Feasibility Analysis of Mass Production for 3D Stacking Technology

Based on existing public information, no specific news reports about Fujitsu and SoftBank’s joint research and development of new memory have been found. However, combined with the current development trend of the semiconductor memory industry, a systematic analysis can be conducted on the

.

is currently the most mature 3D stacking technology, widely used in AI accelerators and high-performance computing fields:

• HBM3/HBM3E
  : Leading manufacturers such as SK Hynix, Samsung, and Micron have achieved mass production
• HBM4
  : According to Samsung’s latest progress, it is advancing the 2026 supply plan [1]
• Technical Architecture
  : Realizes vertical stacking of multiple memory chips through Through-Silicon Via (TSV) technology

also adopts a multi-layer stacking architecture:

• Mainstream products have reached more than 200 layers
• Yangtze Memory Technologies Co., Ltd. (YMTC) is advancing the development of HBFnext technology [2]
• Equipment localization remains an important challenge

Technology Type	Maturity	Mass Production Status
HBM3/HBM3E	High	Mass-produced
HBM4	Medium	Expected in 2026
3D NAND	High	Large-scale mass production
New memory (ReRAM etc.)	Low	Small-batch production

:

• 3D stacking requires precise alignment and bonding technology
• Through-Silicon Via (TSV) processing requires extremely high yield rates
• Thermal management has become a key bottleneck for multi-layer stacking

:

• Wafer fab construction costs are as high as billions of US dollars
• Advanced packaging processes significantly increase the cost per chip
• Currently, the price of a 4TB DDR5 RDIMM kit has exceeded that of a sports car [3]

:

• Supply of specialized equipment is relatively concentrated
• Strict requirements for high-purity materials
• Supply chain security has become a focus of attention for various countries

According to industry forecasts [4]:

• The annual shipment capacity of new memory will grow from 1.4 PB in 2024 to 13.5 EB in 2035
• Revenue scale is expected to increase from 565 million US dollars in 2024 to 171 billion US dollars in 2035
• DRAM and NAND flash prices are expected to continue rising in 2026

• Samsung/SK Hynix
  : Adopt a “profit-first” strategy and expand capacity cautiously [5]
• Micron
  : Expanding production in Boise, Japan, Taiwan, etc.
• YMTC
  : Plans to increase capacity through IPO financing
• TSMC
  : CoWoS packaging capacity continues to expand, and orders for 2026 have exceeded expectations

• Capital Threshold
  : Wafer fab investment starts at over 10 billion US dollars
• Technical Barrier
  : Only a few enterprises master mature processes
• Talent Reserve
  : The training cycle for professional engineers is long

Globally, only

four companies have profitable memory chip production capabilities [6]. New entrants like ASUS have clearly denied plans to build factories, believing that investment in this field is high-risk and does not fit their business model [7].

:

1. Short-term (1-2 years)
   : HBM3E and advanced 3D NAND will continue to expand production, and the technology is fully mature
2. Mid-term (3-5 years)
   : HBM4 and more advanced stacking technologies are expected to become popular, with yield rates and costs continuing to improve
3. Long-term (5-10 years)
   : New memory technologies (such as ReRAM) may enter the stage of large-scale mass production

:

If the two companies do have collaboration intentions, they are more likely to focus on:

• Customized memory solutions
• Application development in specific vertical fields
• Innovation in packaging technology or design level

Given the high investment and high barriers to entry in memory manufacturing, Fujitsu’s role is more likely to be design or system integration rather than front-end manufacturing. SoftBank’s participation as an investor is more in line with Masayoshi Son’s AI investment strategic layout in recent years.

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:
[1] Reuters - “Samsung Electronics highlights progress in HBM4 chip supply” (https://www.reuters.com/world/asia-pacific/samsung-electronics-highlights-progress-hbm4-chip-supply-2026-01-02/)
[2] DIGITIMES Asia - “YMTC’s challenges in localizing equipment for 3D NAND production” (https://www.digitimes.com/news/a20251230PD231/inpaq-passive-components-notebooks-price.html)
[3] VideoCardz - “This 4 TB DDR5 RDIMM kit is now more expensive than a sports car” (https://videocardz.com/newz/this-4-tb-ddr5-rdimm-kit-is-now-more-expensive-than-a-sports-car)
[4] Forbes - “Digital Storage And Memory Projections For 2026, Part 2” (https://www.forbes.com/sites/tomcoughlin/2026/01/02/digital-storage-and-memory-projections-for-2026-part-2/)
[5] Red94 - “Asus RAM production plans denied” (https://www.red94.net/news/59616-asus-ram-production-plans-denied-here-s-why-the-company-won-t-enter-dram-manufac/)
[6] Forbes - Market Analysis of Memory Technology (https://www.forbes.com/sites/tomcoughlin/2026/01/02/digital-storage-and-memory-projections-for-2026-part-2/)
[7] Red94 - “Asus RAM production plans denied” (https://www.red94.net/news/59616-asus-ram-production-plans-denied-here-s-why-the-company-won-t-enter-dram-manufac/)