MPWs: Catalyst of IC Production Innovation
Multi Project Wafer (MPW) Services
Necessity is the mother of invention. For the semiconductor industry, the emergence of Multi-Project Wafers (MPWs) is no exception to the rule. This fundamental enabler of affordable IC fabrication emerged in the 1970's to help university researchers and silicon entrepreneurs prototype their Integrated Circuits (ICs) and demonstrate their work. It was the early days of the semiconductor industry when firms like IBM, Intel, Fairchild, and others were applying tremendous innovation toward building smaller, faster and cheaper chips.
The standard chip design textbook at the time was the groundbreaking "Introduction to VLSI Systems," a collaborative work by computer science pioneers Lynn Conway and Carver Mead. Conway was a visiting professor at MIT. Mead was at Caltech. The book and early courses taught by both professors marked the beginning of the Mead & Conway revolution in VLSI system design.
By 1983, the book was being used at more than 100 universities -- training new generations of chip designers, sparking new IC design tools and methodologies, and laying the foundation for today's electronic design automation industry.
Their contributions to the semiconductor industry extended far beyond creating a formal IC design curriculum. They also pioneered a new internet-based model for rapid-prototyping and short-run fabrication of chip designs in large quantities. Known as Multi-Project Wafers (MPWs) or Multi-Project Chips (MPCs), the model combined designs from multiple companies or diverse designs from a single company and integrated them onto one wafer for production. Mask and wafer costs were shared and sample lots of up to 1,000 devices could be created at costs as low as 10 percent of a dedicated wafer run. It was a revolutionary concept at the time and helped build critical mass for silicon innovations.
MOSIS: The MPW Pioneer
The first well-known MPW service was MOSIS which was established by DARPA in 1981.
At first, MPWs simply provided a channel for researchers and silicon entrepreneurs to prototype their IC designs. Its relevance and value soon became apparent to commercial firms who viewed MPWs as a practical prototyping vehicle that allowed designers to debug and perform essential design adjustments before making substantial strategic investments.
MOSIS was quick to respond. To meet growing demand for MPW services -- from domestic and international customers -- the organization began to build alliances with a global network of foundry partners. At the same time, in-house expertise was boosted to create a competent, expert interface between IC designers and their fabrication partners. Designs were pooled into common lots and run through the fabrication process at partner foundries. The completed chips (packaged and/or unpackaged) were returned to customers.
Over time, most advanced silicon fabrication facilities began to offer MPW services. However, MOSIS has remained at the center of the effort. Since inception, the organization has fabricated more than 60,000 IC designs for a broad mix of customers. They include commercial firms, government agencies, and research and educational institutions. While they initially used MPWs to prototype, many are now turning to MPWs to volume produce their IC designs. They're drawn by the model's flexibility and affordability. For example, to optimize profitability, some companies use a larger portion of the real estate for production chips and a smaller portion to produce prototypes of next-generation chips.
Driving new Cycles of MPW Innovation through Automation
Today, the legacy of MPW innovation is more evident at MOSIS than ever. Only now, the stakes are much higher. Turning a design into silicon has never been more challenging. Process technologies are highly advanced. The manufacturing ecosystem is complex and production costs are soaring.
For fabless IC entrepreneurs, the cost barriers are formidable. It's not easy for them to access the leading-edge technology required to fabricate their devices. At large companies where R&D budgets are constrained and margins tight, cost is also a challenge. For design teams working on new-generation products beyond the company's mainstream portfolio, an affordable prototyping- to- volume-production solutions model is more appealing than ever. It saves money, reduces risk, and speeds time to market.
MOSIS has kept pace by continually streamlining its service offerings, stripping much of the red tape that often comes with the fabrication process, and increasing the value of the MPW model. Automation is central to the effort.
By making its website the control center, the MOSIS service is optimized for simplicity and ease of use. This is essential for designers facing ultra-tight market windows. From this hub, designers can access the information they need quickly and efficiently, and proceed promptly.
The process is straightforward. First, customers are invited to open a MOSIS account. Then, they're asked to select a process from a comprehensive list. To enhance transparency and facilitate budgeting, detailed pricing and schedule is offered. From there, the process technology files can be promptly downloaded, and design and verification essentials can be performed. Once that's done, the GDSII files can be seamlessly submitted to MOSIS via secure FTP. A design review is then performed before committing the files to the customer's preferred fab partner for processing. Following that, it's off to test and assembly. Once that's complete, the packaged die is returned to the customer by MOSIS.
At all times, customers have a secure window on the process -- with visibility at each step enabled by a sophisticated tracking dashboard.
Over the years, MOSIS has found that its customers -- commercial and academic -- are singularly focused on fabricating their designs with minimum fanfare. So the organization continually boosts its MPW services with features to improve automation. For those who are new to the process, in-house expertise is available to advise and guide them, bringing the benefits of MOSIS' three-plus decades of MPW expertise, knowledge, and experience to their production needs.