Dry etching method, method for manufacturing semiconductor element, and cleaning method

1. A dry etching method comprising a dry etching step in which an etching gas containing bromine pentafluoride is brought into contact with a member to be etched including an etching target being a target of etching with the etching gas to etch the etching target without using plasma,

wherein the etching target contains copper; and

wherein the dry etching step is performed under temperature conditions of from 140° C. to 300° C.

2. The dry etching method according to claim 1 , wherein the etching gas is a gas comprising only a gas of bromine pentafluoride or is a mixed gas containing bromine pentafluoride and inert gas which is at least one selected from nitrogen gas, helium, argon, neon, krypton, and xenon.

3. The dry etching method according to claim 2 , wherein an amount of the halogen fluoride contained in the etching gas is from 1% by volume to 90% by volume.

4. The dry etching method according to claim 1 , wherein an amount of bromine pentafluoride contained in the etching gas is from 1% by volume to 90% by volume.

5. The dry etching method according to claim 1 , wherein an amount of oxygen gas contained in the etching gas is 1% by volume or less.

6. The dry etching method according to claim 1 , wherein the dry etching step is performed under pressure conditions of from 50 Pa to 80 kPa.

7. The dry etching method according to claim 1 , wherein the etching target contains at least one of a copper compound containing at least one type of atom among oxygen, nitrogen, and halogen atoms and copper or elemental copper.

8. The dry etching method according to claim 1 , wherein the dry etching step is performed under temperature conditions of from 210° C. to 280° C.

9. The dry etching method according to claim 1 , wherein the member to be etched includes a non-etching target not being the target of the etching with the etching gas and the etching target, the etching target being selectively etched compared to the non-etching target.

10. The dry etching method according to claim 9 , wherein the non-etching target is at least one selected from silicon oxide, photoresist, and amorphous carbon.

11. The dry etching method according to claim 9 , wherein an etching selectivity ratio being a ratio of an etching rate of the etching target to an etching rate of the non-etching target is 5 or more.

12. A method for manufacturing a semiconductor element, the method using the dry etching method according to claim 1 to manufacture the semiconductor element,

wherein the member to be etched is a semiconductor substrate including the etching target; and

wherein the manufacturing method comprises a processing step of removing at least a part of the etching target from the semiconductor substrate by the dry etching method.

13. The method for manufacturing a semiconductor element according to claim 12 , wherein copper wiring is formed on the semiconductor substrate by the processing step.

14. A cleaning method for cleaning an inner surface of a chamber of a semiconductor element manufacturing device using the dry etching method according to claim 1 ,

wherein the member to be etched is the chamber, the chamber having, on the inner surface, a deposit adhered due to operation of the semiconductor element manufacturing device, and the deposit being the etching target; and

wherein the cleaning method comprises a cleaning step of removing the deposit from the inner surface of the chamber by the dry etching method.