Memory device and method of forming the same

A memory device, comprising:

• a multi-layer stack, disposed on a substrate and comprising a plurality of gate electrode layers and a plurality of dielectric layers stacked alternately;
• a first conductive pillar, penetrating through the multi-layer stack;
• a plurality of second conductive pillars, at different sides of the first conductive pillar,
• a plurality of third conductive pillars, disposed between the first conductive pillar and each of the plurality of second conductive pillars, wherein the first conductive pillar, the plurality of second conductive pillars and the plurality of third conductive pillars are alternately arranged with each other;
• a plurality of dielectric pillars, penetrating through the multi-layer stack and disposed on sidewalls of the plurality of third conductive pillars;
• a channel layer, surrounding the first conductive pillar, the second conductive pillars and the plurality of dielectric pillars;
• and
• a memory material layer, disposed between the channel layer and the multi-layer stack.

A memory device, comprising:

• a multi-layer stack, disposed on a substrate and comprising a plurality of dielectric layers and a plurality of conductive layers stacked alternately;
• a first conductive pillar and a second conductive pillar formed extending through the multi-layer stack;
• an assist gate formed between the first conductive pillar and the second conductive pillar;
• a dielectric pillar disposed between adjacent ones of the first conductive pillar, the second conductive pillar and the assist gate;
• a channel layer surrounding the dielectric pillar, the first conductive pillar, the second conductive pillar and the assist gate;
• and
• a memory material layer disposed between the channel layer and the plurality of dielectric layers and between the channel layer and the plurality of conductive layers.