Greg Wong is founder and principal analyst at Forward Insights in North York, Ontario. His areas of focus are the technology, cost, performance, competitive landscape, markets and applications of multi-bit per cell NAND, NOR and NROM flash memories, emerging memories and solid-state drives. Wong previously held management positions in strategic planning, business development and engineering at Hitachi, Siemens, ProMOS and Qimonda/Infineon. At Qimonda/Infineon, Wong was responsible for competitive intelligence and reverse engineering for flash memories.
In short, how does the manufacturing process work for NAND flash chips?
NAND flash chips are made in a factory, or fabrication plant, commonly known as a fab. In the central part of a fab is a clean room, where the environment is controlled to eliminate dust and vibration. Each fab has a maximum capacity based on the equipment at the factory. At the fab, NAND chips are etched onto wafers that are tested and sent to the back-end assembly and test facility. The wafers are sliced into individual die, packaged and tested. The packaged components are then shipped to systems manufacturers that solder the NAND components onto printed circuit boards for whatever devices they are manufacturing.
If a market oversupply situation occurs causing a precipitous drop in pricing, manufacturers will typically suspend production expansion plans. In some cases when prices have fallen below costs, manufacturers have curtailed fab output to bring supply in line with demand.
In the event of a tight supply or undersupply situation, NAND flash chip manufacturers may add production capacity to a fab that still has clean-room space for additional equipment. The ramp-up of this incremental output process generally takes up to three months. The construction of a new fab is not an option for alleviating short-term supply constraints because it can take 18 months from the start of construction at a greenfield site to obtaining output from the fab.
The NAND industry currently has six manufacturers: Intel, Micron, SK Hynix, Samsung, SanDisk and Toshiba. SanDisk and Toshiba have joint manufacturing facilities, but SanDisk allocates its fab capacity only to its own products. Intel has a similar arrangement with Micron. All NAND manufacturers sell NAND components and produce their own solid-state drives (SSDs).
NAND flash chips are used in many devices, including SSDs, laptops, tablets, mobile phones, GPS devices, USB drives and flash memory cards.
This was first published in May 2013