With all the new emerging memories that are being developed there must be quite a number of test runs to study exactly how well these new technologies and materials can perform. If a batch of 300mm wafers must be used for a single test then the cost multiplies, particularly if no other test can be run on that wafer.
Another great difficulty is that most memory manufacturers run their wafers on very high-efficiency and high-volume wafer fabs. It is perilous and wasteful to interrupt a production process to inject a batch of test wafers. Most fab managers would rather have a tooth pulled than to change their flow to accept an experimental lot.
What can be done to improve this situation?
Well the folks at Intermolecular, Inc. (IMI) explained to the Memory Guy that they have a solution: They have built a small fab that allows single wafers to be processed with varying parameters across a single wafer. In this way one wafer can be used to run 36 or more different experiments all at the same time. This is clearly more economical than having to run the experiment on 36 wafers or, even worse, 36 batches of wafers! Intermolecular says that, while production fabs are optimized for manufacturing, their fab is optimized for materials understanding.
The firm calls itself an Continue reading “Accelerating New Memory Materials Research”
The previous post in this series (excerpted from the Objective Analysis and Coughlin Associates Emerging Memory report) explained why emerging memories are necessary. Oddly enough, this series will explain bit selectors before defining all of the emerging memory technologies themselves. The reason why is that the bit selector determines how small a bit cell can get, and that is a very significant component of the overall cost of the technology. Cost, of course, is extraordinarily important because no system designer would use a component that would make a system more expensive than it absolutely needs to be!
A number of the Memory Guy’s readers may never have heard of a selector. I’ll explain it here. It’s not complicated.
Every bit cell in a memory chip requires a selector. This device routes the bit cell’s contents onto a bus that eventually makes its way to the chip’s pins, allowing it to be read or written. The bit cell’s technology determines the type of selector that is appropriate: SRAMs use two transistors, DRAMs use one transistor, and flash memories combine a transistor with the Continue reading “Emerging Memories Today: Understanding Bit Selectors”
Non-silicon memory technologies have been studied for about as long as have silicon-based technologies, but the silicon technologies have always been preferred. Why is that, and why should anything change?
This is a question that The Memory Guy is often asked. The answer is relatively simple.
Silicon memory technologies benefit from the fact that they have always been manufactured on process technologies that are nearly identical to those used to produce CMOS logic, and can therefore take advantage of the advancements that are jointly developed for both memory and logic processes. In fact, before the middle 1980s, logic and memory processes were identical. It wasn’t until then that the memory market grew large enough (over $5 billion/year) that it could support any additional process development on its own.
Even so, memory processes and logic processes are more similar than different. This synergy between memory and logic continues to reduce the process development cost for both memories and logic.
Emerging memories depart from Continue reading “Emerging Memories Today: Why Emerging Memories are Necessary”
There’s never been a more exciting time for emerging memory technologies. New memory types like PCM, MRAM, ReRAM, FRAM, and others have been waiting patiently, sometimes for decades, for an opportunity to make a sizeable markets of their own. Today it appears that their opportunity is very near.
Some of these memory types are already being manufactured in volume, and the established niches that these chips sell into can provide good revenue. But the market is poised to experience a very dramatic upturn as advanced logic processing nodes drive sophisticated processors and ASICs to adopt emerging persistent memory technologies. Meanwhile Intel has started to aggressively promote its new 3D XPoint memory for use as a persistent (nonvolatile) memory layer for advanced computing. It’s no wonder that SNIA, JEDEC, and other standards bodies, along with the Linux community and major software firms are working hard to implement the necessary standards and ecosystems to support widespread adoption of the persistent nature of these new technologies.
This post introduces a Continue reading “Emerging Memories Today: New Blog Series”
There has been a lot of discussion in the trade press lately about new memory technologies. This is with good reason: Existing memory technologies are approaching a limit after which bits can’t be shrunk any smaller, and that limit would put an end to Moore’s Law.
But there are even more compelling reasons for certain applications to convert from today’s leading technologies (like NAND flash, DRAM, NOR flash, SRAM, and EEPROM) to one of these new technologies, and that is the fact that the newer technologies all provide considerable energy savings in computing environments.
