A memory cell includes a first electrode, a second electrode, and phase-change material between the first electrode and the second electrode. The control circuit has a start pulse signal input terminal, a first clock pulse signal input terminal and a power supply voltage input terminal and includes a first control transistor and a second control transistor. The buoy group can be a fluorinated chain end, one or more fluorinated and aliphatic chain ends andor one or more wholly aliphatic chain ends. 5, b*5 to 5 at the center portion, L*13. The worktable also has a inverted hat-shaped channel frame having a pair of side flanges that form the brim of the inverted hat shape.