Semiconductor device and method of manufacturing the same
A semiconductor device includes a first electrode layer and a second electrode layer formed thereon to be spaced from the first electrode layer, a columnar portion penetrating the first and second electrode layers in a first direction and including a semiconductor layer, a first insulating film between the first and second electrode layers and the semiconductor layer and in contact with the first electrode layer, a charge storage layer between the second electrode layer and the first insulating film, and an insulating film between the second electrode layer and the charge storage layer. The semiconductor layer includes a first portion facing the second electrode layer in a second direction intersecting with the first direction and a second portion in contact with the first portion in the first direction. A concentration of a impurity contained in the second portion is higher than that of the impurity contained in the first portion.
1. A semiconductor device comprising:
an under layer;
a first electrode layer on the under layer;
a second electrode layer stacked on the first electrode layer in a stacking direction so as to be spaced from the first electrode layer in first direction, which is the stacking direction;
a columnar portion penetrating the first and second electrode layers in the first direction, the columnar portion including a semiconductor layer;
a first insulating film provided between the first and second electrode layers and the semiconductor layer and in contact with the first electrode layer;
a charge storage layer provided between the second electrode layer and the first insulating film; and
a second insulating film provided between the second electrode layer and the charge storage layer, wherein
the semiconductor layer includes a first portion facing the second electrode layer in a second direction intersecting with the first direction and a second portion being in contact with the first portion in the first direction, and
a concentration of a first impurity contained in the second portion is higher than a concentration of the first impurity contained in the first portion.
2. The semiconductor device according to claim 1 , wherein an air gap is between the first electrode layer and the second electrode layer in the first direction.
3. The semiconductor device according to claim 1 , wherein the first electrode layer is a p-type polysilicon layer, and the second electrode layer is an n-type polysilicon layer.
4. The semiconductor device according to claim 1 , wherein the under layer is a substrate or a peripheral circuit disposed on the substrate.
5. The semiconductor device according to claim 1 , further comprising an insulating layer being in contact with the under layer and the first electrode layer and disposed on the under layer.
6. The semiconductor device according to claim 1 , wherein the second portion is an n-type impurity layer.
7. The semiconductor device according to claim 1 , wherein the first impurity includes any one of phosphorus, arsenic, or antimony.