Objective Analysis has just published a white paper that can be downloaded for free which addresses a number of these technologies. The white paper explains why energy is wasted with today’s technologies and how these new memory types can dramatically reduce energy consumption.
It also provides a Continue reading “Latest White Paper: New Memories for Efficient Computing”
Recently I have been hearing concerns that an impending wafer shortage might drive today’s DRAM and NAND flash shortages to epic proportions.
The Memory Guy doesn’t pretend to have any understanding of the raw wafer business, so I decided to consult Mark Thirsk, managing partner of Linx Consulting. Mark has been in this industry for quite a while and has a very good understanding of the ongoing status of the semiconductor materials supply chain.
Mark and I were on a panel together at SEMICON Korea in February, and he presented an interesting chart to compare the costs of different technologies. I asked him about this chart as well.
Here’s what Mark had to say:
“Our information is that major Continue reading “Wafer Shortages and DRAM/NAND”
With Micron & Intel’s July 28 introduction of their new 3D XPoint memory both companies touted that his is the first new memory in a long time, and that the list of prior new memory types is short.
How short is that list? Interestingly, Intel and Micron have different lists. The Micron list, shown in this post’s graphic (click to enlarge), cites seven types: “Ram” (showing a vacuum tube), PROM, SRAM, DRAM, EPROM, NOR flash, and NAND flash. Intel’s list adds magnetic bubble memory, making it eight. (Definitions of these names appear in another Memory Guy blog post.)
The Memory Guy finds both lists puzzling in that they left out a number of important technologies.
For example, why did Intel neglect EEPROM, which is still in widespread use? EEPROMs (or E²PROMs) are not only found in nearly every application that has a serial number (ranging from WiFi routers to credit cards), requires calibration (like blood glucose monitoring strips and printer ink cartridges), or provides operating parameters (i.e. the serial presence detect – SPD – in DRAM DIMMs), but they still ship in the billions of units every year. In its time EEPROM was an important breakthrough. Over the years EEPROM has had a much greater impact than has PROM.
And, given that both companies were willing to include tubes, a non-semiconductor technology, why did both Continue reading “How Many Kinds of Memory Are There?”
There has been quite a lot of interest over the past few days about the apparently-inadvertent disclosure by Intel of its server platform roadmap. Detailed coverage in The Platform showed a couple of slides with key memory information for the upcoming Purley server platform which will support the Xeon “Skylake” processor family. (A review of this post on 7/13/17 revealed that The Platform’s website has disappeared. The above link and the next one no longer work.)
One slide, titled: “Purley: Biggest Platform Advancement Since Nehalem” includes this post’s graphic, which tells of a memory with: “Up to 4x the capacity & lower cost than DRAM, and 500x faster than NAND.”
The Memory Guy puzzled a bit about what this might be. The only memory chip technology today with a cost structure lower than that of DRAM is NAND flash, and there is unlikely to be any technology within the leaked roadmap’s 2015-2017 time span that will change that. MRAM, ReRAM, PCM, FRAM, and other technologies can’t beat DRAM’s cost, and will probably take close to a decade to get to that point.
Since that’s the case, then what is this mystery memory? If we think of Continue reading “What Memory Will Intel’s Purley Platform Use?”
The Memory Guy was recently asked about using memories in a satellite. What would be a good technology to use in a space application?
The problem with space is that there is a lot of radiation. Radiation on the earth’s surface is lower because it is stopped by the atmosphere, but in space there is an abundance of radiation that interferes with most semiconductors. Radiation is also a concern in certain medical applications where a memory must maintain its contents while undergoing sterilization through irradiation. Experiments on conventional flash memories have shown data loss at only 2% of the Continue reading “Memory Issues in Space & Medical Applications”
Wiley has recently published a new book by Betty Prince titled Vertical 3D NAND Technologies that is one to consider if you want to bring yourself up to speed on recent research behind today’s and tomorrow’s 3D memory technologies.
For those who haven’t previously encountered Dr. Prince, she is the author of a number of key books covering memory design and holds memory patents written over her 30-year career in the field.
The book provides capsule summaries of over 360 papers and articles from scholarly journals on the subject of 3D memories, including DRAM, NAND flash, and stacked chips.
These papers are organized into Continue reading “New Book: Vertical 3D Memory Technologies”