Method of manufacturing semiconductor device
In one embodiment, a method of manufacturing a semiconductor device includes forming a stacked film on a substrate. The method further includes forming, on the stacked film, a mask layer formed of a tungsten compound and including impurity atoms having a concentration of 1.0×10 20 atoms/cm 3 or more. The method further includes etching the stacked film using the mask layer as an etching mask.
1. A method of manufacturing a semiconductor device, comprising:
forming a stacked film on a substrate;
forming, on the stacked film, a mask layer formed of a tungsten compound and including impurity atoms having a concentration of 1.0×10 20 atoms/cm 3 or more; and
etching the stacked film using the mask layer as an etching mask.
2. The method of claim 1 , wherein the tungsten compound includes tungsten, and includes at least any of boron and carbon.
3. The method of claim 2 , wherein the tungsten compound is a WB alloy, a WC alloy or a WBC alloy where W denotes tungsten, B denotes boron, and C denotes carbon.
4. The method of claim 1 , wherein the mask layer is formed using a gas that includes tungsten atoms and the impurity atoms.
5. The method of claim 4 , wherein the mask layer is formed further using at least any of a gas including boron atoms and a gas including carbon atoms.
6. The method of claim 5 , wherein a flow rate of the gas including boron atoms is set to be less than 100 sccm.
7. The method of claim 1 , wherein the mask layer includes the impurity atoms having the concentration of 1.0×10 20 atoms/cm 3 or more and 4.0×10 20 atoms/cm 3 or less.
8. The method of claim 1 , wherein the mask layer includes the impurity atoms having the concentration of 2.0×10 20 atoms/cm 3 or more.
9. The method of claim 1 , wherein the mask layer is an amorphous film.
10. The method of claim 1 , wherein a thickness of the mask layer is 1 to 3 μm.
11. The method of claim 1 , wherein the mask layer is formed under a pressure of 10 Torr or less.
12. The method of claim 1 , further comprising removing the mask layer on the stacked film after etching the stacked film using the mask layer as the etching mask.
13. The method of claim 1 , wherein the impurity atoms are halogen atoms.
14. The method of claim 13 , wherein the halogen atoms are fluorine atoms or chlorine atoms.
15. The method of claim 1 , wherein the impurity atoms are doped into the mask layer in forming the mask layer on the stacked film.
16. The method of claim 1 , wherein the stacked film includes a plurality of first layers and a plurality of second layers that are alternately formed on the substrate.
17. The method of claim 16 , wherein the first layers are insulating layers, and the second layers are insulating layers different from the first layers.
18. The method of claim 16 , further comprising sequentially forming a charge storage layer and a semiconductor layer in a concave portion formed in the stacked film by the etching.
19. The method of claim 18 , further comprising:
forming a plurality of cavities between the first layers by removing the second layers after sequentially forming the charge storage layer and the semiconductor layer in the concave portion; and
forming a plurality of third layers in the cavities.
20. The method of claim 19 , wherein the third layers are electrode layers.