SUMCO CORPORATION
3436・Prime Market・Metal Products
Business
SUMCO Corporation is a specialized manufacturer whose sole business is the production and sale of silicon wafers, which serve as substrate materials for semiconductor devices. Centered on 300mm wafers, the company manufactures wafers of various diameters of 200mm and below, epitaxial wafers, and other products, supplying them to semiconductor manufacturers worldwide. It operates domestic manufacturing sites in Saga, Yamagata, Nagasaki, Hokkaido, Miyazaki, and Mie, and overseas manufacturing sites in Taiwan, the United States, and Indonesia, along with sales and technical support locations in Taiwan, Singapore, the United Kingdom, and the United States. The company was established in 1999 through joint investment by Sumitomo Metal Industries and the Mitsubishi Materials Group, and in 2002 the two companies' silicon wafer businesses were fully integrated. Its principal sales channel is a group of semiconductor manufacturers reached through Sumitomo Corporation (accounting for 27.0% of net sales for the current period), and sales to Taiwan totaled ¥153,232 million, representing approximately 37% of the total.
Business Model
This is a material-supply business model in which polycrystalline silicon is used as a raw material and, through the single-crystal pulling process and wafer processing process, high-precision silicon wafers are manufactured and sold directly to semiconductor manufacturers worldwide. Product differentiation relies on joint development with customers and high-precision processing technology, and maintaining a high share in leading-edge products is the key to profitability. As a capital-intensive industry, depreciation expense (¥115,692 million in the current period) has a significant impact on the earnings structure.
Company Strengths
The company maintains a high share in 300mm wafers for advanced logic, DRAM, and NAND used in AI data centers. Through a close joint-development framework with customers, the company conducts R&D activities aimed at securing 'first call' status for next-generation device wafers, investing ¥11,151 million in R&D during the fiscal year under review (2.7% of net sales).
300mm wafers are manufactured at four sites—Saga, Yamagata, Nagasaki, and Taiwan—while Silicon Wafers 200mm and Below are produced at a total of nine sites, comprising six domestic locations plus the U.S., Indonesia, and Taiwan. This multi-site structure, including the new plant in Omura, Nagasaki, achieves supply stability and diversification of geopolitical risk. Total capital expenditure for the fiscal year under review was ¥79,957 million, mainly directed toward expanding capacity for advanced 300mm products.
The technologies of the former Sumitomo Sitix (production commenced in 1962) and the former Mitsubishi Materials Silicon (established in 1958) were integrated in 2002. As a company specializing exclusively in semiconductor wafers for over 60 years, it possesses extensive manufacturing know-how and continuously promotes open innovation with domestic and overseas universities and suppliers, as well as increasing the precision of evaluation technologies.
ENVALITH's Perspective
Performance Trend
Revenue peaked at ¥441,083 million in FY2022 and then declined, recovering to ¥409,670 million in FY2025, but profit deteriorated rapidly. Operating profit in FY2025 was ¥1,342 million, while net profit fell into a net loss of ¥11,751 million. In Q1 of FY2026 (fiscal year ending December 2026), revenue was ¥101,402 million (down 1.0% year-on-year), with an operating loss of ¥5,273 million and a net loss attributable to owners of the parent of ¥8,469 million, continuing the losses. As an external factor, demand for AI-related advanced products remains strong, but the market polarization—continued weak demand for Silicon Wafers 200mm and Below and non-advanced products—is weighing on performance. A sharp rise in depreciation expenses (¥30,812 million in Q1) driven by expanded capital expenditure has pushed up fixed costs, making profitability improvement difficult without a recovery in the utilization rate. The forecast for the cumulative first half is revenue of ¥213,400 million and an operating loss of ¥7,700 million, indicating an expected widening of the loss.
Growth Strategy
Business restructuring through concentrated investment in 300mm advanced products and reorganization of the production system for Silicon Wafers 200mm and Below
Advancing the sophistication of 300mm manufacturing equipment to respond to strong growth in demand for advanced logic, DRAM, and NAND for AI and data center applications. Growth in NAND demand is also expected to continue in Q2, making the strengthening of capability to handle advanced products the top priority. Construction in progress stood at ¥90,284 million (¥123,432 million at the end of the previous fiscal year), reflecting ongoing capital expenditure.
For Silicon Wafers 200mm and Below, where demand remains sluggish, the Company is reviewing and reorganizing its production system to improve efficiency and profitability. In Q2, demand overall is expected to remain subdued, although some products are showing signs of recovery. Through optimization of the production system, the Company aims to reduce fixed costs and improve profitability.
Promoting the use of AI in manufacturing processes to improve productivity and strengthen cost competitiveness. With fixed cost burden heavy due to a sharp increase in depreciation expenses, reducing variable and manufacturing costs through AI utilization is key to improving profitability. Quantitative disclosure of specific effects has not been confirmed at this time.
Last updated: July 17, 2026