IBM and AMD Create First 22nm SRAM Cell
arcticstoat notes an announcement from IBM that, along with technology partners, they have produced the first working sample of a SRAM cell built on a 22nm fabrication process. According to the article, this represents the next generation after 32nm process chips and won't be in products for some years. "The technology was developed with several partners, including AMD, Toshiba, STMicroelectronics and Freescale, as well as the College of Nanoscale Science and Engineering, where IBM performs a lot of its semiconductor research. IBM says that the cell's development involved 'novel fabrication processes,' including high-NA immersion lithography..., high-K metal gate stacks, extremely thin silicide, damascene copper contacts, and advanced activation techniques."
Well, a single silicon atom has a radius of 110pm. I assume silicon dioxide molecule is ~500pm, which is something like 40X smaller than the 22nm process.
However, silicone dioxide is not perfectly stable and can "leak", as far as I understand it, which limits the process somewhat.
Again, assuming you need something 100X larger area-wise, you're looking at maybe a factor of 4X remaining until the process can't be shrunk any further.
But I am not an engineer.