Dry etching method, fine structure formation method, mold and mold fabrication method
View Patent ↗A WC substrate 7 is etched by using plasma 50 generated from a mixed gas of a gas including a halogen atom and a gas including a nitrogen atom.
1. A dry etching method comprising the step of:
etching a substance including tungsten and carbon by using plasma generated from a mixed gas of a first gas including chlorine, a second gas including at least one of bromine and iodine, and a third gas including nitrogen, wherein
the substance is a substrate or a layer made of a tungsten-carbon alloy or a material in which a total composition ratio of tungsten and carbon is 50 atomic % or more,
a mixing ratio of the second gas to a total flow rate of the first gas and the second gas is set in a range of approximately 10% by volume or higher to approximately 30% by volume or lower, and
a surface and an inside of the substance is etched, thereby forming in the substance a pattern including a sidewall with a substantially downward tapered shape.
2. The dry etching method of claim 1 ,
wherein the gas including nitrogen includes a nitrogen molecule, an ammonia molecule, or a mixture thereof.
3. The dry etching method of claim 1 ,
wherein a gas including oxygen is further mixed into the mixed gas.
4. The dry etching method of claim 1 ,
wherein an inert gas is further mixed into the mixed gas.
5. The dry etching method of claim 1 ,
wherein a gas including hydrogen is further mixed into the mixed gas.
6. The dry etching method of claim 5 ,
wherein the gas including hydrogen includes a hydrogen molecule.
7. A fine structure formation method comprising the steps of:
forming a mask pattern on a substance including tungsten and carbon; and
dry etching, with the mask pattern used, the substance by using plasma generated from a mixed gas of a first gas including chlorine, a second gas including at least one of bromine and iodine, and a third gas including nitrogen, wherein
the substance is a substrate or a layer made of a tungsten-carbon alloy or a material in which a total composition ratio of tungsten and carbon is 50 atomic % or more,
a mixing ratio of the second gas to a total flow rate of the first gas and the second gas is set in a range of approximately 10% by volume or higher to approximately 30% by volume or lower, and
in the step of dry etching, a surface and an inside of the substance is etched, thereby forming in the substance a pattern including a sidewall with a substantially downward tapered shape.
8. The fine structure formation method of claim 7 ,
wherein the gas including nitrogen includes a nitrogen molecule, an ammonia molecule, or a mixture thereof.
9. The fine structure formation method of claim 7 ,
wherein a gas including oxygen is further mixed into the mixed gas.
10. The fine structure formation method of claim 7 , wherein an inert gas is further mixed into the mixed gas.
11. The fine structure formation method of claim 7 ,
wherein a gas including hydrogen is further mixed into the mixed gas.
12. The fine structure formation method of claim 11 ,
wherein the gas including hydrogen includes a hydrogen molecule.
13. A mold fabrication method comprising the step of:
dry etching using plasma generated from a mixed gas of a first gas including chlorine, a second gas including at least one of bromine and iodine, and a third gas including nitrogen, a substance including tungsten and carbon, thereby processing the substance to be a mold, wherein
the substance is a substrate or a layer made of a tungsten-carbon alloy or a material in which a total composition ratio of tungsten and carbon is 50 atomic % or more
a mixing ratio of the second gas to a total flow rate of the first gas and the second gas is set in a range of approximately 10% by volume or higher to approximately 30% by volume or lower, and
in the step of processing the substance to be the mold, a surface and an inside of the substance is etched, thereby forming in the substance a pattern including a sidewall with a substantially downward tapered shape.
14. The mold fabrication method of claim 13 ,
wherein the gas including nitrogen includes a nitrogen molecule, an ammonia molecule, or a mixture thereof.
15. The mold fabrication method of claim 13 ,
wherein a gas including an oxygen is further mixed into the mixed gas.
16. The mold fabrication method of claim 13 ,
wherein an inert gas is further mixed into the mixed gas.
17. The mold fabrication method of claim 13 ,
wherein a gas including hydrogen is further mixed into the mixed gas.
18. The mold fabrication method of claim 17 ,
wherein the gas including hydrogen includes a hydrogen molecule.