Semiconductor storage device and method of manufacturing the same
In one embodiment, a semiconductor storage device includes a substrate, a stacked film including a plurality of first insulating layers and a plurality of electrode layers that are alternately provided on the substrate, and a second insulating layer provided on the stacked film. The device further includes a plurality of pillar portions, each of which including a first insulator, a charge storage layer, a second insulator, a first semiconductor layer and a third insulator that are sequentially provided in the stacked film and the second insulating layer. Furthermore, a width of the second insulating layer sandwiched between the pillar portions is narrower than a width of the stacked film sandwiched between the pillar portions, in at least a portion of the second insulating layer.
1. A semiconductor storage device comprising:
a substrate;
a stacked film including a plurality of first insulating layers and a plurality of electrode layers that are alternately provided on the substrate;
a second insulating layer provided on the stacked film; and
a plurality of pillar portions, each of which including a first insulator, a charge storage layer, a second insulator, a first semiconductor layer, and a third insulator that are sequentially provided in the stacked film and the second insulating layer;
wherein
a width of the second insulating layer sandwiched between the pillar portions is, narrower than a width of the stacked film sandwiched between the pillar portions, in at least a portion of the second insulating layer,
the second insulating layer includes:
a first portion provided on the stacked film; and
a second portion provided on the first portion, a width of the second portion sandwiched between the pillar portions being narrower than the width of the stacked film sandwiched between the pillar portions; and
the first semiconductor layer includes:
a first region provided on a side face of the stacked film and a side face of the first portion of the second insulating layer through the first insulator; and
a second region provided on a side face of the second portion of the second insulating layer through the first insulator, the second region having a thickness larger than a thickness of the first semiconductor layer provided on the side face of the stacked film through the first insulator.
2. The device of claim 1 , wherein the first region has a thickness of 5 nm or less.
3. The device of claim 1 , wherein the second region has a thickness of 5 nm or more.
4. A method of manufacturing a semiconductor storage device, comprising:
forming a stacked film on a substrate, the stacked film alternately including a plurality of first insulating layers and a plurality of first films;
forming a second insulating layer on the stacked film;
forming a plurality of openings in the stacked film and the second insulating layer;
processing the second insulating layer such that a width of the second insulating layer sandwiched between the openings is narrower than a width of the stacked film sandwiched between the openings, in at least a portion of the second insulating layer; and
forming a plurality of pillar portions in the plurality of openings, each of the pillar portions sequentially including a first insulator, a charge storage layer, a second insulator, a first semiconductor layer, and a third insulator;
wherein
the first semiconductor layer is formed such that a thickness of at least of a portion of the first semiconductor layer formed in the second insulating layer is larger than a thickness of the first semiconductor layer formed in the stacked film, and
the second insulating layer is processed with acid after ion implantation into the second insulating layer.
5. A method of manufacturing a semiconductor storage device, comprising:
forming a stacked film on a substrate, the stacked film alternately including a plurality of first insulating layers and a plurality of first films;
forming a second insulating layer on the stacked film;
forming a plurality of openings in the stacked film and the second insulating layer;
processing the second insulating layer such that a width of the second insulating layer sandwiched between the openings is narrower than a width of the stacked film sandwiched between the openings, in at least a portion of the second insulating layer, and
forming a plurality of pillar portions in the plurality of openings, each of the pillar portions sequentially including a first insulator, a charge storage layer, a second insulator, a first semiconductor layer, and a third insulator;
wherein
the first semiconductor layer is formed such that a thickness of at least of a portion of the first semiconductor layer formed in the second insulating layer is larger than a thickness of the first semiconductor layer formed in the stacked film, and
the second insulating layer is processed so as to include:
a first portion provided on the stacked film; and
a second portion provided on the first portion, a width of the second portion sandwiched between the openings being narrower than the width of the stacked film sandwiched between the openings;
the method further comprising removing a portion of the second portion after forming the pillar portions.