Etching method and semiconductor element manufacturing method
An etching method including an etching step of bringing, in the presence of plasma, an etching gas containing a fluorine compound with three or fewer carbon atoms having at least one bond of a carbon-oxygen double bond and an ether bond in a molecule into contact with a target etching member having an etching target and a non-etching target, and selectively etching the etching target in comparison with the non-etching target. A concentration of the fluorine compound in the etching gas is 0.5 vol % or more to 40 vol % or less, and the etching target has silicon nitride.
1 . An etching method comprising:
bringing, in the presence of plasma, an etching gas consisting of a fluorine compound with 3 or fewer carbon atoms either having at least one bond of a carbon-oxygen double bond or having at least one ether bond in a molecule of the fluorine compound, a noble gas, and a nitrogen gas into contact with a target etching member having an etching target which is an object to be etched by the etching gas and a non-etching target which is not an object to be etched by the etching gas, and selectively etching the etching target in comparison with the non-etching target,
wherein a concentration of the fluorine compound in the etching gas is 0.5 vol % or more to 40 vol % or less,
wherein a concentration of the nitrogen gas in the etching gas is 10 vol % or less and 0 vol % or more, and
wherein the etching target has silicon nitride.
2 . The etching method according to claim 1 , wherein
the non-etching target has at least one selected from silicon oxide, a photoresist, and amorphous carbon.
3 . The etching method according to claim 2 , wherein
the etching is performed under a pressure condition of 1 Pa or more to 3 kPa or less.
4 . The etching method according to claim 2 , wherein
the etching is performed under a temperature condition of 0° C. or higher to 200° C. or lower.
5 . The etching method according to claim 2 , wherein
the concentration of the fluorine compound in the etching gas is 1 vol % or more to 30 vol % or less.
6 . The etching method according to claim 1 , wherein the etching is performed under a pressure condition of 1 Pa or more to 3 kPa or less.
7 . The etching method according to claim 6 , wherein
the etching is performed under a temperature condition of 0° C. or higher to 200° C. or lower.
8 . The etching method according to claim 6 , wherein
the concentration of the fluorine compound in the etching gas is 1 vol % or more to 30 vol % or less.
9 . The etching method according to claim 1 , wherein
the etching is performed under a temperature condition of 0° C. or higher to 200° C. or lower.
10 . The etching method according to claim 9 , wherein
the concentration of the fluorine compound in the etching gas is 1 vol % or more to 30 vol % or less.
11 . The etching method according to claim 1 , wherein
the concentration of the fluorine compound in the etching gas is 1 vol % or more to 30 vol % or less.
12 . The etching method according to claim 1 , wherein
the noble gas is at least one selected from helium, argon, neon, krypton, and xenon.
13 . The etching method according to claim 1 , wherein
the fluorine compound is at least one selected from carbonyl fluoride, oxalyl fluoride, and hexafluoropropylene oxide.
14 . A semiconductor element manufacturing method for manufacturing a semiconductor element using the etching method according to claim 1 , wherein
the target etching member is a semiconductor substrate having the etching target and the non-etching target, and
the semiconductor element manufacturing method includes removing at least a part of the etching target from the semiconductor substrate by the etching.