Three-dimensional memory including molybdenum wiring layer having oxygen impurity and method for manufacturing the same
A semiconductor device includes a substrate. The semiconductor device further includes a wiring layer provided on the substrate, the wiring layer including a molybdenum layer including oxygen atoms as an impurity.
1. A semiconductor device comprising:
a substrate; and
a wiring layer provided on the substrate, the wiring layer including a molybdenum layer containing oxygen atoms as an impurity,
wherein a particle diameter of a crystal grain of the wiring layer increases to 25 nanometers (nm) or more through incorporating the oxygen atoms.
2. The semiconductor device according to claim 1 , wherein a concentration of the oxygen atoms in the molybdenum layer is in a range of 1.0×10 20 atoms/centimeter (cm) 3 to 5.0×10 22 atoms/cm 3 .
3. The semiconductor device according to claim 1 , wherein the wiring layer comprises a plurality of electrode layers provided on the substrate, and the semiconductor device further comprises:
a plurality of insulating layers provided alternately with the plurality of electrode layers on the substrate;
a semiconductor layer embedded in the electrode layers and the insulating layers; and
a charge storage layer provided around the semiconductor layer.
4. The semiconductor device according to claim 1 , wherein a concentration of the oxygen atoms in the molybdenum layer is greater than 1.0×10 20 atoms/cm 3 .
5. The semiconductor device according to claim 1 , wherein a concentration of the oxygen atoms in the molybdenum layer is less than 5.0×10 22 atoms/cm 3 .
6. The semiconductor device according to claim 1 , wherein the wiring layer further comprising a metal layer different from the molybdenum layer, the metal layer having oxygen atoms.
7. A method for manufacturing a semiconductor device, the method including forming a wiring layer on a substrate, the wiring layer comprising a molybdenum layer including oxygen atoms as an impurity by oxidizing a metal layer different from the molybdenum layer such that the oxygen atoms are introduced from the metal layer into the molybdenum layer.
8. The method for manufacturing a semiconductor device, according to claim 7 , further comprising heating the molybdenum layer in an atmosphere containing oxygen such that the oxygen atoms are introduced into the molybdenum layer.
9. The method for manufacturing a semiconductor device, according to claim 7 , further comprising oxidizing and heating the molybdenum layer such that the oxygen atoms are introduced into the molybdenum layer.
10. The method for manufacturing a semiconductor device, according to claim 7 , further comprising, after forming the molybdenum layer including the oxygen atoms, decreasing a concentration of the oxygen atoms in the molybdenum layer.
11. The method for manufacturing a semiconductor device, according to claim 10 , wherein decreasing concentration of the oxygen atoms in the molybdenum layer comprises heating the molybdenum layer in an atmosphere containing hydrogen.
12. The method for manufacturing a semiconductor device, according to claim 11 , wherein the molybdenum layer is heated at a temperature in a range of 450° C. to 900° C. in the atmosphere containing hydrogen.
13. The method for manufacturing a semiconductor device, according to claim 11 , wherein the concentration of the oxygen atoms in the molybdenum layer is decreased to no less than 1.0×10 20 atoms/cm 3 .
14. The method for manufacturing a semiconductor device, according to claim 11 , wherein the concentration of the oxygen atoms in the molybdenum layer is decreased to less than 5.0×10 22 atoms/cm 3 .
15. The method for manufacturing a semiconductor device, according to claim 7 , wherein forming the wiring layer comprises forming a plurality of electrode layers alternately stacked with a plurality of insulating layers on the substrate, and the method further comprises:
forming a semiconductor layer embedded in the electrode layers and the insulating layers; and
forming a charge storage layer embedded in the semiconductor layer, the electrode layers and the insulating layers.
16. The method for manufacturing a semiconductor device, according to claim 7 , the method further comprising:
forming a plurality of first films alternately with a plurality of insulating layers on the substrate;
forming a charge storage layer in the first films and the insulating layers;
forming a semiconductor layer in the first films and the insulating layers;
removing the first films and forming a plurality of recess portions between the insulating layers; and
forming, as at least a portion of the wiring layer, a plurality of electrode layers in the recess portions.