Non-volatile memory device and method for fabricating the same
A non-volatile memory device includes a pair of columnar cell channels vertically extending from a substrate, a doped pipe channel arranged to couple lower ends of the pair of columnar cell channels, insulation layers over the substrate in which the doped pipe channel is buried, memory layers arranged to surround side surfaces of the columnar cell channels, and control gate electrodes arranged to surround the memory layers.
1. A method for fabricating a non-volatile memory device, comprising:
forming a multilayer over a substrate, the multilayer comprising an insulation layer formed with a pipe channel hole and a pair of cell channel holes coupled to the pipe channel hole;
forming a pair of columnar cell channels in the cell channel holes, and a pipe channel arranged to electrically couple lower ends of the pair of columnar cell channels to each other;
forming a slit by etching the multilayer such that an upper end of the pipe channel is tunneled through; and
doping an impurity in the pipe channel through the slit.
2. The method of claim 1 , wherein the pipe channel is doped with the impurity by using plasma doping.
3. The method of claim 2 , wherein the pipe channel is doped with an N type impurity by using plasma doping.
4. The method of claim 1 , wherein the forming of the multilayer comprises:
forming a first insulation layer over the substrate;
forming a sacrificial pattern over the first insulation layer;
forming a second insulation layer over the sacrificial pattern;
planarizing the second insulation layer such that the sacrificial pattern is exposed;
forming the multilayer by alternately stacking a third insulation layer and a conductive layer for a control gate electrode on the planarized second insulation layer;
forming the cell channel holes by etching the multilayer; and
forming the pipe channel hole by removing the sacrificial pattern.
5. The method of claim 4 , wherein the first insulation layer and the second insulation layer include a silicon oxide layer, and the sacrificial pattern includes a silicon nitride layer.
6. The method of claim 4 , wherein the multilayer is formed by alternately stacking an oxide layer and a polysilicon layer in a vertical direction.
7. The method of claim 1 , wherein each of the columnar cell channels fills the corresponding cell channel hole.
8. The method of claim 1 , wherein each of the columnar cell channels is formed to partially fill the corresponding cell channel hole so that each of the columnar cell channel includes a penetrating hole therein.
9. A method for fabricating a non-volatile memory device, comprising:
forming a multilayer over a substrate, the multilayer comprising an insulation layer formed with a pipe channel hole and a pair of cell channel holes coupled to the pipe channel hole;
forming a pair of columnar cell channels in the cell channel holes, and a pipe channel arranged to electrically couple lower ends of the pair of columnar cell channels to each other;
forming a doped layer coupled to the pipe channel and doped with an impurity; and
diffusing the impurity to the pipe channel.
10. The method of claim 9 , further comprising forming a slit by etching the multilayer such that an upper end of the pipe channel is tunneled through and forming a doped layer includes forming a doped layer coupled to the pipe channel through the slit.
11. The method of claim 10 , wherein the forming of the doped layer comprises:
forming a doped polysilicon layer over the etched multilayer including the slit;
forming an insulation layer over the doped polysilicon layer; and
recessing the insulation layer and the doped polysilicon layer.
12. The method of claim 11 , wherein the doped polysilicon layer includes a polysilicon layer doped with an N type impurity.
13. The method of claim 9 , wherein impurity is diffused through a heat treatment process.
14. The method of claim 9 , wherein the columnar cell channels and the pipe channel include an undoped polysilicon layer.
15. The method of claim 9 , wherein each of the columnar cell channels fills the corresponding cell channel hole.
16. The method of claim 9 , wherein each of the columnar cell channels is formed to partially fill the corresponding cell channels hole so that each of the columnar cell channel includes a penetrating hole therein.