China Does It Again

A NAND Memory Market First

TechInsights has discovered the world's most advanced 3D NAND memory chip in a consumer device, and in a surprise technology leap, it comes from YMTC – China’s top 3D NAND manufacturer. 3D NAND memory is an essential component for high-performance computing (HPC) such as artificial intelligence (AI) and machine-learning. 3D NAND memory represents the bleeding edge of memory chip design, and is critical for high-performance, high-bandwidth computing such as AI. This is the first quad-level cell (QLC) 3D NAND die with more than two hundred active word lines that TechInsights has seen.

Figure 1: Image of YMTC 232L QLC Die. TechInsights, 2023.

The 232-layer QLC 3D NAND die manufactured by YMTC (Figure 1), was found in the ZhiTai Ti600 1TB solid state drive (SSD) which was launched in July 2023 without much fanfare (Figure 2 and Figure 3). This new QLC die has the highest bit density seen in a commercially available NAND product at 19.8 Gb/mm².

Key takeaways from this discovery include:

YMTC proved again the merits of the Xtacking Hybrid Bonding technology they developed for 3D NAND TLC and QLC applications. BSSC technology adopted for Xtacking3.0 232L realized yield and performance improvements, and cost reduction as well.
YMTC is quietly developing advanced technology despite being hampered by issues following sanctions including limiting the company from supplying parts to Apple for China-based iPhones and being placed on the United States’ entity list.
The recent memory downturn, as well as many memory manufacturers focused on cost saving measures, may have provided YMTC an opportunity to pull ahead with its higher bit density 3D Xtacking NAND.
This discovery usurps Micron and Intel (Solidigm) who are also developing 232-layer QLC 3D NAND devices. It should be noted that Samsung is not developing QLC on its 236-layer (V8) 3D NAND because its current strategy is to focus on the V9 3D NAND TLC and QLC. However, at Samsung’s Memory Tech Day last week, the company announced the first QLC product targeting the mobile market, a 512GB UFS 3.1 product with 176-layers (V7) technology. SK Hynix is mostly focused on TLC devices rather than QLC products.
Like the innovation revealed by TechInsights in the Huawei Mate 60 Pro’s HiSilicon Kirin 9000s processor (which used SMIC 7nm (N+2) process) evidence is mounting that China’s momentum to overcome trade restrictions and build its own domestic semiconductor supply chain is more successful than expected.