Method for manufacturing semiconductor device
According to one embodiment, a method for manufacturing a semiconductor device includes forming a mask layer on a layer to be etched. The mask layer contains at least one type of a metal, boron, and carbon. The metal is selected from a group including tungsten, tantalum, zirconium, hafnium, molybdenum, niobium, ruthenium, osmium, rhenium and iridium. A composition ratio of the metal is higher than a composition ratio of the boron and a composition ratio of the carbon. The method includes making a hole or a slit in the layer to be etched by performing a dry etching to the layer to be etched using the mask layer being patterned.
1. A method for manufacturing a semiconductor device, comprising:
forming a mask layer on a layer to be etched, the mask layer containing at least one type of a metal, boron, and carbon, the metal being selected from a group including tungsten, tantalum, zirconium, hafnium, molybdenum, niobium, ruthenium, osmium, rhenium and iridium, a composition ratio of the metal being higher than a composition ratio of the boron and a composition ratio of the carbon;
patterning the mask layer; and
performing a dry etching to the layer to be etched using the mask layer being patterned.
2. The method for manufacturing the semiconductor device according to claim 1 , wherein the mask layer further contains nitrogen.
3. The method for manufacturing the semiconductor device according to claim 1 , wherein the mask layer further contains silicon.
4. The method for manufacturing the semiconductor device according to claim 1 , wherein
the layer to be etched contains silicon,
the layer to be etched is etched using a gas containing fluorine.
5. The method for manufacturing the semiconductor device according to claim 1 , wherein
the layer to be etched is a stacked body including a plurality of first layers and a plurality of second layers, the first layers and the second layers including a first layer and a second layer stacked repeatedly, the second layers being layers of a different type of material from the first layers.
6. The method for manufacturing the semiconductor device according to claim 5 , wherein the first layer includes a silicon nitride film, and the second layer includes a silicon oxide film.
7. The method for manufacturing the semiconductor device according to claim 5 , wherein the layer to be etched is performing the dry etching for making a hole or a slit in the layer to be etched.
8. The method for manufacturing the semiconductor device according to claim 7 , further comprising:
removing the first layers by etching through the hole or the slit, and making gaps between the second layers; and
forming conductive layers in the gaps.
9. The method for manufacturing the semiconductor device according to claim 1 , further comprising:
forming a film containing a metal nitride, the film being provided between the layer to be etched and the mask layer.
10. The method for manufacturing the semiconductor device according to claim 9 , further comprising:
forming a first intermediate layer on the mask layer, the first intermediate layer being of a different type of material from the mask layer,
wherein the mask layer is patterned by etching using the first intermediate layer as a mask.
11. The method for manufacturing the semiconductor device according to claim 1 , further comprising:
forming a first intermediate layer on the mask layer, the first intermediate layer being of a different type of material from the mask layer,
wherein the mask layer is patterned by etching using the first intermediate layer as a mask.
12. The method for manufacturing the semiconductor device according to claim 1 , further comprising:
forming a second intermediate layer between the layer to be etched and the mask layer, the second intermediate layer being of a different type of material from the layer to be etched and the mask layer.
13. The method for manufacturing the semiconductor device according to claim 11 , further comprising:
forming a second intermediate layer between the layer to be etched and the mask layer, the second intermediate layer being of a different type of material from the layer to be etched and the mask layer.
14. The method for manufacturing the semiconductor device according to claim 11 , wherein the first intermediate layer contains carbon, boron carbide, boron nitride, silicon oxide, silicon nitride, or amorphous silicon as a main component.
15. The method for manufacturing the semiconductor device according to claim 12 , wherein the second intermediate layer contains carbon, boron carbide, boron nitride, or amorphous silicon as a main component.
16. The method for manufacturing the semiconductor device according to claim 1 , wherein the mask layer is formed by chemical vapor deposition (CVD).
17. The method for manufacturing the semiconductor device according to claim 1 , wherein the mask layer is substantially amorphous.