LONDON – Leading storage memory supplier SanDisk Corp. (Milpitas. Calif.) does not expect to use extreme ultraviolet (EUV) lithography for the manufacture of memories until it begins manufacturing resistive RAM sometime in the second half of this decade.
A response by Judy Bruner, executive vice president of administration and chief financial officer at SanDisk, to a question at a Morgan-Stanley financial event late February provided an outline of the expected transition of memory types coming at SanDisk.
When asked if SanDisk could avoid involvement with the much-delayed EUV lithography because the company would be moving to vertically-stacked memory structures Bruner said: "We'd like to use EUV at some point, but we don't think we need EUV for three-dimensionl NAND or what we refer to as BiCS [bit cost scalable]. So we view BiCS as a mid-term technology after we get through planar NAND."
Bruner then said that the three would be two more nodes of planar NAND production above 10-nm minimum geometry that would be ramped up before the move to 3-D structures. The 1Y-node would ramp in the second half of 2013 and would be followed by a 1Z-node that could start very late in 2014 and ramp during 2015. After that memory production would likely to go to 3-D NAND.
"We believe we would go to three-dimensional NAND or BiCS and won't need EUV for that. But when we get to 3-D resistive RAM, then we do believe we will need EUV. So it's several years out before we would require EUV," concluded Bruner.
Bruner's questioner interpreted that to mean 2017 or 2018. Bruner qualified that by saying: "Sometime in the second half of this decade."
I think the implication here is that NAND flash cannot scale below the 1Z-nm node although it can go vertical at the same planar dimensions
ReRAM can scale below 10-nm but would need to be deployed in a vertical structure to compete.