Leading flash vendors are breaking the multi-level cell flash limits. The 3D NAND flash memory is a newer flash chip design architecture. Manufacturers stack several layers of memory cells into a vertical structure in 3D NAND. The stacking approach eliminates the electrical interference that occurs while shrinking the cell sizes. Leading 3D NAND flash producers include Intel Corp. Samsung Hynix, SK and Western Multimedia Corp., a companion to Toshiba. The future of the Toshiba-Western Digital relationship is uncertain due to a conflict with Western Digital affiliate SanDisk, which contesting Toshiba’s proposed sale to a coalition of Apple Corp., Dell Technologies Resources, Kingston Technology Corp. and Seagate innovations. Based on a 64-layer 3D NAND system architecture, Samsung has disclosed preliminary design for quad-level cell flash.