As the battle of HBM intensifies between memory giants, the competition of NAND is also heating up. According to a report by Korean media outlet etnews, SK hynix is developing 400-layer NAND flash memory, aiming to get the technology ready for mass production by the end of 2025.

Citing sources familiar with the matter, the report notes that SK hynix is currently working with supply chain partners to develop process technologies and equipment needed for 400-layer and above NANDs. As the company plans to apply hybrid bonding to achieve the breakthrough, many packaging materials and components suppliers are expected to enter the new supply chain.

According to the report, SK hynix is reviewing new materials for bonding and various technologies for connecting different wafers, including polishing, etching, deposition, and wiring. With the goal of getting the technology and infrastructure ready by the end of next year, full-scale production for the 400-layer NAND is anticipated to begin in the first half of 2026.

Currently, the Big Three in the memory sector are all trying to push the boundaries on the layers of NAND. Earlier in April, Samsung confirmed that it has begun mass production for its one-terabit (Tb) triple-level cell (TLC) 9th-generation vertical NAND (V-NAND), with the number of layers reaching 290. For now, the company aims to stack V-NAND to over 1000 layers by 2030.

Micron, on the other hand, has announced the 2650 client SSD, its first product built from 276-layer 3D NAND on July 30^th. Japanese memory chipmaker Kioxia, after successfully increasing the number of 3D NAND layers to 218 in 2023, even stated that achieving a 1,000-layer level by 2027 would be possible.

In August, 2023, SK hynix showcased its sample of the world’s first 321-layer NAND product. Now, as the limit is expected to be pushed up to 400 layers, the company plans to apply hybrid bonding to the manufacturing, which adopts a “wafer-to-wafer” (W2W) structure, etnews notes.

According to the report, until now, SK hynix has been stacking cells on top of the peripherals, the driving circuit area, using the method of “Peripheral Under Cell (PUC)” to manufacture NAND. The structure is similar to a mixed-use high-rise apartment where the peripheral (commercial space) is at the bottom and the cells (residential units) are stacked on top.

However, as the number of NAND layers increases, the peripheral is prone to be damaged during the cell stacking process due to the high heat and pressure generated during the cell process, the report explains.

Therefore, SK hynix plans to apply hybrid bonding to overcome the issues. By implementing cells and peripherals on separate wafers and then bonding the two wafers together, the method allows the peripheral wafer that drive the cells to be separately manufactured, thus enabling a stable increase in NAND layers.

Regarding the progress on the development of 400-layer NAND, SK hynix stated that it cannot confirm details about its technology development or mass production timeline, the report notes.

Read more

• [News] SK Hynix Plans to Manufacture 3D NAND over 400 Layers at -70°C with the Help of TEL
• [News] Outpacing Samsung or the End of Race? Kioxia Aims 1000-layer NAND by 2027

(Photo credit: SK hynix)

According to TrendForce’s latest memory spot price trend report, neither did the DRAM nor NAND spot prices sees much momentum last week. Spot prices of DDR4 and DDR5 products didn’t show significant fluctuations as the market has not seen a demand uptick. As for NAND flash, the wave of stocking demand during July in response with the peak season in the third quarter of each year didn’t appear. Details are as follows:

DRAM Spot Price:

In the spot market, the overall trading volume has fallen further because the demand for consumer electronics has yet to rebound, and Taiwan’s spot trading was suspended for two days (from July 24th to 25th) due to a typhoon. The spot market as a whole has not seen a demand uptick compared to the previous week, and buyers are mostly waiting for further developments. Consequently, spot prices of DDR4 and DDR5 products have not shown significant fluctuations. The average spot price of the mainstream chips (i.e., DDR4 1Gx8 2666MT/s) dropped by 0.35% from US$2 last week to US$1.993 this week.

NAND Flash Spot Price:

The spot market would usually generate a wave of stocking demand during July in response with the peak season in the third quarter of each year, but has been rather sluggish this year due to the sufficient extent of inventory among end clients, as well as enervated market demand. A small number of spot traders were attempting to lower their quotations tentatively last week in the hope of revitalizing buyers’ demand, which was proven to be quite ineffective. Generally speaking, recent spot market prices have been somewhat lethargic alongside a continuous shrinkage of transactions. Spot price of 512Gb TLC wafers remains unchanged this week at US$3.253.

