1000层3D NAND，实现路径

Core Viewpoint - The article discusses the evolution and advancements in NAND flash memory technology, particularly focusing on 3D NAND and its implications for data storage density and efficiency in various applications, including artificial intelligence and data centers [2][10]. Group 1: NAND Flash Memory Evolution - NAND flash memory has transformed data storage and retrieval since its introduction in the late 1980s, becoming essential in devices from smartphones to data centers [2]. - The shift from 2D to 3D NAND technology has allowed semiconductor companies to overcome limitations in traditional memory size reduction, leading to increased storage density [2][10]. - The industry is now focusing on enhancing storage unit density (measured in Gb/mm²) while reducing the cost per bit, with commercial NAND flash reaching up to four bits per cell [2][10]. Group 2: Technological Innovations - A significant advancement is the transition from floating gate transistors to charge trap cells, which improves read/write performance and allows for higher storage density due to smaller manufacturing sizes [3][10]. - The GAA (Gate-All-Around) architecture is being applied in 3D NAND, allowing for vertical stacking of storage units and efficient addressing through horizontal word lines [5][10]. - Future developments aim to achieve over 1000 layers in 3D NAND by 2030, with current chips already exceeding 300 layers, presenting challenges in maintaining uniformity and increasing manufacturing complexity [10][12]. Group 3: Addressing Challenges - The reduction of z-axis spacing between storage layers is crucial for lowering costs while increasing storage capacity, with current spacing around 40 nanometers [15][31]. - Techniques such as integrating air gaps between adjacent word lines are being explored to mitigate cell interference and improve performance [17][22]. - The introduction of charge trap layer separation is being tested to enhance the storage window and prevent charge migration, which could lead to better data retention and performance [26][29]. Group 4: Future Directions - The semiconductor industry is actively researching innovative architectures to maintain advancements in storage density beyond 2030, including horizontal arrangements of conductive channels and trench architectures [32]. - The demand for higher storage capacities is driven by applications in cloud computing and artificial intelligence, pushing the industry towards achieving 100 Gb/mm² storage density [32].