US 2020/0286908 A1 · Semiconductor Storage Device

Abstract

According to one embodiment, a semiconductor storage device includes: a substrate; a plurality of first gate electrodes arranged in a first direction intersecting with a substrate surface; a first semiconductor film extending in the first direction and facing the plurality of first gate electrodes; a first gate insulating film provided between the plurality of first gate electrodes and the first semiconductor film; a second gate electrode disposed farther away from the substrate than the plurality of first gate electrodes; a second semiconductor film that extends in the first direction, faces the second gate electrode, and has, in the first direction, one end connected to the first semiconductor film; and a second gate insulating film provided between the second gate electrode and the second semiconductor film. The second gate electrode includes: a first portion; and a second portion provided between the first portion and the second semiconductor film, and facing the second semiconductor film. At least a portion of the second portion is provided closer to a side of the substrate than a surface of the first portion on the side of the substrate side in the first direction.

Claims11

Dependent claims

A semiconductor storage device comprising:

a substrate;
a plurality of first gate electrodes spaced apart from one another along a first direction perpendicular to a surface of the substrate;
a first semiconductor film extending along the first direction and facing the plurality of first gate electrodes;
a first gate insulating film provided between the plurality of first gate electrodes and the first semiconductor film;
a second gate electrode disposed farther away from the substrate than the plurality of first gate electrodes along the first direction;
a second semiconductor film, extending along the first direction, that faces the second gate electrode and includes one end connected to an upper surface of the first semiconductor film;
and
a second gate insulating film provided between the second gate electrode and the second semiconductor film,
wherein the second gate electrode includes:
a first portion;
and
a second portion, provided between the first portion and the second semiconductor film, that faces the second semiconductor film, and
wherein at least a portion of the second portion is provided closer to the plurality of first gate electrodes than the first portion along the first direction.

10 more elements

A method, comprising:

stacking a plurality of first sacrificial layers on a substrate along a first direction;
forming a first semiconductor film extending through the plurality of first sacrificial layers, the first semiconductor film facing the plurality of first sacrificial layers with a first gate insulating film disposed therebetween;
removing a portion of the first semiconductor film to form an uneven upper surface of the first semiconductor film;
stacking a plurality of second sacrificial layers on the first semiconductor film;
forming a second semiconductor film extending through the plurality of second sacrificial layers, the second semiconductor film facing the plurality of second sacrificial layers with a second gate insulating film disposed therebetween;
and
replacing the plurality of first sacrificial layers and the plurality of second sacrificial layers with a conductive material to form a plurality of first gate electrodes and a plurality of second gate electrodes, respectively.

4 more elements

Dependencies are inferred from the claim text.

Semiconductor Storage Device

Life of this patent

Semiconductor Storage Device

Life of this patent

Abstract

Claims11