REGISTER | LOGIN
Breaking News
News & Analysis

64 Layers is 3D NAND's Sweet Spot

6/19/2017 05:31 PM EDT
15 comments
NO RATINGS
More Related Links
View Comments: Newest First | Oldest First | Threaded View
Page 1 / 2   >   >>
wgt0823
User Rank
Author
Re: The Missing Piece
wgt0823   6/23/2017 2:37:31 PM
NO RATINGS
 

The following slide is from Bhatia's presentation at the WDC 2016 Investor Day.  Note the 5-6X CapEX per wafer output and the 3X - 4X more tools.   The question i have is if this is true how are they are cost crossover?  I am assuming that current yields are not very good for the 64L process so at most they are at roughly 32TB of bit yield versus the 15nm planar TLC yield of approx. 7TB.  What am I missing?



wgt0823
User Rank
Author
Re: The Missing Piece
wgt0823   6/23/2017 2:01:13 PM
NO RATINGS
To be clear, Micron has claimed (various presentations and concalls) that they got cost crossover vs. their 16nm planar MLC with 32L MLC and got the 30% cost reduction only when they compared 32L TLC.   They have also claimed "mature" yields, while implying but never actually saying that they are close to the planar process yields.  I have assumed in my modeling that the term "mature" implies somthing close to 90% yield.  Do you agree?

Thanks for all of your informative posts.

ScottenJ
User Rank
Author
Re: The Missing Piece
ScottenJ   6/20/2017 10:31:02 PM
NO RATINGS
I'm not at my computer right now but my recollection is they showed it at the IMEC technology forum at SEMICON West last year.

realjjj
User Rank
CEO
Re: The Missing Piece
realjjj   6/20/2017 10:19:11 PM
NO RATINGS
Yes those are conversion too.

However, the new fabs are a consequence of the clearnroom space requirements for 3D. In the end it is a mix of new and old fabs as capacity transitions to 3D.

Stating that folks are ramping as fast as they can is courageous, it doesn't make economic sense to ever do that, even less so when you have to deploy this kind of Capex. if anything, the transition is slower than with a shrink- that's a fact as bit growth is bellow average and demand. this year. And do remember that bit crossover and wafer output crossover are very different here. The industry usually talks bits. Note that i do not argue that costs aren't better, at least for some. Micron and WD are ramping but WD did not do that with 48 layer while Micron changed its mind rather fast on 32 layer MLC.

realjjj
User Rank
CEO
Re: The Missing Piece
realjjj   6/20/2017 9:50:03 PM
NO RATINGS
I had it saved on the HDD, it is from Western Digital but can't quite remember where it was shown. Will edit this comment if i figure it out.

ScottenJ
User Rank
Author
Re: The Missing Piece
ScottenJ   6/20/2017 9:43:43 PM
NO RATINGS
Once again, these are transition costs. A greenfield 3D NAND fab is not 5 to 6x the cost of a greenfield 2D NAND fab. Build a greenfield 3D NAND fab next.to a greenfield 2D NAND fab and day one the 3D NAND cost per bit will be a lot lower and it won't take 64 layers to get there either. Every major NAND producer is ramping 3D NAND as fast as they can and starting to ship more 3D NAND than 2D NAND, they wouldn't do that if it didn't make sense from a cost perspective.

Sang-Yun
User Rank
Blogger
Re: The Missing Piece
Sang-Yun   6/20/2017 9:43:08 PM
NO RATINGS
Could share the source of the graph?

realjjj
User Rank
CEO
Re: The Missing Piece
realjjj   6/20/2017 9:33:04 PM
NO RATINGS
Just to add a bit, WD showed this graph not too long ago.



Ofc that's just a matter of CAPEX, cost depends on much more.

CAPEX might be what will drive string stacking.

resistion
User Rank
Author
Re: The Missing Piece
resistion   6/20/2017 9:13:31 PM
NO RATINGS
That's interesting. It also means Samsung will also be plagued by new fab costs.

ScottenJ
User Rank
Author
Re: The Missing Piece
ScottenJ   6/20/2017 9:07:13 PM
NO RATINGS
Those graphs compare a 2D transition from one node to the next to a 2D to 3D transition. 3D isn't 3 to 5x the capital cost of 2D or 3 to 5x the space just the transition is because 2D is litho centric and 3D is dep and etch centric. A converted fab is still cheaper than a new fab and can make use of some fully depreciated equipment. Yes you need a lot of new equipment too but it helps.

Page 1 / 2   >   >>
Like Us on Facebook
EE Times on Twitter
EE Times Twitter Feed