It appears that SanDisk has been talking up some technology which is a spectacular failure for Moore’s Law.
For those who came in late, Moore’s Law is the self-fulfilling prophecy that transistor counts on integrated circuits double every two years. It has been working pretty much as a prophecy since Moore came up with it.
But SanDisk seems to have managed to break the law with its 1Y generation of NAND flash nonvolatile memory. It has announced that it would be manufactured using 19-nm minimum geometry which is the the same as its 1X generation.
1X-nm is a term coined to denote a manufacturing process node somewhere between 10- and 19-nm. 1Y and 1Z imply nodes also between 10- and 19-nm but different to the 1X node.
According to eeTimes, SanDisk stared into the abyss of triple or quadruple patterning using masks and immersion lithography to define minimum geometries of 15-nm.
It thought while the technical possibility of getting to 15 or even 10-nm with multiple patterning was straight forward enough, there were too many concerns about the extra dwell time on machines, the complexity of additional process steps and the impact on yield.
SanDisk found a way to improve the memory cell through design by reducing the area by about 25 percent without scaling the geometry.
All this lateral thinking certainly runs against the “spirit” of Moore’s Law. But really this sort of thing could have been predicted a while back as his black and white principles started to grey. First there was the introduction of such terms like 1X, 1Y and 1Z which are pretty confusing, and in the logic world FinFET processes are also chucking a spanner in the works. After all they are based on 20-nm back-end of line processes but labelled at 16-nm and 14-nm.
What appears to be really happening is that it is no longer economical to move to the next manufacturing process node and that means, for some, Moore’s law is not the ultimate truth.