Two 450-layer cell wafers bonded
Wafer warpage and misalignment errors overcome
Countering China's volume and pricing offensive
Samsung Electronics Co. has successfully implemented the world's first 900-layer-class Vertical NAND (V-NAND) prototype technology, taking another step closer to the era of “1,000-layer NAND.” Amid the recent intense stacking competition with rivals, evaluation shows that the company has secured a “super-gap” technology in one fell swoop.
According to the semiconductor industry on May 25, Samsung recently implemented an integrated 900-layer-class V-NAND system using its proprietary “Cell Multi-Bonding (CMB)” technology, which bonds two 450-layer cell wafers into one.
NAND flash memory, which stores data, is a core component for artificial intelligence (AI) servers, smartphones, and data center solid-state drives (SSDs). Just like an apartment building, stacking higher layers increases capacity, allowing more data to be packed into a limited chip size while maximizing power efficiency. It is considered a key technology to seize dominance in the AI server and on-device AI markets, where high-capacity and high-efficiency components are essential.
In the current mass-production market, SK Hynix Inc. holds the highest layer count with its 321-layer 4D NAND. However, Samsung has positioned itself advantageously in the next-generation NAND market by simultaneously preparing for mass production of its 10th-generation V-NAND (V10, 400-plus layers) this year while reaching the 900-layer milestone at the research stage in a single bound.
Regarding these research results, Samsung stated, “Normal cell operation characteristics were verified,” emphasizing that the technology has reached a level where actual operation is possible, moving beyond a simple theoretical stack.
Since commercializing the world's first 3D V-NAND in 2013, Samsung has constantly evolved its manufacturing processes to overcome stacking limits. In the past, the company used a “single-stack” method where microscopic holes were drilled and stacked at once, but it faced physical limitations such as wafer warpage or misalignment as the number of layers increased.
Samsung solved the wafer warpage issue--the biggest obstacle in implementing the 900-layer structure--by introducing an advanced upper chuck design. Furthermore, microscopic misalignment errors occurring during bonding were overcome through its proprietary “new overlay correction” technology. Thanks to the newly introduced bitline (BL) and wordline (WL) structures, the company also achieved meaningful results by simultaneously reducing power consumption and chip size.
In the global market, China is chasing Korean companies, centering around Yangtze Memory Technologies Co. (YMTC) at the threshold of mass-producing 300-layer-class NAND stacking. Backed by government support and the localization of domestic equipment, China is simultaneously pursuing production capacity expansion and technological advancement.
If YMTC successfully mass-produces 300-plus layers within this year, price competition is highly likely to intensify, putting pressure on the profitability of Korean companies. For this reason, Samsung's implementation of the 900-layer structure is highly evaluated as a strategic response to erect technological barriers over the medium to long term.
An industry insider said, “The 900-layer NAND technology is not simply three times the layers of 300 layers, but a technology that shifts the paradigm of the stacking process.” The insider added, “This sends a message to global customers that Samsung remains the technology leader, and it will have the effect of limiting the volume and pricing offensive of Chinese companies.”
