Virtual Source/Drain을 가지는 Folded NAND Flash Memory

The folded NAND flash with a vertical channel is promising 3-dimensional array structure for highlyscaled memory architecture. But, one of the scaling issues of the folded NAND flash is BJT　leakage current. To solve this problem, inversion-type virtual S/D structure has been employed for a scaled vertical NAND flash memory. Using a virtual source and drain structure, vertical NAND flash memory can be scaled down to 20 ㎚ having immunity of leakage current.