A Critical Step to Reduce PV Manufacturing Cost

A Critical Step to Reduce PV Manufacturing Cost: International Standards

By Bettina Weiss, SEMI

Introduction

Many readers equate SEMI with the SEMICON trade shows around the world, business and technical conferences, EHS and advocacy initiatives and yes… industry standards. Currently, SEMI has close to 2,000 member companies, with about 20% active in the photovoltaic sector. These companies form a community called the PV Group which is a community that addresses opportunities and obstacles collectively. Its goal is to bring low-cost PV technology and sustainable clean energy to the world. SEMI supports this segment by expanding its key competencies— shows, standards, advocacy, and market research— into this new space. SEMI listens closely to constituents’ needs and is committed to developing unique approaches to unique problems. For 38 years, SEMI has connected markets and industries that benefit from dialogue. With former semiconductor professionals moving into PV, pure PV manufacturers and a startling number of start-ups, fertile ground exists for collective discussions all over the world— and that is what it will take to propel us forward.

PV Group Mission

For SEMI Members in the PV supply chain, including their customers, SEMI will serve the photovoltaic market with events, standards and services. Working with other industry groups throughout the world, SEMI will be dedicated to advancing the growth and profitability of its members, and to achieve overall cost reduction to enable PV energy adoption worldwide.

The SEMI International Standards Program, established in 1973, is celebrating its 35th anniversary this year. With 35 years of growth in technology breadth, geography and people, SEMI volunteer experts around the world have developed almost 800 SEMI Standards and Safety Guidelines— to improve equipment, materials and processes for a variety of industries.

SEMI International Standards efforts started with the historic agreement on a universal wafer diameter in semiconductor processing. It has evolved over the years into a global volunteer program of currently 1,800 individuals. These volunteers embrace new and emerging technologies in all corners of the planet, as well as populate the technical committees and task forces needed to develop the Standards. The Standards Program helps companies tackle new manufacturing challenges and new business opportunities. It is vital to a sustainable global supply chain and market community.

Why PV Standards?

The quick answer to this question is: “There aren’t any and we need them urgently.” Representatives of our member companies as well as their customers have remarked that often there is not even agreement on basic parameters, that materials specifications and test methods vary and that industry stakeholders are worried about giving up their intellectual property for the collective good but with no gain for themselves.

The long answer is more complex. First, it is not entirely obvious where consensus standards are needed, and when. Pain points, such as cost, waste, time-to-market and environmental concerns, could clearly be addressed by standardized approaches but lack the collective industry voice to move forward. Secondly, several standards developing organizations (SDOs) are active and could, potentially, create more confusion and delays. And thirdly, there are the complexities that come with a global market and a global supply chain. Determining where standards can strengthen weak links, open borders and create a global understanding and acceptance of PV manufacturing challenges is difficult— but possible if stakeholders work together with common objectives, determination and a collaborative spirit. We’ve seen it happen— and succeed— before.

PV Standards Efforts in SEMI

As soon as SEMI member companies began expanding into the photovoltaic space and SEMI began developing supporting products and services to ease the transition, “Standards” was the first key word that entered the equation. At the first informal Photovoltaic Standards meeting in September 2006, executives from the PV industry discussed where SEMI could most positively influence and contribute to the growth of the PV industry. Standards at the both the manufacturing equipment and materials level were identified as missing but absolutely critical to lower trade barriers and reduce cost of ownership for cell and module manufacturers.

Within a year (2007), both Europe (with support and endorsement from EPIA, the European Photovoltaic Industry Association) and North America established formal PV Standards Committees and jointly produced the following global committee charter:

Goal: Reduce manufacturing cost in the photovoltaic (PV) Industry

  • Method: Explore, evaluate, discuss, and create consensus-based standard measurement methods, specifications, guidelines, and practices.
  • Process: Through voluntary compliance, these “standards” will promote mutual understanding and improved communication between users and suppliers of photovoltaic manufacturing equipment, materials and services.
  • Results: Improved manufacturing efficiency and capability.

While agreement exists on the overall scope (and, by the same token, the limitations) of work to be done, Europe and North America started their efforts in different areas. In the spirit of developing standards “by the industry, for the industry”, the first working group established under the North American PV Standards Committee was the Analytical Test Methods Task Force, led by Richard Hockett of the Evans Analytical Group.

This task force has developed a draft document titled “Test Method for the Measurement of Elemental Impurity Concentrations in PV Silicon Feedstock by Glow Discharge Mass Spectrometry”. The initial ballot failed the technical review and will be reballoted with revisions based on the feedback received, which will improve the standard in the end. This is one of the biggest benefits of a global Standards development process: Even if a company does not participate actively in a task force or committee, it will have the opportunity to review and comment on the drafts prior to approval and publication— ensuring that additional perspectives and obstacles are addressed that may have been missed during the first round. And with 7 ballot cycles per year, the volunteer experts in the SEMI Standards Program don’t have to sacrifice quality for speed.

