96-Layer NAND in Perspective: WDC Video

WDC 96-Layer NAND Model with The Memory GuyIt’s pretty easy to go from talking about the earliest 24-layer 3D NAND to talking about the next-generation 32-layer 3D NAND, and then to progress through 48, 64, and more layers, but the amazing scale of a 96-layer part doesn’t really sink in when you just talk about numbers.

That’s why The Memory Guy was so charmed when Western Digital Corp. (WDC) invited me in for a briefing that gave me a more solid idea of how significant of a number 96 really is.  The company brought along a plastic model that replicated the structure of its 96-layer BiCS NAND chip using clear plastic which was dramatically lighted from the inside.

WDC’s model was constructed using standard plastic sheeting, probably 1/8″ thick (~3mm), one sheet to represent the conductive polysilicon and one to represent the insulating silicon dioxide for each layer.  Naturally, there are more than 96 layers in 96-layer NAND since there are source select transistors at the bottom and drain select transistors at the top.  This adds a little bit to the layer count.

Another layer in the middle of Continue reading “96-Layer NAND in Perspective: WDC Video”

Amazing 3D NAND Video

Carl Zeiss 3D NAND SEM videoChip reverse-engineering consultant Dick James pointed The Memory Guy to an absolutely amazing 25-second video of a 3D NAND chip.  The video’s made by the Carl Zeiss company.  It’s the second one from the top on this page: https://www.zeiss.com/semiconductor-manufacturing-technology/products-solutions/process-control-solutions/crossbeam-fib-sem.html

The video zooms around a portion of a 3D NAND die as layers are etched away and then restored.  Only the tungsten parts of the chip are shown, with the rest appearing to be empty space.  This serves to clarify it a good bit.  Dick James says that this makes it the equivalent of a 3D x-ray tomograph.

It’s a promotional piece for a Zeiss tool called the “Crossbeam FIB-SEM” that can both image and mill a chip.

Now I doubt that most Memory Guy readers would have a need for this tool, nor be able to afford something which is doubtlessly very expensive, but I am sure that anyone would admire what  it can do.  I certainly find it to be impressive!

Naturally, Dick James was able to identify the chip just by looking at it.  He says that it’s Samsung’s 32-layer part.