Dynamic RAM Smallest Feature Size, DRAM Half Pitch (nm), Logarithmic Plot, pg 57.
Source: Data from 1967–1999, Intel data, see Gordon E. Moore, “Our Revolution,” http://www.sia-online.org/downloads/Moore.pdf.
Data from 2000–2016, International Technology Roadmap for Semiconductors (ITRS) 2002 Update and 2004 Update, http://public.itrs.net/Files/2002Update/2002Update.pdf and http://www.itrs.net/Common/2004Update/2004_00_Overview.pdf.