How SEMI Standard E175 is saving energy and cutting costs

2017-06-20 13:33:08

Industry experts answer questions about the new standard in a virtual roundtable.

In recent years, energy consumption has decreased due to several innovations that have helped to improve the energy efficiency of process tools and sub-fab equipment, but an increase in the number of processes and the growing complexity of processing at the current node has resulted in a spike in energy consumption in the fab. Approximately 43% of the energy consumed in the fab is due to the processing equipment and, of this, 20% is vacuum and abatement (8% overall).

A new standard from SEMI, E175, defines energy saving modes, which combined with the EtherCAT signaling standard, can help fabs save energy and other gas/utility costs when the tool is not processing and with no impact on subsequent wafer processing.

EtherCAT, based on industrial Ethernet, provides high- speed control and monitoring. It is the communication standard of choice for the latest semiconductor tool controllers to connect to sensors and actuators around the tool, including vacuum and abatement systems.

SEMI E175 defines how process tools communicate with sub-fab equipment, such as vacuum pumps and gas abatement systems, to reduce utility consumption at times when wafers are not being processed by the tool, and returning to full performance when the tool is again required to process wafers. It builds on SEMI E167, which defines communication between the fab host/ WIP controller and the process tools for the purpose of utility saving.

Collaboration between the E175 and EtherCAT groups has seen a harmonization of the communication standards to provide co-ordinated energy saving across devices in the fab.
We invited experts in this area to answer a few questions in a virtual roundtable. The participants are:

GERALD SHELLEY, Senior Product Manager Communication and Control at Edwards, and the EtherCAT Chair Abatement / Roughing pump working groups, E175 task force.

MIKE CZERNIAK, Environmental Solutions Business Development Manager at Edwardsm Co-Chair of E167 & E175, and campaigner for energy saving

GINO CRISPIERI, Applied Materials - Past Co-chair of E175 (originally SEMATECH/ISMI, then independent consultant, prior to Applied Materials)

MARTIN ROSTAN, Executive Director, EtherCAT Technology Group

Q: Please explain what drove the standards work on energy saving and the achievements to date.

SHELLEY: There is increased pressure on the industry to reduce energy and utility saving from both a cost and environmental standpoint. Subfab equipment is a major consumer of utilities, which is wasted when a tool is not in use. Different manufacturers have implemented energy saving solutions, with minimal direct connection to the tool. However, direct tool connection has emerged as the best way to maximize saving without any risk to wafer processing.

CZERNIAK: This work originated in the ISMI part of SEMATECH as a follow-on to generic work aimed at reducing the overall utilities footprint of modern fabs. In response to this and requests from customers, Edwards developed vacuum pumps and gas abatement systems that had energy-saving functionality. However, it soon became clear that the limitation to implementing such savings was the absence of standardised signalling between the process tool and sub-fab equipment.

CRISPIERI: A SEMATECH project around 2009 started to look into opportunities for saving energy in the semiconductor factories. At that time, suppliers of pumps and abatement systems already had started initiatives to provide their own solutions to the initiative. Since that time, the industry has adopted two new standards: SEMI E167 Specification for Equipment Energy Saving Mode Communication (between factory and semicon- ductor equipment) and SEMI E175 Specification for Subsystem Energy Saving Mode Communication (between semiconductor equipment and subsystems).

Q: Please describe how the energy saving task force was born and why you decided to get involved.

CRISPIERI: Back in 2009 while working for SEMATECH in Austin, Texas, prior to SEMATECH’s move the New York, Thomas Huang an assignee for GlobalFoundries to the EHS Program approached and asked me if I would be interested in helping him drive a standard for equipment suppliers to enable their equipment to save energy during idle times. Because of my previous experience working with equipment suppliers and developing standards for equipment and factory communication, I accepted to chair a task force to drive the equipment supplier’s new capability requirement into a standard. At first, we thought it would be an easy task and that everyone would jump to help create and approve the standard in a short amount of time because of its benefits. A two phase approach was defined to drive the standardization process and engage semiconductor and sub-fab equipment suppliers accordingly. It took almost three years to complete the Phase I (2013) and another three to complete the Phase II (2016) standards.

SHELLEY: The task force was an extension of E167 which previously defined the communication into the tool from the supervisory systems, however to achieve maximum benefit signalling to tool subsystems was key and the E175 task force was the result.

CZERNIAK: Following-on from the above, the ISMI working group became a SEMI Standards Task Force and began work at developing a standard, initially for Host to process tool (E167) and then from tool to sub-fab (E175), which I was co-chair for to ensure continuity and clear the signalling “roadblock”.

Q: How have suppliers collaborated on E175?

