Method for manufacturing semiconductor memory device and semiconductor memory device
According to one embodiment, a method for manufacturing a semiconductor memory device includes simultaneously forming a plurality of first holes and a plurality of second holes in a stacked body. The stacked body includes a plurality of first layers and a plurality of second layers. The method includes etching a portion between the second holes next to each other in the stacked body, and connecting at least two or more second holes to form a groove. The method includes forming a film including a charge storage film on a sidewall of the first holes. The method includes forming a channel film on a sidewall of the film including the charge storage film.
1. A semiconductor memory device comprising:
a stacked body including a plurality of electrode layers stacked with insulators interposed between the electrode layers;
a separation portion extending in a stacking direction of the stacked body and in a first direction orthogonal to the stacking direction, and separating the stacked body into a first portion and a second portion of the stacked body in a second direction orthogonal to the stacking direction and the first direction, the separation portion being disposed between the first and second portions of the stacked body, the first and second portions having a pair of sidewalls facing each other with the separation portion interposed; and
a plurality of columnar portions penetrating through the stacked body in the stacking direction, and each including a semiconductor film extending in the stacking direction and a cylindrical film provided between the electrode layers and the semiconductor film, the plurality of columnar portions including first columnar portions penetrating through the first portion of the stacked body in the stacking direction and second columnar portions penetrating through the second portion of the stacked body in the stacking direction,
the pair of sidewalls including a sidewall on the first portion side and a sidewall on the second portion side,
first concave portions being disposed at the sidewall on the first portion side along the first direction and second concave portions being disposed at the sidewall on the second portion side along the first direction,
in a transversal cross section of the first and second portions of the stacked body orthogonal to the stacking direction, the first columnar portions being provided in first openings of the first portion of the stacked body respectively and the second columnar portions being provided in second openings of the second portion of the stacked body respectively,
the first openings and third openings corresponding to the first concave portions being periodically arrayed in the transversal cross section, each of the first concave portions in the transversal cross section being a part of a corresponding third opening of the third openings respectively, and the second openings and fourth openings corresponding to the second concave portions being periodically arrayed in the transversal cross section, each of the second concave portions in the transversal cross section being a part of a corresponding fourth opening of the fourth openings respectively, and
a width in the second direction between the pair of sidewalls being larger than a diameter of the first openings and a diameter of the second openings.
2. The device according to claim 1 , wherein
the first columnar portions and the first concave portions are arranged in a staggered arrangement in the first portion of the stacked body, and the second columnar portions and the second concave portions are arranged in a staggered arrangement in the second portion of the stacked body.
3. The device according to claim 2 , wherein
the first concave portions are arranged at same positions as the second concave portions in the first direction respectively.
4. The device according to claim 3 , wherein
the first columnar portions proximal to the separation portion in the second direction are arranged in a position relationship with a half pitch shifted in the first direction from the first concave portions and the second concave portions, and the second columnar portions proximal to the separation portion in the second direction are arranged in a position relationship with a half pitch shifted in the first direction from the first concave portions and the second concave portions.
5. The device according to claim 4 , wherein
the first columnar portions proximal to the separation portion are arranged at same positions as the second columnar portions proximal to the separation portion in the first direction respectively.
6. The device according to claim 1 , wherein the first and second openings have a circular shape respectively and the first concave portions and the second concave portions have curvature.
7. The device according to claim 1 , wherein
each of the first to fourth openings has a circular shape of a substantially same diameter with one another.
8. The device according to claim 7 , wherein
an arrangement of the first and third openings in the first portion of the stacked body have a same pitch as an arrangement of the second and fourth openings in the second portion of the stacked body.
9. The device according to claim 8 , wherein
one first concave portion of the first concave portions and one second concave portion of the second concave portions face each other with the separation portion interposed, the one first concave portion and the one second concave portion having symmetric positional relationship with respect to the separation portion, and
wy, py, and dm satisfy wy=2py+dm,
wherein wy defines a maximum width between the pair of sidewalls in the second direction in a region where the one first concave portion and the one second concave portion face each other, py defines a pitch between the first openings and the third openings in the second direction, and dm defines the diameter of the first openings.
