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US-12624445-B2 - Method for removing molybdenum monofluoride to molybdenum pentafluoride and method for producing semiconductor device

US12624445B2US 12624445 B2US12624445 B2US 12624445B2US-12624445-B2

Abstract

The present invention relates to a method for removing MoF x or MoF x and MoOF x , including: bringing a halogen-containing gas into contact with a member having a deposit or a coating of MoF x or MoF x and MoOF x (where x represents a number greater than 0 and less than 6); and removing MoF x or MoF x and MoOF x from the member, a method for removing a deposit or a coating from a member having the deposit or the coating of MoF x or MoF x and MoOF x mixed as impurities in MoF 6 by a method for producing a semiconductor device including the above removing method, and a method for producing a semiconductor device that includes removing a deposit or a coating from a semiconductor device production apparatus having a deposit or coating of MoF x or MoF x and MoOF x , and that can avoid clogging or contamination of the production apparatus.

Inventors

  • Akiou Kikuchi
  • Masato SHINAGAWA

Assignees

  • CENTRAL GLASS CO., LTD.

Dates

Publication Date
20260512
Application Date
20220629
Priority Date
20210705

Claims (14)

  1. 1 . A method for producing a semiconductor device comprising: circulating a gas containing MoF 6 in a semiconductor processing apparatus comprising: a chamber and a pipe connected to the chamber, so as to bring the MoF 6 in the gas into contact with a semiconductor substrate; and bringing a halogen-containing gas into contact with at least one of the chamber and the pipe, each having a deposit or coating of (i) the MoF x , or (ii) a mixture of the MoF x and MoOF x , where x represents a number greater than 0 and less than 6, wherein the halogen-containing gas oxidizes (i) the MoF x , or (ii) the mixture of MoF x and MoOF x present in the deposit or the coating, so as to form a compound having a lower boiling point than a boiling point of (i) the MoF x , or a boiling point of (ii) the mixture of MoF x and MoOF x , present in the deposit or the coating, respectively.
  2. 2 . The method for producing a semiconductor device according to claim 1 , wherein the halogen-containing gas is a fluorine-containing gas.
  3. 3 . The method for producing a semiconductor device according to claim 1 , wherein the halogen-containing gas is a fluorine gas.
  4. 4 . The method for producing a semiconductor device according to claim 1 , wherein at least one of the chamber or the pipe with which the halogen-containing gas is brought into contact has a temperature in a range from 0° C. to 400° C.
  5. 5 . The method according to claim 1 , wherein the halogen-containing gas is selected from the group consisting of fluorine gas (F 2 ), chlorine trifluoride (ClF 3 ), iodine heptafluoride (IF 7 ), and molybdenum hexafluoride (MoF 6 ).
  6. 6 . The method for producing a semiconductor device according to claim 1 , wherein the halogen-containing gas is a gas of a compound having a bond between a fluorine atom and an atom other than the fluorine atom, and a bond energy between the fluorine atom and the atom other than the fluorine atom is 2.5 eV or less.
  7. 7 . The method for producing a semiconductor device according to claim 6 , wherein the bond energy is in a range from 1.7 eV to 2.5 eV or less.
  8. 8 . A method for removing (i) MoF x , or (ii) a mixture of MoF x and MoOF x , comprising: bringing a halogen-containing gas into contact with a member having a deposit or a coating of (i) the MoF x , or (ii) the mixture of MoF x and MoOF x ; and removing (i) the MoF x , or (ii) the mixture of MoF x and MoOF x from the member, respectively, where x represents a number greater than 0 and less than 6, wherein the halogen-containing gas oxidizes (i) the MoF x , or (ii) the mixture of MoF x and MoOF x to form a compound having a lower boiling point than a boiling point of (i) the MoF x , or a boiling point of (ii) the mixture of MoF x and MoOF x , respectively.
  9. 9 . The method according to claim 8 , wherein the halogen-containing gas is a fluorine-containing gas.
  10. 10 . The method according to claim 8 , wherein the halogen-containing gas is a fluorine gas.
  11. 11 . The method according to claim 8 , wherein the member with which the halogen-containing gas is brought into contact has a temperature in a range from 0° C. to 400° C.
  12. 12 . The method according to claim 8 , wherein the halogen-containing gas is selected from the group consisting of fluorine gas (F 2 ), chlorine trifluoride (ClF 3 ), iodine heptafluoride (IF 7 ), and molybdenum hexafluoride (MoF 6 ).
  13. 13 . The method according to claim 8 , wherein the halogen-containing gas is a gas of a compound having a bond between a fluorine atom and an atom other than the fluorine atom, and a bond energy between the fluorine atom and the atom other than the fluorine atom is 2.5 eV or less.
  14. 14 . The method according to claim 13 , wherein the bond energy is in a range from 1.7 eV to 2.5 eV.

