METHOD OF CLEANING UV IRRADIATION CHAMBER

• US 20080066778A1
• Filed: 09/19/2007
• Published: 03/20/2008
• Est. Priority Date: 09/19/2006
• Status: Active Grant

• Current Assignee: ASM Japan K.K. (ASM International NV)
• Original Assignee: ASM Japan K.K. (ASM International NV)
• Inventors: Matsushita, Kiyohiro, Fukuda, Hideaki, Kagami, Kenichi
• Granted Patent: US 7,789,965 B2
• Time in Patent Office: Days
• US Class Current: 134/1.2
• CPC Class Codes: B08B 7/0057 by ultraviolet radiation
• CPC Class Codes: C23C 16/4405 Cleaning of reactor or parts inside the reactor by using reactive gases
• CPC Class Codes: C23C 16/452 by activating reactive gas streams before their introduction into the reaction chamber, e.g. by ionisation or addition of reactive species
• CPC Class Codes: C23C 16/482 using incoherent light, UV to IR, e.g. lamps
• CPC Class Codes: Y10S 134/902 Semiconductor wafer

Abstract

A method of cleaning a UV irradiation chamber includes steps of: (i) after completion of irradiating a substrate with UV light transmitted through an optical transmitted window provided in the UV irradiation chamber, generating radical species of a cleaning gas outside the UV irradiation chamber; and (ii) introducing the radical species from the outside of the UV irradiation chamber into the UV irradiation chamber, thereby cleaning the optical transmitted window.

Claims

1. A method of cleaning a UV irradiation chamber comprising steps of:

after completion of irradiating a substrate with UV light transmitted through an optical transmitted window provided in the UV irradiation chamber, generating radical species of a cleaning gas outside the UV irradiation chamber; and

introducing the radical species from the outside of the UV irradiation chamber into the UV irradiation chamber, thereby cleaning the optical transmitted window.

2. The method according to claim 1, wherein the cleaning gas is an oxygen gas.

3. The method according to claim 2, further comprising further exciting the radical species by irradiating the radical species with the UV light through the optical transmitted window.

4. The method according to claim 1, wherein the cleaning gas is a gas containing fluorine in a molecule.

5. The method according to claim 4, wherein the optical transmitted window is constituted by a crystal of CaF₂, MgF₂, BaF₂, or Al₂O₃.

6. The method according to claim 4, wherein the optical transmitted window is constituted by a synthetic quartz coated with CaF₂, MgF₂, BaF₂, or Al₂O₃.

7. The method according to claim 1, wherein the generation step comprises generating the radical species by a method other than UV irradiation.

8. The method according to claim 7, wherein the generation step comprises generating the radical species in a remote plasma unit.

9. A method of semiconductor-processing by UV irradiation and cleaning a UV irradiation chamber for semiconductor-processing, comprising the steps of:

processing a semiconductor substrate placed on a susceptor provided in a UV irradiation chamber, by irradiating the substrate with UV light through an optical transmitted window provided in the UV chamber between a UV light source and the susceptor; and

after completion of the processing step, introducing radical species of a cleaning gas from the outside of the UV irradiation chamber into a space defined between the optical transmitted window and the susceptor, thereby cleaning the optical transmitted window.

10. The method according to claim 9, wherein the UV light has a wavelength of 200 nm to 500 nm.

11. The method according to claim 9, wherein in the processing step, a low dielectric film or a silicon carboxide film is formed on the substrate.

12. The method according to claim 9, wherein the cleaning gas is an oxygen gas.

13. The method according to claim 12, further comprising further exciting the radical species by irradiating the radical species with the UV light through the optical transmitted window.

14. The method according to claim 9, wherein the cleaning gas is a gas containing fluorine in a molecule.

15. The method according to claim 14, wherein in the processing step, the substrate is irradiated through the optical transmitted window constituted by a crystal of CaF₂, MgF₂, BaF₂, or Al₂O₃.

16. The method according to claim 14, wherein in the processing step, the substrate is irradiated through the optical transmitted window constituted by a synthetic quartz coated with CaF₂, MgF₂, BaF₂, or Al₂O₃.