Stair contact structure, manufacturing method of stair contact structure, and memory structure
A stair contact structure, a manufacturing method of a stair contact structure, and a memory structure are provided. The stair contact structure includes several layers of stacking structures and a first etch stop layer. Each stacking structure includes a conductive layer and an insulating layer. The conductive layers and the insulating layers are interlaced. The first etch stop layer penetrates through the stacking structures and extends along a first horizontal direction. The conductive layers of the stacking structures located at a first sidewall of the first etch stop layer have a plurality of contact points, and the contact points are arranged along the first horizontal direction to form a stair structure having a plurality of stages.
1. A stair contact structure adjacent to a memory array, comprising:
a plurality of layers of stacking structures, wherein each stacking structure comprises a conductive layer and an insulating layer, and the conductive layers and the insulating layers are interlaced; and
a first etch stop layer penetrating through the stacking structures vertically and extending along a first horizontal direction, wherein the conductive layers of the stacking structures located at a first sidewall of the first etch stop layer have a plurality of contact points, and the contact points are arranged along the first horizontal direction to form a stair structure having a plurality of stages, wherein a length along the first horizontal direction of one of the conductive layers of said each stacking structure is smaller than a length along the first horizontal direction of one of the insulating layers positioned on and directly contacting said one of the conductive layers of said each stacking structure;
wherein the stair contact structure and the memory array are disposed along a second horizontal direction vertical to the first horizontal direction.
2. The stair contact structure according to claim 1 , wherein the first etch stop layer has a first length along the first horizontal direction, the stacking structures have a second length along the first horizontal direction, and the second length is larger than the first length.
3. The stair contact structure according to claim 1 , wherein the first etch stop layer has a second sidewall opposite to the first sidewall, the first etch stop layer has a top surface, the top surface is kept apart from one contact point of the plurality of contact points by a first distance, the top surface is kept apart from the topmost conductive layer of the conductive layers located at the second sidewall of the first etch stop layer by a second distance, and the first distance is larger than the second distance.
4. The stair contact structure according to claim 1 , further comprising:
a second etch stop layer penetrating through the stacking structures vertically and extending along the first horizontal direction, wherein the contact points are located between the first etch stop layer and the second etch stop layer.
5. The stair contact structure according to claim 4 , wherein the second etch stop layer has a third length along the first horizontal direction, the stacking structures have a second length along the first horizontal direction, and the second length is larger than the third length.
6. The stair contact structure according to claim 4 , wherein the conductive layers located between the first etch stop layer and the second etch stop layer have a plurality of lengths along a second horizontal direction, the second horizontal direction is perpendicular to the first horizontal direction, and the lengths are different.
7. The stair contact structure according to claim 6 , wherein the lengths of the conductive layers increase downwards along a vertical direction, and the vertical direction is perpendicular to the first horizontal direction and the second horizontal direction.
8. The stair contact structure according to claim 1 , further comprising:
a plurality of conductive lines, each conductive line electrically connected to each contact point.
9. A memory structure, comprising:
a first stair contact structure and a second stair contact structure separated from each other by a trench, the first stair contact structure and the second stair contact structure respectively comprising a plurality of layers of stacking structures, wherein each stacking structure comprises a conductive layer and an insulating layer, the conductive layers and the insulating layers are interlaced, the conductive layers of the first stair contact structure have a plurality of first contact points, the conductive layers of the second stair contact structure have a plurality of second contact points, the first contact points and second contact points are arranged respectively along a first direction and a second direction to form a first stair structure and a second stair structure having a plurality of stages, and the first direction is different from the second direction, wherein a length along the first direction of one of the conductive layers of the first stair contact structure is smaller than a length along the first direction of one of the insulating layers positioned on and directly contacting said one of the conductive layers of the first stair contact structure; and a length along the second direction of one of the conductive layers of the second stair contact structure is smaller than a length along the second direction of one of the insulating layers positioned on and directly contacting said one of the conductive layers of the second stair contact structure; and
a first memory block and a second memory block respectively electrically connected to the first stair contact structure and the second stair contact structure, wherein the first stair contact structure further comprises:
a first etch stop layer penetrating through the stacking structures of the first stair contact structure vertically and extending along a first horizontal direction, wherein the first contact points are located at a first sidewall of the first etch stop layer.
10. The memory structure according to claim 9 , wherein the conductive layers of the first stair contact structure have a plurality of lengths along the first direction, and the lengths of the conductive layers of the first stair contact structure increase downwards along a vertical direction.
11. The memory structure according to claim 9 , wherein the conductive layers of the first stair contact structure have a plurality of first notches, the conductive layers of the second stair contact structure have a plurality of second notches, and the sizes of the first notches and the sizes of the second notches decrease downwards along a vertical direction.
12. The memory structure according to claim 9 , further comprising:
a plurality of conductive lines, each conductive line correspondingly electrically connected to each first contact point or each second contact point.