Semiconductor storage device and manufacturing method therefor
A semiconductor storage device includes a plurality of first wirings extending in a first direction and a plurality of second wirings extending in a second direction intersecting the first direction. A plurality of memory cells are connected between the plurality of first wirings and the plurality of second wirings and include selectors each connected in series to variable resistance elements. Each selector includes a selector material switching a current flowing to the variable resistance element according to a voltage difference between the first wiring and the second wiring, and first and second electrodes sandwiching the selector material in a portion between the first wiring and the variable resistance element. A contact area between the first electrode and the selector material is less than an area of the selector material when viewed in a stacking direction of the selector and the variable resistance element.
1 . A semiconductor storage device comprising:
a plurality of first wirings extending in a first direction;
a plurality of second wirings extending in a second direction intersecting the first direction; and
a plurality of memory cells connected between the plurality of first wirings and the plurality of second wirings and including selectors each connected in series to variable resistance elements, wherein
each of the selectors includes a selector material switching a current flowing to the variable resistance element according to a voltage difference between the first wiring and the second wiring, and first and second electrodes sandwiching the selector material in a portion between the first wiring and the variable resistance element, and
a contact area between the first electrode and the selector material is less than an area of the selector material when viewed in a stacking direction of the selector and the variable resistance element.
2 . The semiconductor storage device according to claim 1 , wherein the first electrode has a cylindrical shape having a through via hole at a central portion when viewed in the stacking direction.
3 . The semiconductor storage device according to claim 1 , wherein the first electrode has a diameter less than the selector material when viewed in the stacking direction.
4 . The semiconductor storage device according to claim 1 , wherein the first electrode deviates from a center of the selector material when viewed in the stacking direction.
5 . The semiconductor storage device according to claim 1 , wherein an oxide of a material of the first electrode having resistance higher than resistance of a central portion of the first electrode is provided in an outer circumferential portion of the first electrode.
6 . The semiconductor storage device according to claim 1 , wherein a conductive layer in which an impurity is introduced into a material of the first electrode is provided in an outer circumferential portion of the first electrode.
7 . The semiconductor storage device according to claim 1 , wherein the first electrode includes a plurality of conductive lines provided in an insulator.
8 . A semiconductor storage device comprising:
a plurality of first wirings extending in a first direction;
a plurality of second wirings extending in a second direction intersecting the first direction;
a plurality of memory cells connected between the plurality of first wirings and the plurality of second wirings and including selectors each connected in series to variable resistance elements; and
a first insulating film provided between the plurality of memory cells, wherein
each of the selectors includes a selector material switching a current flowing to the variable resistance element according to a voltage difference between the first wiring and the second wiring, and a first electrode provided between the variable resistance element and the selector material,
the selector material is provided between the first electrode and the first wiring and is formed of a first insulating material that contains a first impurity,
the first insulating film is formed of the first insulating material that does not contain the first impurity, and
an area of the selector material is less than an area of the variable resistance element when viewed in a stacking direction of the selector and the variable resistance element.
9 . The semiconductor storage device according to claim 8 , wherein the area of the selector material is less than an area of the first electrode when viewed in the stacking direction.
10 . The semiconductor storage device according to claim 8 , wherein the first insulating material includes silicon (Si) and oxygen (O).
11 . The semiconductor storage device according to claim 8 , wherein the variable resistance element is a magnetoresistive element.
12 . The semiconductor storage device according to claim 8 , wherein an area of the first electrode on a side of the selector material is less than an area of the first electrode on a side of the variable resistance element when viewed in the stacking direction.
13 . The semiconductor storage device according to claim 8 , wherein an area of the first electrode on a side of the variable resistance element is less than an area of the variable resistance element on a side of the first electrode when viewed in the stacking direction.
14 . The semiconductor storage device according to claim 8 , further comprising:
a second insulating film having an area greater than an area of the first electrode and provided around the selector when viewed in the stacking direction, wherein
the second insulating film includes one of beryllium (Be), magnesium (Mg), and nitrogen (N).
15 . The semiconductor storage device according to claim 8 , wherein the first impurity includes one of arsenic (As), phosphorus (P), antimony (Sb), and boron (B).
16 . A semiconductor storage device comprising:
a plurality of first wirings extending in a first direction;
a plurality of second wirings extending in a second direction intersecting the first direction; and
a plurality of memory cells connected between the plurality of first wirings and the plurality of second wirings and including selectors each connected in series to variable resistance elements, wherein
each of the selectors includes a first selector material switching a current flowing to the variable resistance element according to a voltage difference between the first wiring and the second wiring, and a first electrode provided between the variable resistance element and the first selector material,
the first selector material is provided between the first electrode and the first wiring and is formed of an insulating film that contains a first impurity,
an area of the first selector material is greater than an area of the first electrode when viewed in a stacking direction of the selector and the variable resistance element, and
an area of the first electrode on a side of the first selector material is less than an area of the variable resistance element when viewed in the stacking direction.
17 . The semiconductor storage device according to claim 16 , wherein the first selector material is provided around the first electrode.
18 . The semiconductor storage device according to claim 16 , wherein the first selector material includes one of arsenic (As), phosphorus (P), antimony (Sb), and boron (B) as the first impurity.
19 . The semiconductor storage device according to claim 16 , wherein an area of the first electrode on a side of the first selector material is less than an area of the first electrode on a side of the variable resistance element when viewed in the stacking direction.
20 . The semiconductor storage device according to claim 16 , wherein an area of the first electrode on a side of the variable resistance element is less than an area of the variable resistance element on a side of the first electrode when viewed in the stacking direction.