Vertical memory devices with bending prevention layers

1. A vertical memory device, comprising:

a circuit pattern on a first substrate;

an insulating interlayer on the first substrate, the insulating interlayer covering circuit pattern;

an intermediate insulation layer on the insulating interlayer, the intermediate insulation layer extending in a first direction substantially parallel to an upper surface of the first substrate, and the intermediate insulation layer having a plurality of recesses on an upper surface thereof, wherein each of the plurality of recesses extends in a third direction substantially parallel to the upper surface of the first substrate, and sidewalls of one of the plurality of recesses are spaced apart from a first contact plug extending through the one of the plurality of recesses such that a buffer layer is provided in the recess with the first contact plug;

a second substrate on the intermediate insulation layer;

gate electrodes spaced apart from each other in a second direction on the second substrate, the second direction being substantially perpendicular to the upper surface of the first substrate; and

a channel extending through the gate electrodes in the second direction.

2. The vertical memory device of claim 1 , wherein the third direction is substantially perpendicular to the first direction.

3. The vertical memory device of claim 2 , wherein the plurality of recesses include:

a first group including first recesses spaced apart from each other in the third direction; and

a second group including second recesses spaced apart from each other in the third direction, the second group being spaced apart from the first group in the first direction.

4. The vertical memory device of claim 1 , wherein each of the gate electrodes extends in the first direction.

5. The vertical memory device of claim 1 , wherein each of the gate electrodes extends in the third direction.

6. The vertical memory device of claim 1 , wherein the third direction makes an acute angle with the first direction.

7. The vertical memory device of claim 1 , wherein each of the plurality of recesses has a bar shape extending in the third direction on the upper surface of the intermediate insulation layer.

8. The vertical memory device of claim 7 , wherein the buffer layer is on the intermediate insulation layer, the buffer layer fills the recess and has a flat upper surface.

9. The vertical memory device of claim 1 , wherein the intermediate insulation layer is a first intermediate insulation layer, and

wherein the vertical memory device further comprises;

wirings on the gate electrodes, the wirings being electrically connected to the gate electrodes; and

a second intermediate insulation layer on the wirings.

10. The vertical memory device of claim 1 , wherein the intermediate insulation layer is a first intermediate insulation layer, and

wherein the vertical memory device further comprises a second intermediate insulation layer between the first substrate and the insulating interlayer.

11. The vertical memory device of claim 1 , further comprising a contact plug structure extending in the second direction through the gate electrodes and the second substrate to be electrically connected to the circuit pattern,

wherein the contact plug structure includes a contact plug and an insulation spacer covering a sidewall of the contact plug.

12. The vertical memory device of claim 11 , wherein the contact plug structure extends through the intermediate insulation layer and contacts the intermediate insulation layer.

13. The vertical memory device of claim 11 , wherein the contact plug structure extends between the intermediate insulation layer, is spaced apart from the intermediate insulation layer and does not contact the intermediate insulation layer.

14. The vertical memory device of claim 11 , wherein the intermediate insulation layer is a first intermediate insulation layer, the vertical memory device further comprises a second intermediate insulation layer spaced apart from the first intermediate insulation layer in a horizontal direction substantially parallel to the upper surface of the first substrate, and

wherein the contact plug structure extends between the first and second intermediate insulation layers, and does not contact the first and second intermediate insulation layers.

15. The vertical memory device of claim 1 , wherein the intermediate insulation layer includes first and second layers sequentially stacked, and

wherein the first layer includes a metal nitride, and the second layer includes a metal.

16. The vertical memory device of claim 1 , wherein the insulating interlayer is a first insulating interlayer, and

wherein the vertical memory device further comprises:

an insulating interlayer pattern on the intermediate insulation layer at the same level as the second substrate, the insulating interlayer pattern covering a sidewall of the second substrate;

a second insulating interlayer on the second substrate and the insulating interlayer pattern, the second insulating interlayer covering sidewalls of the gate electrodes; and

the first contact plug extending in the second direction through the second insulating interlayer and the insulating interlayer pattern, the first contact plug being electrically connected to the circuit pattern.

17. The vertical memory device of claim 1 , further comprising a second contact plug extending in the second direction from a bottom surface of the second substrate to be electrically connected to the circuit pattern.

18. A vertical memory device, comprising:

a circuit pattern on a first substrate, the first substrate including a cell region and a peripheral circuit region adjacent to the cell region;

a first insulating interlayer on the first substrate, the first insulating interlayer covering the circuit pattern;

a first intermediate insulation layer on the first insulating interlayer on the cell region and the peripheral circuit region, the first intermediate insulation layer having at least one recess on an upper surface thereof;

a second substrate on the first intermediate insulation layer on the cell region;

gate electrodes spaced apart from each other in a first direction on the second substrate on the cell region, the first direction substantially perpendicular to an upper surface of the first substrate;

a channel extending through the gate electrodes in the first direction on the cell region; and

a first contact plug extending in the first direction through the first intermediate insulation layer and the first insulating interlayer on the peripheral circuit region, the first contact plug being electrically connected to the circuit pattern,

wherein the first intermediate insulation layer includes a plurality of patterns spaced apart from each other in a direction substantially parallel to an upper surface of the first substrate and substantially perpendicular to the first direction.

19. A vertical memory device, comprising:

transistors on a first substrate;

lower wirings on the first substrate, the lower wirings being electrically connected to the transistors;

a first insulating interlayer on the first substrate, the first insulating interlayer covering the transistors and the lower wirings;

an intermediate insulation layer on the first insulating interlayer, the intermediate insulation layer extending in a first direction substantially parallel to an upper surface of the first substrate, and the intermediate insulation layer having at least one recess on an upper surface thereof;

a second substrate on the intermediate insulation layer;

gate electrodes spaced apart from each other in a second direction on the second substrate, the second direction being substantially perpendicular to the upper surface of the first substrate;

a second insulating interlayer on the second substrate, the second insulating interlayer covering sidewalls of the gate electrodes;

channels extending through the gate electrodes in the second direction;

upper wirings on the gate electrodes, the upper wirings being electrically connected to the gate electrodes;

a first contact plug structure extending through the gate electrodes, the second substrate and the intermediate insulation layer, the first contact plug structure being electrically connected to a first lower wiring of the lower wirings; and

a second contact plug extending through the second insulating interlayer and the intermediate insulation layer, the second contact plug being electrically connected to a second lower wiring of the lower wirings.

20. The vertical memory device of claim 19 , wherein the intermediate insulation layer includes a plurality of patterns spaced apart from each other in a third direction substantially parallel to the upper surface of the first substrate and crossing the first direction.