The beat goes on for NAND flash, as Hynix shows in an IEDM paper a "middle-1Xnm" NAND flash memory cell. Several issues had to be addressed: how to pattern the device (solution: quad-spacer patterning with ArF immersion), CG poly filling/interference (solution: FG slimming), and charge loss/UV Vt decrease (solution: airgap and N&plusmn1 WL bias control). [Paper #9.1: A Middle-1X nm NAND Flash Memory Cell (M1X-NAND) with Highly Manufacturable Integration Technologies"]