Semiconductor memory element and semiconductor memory device
According to one embodiment, a semiconductor memory element includes a semiconductor layer, a tunnel insulator provided on the semiconductor layer, a charge accumulation film provided on the tunnel insulator having a film thickness of 0.9 nm or more and 2.8 nm or less and the charge accumulation film containing cubic HfO 2 particles, a block insulator provided on the charge accumulation film, and a control electrode provided on the block insulator.
1. A semiconductor memory element, comprising:
a semiconductor layer;
a tunnel insulator provided on the semiconductor layer;
a charge accumulation film provided directly on the tunnel insulator having a film thickness of 0.9 nm or more and 2.8 nm or less and the charge accumulation film containing cubic HfO 2 particles;
a block insulator directly provided on the charge accumulation film; and
a control electrode provided on the block insulator.
2. The memory element of claim 1 , wherein
the cubic HfO 2 particles contain tervalent silicon, and the charge accumulation film contains silicon and oxygen.
3. The memory element of claim 1 , wherein a component of a material in the charge accumulation film between the cubic HfO 2 particles and at least one of the tunnel insulator and the block insulator is the same as a component of a material contained in at least one of the tunnel insulator and the block insulator, respectively.
4. The memory element of claim 1 , wherein
the cubic HfO 2 particles in the charge accumulation film are offset toward the tunnel insulator from the middle of the charge accumulation film in a layer thickness direction,
a component of a material contained in the block insulator is decreased towards the charge accumulation film, and
a component of a material in the charge accumulation film between the cubic HfO 2 particles and the block insulator is decreased towards the block insulator.
5. The memory element of claim 1 , wherein
the cubic HfO 2 particles contained in the charge accumulation film are offset toward the block insulator from the middle of the charge accumulation film in the layer thickness direction,
a component of a material contained in the tunnel insulator is decreased towards the charge accumulation film, and
a component of a material in the charge accumulation film between the cubic HfO 2 particles and the tunnel insulator is decreased towards the tunnel insulator.
6. The memory element of claim 1 , wherein components of materials between the cubic HfO 2 particles and the tunnel insulator, and between the cubic HfO 2 particles and the block insulator are the same as components of materials contained in the tunnel insulator and the block insulator, respectively.
7. The memory element of claim 1 , wherein
a component of a material contained in the tunnel insulator is decreased towards the charge accumulation film,
a component of a material between the cubic HfO 2 particles and the tunnel insulator in the charge accumulation film is decreased towards the tunnel insulator,
a component of a material contained in the block insulator is decreased towards the charge accumulation film, and
a component of a material between the cubic HfO 2 particles and the block insulator in the charge accumulation film is decreased towards the block insulator.
8. The memory element of claim 1 , wherein a surface density of the cubic HfO 2 particles contained in the charge accumulation film is 0.040 particles/nm 2 or more and 0.945 particles/nm 2 or less.
9. The memory element of claim 1 , wherein a material of the block insulator is different from a material of the charge accumulation film.
10. The memory element of claim 1 , wherein the cubic HfO 2 particles include silicon.
11. A semiconductor memory device, comprising:
a stacked body in which an insulator and a control electrode are alternately stacked on a substrate;
a block insulator provided on a side surface of a hole configured to penetrate in a stacking direction of the stacked body from an upper surface of the stacked body to the control electrode of the lowermost layer;
a charge accumulation film provided on an inner surface of the block insulator having a film thickness of 0.9 nm or more and 2.8 nm or less, and containing cubic HfO 2 particles;
a tunnel insulator provided on an inner surface of the charge accumulation film; and
a semiconductor layer provided on an inner surface of the tunnel insulator.
12. A semiconductor memory element, comprising:
a semiconductor layer;
a tunnel insulator provided on the semiconductor layer;
a block insulator provided apart from the tunnel insulator, a surface of the block insulator being opposed to a surface of the tunnel insulator, a distance between the tunnel insulator and the block insulator being 0.9 nm or more and 2.8 nm or less;
a charge accumulation film provided between the tunnel insulator and the block insulator, the charge accumulation film containing cubic HfO 2 particles; and
a control electrode provided on the block insulator.
13. The memory element of claim 12 , wherein the cubic HfO 2 particles contain tervalent silicon, and the charge accumulation film contains silicon and oxygen.
14. The memory element of claim 12 , wherein a component of a material in the charge accumulation film between the cubic HfO 2 particles and at least one of the tunnel insulator and the block insulator is the same as a component of a material contained in at least one of the tunnel insulator and the block insulator, respectively.
15. The memory element of claim 12 , wherein
the cubic HfO 2 particles in the charge accumulation film are offset toward the tunnel insulator from the middle of the charge accumulation film in a layer thickness direction,
a component of a material contained in the block insulator is decreased towards the charge accumulation film, and
a component of a material in the charge accumulation film between the cubic HfO 2 particles and the block insulator is decreased towards the block insulator.
16. The memory element of claim 12 , wherein
the cubic HfO 2 particles contained in the charge accumulation film are offset toward the block insulator from the middle of the charge accumulation film in the layer thickness direction,
a component of a material contained in the tunnel insulator is decreased towards the charge accumulation film, and
a component of a material in the charge accumulation film between the cubic HfO 2 particles and the tunnel insulator is decreased towards the tunnel insulator.
17. The memory element of claim 12 , wherein components of materials between the cubic HfO 2 particles and the tunnel insulator, and between the cubic HfO 2 particles and the block insulator are the same as components of materials contained in the tunnel insulator and the block insulator, respectively.
18. The memory element of claim 12 , wherein
a component of a material contained in the tunnel insulator is decreased towards the charge accumulation film,
a component of a material between the cubic HfO 2 particles and the tunnel insulator in the charge accumulation film is decreased towards the tunnel insulator,
a component of a material contained in the block insulator is decreased towards the charge accumulation film, and
a component of a material between the cubic HfO 2 particles and the block insulator in the charge accumulation film is decreased towards the block insulator.
19. The memory element of claim 12 , wherein a surface density of the cubic HfO 2 particles contained in the charge accumulation film is 0.040 particles/nm 2 or more and 0.945 particles/nm 2 or less.
20. The memory element of claim 12 , wherein a material of the block insulator is different from a material of the charge accumulation film.
21. The memory element of claim 12 , wherein the cubic HfO 2 particles include silicon.