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NEO Semiconductor's 3D X-DRAM for AI processors has passed proof-of-concept validation — company secures funding to develop next-gen HBM alternative

Fred Chen

Moderator
By Etiido Uko published 17 hours ago

Next-gen memory designed as a lower-cost, lower-power HBM alternative for AI workloads

NEO Semiconductor 3D X-DRAM


NEO Semiconductor 3D X-DRAM (Image credit: NEO Semiconductor)

NEO Semiconductor announced on April 23rd that its 3D X-DRAM technology has successfully passed proof-of-concept (POC) validation, demonstrating that a new class of high-density DRAM can be manufactured using existing 3D NAND infrastructure. The company simultaneously announced a new strategic investment led by Stan Shih, founder and former Chairman and CEO of Acer, and a board director of TSMC for over two decades.

At the center of the announcement is the company’s 3D X-DRAM technology, a new class of DRAM that aims to break past conventional memory scaling limits by adopting a vertically stacked architecture designed for higher density, lower power consumption, and improved suitability for AI-driven workloads.

NEO’s 3D X-DRAM’s architecture draws heavily on 3D NAND manufacturing techniques. According to the company, the POC chips were produced using mature 3D NAND processes, including existing equipment and materials. This is a critical point, as one of the main constraints in advanced memory development is not design innovation, but fabrication cost and process compatibility.

The proof-of-concept chips, fabricated and tested at Taiwan's National Institutes of Applied Research - Taiwan Semiconductor Research Institute (NIAR-TSRI) in collaboration with National Yang Ming Chiao Tung University, delivered the following results:

Read/write latency: under 10 nanoseconds
Data retention: over 1 second at 85°C/185°F (claimed 15× improvement over JEDEC standard)
Bit-line disturbance: over 1 second at 85°C (185°F)
Word-line disturbance: over 1 second at 85°C
Endurance: greater than 10¹⁴ cycles

"These results validate a new scaling path for DRAM," said Andy Hsu, Founder & CEO of NEO Semiconductor. "We believe this technology can enable significantly higher density, lower cost, and improved energy efficiency for the AI era. By leveraging established 3D NAND manufacturing processes and ecosystem, we aim to bring 3D DRAM to reality sooner. NEO is actively engaging with leading global memory and semiconductor companies on potential co-development opportunities, and we believe our technology is well suited for a scalable licensing and partnership model to bring next-generation AI memory solutions to market."

Industry commentary included in the announcement was quite positive — although this does not imply confirmation of viability at scale. TechInsights’ Jeongdong Choe described the results as a “significant milestone” in the shift toward 3D memory architectures, noting that conventional DRAM scaling is approaching physical limits and that the industry is increasingly exploring vertical alternatives.

The broader context behind this development is the growing strain AI workloads are placing on memory systems. While GPU compute performance has scaled aggressively over the past decade, memory bandwidth — the rate at which data can be fed to those processors — has become a limiting factor in large-scale AI training and inference systems. This has already driven widespread adoption of high-bandwidth memory (HBM), a vertically stacked DRAM architecture integrated close to GPUs. However, HBM presents complex 3D stacking and bonding requirements and high manufacturing costs.

Quick clarification sidebar: 3D X-DRAM and HBM both use vertical stacking concepts, but they stack different things in different ways. HBM stacks multiple finished DRAM dies on top of each other, then connects them with through-silicon vias (TSVs) and places them beside/near a GPU or CPU on an interposer. 3D X-DRAM, based on NEO’s claims. aims to build memory cells in a 3D NAND-like monolithic vertical structure, where layers are fabricated as part of the memory array itself rather than stacking separate packaged DRAM dies.

3D X-DRAM is just one of several technologies under development to address the AI memory problem. Just a day before NEO Semiconductor’s announcement, we reported that SAIMEMORY and its ZAM architecture, backed by SoftBank and Intel with Japanese government support, is pursuing a similar goal on a parallel track.

NEO Semiconductor’s device successfully passed extensive electrical and reliability evaluations, confirming the robustness and stability of the proposed memory architecture. It is important to reiterate that this is a proof of concept, not a production-ready memory chip. The road from validated POC to commercial volume is long — and littered with the remains of promising memory technologies that never made it out of the lab. However, with NEO Semiconductor's usage of established 3D NAND processes, the future is bright.

"The successful proof-of-concept not only demonstrates the potential of innovative memory architectures, but also confirms the feasibility of implementing advanced memory technologies using mature processes. This collaboration among NEO, NYCU IAIS, and NIAR-TSRI further underscores the value of industry–academia partnerships in accelerating innovation from concept to practical implementation," said Jack Sun, Senior Vice President of NYCU and Dean of IAIS, and former CTO of TSMC.

 
Great progress by the Andy, Ray, and NEO team. wonder which main memory vendors will pick up this company and technology
 
Great progress by the Andy, Ray, and NEO team. wonder which main memory vendors will pick up this company and technology

Samsung had prototype level 3D DRAMs in labs for like 10 years. A big mystery is why they are not commercializing any yet, and went down the road of making <10nm 2D DRAMs instead.
 
