase specifications. Until tool suppliers begin to see purchase managers asking for improved energy efficiency they will continue to say; "No one is asking for this so why should I design it into my tool."

Although many wafer fabs have improved greatly in their energy performance, there are still many other opportunities open to fab owners. They need to be examining their operating specifications to understand where energy is being used. In the future every "Watt" will be important, as excess power generates excess heat and often results in over engineered tools that require more space. The energy reduction race will ensure optimum design tools, with smaller footprints for better performance. Downsizing of tools will also drive downsizing of facilities and installations, leading to much greater energy economies. Just like the semiconductor device industry itself, smaller chips result in better performance and less energy consumption. This in turn drives the performance and energy demands of consumer products such as mobile phones, laptops and digital cameras. The equipment suppliers should learn from their own industry by applying the same techniques to process tools and sub-components. The end result will be tools that are smarter and more efficient. Energy conservation must become one of the technology challenges and main drivers for next generation tools.

The target should be; "Use only what is really needed". We need to re-think our design criteria by treating energy as a limited resources. People have a habit of suddenly becoming ingenious when resources are limited. We need to put energy consumption back on the agenda, perhaps by making energy consumption a key selection criteria for equipment buyers. We must change attitudes and awareness.

To stimulate energy conservation awareness on a global basis, SEMI has organised initiatives such as Global Care and organized several international Energy Conservation workshops. A White Paper developed jointly in May 2005 with the World Semiconductor Council addressed the topic; "Energy Efficiency of Tools and Supporting Equipment". In March this year SEMI published SEMI S23, a Guide for Conservation of Energy, Utilities and Materials used by Semiconductor Manufacturing Equipment. At the Energy Conservation workshop in April during SEMICON Europa 2005, it was pointed out that there were already a lot of experience, ideas and solutions available to the industry.

The main challenge is in integrating or implementing these ideas into concrete actions in the field. Following this workshop it was decided to set up an International Energy Conservation Initiatives task force in order to explore these ideas with the view to preparing guidelines and standards to encourage their implementation. Task force members represent main players in the semiconductor industry; equipment and component suppliers, as well as end users.

The group is also global, with representatives from Europe, Japan and North America. The next workshop will take place on 25 October in Leuven, Belgium, in conjunction with the SEMI Europe Standards Autumn Conference and Meetings (www.semi.org/eustandards)

Next time you ask an equipment or component supplier about their equipments performance, first ask how much energy the tool consumes per wafer. After hearing the same request several times, attitudes and maybe priorities might change.

Comments and feedback will be appreciated, please contact Dominic Potter, leader of the SEMI Standards International Energy Conservation Initiatives task force, at dpotter@smcfrance.fr