10. The device according to claim 9 , wherein
py is equal to px(√3)/2, px defining a pitch of the first openings in the first direction.
11. A semiconductor memory device comprising:
a stacked body including a plurality of electrode layers stacked with insulators interposed between the electrode layers;
a separation portion extending in a stacking direction of the stacked body and in a first direction orthogonal to the stacking direction, and separating the stacked body into a first portion and a second portion of the stacked body in a second direction orthogonal to the stacking direction and the first direction, the separation portion being disposed between the first and second portions of the stacked body, the first and second portions having a pair of sidewalls facing each other with the separation portion interposed; and
a plurality of columnar portions penetrating through the stacked body in the stacking direction, and each including a semiconductor film extending in the stacking direction and a cylindrical film provided between the electrode layers and the semiconductor film, the plurality of columnar portions including first columnar portions penetrating through the first portion of the stacked body in the stacking direction and second columnar portions penetrating through the second portion of the stacked body in the stacking direction,
the pair of sidewalls including a sidewall on the first portion side and a sidewall on the second portion side,
first concave portions being disposed at the sidewall on the first portion side along the first direction and second concave portions being disposed at the sidewall on the second portion side along the first direction,
in a transversal cross section of the first and second portions of the stacked body orthogonal to the stacking direction, the first columnar portions being provided in first circular openings of the first portion of the stacked body respectively and the second columnar portions being provided in second circular openings of the second portion of the stacked body respectively, and
the first circular openings and third circular openings corresponding to the first concave portions being periodically arrayed in the transversal cross section, each of the first concave portions in the transversal cross section being a part of a corresponding third circular opening of the third circular openings respectively, and the second circular openings and fourth circular openings corresponding to the second concave portions being periodically arrayed in the transversal cross section, each of the second concave portions in the transversal cross section being a part of a corresponding fourth circular opening of the fourth circular openings respectively, and
a distance between the third circular openings and the fourth circular openings in the second direction is larger than a diameter of the first circular openings and a diameter of the second circular openings.
12. The device according to claim 11 , wherein
the first columnar portions and the first concave portions are arranged in a staggered arrangement in the first portion of the stacked body, and the second columnar portions and the second concave portions are arranged in a staggered arrangement in the second portion of the stacked body.
13. The device according to claim 12 , wherein
the first concave portions are arranged at same positions as the second concave portions in the first direction respectively.
14. The device according to claim 13 , wherein
the first columnar portions proximal to the separation portion in the second direction are arranged in a position relationship with a half pitch shifted in the first direction from the first concave portions and the second concave portions, and the second columnar portions proximal to the separation portion in the second direction are arranged in a position relationship with a half pitch shifted in the first direction from the first concave portions and the second concave portions.
15. The device according to claim 14 , wherein
the first columnar portions proximal to the separation portion are arranged at same positions as the second columnar portions proximal to the separation portion in the first direction respectively.
16. The device according to claim 11 , wherein the third circular openings and the fourth circular openings are disposed independently each other in the transversal cross section.
17. The device according to claim 11 , wherein
each of the first to fourth circular openings has a substantially same diameter with one another.
18. The device according to claim 17 , wherein
an arrangement of the first and third circular openings in the first portion of the stacked body have a same pitch as an arrangement of the second and fourth circular openings in the second portion of the stacked body.
19. The device according to claim 18 , wherein
one first concave portion of the first concave portions and one second concave portion of the second concave portions face each other with the separation portion interposed, the one first concave portion and the one second concave portion having symmetric positional relationship with respect to the separation portion, and
wy, py, and dm satisfy wy=2py+dm,
wherein wy defines a maximum width between the pair of sidewalls in the second direction in a region where the one first concave portion and the one second concave portion face each other, py defines a pitch between the first circular openings and the third circular openings in the second direction, and dm defines a diameter of the first circular openings.
20. The device according to claim 19 , wherein
py is equal to px(√3)/2, px defining a pitch of the first circular openings in the first direction.