Methods and structures for forming semiconductor channels based on gate fringing effect are disclosed. In one embodiment, a NAND flash memory device comprises multiple NAND strings of memory transistors. Each memory transistor includes a charge trapping layer and a gate electrode formed on the charge trapping layer. The memory transistors are formed close to each other to form a channel between an adjacent pair of the memory transistors based on a gate fringing effect associated with the adjacent pair of the memory transistors.