(The following is an update of a post that originally ran on 6 December 2013. It was republished in 2024 as a part of a series on The Memory Guy blog to honor the 3D NAND inventors who have received the 2024 FMS Lifetime Achievement Award.)
A very unusual side effect of the move to 3D NAND was Continue reading “3D NAND’s Impact on the Equipment Market”
(The following is an update of a post that originally ran on 29 November 2013. It was republished in 2024 as a part of a series to honor the 3D NAND inventors who have received the 2024 FMS Lifetime Achievement Award.)
Some of my readers have asked: “How is 3D NAND Continue reading “How Do You Erase and Program 3D NAND?”
(The following is an update of a post that originally ran on 22 November 2013. It was republished in 2024 as a part of a series to honor the 3D NAND inventors who have received the 2024 FMS Lifetime Achievement Award.)
A prior post in this series (3D NAND: Making a Vertical String) discussed the difficulties of Continue reading “3D NAND: Benefits of Charge Traps over Floating Gates”
(The following is an update of a post that originally ran on 1 November 2013. It was republished in 2024 as a part of a series to honor the 3D NAND inventors who have received the 2024 FMS Lifetime Achievement Award.)
Let’s look at how one form of 3D NAND is manufactured. For this post we will explore Continue reading “3D NAND: Making a Vertical String”
I was saddened to hear last week of the death this month of Simon Sze, the co-inventor of the floating gate, which was the basis of EPROM, E²PROM, and nearly all flash memory prior to the advent of 3D NAND, which uses a charge trap instead.
Dr. Sze was not only responsible for the floating gate, but he was a pioneer in Continue reading “Remembering Simon Sze”
I recently was asked how much 3D NAND pitches had shrunk since the technology’s 2013 introduction. Samsung made a big to-do about using 40nm back in 2015, but the company and its competitors don’t seem to have given an update since then. Shouldn’t it have gone to smaller processes like 35nm, 25nm, 20nm, etc.?
The Memory Guy’s reply was that it’s nearly impossible Continue reading “Why 3D NAND is Stuck at 40nm”
A significant transition has occurred over the past few years that many people don’t know about: Flash memory has moved almost wholesale from the floating gate bit cells, the process that they had always used before, to charge trap bit cells.
Until 2002 all flash used a floating gate. That year partners AMD & Fujitsu, who later merged Continue reading “The Invention of Charge Trap Memory – John Szedon”
In a little 3-minute video released this week for the SEMICON West conference, Applied Materials dramatizes the 3D NAND manufacturing process by using hailstorms for atomic level deposition (ALD) and lightning bolts for etch, all while explaining that the wafer’s surface reaches temperatures hotter than the surface of the sun.
For those who already understand 3D NAND manufacture it’s an interesting Continue reading “Applied Materials Video Dramatizes 3D NAND Manufacture”
This week both the Toshiba-Western Digital team and Samsung disclosed details of their 64-layer 3D NAND designs at the IEEE’s International Solid-State Circuits Conference (ISSCC). The Memory Guy thought that it would be interesting to compare these two companies’ 64-layer chips against each other and against the one that Micron presented at last year’s ISSCC.
Allow me to point out that it’s no easy feat to get to 64 layers. Not only must the process build all 64 layers (or actually pairs of layers plus some additional ones for control) across the entire 300mm wafer with high uniformity and no defects, but then holes must be etched through varying materials from the top to the bottom with absolutely parallel sides at aspect ratios of about 60:1, that is, the hole is 60 times as deep as it is wide. After this the fab must deposit uniform layers of material onto the sides of these skinny holes without any variation in thickness.
None of these processes have ever been used to build any other semiconductor — it’s all brand new. This is what makes 3D NAND so challenging, and it’s why the technology is already 3 years behind its original schedule.
It’s not easy to tell from the conference papers whether or not Continue reading “64-Layer 3D NAND Chips Revealed at ISSCC”
At the Flash Memory Summit yesterday ES Jung, PhD, EVP & GM for the Samsung R&D Center, explained the inner workings of Samsung’s new V-NAND vertical NAND flash technology. I will shortly be writing a series to explain what a 3D NAND is since there is little on the web that gives clear details about the technology.
One key attribute of most 3D NAND approaches is the use of a charge trapping layer. This has to do with the difficulty of manufacturing sideways floating gates.
Dr Jung delighted the show’s audience by explaining that a standard floating gate is like Continue reading “Samsung’s View on Charge Trap Flash”
