China launches 300mm manufacturing
02/01/2005
It was not long ago that China’s leading-edge integrated circuit (IC) manufacturing capability lagged behind the rest of the world by two or more generations. However, due in part to new wafer fab investments and the Chinese government’s efforts in promoting the domestic semiconductor industry’s development through strategic long-term planning and supportive policies, the past 10 years have seen China rapidly gain ground in terms of technology and IC manufacturing capabilities.
During the Ninth Five-Year Plan period (1996-2000), China invested in and developed domestic IC production capabilities in the Pudong New Area of Shanghai. The Tenth Five-Year Plan (2001-2005) has further encouraged IC design efforts in China and the formation of chip design centers for specific 0.25µm and 0.18µm applications in communications, computers, and consumer (“3C”) market applications. The plan also calls for policies that encourage companies to invest financially and technologically in IC production in China. About 35 companies now operate wafer fabs in China. In addition, there are now ~180 chip assembly houses and 460 IC design companies, according to estimates at the end of 2004.
China’s first steps into 300mm wafer processing were taken in July 2004, when Semiconductor Manufacturing International Corp. (SMIC) commenced pilot production at its new fabrication facility in Beijing. This milestone further illustrates the fast-paced progress occurring in China’s IC industry. SMIC’s 300mm Fab 4 began ramping production in the final three months of 2004, putting it on track to reach a capacity of 3000 wafer starts/month at the beginning of 2005.
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Beijing was a natural location for China’s first 300mm fab. As the capital city of China, Beijing’s political and economic clout has long attracted the presences of both domestic and international companies. With local top-tier academic institutions such as Tsinghua U. and Peking U. helping to provide a constant supply of highly qualified engineering graduates, Beijing has emerged as a hub for IC design companies and fabless chip operations, such as Datang Microelectronics Technology Co. Ltd. - which is China’s top IC design house, in terms of revenue.
The geographic proximity of production and IC design operations is an important consideration. China’s domestic customers expect their foundry partners to work closely with them to meet their needs. Having a nearby presence enhances overall communications, simplifies supply chain logistics, and results in shortened ramp-to-manufacturing cycle times.
What’s behind China’s growth
As the country’s annual per capita disposable income continues to climb, the rapid growth in the domestic economy is driving China’s demand for electronic products such as mobile phones, personal computers, and DVD players. Consequently, China’s need for semiconductors also is rising rapidly. The China Center for Information Industry Development (CCID) projects that the domestic IC market will climb at a compound annual growth rate of 25%, at least through 2010. However, CCID also has stated that China’s domestically supplied ICs currently can meet <20% of China’s overall demand. Fueled by a booming electronics sector, which Gartner Dataquest forecasts will reach $200 billion in revenues by 2007, China’s strong appetite for ICs is expected to ensure domestic semiconductor growth rates that will continue to outpace worldwide markets.
Furthermore, mainland China has emerged as a global manufacturing center for electronic products, which are sold in the domestic market and abroad. An increasing number of contract electronics systems manufacturers, such as Flextronics Corp. and Solectron Corp., are relocating production facilities to China. According to International Finance Corp. (IFC), the private investment arm of the World Bank, China is on track to become the world’s third-largest electronics manufacturing market by 2005, placing it behind North America and Japan. IFC estimates that $46 billion, or 77%, of “emerging markets” production growth will be attributable to China through 2005. With such potential, China’s heavy reliance on IC imports presents a challenge and a need to increase its supply of domestically produced semiconductors in order to reduce production cycle times, lower costs, simplify supply chain logistics, and meet local content requirements.
In the capital-intensive IC supply chain, any cost savings in the manufacturing process can translate into key savings for downstream customers and, ultimately, consumers. Because 300mm wafers have a surface area 2.25× larger than 200mm wafers, the manufacturing cost/good die on these large silicon substrates can be as much as 30% less than a 200mm wafer. Coupled with comparatively low costs for labor, land, and utilities in China, 300mm manufacturing on fully utilized fab equipment can provide significant cost savings.
Putting China on the 300mm map
In 2000, as the global semiconductor industry headed into its worst downturn ever, newly launched SMIC began planning and constructing its first 200mm fabs so that it would be ready for the next upturn. While SMIC was constructing its 200mm fabs in Shanghai, some semiconductor companies outside China were building and equipping the industry’s first 300mm production fabs. When SMIC was ready to begin construction of its planned 300mm facility in Beijing, experienced vendors were available to help build and equip the fab.