The second North American PV Standards Task Force, led by Mark Frederick of Entegris, is currently drafting a “Specification on 150 mm, 156 mm, and 200 mm Wafer and Cell Transfer Carriers for Use in PV Manufacturing”, which will be distributed as a technical ballot in the fall.

The results of a third ballot, “Revision to SEMI M6-0707 Specification for Silicon Wafers for Use as Photovoltaic Solar Cells”, were reviewed at the North American PV Standards Committee meeting at SEMICON West 2008, and the document was approved for publication. This particular document now includes the 156mm x 156mm wafer specification, which is heavily used in the PV industry.

In Europe, on the other hand, a heated debate over equipment interfaces now appears to be resolved. The PV Equipment Interface Specification Task Force (PV-EIS TF), chaired by SolarWorld and Manz Automation, worked through challenging discussions around the issue of whether or not SECS/GEM will be the present and future interface in PV manufacturing. The answer is a resounding “yes”, especially since major cell manufacturers have supported this choice, which should come as a relief to equipment vendors. The task force now plans to issue a draft “Guide for PC Equipment Communication Interfaces” as an informational ballot in time for their next meeting during PVSEC in Valencia, Spain in early September. This document will reference existing semiconductor standards that are applicable to PV manufacturing with only minor modifications.

Other regions are coming up to speed quickly. Taiwan, for example, has assembled a SEMI PV Standards Working Group in a very short period of time— with the desire to become a formal regional committee in the near future. Chaired jointly by Chroma, Delsolar, PVTC/ITRI and UL Taiwan, the working group aims to investigate standards opportunities in the areas of: Si feedstock, cell performance, system performance, module performance, equipment interfaces (liaison with EU PV-EIS TF)—and has already established subgroups on all of these issues.

SEMI Global PV Standards Roadmap

Ongoing standardization work is a step towards the future, but it may not beat the current speed of innovation and growth. To provide both a truly global platform for solar standardization as well as an outlook of future requirements that will impact today’s design, manufacturing processes and end products, SEMI is spearheading a Global PV Standards Roadmap project. A core team of equipment and materials suppliers, cell and module makers, academia and other interests was established in May 2008. After two teleconferences, core team members met at SEMICON West 2008 to begin development of a first Roadmap guidance document, based on a high-level assessment of the International Technology Roadmap for Semiconductors (ITRS). Sections immediately applicable to PV will be transferred, and the most attention will be given to unique challenges in PV manufacturing that deserve a unique approach and collective solution. In the materials area in particular, we expect a lot of work to be needed. The guidance document will further define the purpose and scope of the Roadmap, including the timeline and the individual elements, (such as materials, process equipment, environmental, health and safety considerations, facilities aspects, and critical cell and module issues). The document will drill down into areas where a standardized approach will help mitigate risks, reduce costs, improve time-to-market and cost of ownership. Completion of the Project Plan is tentatively scheduled for December 2008.

Phase 2 of the Roadmap project will include a broad, global industry effort to develop substantive, consensus-driven content to the individual Roadmap elements. SEMI will provide regular updates about Roadmap development, and recruit experts to aid in the effort. Phase 2 should end by December 2009, earlier if possible. Core team members agree that this document should be available to the industry as soon as possible and is working with a sense of urgency to make it happen.

Phase 3, the actual development of Standards to address the needs and requirements identified in the Roadmap, is envisioned to overlap with Phase 2, and we expect many volunteer experts to be active in defining the requirements as well as aiding in the document development process. It will be an exciting 18 months!

Partnerships and Strategic Alliances

While these activities and initial results are very encouraging, we realize that no organization can do all the work that needs to be done by itself. For decades, SEMI has engaged not only SEMI member companies and their customers, but has also partnered with other SDOs, institutes and associations to ensure that any community that could potentially be impacted by a standard gets an opportunity for comment. At SEMI, this is typical for many other related areas as well, such as EH&S sustainability and environmental stewardship activities, which require close collaboration among participating countries, in particular with respect to new regulatory and compliance legislation. Partnering and outreach will likely impact the development of related PV Safety Guidelines to address unique challenges in the areas of hazardous materials, waste management, raw material supply, etc. The photovoltaics industry is supported by a global supply chain which will benefit from the availability of collectively developed globally applicable and accepted standards and guidelines.

To learn more about SEMI, PV Group, standards activities worldwide, and find out how you can participate, please contact the author: Bettina Weiss, Senior Director, Photovoltaic Segment (North America) at bweiss@semi.org or by phone at 408.943.6998.

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