Samsung had prototype level 3D DRAMs in labs for like 10 years. A big mystery is why they are not commercializing any yet, and went down the road of making <10nm 2D DRAMs instead.
From: https://www.thelec.net/news/articleView.html?idxno=6808

"The 10a node represents the first generation below 10 nanometers, with actual line widths estimated at around 9.5 to 9.7 nanometers."

"The company plans to use the 4F² and VCT structures across three generations — 10a, 10b and 10c — before transitioning to 3D DRAM at 10d."

It is relatively easy to stack up to ~10 layers but to go over >100 layers is still yet to be proven. Also, they have been trying non-silicon transistors.
 
Is the cycle endurance quoted here (10^14) in line with other DRAM on the latest manufacturing nodes?
These days, a new DRAM technology like IGZO, they often test to 1e11-1e12 cycles. Really we expect should go to 1e15 cycles, but that's 3 years of 100 ns cycles.
 
Memory does age by the way. Some memory tech actually sees error rates going down with age, rather than the opposite. Therefore an accelerated error test of physically fresh from the oven chips is not the same as the same test in a few years.
 
From: https://www.thelec.net/news/articleView.html?idxno=6808

"The 10a node represents the first generation below 10 nanometers, with actual line widths estimated at around 9.5 to 9.7 nanometers."

"The company plans to use the 4F² and VCT structures across three generations — 10a, 10b and 10c — before transitioning to 3D DRAM at 10d."

It is relatively easy to stack up to ~10 layers but to go over >100 layers is still yet to be proven. Also, they have been trying non-silicon transistors.

Is this true that 3D DRAM tech processes are so different that you cannot really upgrade a 2D RAM fab for it?

From what I hear first hand, Samsung's hesitancy to move 3D is exactly because most of 2D DRAM expertise, tools, and know-how is inapplicable. A move from 2 to 3 D for Samsung would be like starting its DRAM business anew.
 
3D DRAM is much harder to make than 3D NAND. If it's Si-based, you need to start with a Si/SiGe superlattice with 100+ layers that is both cost-effective and free of dislocations (to name one challenge). If it's IGZO-based... well, IGZO has made some progress recently but there are still some process issues. Neither of these two options is ready for production. Also, soon DRAM CBA (CMOS bonded Array) will come along and open alternative innovation paths that will be less risky than 3DNAND-style 3D DRAM.
 
Memory does age by the way. Some memory tech actually sees error rates going down with age, rather than the opposite. Therefore an accelerated error test of physically fresh from the oven chips is not the same as the same test in a few years.
In my experience - (DRAM) memory seems to age whether it's being used or not :). Though the ones that age to failure "on the shelf" are long past being mainstream memory chips.

That is interesting re: getting better with time. Is it a physical attribute, or is it more statistical -- those that survive the early days just bring the average longevity time up?
 
From POC to manufacturing is more than 8 years. and this POC was done in a lab, not a fab. I have a detailed lifecycle that expalins why.

Everyone is working on 3D DRAM and has been (as mentioned) for 5-10 year. the issues from my inputs are Cost and performance. Cost needs to be an advantage compared to doing a 15% area reduction. Performance is more difficult. NAND is a very low performance transistor technology. DRAM is not like that. Since DRAM is not really storing a bit, it is moving it from a latch to a capacitor and back continuously .... performance is important. and it needs random access. I have not heard any inputs from a memory company saying that 3D DRAM is lower cost and meeting performance goals. 4F is better off and definitely has line of site to lower cost.... performance I am not sure.

As a result 4F ramps in 2030, Our forecast for 3D is after 2035 but only for some parts of the market (a previous forecast had it tied to CXL high capacity DRAM).
 
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That is interesting re: getting better with time. Is it a physical attribute, or is it more statistical -- those that survive the early days just bring the average longevity time up?

Hmm, that's a quite interesting testing problem. Would anyone volunteer to give a lot of virgin, unused DRAM and flash of around 5 years for testing?

Faulty flash lots obviously delete products built with them from the market very early. Faulty DRAMs can probably linger much longer, given the practice of cheap, downgraded lots being preferred for ECC DRAM.
 
A
From POC to manufacturing is more than 8 years. and this POC was done in a lab, not a fab. I have a detailed lifecycle that expalins why.

Everyone is working on 3D DRAM and has been (as mentioned) for 5-10 year. the issues from my inputs are Cost and performance. Cost needs to be an advantage compared to doing a 15% area reduction. Performance is more difficult. NAND is a very low performance transistor technology. DRAM is not like that. Since DRAM is not really storing a bit, it is moving it from a latch to a capacitor and back continuously .... performance is important. and it needs random access. I have not heard any inputs from a memory company saying that 3D DRAM is lower cost and meeting performance goals. 4F is better off and definitely has line of site to lower cost.... performance I am not sure.

As a result 4F ramps in 2030, Our forecast is after 2035 but only for some parts of the market (a previous forecast had it tied to CXL high capacity DRAM).
A very illuminating input. Now, I got it. 3D will likely lag behind 2D DRAM on anything, but capacity, and therefore the big S hesitates
 
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