The company’s 300mm wafer fabrication facility utilizes a tri-fab architecture to separate front-end-of-line (FEOL) and aluminum metallization processing from copper back-end-of-line (BEOL) interconnect steps. This distinctive design concept was used to set up initial 200mm fabs in Shanghai. The unique fab arrangement enhances wafer manufacturing by physically segregating the copper manufacturing steps from other processes to minimize the risk of cross-contamination. In addition, the tri-fab design incorporates a built-in opportunity for a new foundry business model, which is focused on providing copper interconnect layers for advanced logic ICs. This enables integrated device manufacturers (IDM) to outsource copper processes, and it reduces their levels of investment in fabs.
 Automation is used in SMIC’s 300mm Fab 4 to perform wafer-level tracking and to support multilot ecipe capabilities in a single FOUP carrier. |
In the final months of 2004, SMIC’s Fab 4 was ramping “front-end heavy” 0.11µm DRAM processes for strategic foundry customer Infineon Technologies AG of Germany. Fab 4 also is being used to manufacture 300mm wafers with 0.10µm DRAM processes for Elpida Memory Inc. of Japan. Another phase of the Beijing manufacturing center is Fab 6C, which initially will be used to run BEOL copper processes for customers. This 300mm line will service SMIC’s foundry agreement with Texas Instruments Inc. and will provide full-flow 90nm logic processes. Also in Beijing, Fab 5 - a planned 300mm logic fab module currently under construction - will ramp up later in accordance with market demand.
Like other 300mm fabs worldwide, the SMIC Beijing facility was designed from the ground up with high levels of automation and wafer transport capabilities. The facility employs a design layout that allows for fully integrated fab-automation systems. Its state-of-the-art computer integrated manufacturing system is based on the company’s 200mm manufacturing execution system with additional 300mm functions for front-opening unified pod (FOUP) management, sorter automation, wafer-level tracking, and support of multilot
ecipe capabilities in one FOUP (see photo this page).
One of the keys to running a successful 300mm manufacturing business is the ability to offer multiple technologies and processes, while achieving efficiency equal to or higher than 200mm production. As of late November 2004, the SMIC Beijing facility had achieved 300mm yields that were equal to or better than 200mm processing. However, the new 300mm fab continues to focus on maintaining stable yields as production ramps to higher volumes. The ultimate target for 300mm fabrication is to provide full-foundry capabilities for memory, logic, and mixed-signal applications, using technologies down to 65nm. To this end, the 300mm foundry plant was scheduled to qualify for its first logic process for 0.15µm technology by the end of 2004, with 90nm “risk” production scheduled to start in the third quarter of 2005. The 300mm capacity is expected to grow from about 3000 wafers/month at the end of 2004 to 22,000/month by the end of 2005.
Tailoring 300m fabs for Beijing
Constructing and operating a 300mm wafer fab in Beijing presents some unique challenges to overcome. As perennial sand storms sweep across the Mongolian deserts to Beijing at least twice a year, special design features were implemented to ensure that fab buildings would not be infiltrated by dust and sand. The three levels of protection - sand trip louvers, auto roll filters, and air filters and washers - effectively work to keep out sand particles. These measures help maintain Class 100 and Class 1000 cleanroom air standards in the photolithography bay area and elsewhere in the fab, respectively.
In addition, the design of the 300mm facility had to take into account Beijing’s limited water resources and the high cost of water and wastewater treatment. This prompted additional features to the building design to maximize water conservation. Rainwater collection tanks, with a total capacity of 2600m3, collect and store rainwater for daily operational usage. Additionally, an intricate network of water collection and reclamation systems helps to re-use cleanroom and industrial water. By the end of 2006, the reclaim ratio of ultrapure water used in the facility’s cleanrooms for wafer manufacturing is expected to reach 80%.
Beijing’s winter temperature also provides opportunities for saving energy. During the cold season, from November to March, cooling towers take advantage of the outside air to create a “free” cooling system for chilling operations, enabling the shutdown of all chillers normally used to supply the process-cooling water system, dry coils, and make-up air units. Heat also is reclaimed from steam and reused for operational needs. Also, the Beijing site’s buildings were designed and constructed to insulate against temperatures as low as -15°C.
Conclusion
In the initial stage of 300mm manufacturing in China, it is more advantageous for foundries to follow an IDM model by offering few products in large volumes. However, as 300mm manufacturing systems mature, foundries in China should become more flexible in processing large-diameter wafers, and that will lead to greater diversity in technology offered in 300mm fabs. Cost pressures and the need for greater capacity will influence a growing number of advanced IC players to consider manufacturing investments in China. Thus, China’s IC industry will move even closer to the forefront of advanced technology and manufacturing capability by decade’s end.
Marco Mora received his masters in physics from the U. of Milan, Italy, and is COO of SMIC, No. 18 Zhangjiang Road, Pudong New Area, Shanghai, People’s Republic of China 201203; ph/86/21-5080-2000, fax 86/21-5080-2868, e-mail [email protected].