Plasma etching method and method for manufacturing semiconductor element
A plasma etching method capable of selectively etching an etching object containing oxide of at least one of tin and indium compared to a non-etching object. The plasma etching method includes: an etching step of bringing an etching gas containing an unsaturated compound having a fluorine atom and a bromine atom in the molecule thereof into contact with a member to be etched including an etching object to be etched by the etching gas and a non-etching object not to be etched by the etching gas in the presence of plasma, performing etching while applying a bias power exceeding 0 W to a lower electrode supporting the member to be etched, and selectively etching the etching object compared to the non-etching object. The etching object contains oxide of at least one of tin and indium and the non-etching object contains at least one of a silicon-containing compound and a photoresist.
1 . A plasma etching method comprising:
an etching step of bringing an etching gas containing an unsaturated compound having a fluorine atom and a bromine atom in a molecule of the unsaturated compound into contact with a member to be etched including an etching object to be etched by the etching gas and a non-etching object not to be etched by the etching gas in a presence of plasma, performing etching while applying a bias power exceeding 0 W to a lower electrode supporting the member to be etched, and selectively etching the etching object compared to the non-etching object, wherein
the etching object contains oxide of at least one of tin and indium and the non-etching object contains at least one of a silicon-containing compound and a photoresist.
2 . The plasma etching method according to claim 1 , wherein the etching gas is a mixed gas containing an unsaturated compound and a gas selected from the group consisting of nitrogen gas, helium, neon, argon, krypton and xenon.
3 . The plasma etching method according to claim 2 , wherein a concentration of the unsaturated compound in the mixed gas is 1% by volume or more and 50% by volume or less.
4 . The plasma etching method according to claim 3 , wherein the unsaturated compound is bromofluoroethylene.
5 . The plasma etching method according to claim 3 , wherein the silicon-containing compound is a compound having at least one of an oxygen atom and a nitrogen atom and a silicon atom, or amorphous silicon.
6 . The plasma etching method according to claim 3 , wherein the etching is performed under a process pressure of 1 Pa or more and 10 Pa or less.
7 . The plasma etching method according to claim 2 , wherein the unsaturated compound is bromofluoroethylene.
8 . The plasma etching method according to claim 2 , wherein the silicon-containing compound is a compound having at least one of an oxygen atom and a nitrogen atom and a silicon atom, or amorphous silicon.
9 . The plasma etching method according to claim 2 , wherein the etching is performed under a process pressure of 1 Pa or more and 10 Pa or less.
10 . The plasma etching method according to claim 1 , wherein the unsaturated compound is bromofluoroethylene.
11 . The plasma etching method according to claim 10 , wherein the bromofluoroethylene is at least one of bromotrifluoroethylene, 1-bromo-2,2-difluoroethylene, (E)-1-bromo-1,2-difluoroethylene, (Z)-1-bromo-1,2-difluoroethylene, 1-bromo-1-fluoroethylene, (E)-1-bromo-2-fluoroethylene, (Z)-1-bromo-2-fluoroethylene, 1,1-dibromo-2-fluoroethylene, (E)-1,2-dibromo-2-fluoroethylene, (Z)-1,2-dibromo-2-fluoroethylene, and tribromofluoroethylene.
12 . The plasma etching method according to claim 11 , wherein the silicon-containing compound is a compound having at least one of an oxygen atom and a nitrogen atom and a silicon atom or amorphous silicon.
13 . The plasma etching method according to claim 11 , wherein the etching is performed under a process pressure of 1 Pa or more and 10 Pa or less.
14 . The plasma etching method according to claim 10 , wherein the silicon-containing compound is a compound having at least one of an oxygen atom and a nitrogen atom and a silicon atom or amorphous silicon.
15 . The plasma etching method according to claim 10 , wherein the etching is performed under a process pressure of 1 Pa or more and 10 Pa or less.
16 . The plasma etching method according to claim 1 , wherein the silicon-containing compound is a compound having at least one of an oxygen atom and a nitrogen atom and a silicon atom, or amorphous silicon.
17 . The plasma etching method according to claim 16 , wherein the etching is performed under a process pressure of 1 Pa or more and 10 Pa or less.
18 . The plasma etching method according to claim 1 , wherein the etching is performed under a process pressure of 1 Pa or more and 10 Pa or less.
19 . The plasma etching method according to claim 1 , wherein the etching is performed while applying a bias power of 10 W or more and 1200 W or less to the lower electrode supporting the member to be etched.
20 . A method for manufacturing a semiconductor element for manufacturing a semiconductor element using the plasma etching method according to claim 1 ,
the member to be etched being a semiconductor substrate having the etching object and the non-etching object, the method comprising:
a treatment step of removing at least a part of the etching object from the semiconductor substrate by the etching.