PLASMA PROCESSING METHOD AND COMPUTER READABLE STORAGE MEDIUM

• US 20090275207A1
• Filed: 03/31/2009
• Published: 11/05/2009
• Est. Priority Date: 03/31/2008
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: NAKAYA, Michiko, HONDA, Masanobu
• Granted Patent: US 8,263,499 B2
• Time in Patent Office: Days
• US Class Current: 438/729
• CPC Class Codes: H01J 37/32027 DC powered
• CPC Class Codes: H01J 37/32091 the radio frequency energy being capacitively coupled to the plasma
• CPC Class Codes: H01L 21/0273 characterised by the treatment of photoresist layers
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/31144 using masks

Abstract

A plasma etching method includes disposing first electrode and second electrodes; preparing a part in a processing chamber; supporting a substrate by the second electrode to face the first electrode; vacuum-evacuating the processing chamber; supplying a first processing gas containing an etchant gas into a processing space between the first electrode and the second electrode; generating a plasma of the first processing gas in the processing space by applying a radio frequency power to the first electrode or the second electrode; and etching a film on the substrate by using the plasma. Further, a resist modification process includes vacuum-evacuating the processing chamber; supplying a second processing gas into the processing space; generating a plasma; and applying a negative DC voltage to the part, the part being disposed away from the substrate in the processing chamber and injecting electrons discharged from the part into the resist pattern on the substrate.

Claims

1. A plasma etching method comprising:

disposing a first electrode and a second electrode in parallel to each other with a gap therebetween in a vacuum evacuable processing chamber;

preparing a part in the processing chamber;

supporting a substrate to be processed by the second electrode to face the first electrode;

vacuum-evacuating the processing chamber to a predetermined pressure;

supplying a first processing gas containing an etchant gas into a processing space between the first electrode and the second electrode;

generating a plasma of the first processing gas in the processing space by applying a radio frequency power to the first electrode or the second electrode; and

etching a film to be processed on the substrate by using the plasma while using as a mask a resist pattern formed on the film,

wherein a resist modification process is performed on the substrate in the processing chamber before etching the film and includes;

vacuum-evacuating the processing chamber to a desired pressure;

supplying a second processing gas into the processing space;

generating a plasma of the second processing gas in the processing space by applying the radio frequency power to the first electrode or the second electrode; and

applying a negative DC voltage to the part exposed to the plasma, the part being disposed away from the substrate in the processing chamber and injecting electrons discharged from the part into the resist pattern on the substrate to thereby improve an etching resistance of the resist pattern.

2. The plasma etching method of claim 1, wherein in the resist modification process, an absolute value of the negative DC voltage is selected so as to inject the electrons discharged from the part into the resist pattern at an energy greater than or equal to about 1000 eV.

3. The plasma etching method of claim 1, wherein an absolute value of the negative DC voltage is selected to be greater or equal to about 1000 V.

4. The plasma etching method of claim 1, wherein in the resist modification process, an absolute value of the negative DC voltage is selected so as to inject the electrons discharged from the part into the resist pattern at an energy greater than or equal to about 1500 eV.

5. The plasma etching method of claim 1, wherein an absolute value of the negative DC voltage is selected to be greater or equal to about 1500 V.

6. The plasma etching method of claim 1, wherein in the resist modification process, the radio frequency power for plasma generation is applied to the first electrode, and an additional radio frequency power for ion attraction is applied to the second electrode to form a self-bias lower than or equal to about 100 V on the second electrode.

7. The plasma etching method of claim 1, wherein in the resist modification process, the radio frequency power for plasma generation is applied to the first electrode, and an additional radio frequency power for ion attraction is applied to the second electrode at a power lower than or equal to about 50 W.

8. The plasma etching method of claim 1, wherein in the resist modification process, the radio frequency power for plasma generation is applied to the first electrode without applying a radio frequency power to the second electrode.

9. The plasma etching method of claim 1, wherein a trimming process for trimming the resist pattern in the processing chamber in a horizontal direction in parallel with a pattern surface is performed between the resist modification process and the etching process of the film.

10. The plasma etching method of claim 9, wherein the trimming process includes:

vacuum-evacuating the processing chamber;

supplying a third processing gas containing an etchant gas into the processing space;

generating a plasma of the third processing gas in the processing space by applying the radio frequency to the first electrode or the second electrode; and

etching the resist pattern in a desired size by using the plasma.

11. The plasma etching method of claim 1, wherein the part is the first electrode.

12. The plasma etching method of claim 1, wherein a surface of the first electrode which is exposed to the plasma is made of a Si-containing conductive material, and the second processing gas contains a halogen gas.

19. The plasma etching method of claim 1, wherein the resist pattern includes a resist using an ArF excimer laser beam as an exposure beam.

20. A computer readable storage medium storing therein a control program operating on a computer, wherein the control program, when executed, controls a plasma processing apparatus to perform the plasma processing method described in claim 1.

13. A plasma etching method comprising:

disposing a first electrode and a second electrode in parallel to each other with a gap therebetween in a vacuum evacuable processing chamber;

preparing a part in the processing chamber;

supporting a substrate to be processed by the second electrode to face the first electrode;

vacuum-evacuating the processing chamber to a predetermined pressure;

supplying a processing gas containing an etchant gas into a processing space between the first electrode and the second electrode;

generating a plasma of the etching gas in the processing space by applying a radio frequency to the first electrode or the second electrode; and

etching a film to be processed on the substrate by using the plasma while using as a mask a resist pattern formed on the film,

wherein while the film is being etched in the processing chamber, a negative DC voltage is applied to the part exposed to the plasma, the part being disposed away from the substrate in the processing chamber and electrons discharged from the part are injected into the resist pattern to thereby improve an etching resistance of the resist pattern, and

wherein a gas pressure in the processing chamber and etching time are selected so as to etch the resist pattern in a desired size in a horizontal direction in parallel with a pattern surface during the etching process of the film.

15. The plasma processing method of claim 13, wherein an absolute value of the negative DC voltage is selected so as to inject the electrons discharged from the part into the resist pattern at an energy greater than or equal to about 1500 eV.

16. The plasma processing method of claim 13, wherein the radio frequency power for plasma generation is applied to the first electrode, and an additional radio frequency power for ion attraction is applied to the second electrode.

17. The plasma processing method of claim 13, wherein the first radio frequency power for plasma generation and an additional radio frequency power for ion attraction are superposedly applied to the second electrode.

18. The plasma etching method of claim 13 wherein the part is the first electrode.

14. A plasma etching method comprising:

disposing a first electrode and a second electrode in parallel to each other with a gap therebetween in a vacuum evacuable processing chamber;

preparing a part in the processing chamber;

supporting a substrate to be processed by the second electrode to face the first electrode;

vacuum-evacuating the processing chamber to a predetermined pressure;

supplying a processing gas containing an etchant gas into a processing space between the first electrode and the second electrode;

generating a plasma of the processing gas in the processing space by applying a radio frequency power to the first electrode or the second electrode; and

etching a film to be processed on the substrate by using the plasma while using as a mask a resist pattern formed on the film,

wherein while the film is being etched in the processing chamber, a negative DC voltage is applied to the part exposed to the plasma, the part being disposed away from the substrate in the processing chamber and electrons discharged from the part are injected into the resist pattern to thereby improve an etching resistance of the resist pattern.