广发证券：存储代工模式迎来产业变革机会 关注晶圆代工和上游半导体设备公司

Group 1 - The core viewpoint of the report is that storage technology is advancing towards a dual-wafer stacking architecture (storage wafer + logic wafer) to achieve better overall system performance [1] - The domestic industry is expected to leverage abundant logic foundry resources to realize the synergistic development of storage IDM and logic foundry [1][2] - The report suggests focusing on wafer foundry and upstream semiconductor equipment companies as potential investment opportunities [1] Group 2 - In 3D NAND technology, domestic Xtacking technology and overseas BiCS technology have achieved discrete processing and integrated application of storage arrays and logic circuits, showing excellent product performance [1] - For example, Yangtze Memory's Xtacking architecture has improved NAND I/O interface speed from 800 MT/s to 3.6 GT/s, representing a more than fourfold increase since its introduction six years ago [1] - Future DRAM chips are expected to benefit from CBA technology, which separates the manufacturing of storage array wafers and logic control unit wafers, enhancing overall system performance [1] Group 3 - Logic wafers are expected to transition to a foundry model, allowing for the use of different processes and technologies compared to storage wafers, thus optimizing system-level performance [2] - For instance, Samsung's 10th generation V-NAND uses its logic process to manufacture peripheral circuits on separate wafers [2] - SK Hynix plans to adopt TSMC's advanced logic processes for its HBM4 products, which could enhance functionality through ultra-fine processes [2] Group 4 - The ongoing expansion of AI applications is significantly boosting the storage industry's prosperity, increasing the urgency for capacity expansion and technological upgrades in storage manufacturing [3] - The emerging model of storage foundry characterized by logic wafer foundry is expected to develop rapidly, improving semiconductor product performance, area, cost, and time to market [3] - As technology continues to evolve and iterate, the related supply chain is anticipated to benefit fully [3]