According to TrendForce’s latest memory spot price trend report, DRAM spot prices have finally stabilized as Samsung is committed to propping them up. Spot prices of DDR4 products, in particular, continue the momentum. As for NAND flash, demand for a small extent of inventory replenishment remains possible for 3Q24, which may help the sales performance from the spot market to improve from that of 2Q24. Details are as follows:

DRAM Spot Price:

DRAM spot prices, which had experienced a long period of decline, have finally stabilized as Samsung is committed to propping them up. Spot prices of DDR4 products, in particular, have risen slightly. Additionally, since spot prices are currently lower than contract prices for both DDR4 and DDR5 products, module houses and other buyers prefer spot trading. This, in turn, has helped stabilize spot prices. The average spot price of mainstream chips (i.e., DDR4 1Gx8 2666MT/s) has increased by 0.81% from US$1.979 last week to US$1.995 this week.

NAND Flash Spot Price:

Spot prices have started to stabilize recently as a result of reluctance in truncation from spot traders and module houses, as well as the consideration on how the growth of demand has been exceedingly confined by the drop of prices. Demand for a small extent of inventory replenishment remains possible for 3Q24, when sales performance from the spot market is expected to improve from that of 2Q24. On the whole, spot prices would first maintain equilibrium whilst awaiting for the final development of suppliers’ contract prices and the market status for 3Q24, before deciding on subsequent actions. Spot prices of 512Gb TLC wafers have dropped by 0.58% this week, arriving at US$3.272.

Chul Joo Hwang, Chairman of South Korean semiconductor equipment company Jusung Engineering, recently stated that future semiconductors will stack transistors together, as the expansion of DRAM and logic chips has reached its limit. Stacking transistors like NAND is necessary to overcome these challenges.

According to a report from South Korean media outlet The Elec, Hwang believes this means developing more atomic layer deposition (ALD) technology to reduce the use of extreme ultraviolet (EUV) lithography steps in the production process of advanced chips.

ALD technology is a thin film process that allows materials to grow layer by layer, offering high uniformity, precise thickness control, and excellent step coverage, overcoming challenges faced by traditional process technologies.

Reportedly, stacking transistors can reduce the need for further scaling of transistors. As evidence, deep ultraviolet (DUV) equipment is expected to be used in 3D DRAM production.

Hwang believes that as stacking becomes increasingly important, the demand for ALD equipment will also rise. Additionally, the production of III-V semiconductors and IGZO semiconductors requires ALD equipment.

Read more

• [News] Robust Demand in AI Drives South Korea’s Chip Exports in June to Record High
• [News] South Korea to Boost Semiconductor with a 26 Trillion Won Subsidy Program Starting in July

(Photo credit: Jusung Engineering)

According to TrendForce’s latest memory spot price trend report, prices of DDR4 chips have risen noticeably. Though inventory levels are still high for DDR4, buyers prefer DDR4 over DDR5 due to the price discount. On the other hand, the NAND Flash spot market remains lethargic in transactions. Details are as follows:

DRAM Spot Price:

Recent developments in the spot market show that prices of DDR4 chips have risen noticeably. Even though inventory levels are still high for DDR4 products at this moment, buyers prefer DDR4 over DDR5 due to the price discount. Moreover, DRAM suppliers intend to stabilize spot prices of DDR4 products and halt the ongoing decline. Hence, there has been an improvement with respect to the price trend. Nevertheless, further monitoring of inventory levels is necessary in order to determine whether this rally will continue for a longer while. The average spot price of mainstream chips (i.e., DDR4 1Gx8 2666MT/s) has risen by 2.92% from US$1.918 last week to US$1.974 this week.

NAND Flash Spot Price:

The NAND Flash spot market remains lethargic in transactions, and various products are starting to experience a drop in prices after the mainstream 512Gb TLC wafer dipped below the US$3 threshold last week. With that said, buyers are still showing hesitation towards price inquiries despite slowed down decrement of spot prices, thus leaving no room for optimism on transactions. 512Gb TLC wafer spots remain unchanged in prices this week at US$3.291.