Plasma processing method

• US 5,681,424 A
• Filed: 02/20/1996
• Issued: 10/28/1997
• Est. Priority Date: 05/20/1993
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Fujimoto, Kenji, Saito, Go, Yoshigai, Motohiko
• Primary Examiner(s): Breneman, R. Bruce
• Assistant Examiner(s): ADJODHA, MICHAEL
• Application Number:
  US08/553,435
• Time in Patent Office: 616 Days
• Field of Search: 156/643.1, 134/1.1, 134/1.2, 134/1.3, 216/67, 216/69, 216/70
• US Class Current: 438/716
• CPC Class Codes: H01J 37/32862 In situ cleaning of vessels and/or internal parts
• CPC Class Codes: H01L 21/02071 the processing being a delineation, e.g. RIE, of conductive layers
• CPC Class Codes: H01L 21/302 to change their surface-physical characteristics or shape, e.g. etching, polishing, cutting
• CPC Class Codes: H01L 21/32136 using plasmas
• CPC Class Codes: Y10S 438/905 Cleaning of reaction chamber

Abstract

A method of cleaning an etching chamber, with a high throughput, of a plasma processing apparatus for etching by use of hydrogen bromide (HBr) as an etching gas while holding a wafer on an electrode by electrostatic chuck. When the static charge on the wafer electrostatically chucked on the electrode is eliminated after the completion of the etching, O₂ gas is introduced into the etching chamber from a gas flow-rate controller. A plasma of O₂ gas is generated to cause the electric charge on the wafer to flow to the earth through the plasma, and at the same time, the interior of the etching chamber is cleaned.

Claims

1. A plasma processing method for performing an etching process on a wafer while holding the wafer on an electrode in a chamber by electrostatic attraction, the etching process causing deposition of a polymer including carbon in the chamber, wherein after the wafer has been etched, the method includes a further step of eliminating a residual electrostatic attractive force remaining on said wafer after completion of said etching process through use of a gas plasma of O₂ gas to deelectrify residual electric charge on said wafer by discharging into said plasma, and wherein said polymer is eliminated through said use of the gas plasma of O₂ gas, to clean the chamber.

2. The plasma processing method according to claim 1, wherein said etching process uses hydrogen bromide as an etching gas.

3. The plasma processing method according to claim 2, wherein the wafer has a resist film thereon during the etching process.

4. The plasma processing method according to claim 1, wherein the residual electrostatic attractive force remaining on the wafer and said polymer in the chamber are eliminated at a same time through use of the gas plasma of O₂ gas.

5. The plasma processing method according to claim 1, wherein a plurality of the wafers are etched in sequence, and wherein the gas plasma of O₂ gas is used to deelectrify residual electric charge on said wafer and to eliminate said polymer after etching each wafer.

6. The plasma processing method according to claim 1, wherein the wafer has a resist film thereon during the etching process.

7. The plasma processing method according to claim 1, wherein the wafer includes a silicon-containing film, said silicon-containing film being etched during said etching process.

9. The plasma processing method according to claim 3, wherein said bromine-containing gas is a mixture gas of HBr and O₂.

10. The plasma processing method according to claim 3, wherein said film of the silicon-containing material is a poly-silicon material.

11. The plasma processing method according to claim 3, wherein said film of the silicon-containing material is formed to have a step-wise structure.

12. The plasma processing method according to claim 3, wherein a surface of the wafer to be etched has a step structure, and any residual material to be etched in a corner of the step structure is removed during the post-processing.

14. The plasma processing method according to claim 7, wherein said film of the silicon-containing material is a poly-silicon material.

15. The plasma processing method according to claim 7, wherein said film of the silicon-containing material is formed to have a step-wise structure.

16. The plasma processing method according to claim 7, wherein a surface of the wafer to be etched has a step structure, and any residual material to be etched in a corner of the step structure is removed during the post-processing.

8. A plasma processing method for performing an etching process on a wafer having a film of a silicon-containing material, to etch the film, while holding the wafer on an electrode in a chamber by electrostatic attraction, wherein after the etching process has been performed using a plasma of a bromine-containing gas, the method includes a further step of post-processing said film of the silicon-containing material using a plasma of a mixture gas containing O₂ and CHF₃ continuously in vacuum after said film has been etched.

13. A plasma processing method for performing an etching process on a wafer having a film of a silicon-containing material, to etch the film, while holding the wafer on an electrode in a chamber by electrostatic attraction, wherein after the etching process has been performed using a plasma of a chlorine-containing gas, the method includes a further step of post-processing said film of the silicon-containing material using a plasma of a mixture gas containing O₂ and CHF₃ continuously in vacuum after said film has been etched.

17. A plasma processing method comprising the steps of:

performing an etching process on a wafer in a chamber, which causes the deposition of a polymer including carbon components in the chamber; and

producing a plasma of O₂ gas in the chamber, and eliminating the polymer deposited in the chamber by reacting with the plasma of O₂ gas.

18. The plasma processing method according to claim 17, wherein the wafer has a resist film thereon.

19. The plasma processing method according to claim 18, wherein said etching process is performed using hydrogen bromide as an etching gas.

20. The plasma processing method according to claim 17, wherein said etching process is a plasma etching process.

21. The plasma processing method according to claim 17, wherein said wafer remains in said chamber during said producing the plasma of O₂ gas and eliminating the polymer deposited in the chamber.