CRISPIERI: Compared with the suppliers who partic- ipated in SEMI E167 development, the suppliers involved in the development and approval of SEMI E175 were more committed to make it happen and helped drive the standardization process to conclusion much more efficiently. Edwards, AMAT, TEL, Hitachi- Kokusai and DAS-Europe regularly participated and provided inputs to standardize behavior and require- ments for their own equipment. We run into some difficulty getting aligned with other standard activities that were driven by SEMI’s EHS Committee because their changes affected our standardization process. I must note that the overall participation was excellent in particular from Edwards Vacuum and AMAT.

ROSTAN: Within the ETG Semiconductor Technical Working Group individual task groups already had multiple suppliers collaborating on the detail of the EtherCAT profiles for all devices, with technical support from the EtherCAT Technical Group. We were fortunate to have a delegate from Edwards in both the Semi E175 Task Force and key EtherCAT Task Groups to informally broker agreement between the teams.

SHELLEY: The suppliers were able to use their collective experience to work through a number of options to find the optimum way of controlling subfab equipment, tackling variability in wakeup time and control architec- tures between device types and equipment technology.

CZERNIAK: Suppliers, automation providers, tool OEMs and end-users have all collaborated to help develop a standard that works for everyone and aligns with earlier standards like S23.

Q: How was the EtherCAT collaboration beneficial to E175?

SHELLEY: By sharing information and understanding in real time we demonstrated the E175 concept is achievable using the favored protocol for new tool platforms and defined how it would be implemented. We co-operated to take both these standards to alignment in one simul- taneous step, saving considerable committee time on both sides that would have been necessary to resolve any divergence of the detail.

ROSTAN: By devising the implementation of E175 in parallel the EtherCAT Task Groups involved were able to feedback detailed technical proposals and show the E175 standard could be implemented relatively easily within the existing EtherCAT standards.

CRISPIERI: Participation and collaboration from the EtherCAT Working Group was critical to accelerate the implementation and adoption of the standard. Dry Contacts and EtherCAT communication protocol messages were added to two Related Information sections and included in the SEMI E175 standard at the time of its publication.

CZERNIAK: This enables a “richer” signalling environment than simple dry contacts (which are also supported) that enables even greater utility savings to be made.

Q: How has EtherCAT been able to support the require- ments of the tool and Semi E175?

CZERNIACK: By providing timing information; the longer the time the tool is inactive, the greater the savings possible.

ROSTAN: As the control network of choice for the latest semiconductor tools, EtherCAT has been ideally placed to support enhancements, such as the energy saving connectivity increasingly being requested by the fabs. In particular, it was good to see the Pump and Abatement Task Groups of the existing Semiconductor Technical Working Group formulate an E175 compliant solution within the timescales of the second release of the EtherCAT semiconductor device profiles. The EtherCAT Technology Group was also more than happy to support the publication of extracts of the EtherCAT standards being used as protocol examples in the Imple- mentation guidelines of the Semi E175 document.

SHELLEY: EtherCAT has the fast / deterministic connec- tivity and proven integration with tool controllers that allows E175 functionality to be easily added without any loss of performance. By including the requirements of Semi E175 in the EtherCAT standards, both equipment suppliers and tool vendors can establish energy saving communication quickly and easily.

CRISPIERI: The coordination between EtherCAT Working Group and the SEMI ESEC task force group was conducted by Mr. Gerald Shelley from Edwards Vacuum. With his help and leadership, we reached effortlessly agreement and acceptance for the required messages, parameters and values into the EtherCAT respective Pump and Abatement Profile documents. Havingworking usage scenarios and support from the EtherCAT Working Group has been invaluable.

Q: Why is energy saving important to the industry?

ROSTAN: In the industrial world, EtherCAT users are increasingly using our communication and control technologies to drive down energy consumption. The semiconductor industry operates in parts of the world where energy is a limited and expensive resource, whilst the latest wafer processing requires more power. The manufacturers are therefore in great need for energy saving opportunities, such as when the tool subsystems are not in use.

SHELLEY: The fabs are being squeezed by an increase in the complexity and number of processes involved in manufacturing a wafer, driving consumption up and increasing scarcity of energy supply. This is further compli- cated with associated cost and government pressure to “keep the lights on”.

CRISPIERI: It is not hard to see why is so important for device makers or the semiconductor manufacturing industry to adopt and require energy conservation capabilities in their factories. Energy consumed by many equipment components and support systems, such as pumps and abatement systems, never stop from running even when the equipment is idle and waiting for product to be delivered for processing. These components and support systems can save millions of dollars each year if their power consumption is reduced. This energy consumption reduction extends their life cycle thus reducing costs of maintenance and parts replacement. Any effort to reduce energy consumption helps lower costs and adds gains to not only the manufacturer but to those who have to generate the energy for consumption.

CZERNIACK: Cost reduction is always important, but electrical supply is limited in some areas.