Description

TECHNICAL FIELD The present invention relates to a method for removing molybdenum monofluoride to molybdenum pentafluoride and a method for producing a semiconductor device. BACKGROUND ART Molybdenum hexafluoride (MoF6) is used as a raw material for depositing molybdenum metal by chemical vapor deposition (CVD) in production of semiconductor devices, solar cells, and the like. In addition, MoF6 is used as an etching material in a process of producing a semiconductor device (Patent Literature 1). Paragraph in Patent Literature 2 discloses that unreacted elemental metal (Mo) and intermediates of molybdenum monofluoride to molybdenum pentafluoride (MoF, MoF2, MoF3, MoF4, MoF5) may be mixed as impurities during the production of MoF6, and such impurities not only cause a decrease in a purity of MoF6, but also may accumulate inside a reaction device, and this may cause a problem of clogging in a reaction system and a problem in maintenance of the reaction device. CITATION LIST Patent Literature Patent Literature 1: JP2019-502253APatent Literature 2: WO 2019/189715 SUMMARY OF INVENTION Technical Problem A method for removing a deposit or a coating of MoFx (x represents a number greater than 0 and less than 6, and the same applies to x below), or MoFx and MoOFx, from a member having the deposit or the coating of MoFx mixed as impurities in MoF6, or a member having the deposit or the coating of MoFx and MoOFx mixed as impurities in MoF 6 is desired. In addition, when MoF6 is used as a film-forming material or an etching material for Mo in the process of producing a semiconductor device, a method for stably producing a semiconductor device that includes removing a deposit or a coating of MoFx or a deposit or a coating of MoFx and MoOFx, from a semiconductor device production apparatus (for example, a chamber or a pipe) having a deposit or a coating of MoFx or a deposit or a coating of MoFx and MoOFx mixed as impurities in MoF6, and that can avoid clogging and contamination of the production apparatus is desired. The present invention has been made in view of the above circumstances, and an object thereof is to provide a method for removing a deposit or a coating of MoFx or MoFx and MoOFx mixed as impurities in MoF6 from a member having the deposit or the coating of MoFx or MoFx and MoOFx, and a method for producing a semiconductor device that includes removing a deposit or a coating of MoFx or MoFx and MoOFx from a semiconductor device production apparatus (for example, a chamber or a pipe) having the deposit or the coating of MoFx or MoFx and MoOFx, and that can avoid clogging or contamination of the production apparatus. Solution to Problem As a result of extensive studies in view of such a problem, the present inventors have found that when a member having a deposit or a coating of MoFx or MoFx and MoOFx is brought into contact with a halogen-containing gas, the deposit or the coating can be removed from the member. That is, the present inventors have found that the above problem can be solved by the following configurations. [1] A method for removing MoFx or MoFx and MoOFx, including: bringing a halogen-containing gas into contact with a member having a deposit or a coating of MoFx or MoFx and MoOFx; andremoving MoFx or MoFx and MoOFx from the member, where x represents a number greater than 0 and less than 6. [2] The method for removing MoFx or MoFx and MoOFx according to [1], in which the halogen-containing gas is a gas of a compound having a bond between a fluorine atom and an atom other than the fluorine atom, and a bond energy between the fluorine atom and the atom other than the fluorine atom is 2.5 eV or less. [3] The method for removing MoFx or MoFx and MoOFx according to [2], in which the bond energy is 1.7 eV or more and 2.5 eV or less. [4] The method for removing MoFx or MoFx and MoOFx according to [1], in which the halogen-containing gas is a fluorine-containing gas. [5] The method for removing MoFx or MoFx and MoOFx according to [1], in which the halogen-containing gas is a fluorine gas. [6] The method for removing MoFx or MoFx and MoOFx according to any one of [1] to [5], in which the member with which the halogen-containing gas is brought into contact has a temperature of 0° C. to 400° C. [7] A method for producing a semiconductor device including: (1) circulating a gas containing MoF6 in a semiconductor processing apparatus including a chamber and a pipe connected to the chamber to bring MoF6 into contact with a semiconductor substrate; and(2) bringing a halogen-containing gas into contact with at least one of the chamber and the pipe having a deposit or coating of MoFx or MoFx and MoOFx, in which where x represents a number greater than 0 and less than 6. [8] The method for producing a semiconductor device according to [7], in which the halogen-containing gas is a gas of a compound having a bond between a fluorine atom and an atom other than the fluorine atom, and a bond energy between the flu