PLASMA ETCHING APPARATUS

• US 20100133234A1
• Filed: 02/04/2010
• Published: 06/03/2010
• Est. Priority Date: 07/30/2004
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: SUZUKI, Hiroshi, YOSHIDA, Tetsuo, YOSHIDA, Ryoichi, AOYAMA, Hayato, OBI, Akira, WAKAKI, Toshikatsu, SAITO, Michishige
• Granted Patent: US 8,821,742 B2
• Time in Patent Office: Days
• US Class Current: 216/67
• CPC Class Codes: H01J 37/32091 the radio frequency energy being capacitively coupled to the plasma
• CPC Class Codes: H01J 37/3244 Gas supply means
• CPC Class Codes: H01J 37/32449 Gas control, e.g. control of the gas flow
• CPC Class Codes: H01L 21/31116 by dry-etching

Abstract

A plasma etching method by using a plasma etching apparatus having a depressurizable processing chamber; a lower electrode for mounting thereon a substrate to be processed in the processing chamber; an upper electrode facing the lower electrode in the processing chamber with a plasma generation region formed therebetween; a radio frequency power supply unit for applying a radio frequency power between the upper electrode and the lower electrode to thereby form a radio frequency electric field in the plasma generation region, the method comprising: supplying a first gas including etchant gas to an upper gas inlet to introduce the first gas through the upper electrode into the plasma generation region; and feeding a second gas including dilution gas to a side gas inlet to introduce the second gas through a sidewall of the processing chamber into the plasma generation region.

Claims

1. A plasma etching method by using a plasma etching apparatus having a depressurizable processing chamber;

a lower electrode for mounting thereon a substrate to be processed in the processing chamber;

an upper electrode facing the lower electrode in the processing chamber with a plasma generation region formed therebetween;

a radio frequency power supply unit for applying a radio frequency power between the upper electrode and the lower electrode to thereby form a radio frequency electric field in the plasma generation region, the method comprising;

supplying a first gas including etchant gas to an upper gas inlet to introduce the first gas through the upper electrode into the plasma generation region; and

feeding a second gas including dilution gas to a side gas inlet to introduce the second gas through a sidewall of the processing chamber into the plasma generation region.

2. The plasma etching method of claim 1, wherein the upper gas inlet has an upper gas injection portion provided at the upper electrode, and the first gas is injected through the upper gas injection portion toward the plasma generation region, and

wherein the upper gas inlet has a first gas supply line for supplying the first gas toward the upper gas injection portion and an upper gas buffer space for accumulating the first gas supplied through the first gas supply line in front of the upper gas injection portion.

3. The plasma etching method of claim 1, wherein the side gas inlet has one or more side gas injection portions provided at the sidewall of the processing chamber, and the second gas is injected through said one or more side gas injection portions toward the plasma generation region.

4. The plasma etching method of claim 3, wherein the number of the side gas injection portions is greater than one and the side gas injection portions are circumferentially provided at the sidewall of the processing chamber at regular intervals.

5. The plasma etching method of claim 3, wherein the side gas injection portion is made of a material selected from a group consisting of Si, SiC and quartz.

6. The plasma etching method of claim 3, wherein the side gas inlet has a second gas supply line for supplying the second gas toward the side gas injection portion and a side gas buffer space for accumulating the second gas supplied through the second gas supply line in front of the side gas injection portion.

7. A plasma etching method by using a plasma etching apparatus having a depressurizable processing chamber;

a lower electrode for mounting thereon a substrate to be processed in the processing chamber;

an upper electrode facing the lower electrode in the processing chamber with a plasma generation region formed therebetween;

a radio frequency power supply unit for applying a radio frequency power between the upper electrode and the lower electrode to thereby form a radio frequency electric field in the plasma generation region, the method comprising;

supplying a second gas including dilution gas to an upper central gas inlet to introduce the second gas through a central portion of the upper electrode into the plasma generation region;

feeding a first gas including etchant gas to an upper peripheral gas inlet to introduce the first gas through a peripheral portion provided at an outside of the central portion of the upper electrode along its radial direction into the plasma generation region; and

supplying the second gas including dilution gas to a side gas inlet to introduce the second gas through a sidewall of the processing chamber into the plasma generation region.

8. The plasma etching method of claim 7, wherein the upper central gas inlet has an upper central gas injection portion provided at the central portion of the upper electrode, and the second gas is injected through the upper central gas injection portion toward the plasma generation region, and

wherein the upper central gas inlet has a first gas supply line for supplying the second gas toward the upper central gas injection portion and an upper central gas buffer space for accumulating the second gas supplied through the first gas supply line in front of the upper central gas injection portion.

9. The plasma etching method of claim 7, wherein the upper peripheral gas inlet has an upper peripheral gas injection portion provided at an outside of the central portion of the upper electrode along its radial direction, and the first gas is injected through the upper peripheral gas injection portion toward the plasma generation region, and

wherein the upper peripheral gas inlet has a second gas supply line for supplying the first gas toward the upper peripheral gas injection portion and an upper peripheral gas buffer space for accumulating the first gas supplied through the second gas supply line in front of the upper peripheral gas injection portion.

10. The plasma etching method of claim 7, wherein the side gas inlet has one or more side gas injection portions provided at the sidewall of the processing chamber, and the second gas is injected through said one or more side gas injection portions toward the plasma generation region.

11. The plasma etching method of claim 10, wherein the number of the side gas injection portions is greater than one and the side gas injection portions are circumferentially provided at the sidewall of the processing chamber at regular intervals.

12. The plasma etching method of claim 10, wherein the side gas injection portion is made of a material selected from a group consisting of Si, SiC and quartz.

13. The plasma etching method of claim 10, wherein the side gas inlet has a third gas supply line for supplying the second gas toward the side gas injection portion and a side gas buffer space for accumulating the second gas supplied through the third gas supply line in front of the side gas injection portion.

14. The plasma etching method of claim 7, wherein the plasma etching apparatus further comprises a flow rate ratio control unit for controlling a flow rate ratio of the second gas depending on processes.

15. The plasma etching method of claim 7, wherein the second gas contains all or most of an additive gas.

16. The plasma etching method of claim 7, wherein the first gas contains all or most of an additive gas.

17. A plasma etching method by using a plasma etching apparatus having a depressurizable processing chamber;

a lower electrode for mounting thereon a substrate to be processed in the processing chamber;

an upper electrode facing the lower electrode in the processing chamber with a plasma generation region formed therebetween;

a radio frequency power supply unit for applying a radio frequency power between the upper electrode and the lower electrode to thereby form a radio frequency electric field in the plasma generation region, the method comprising;

supplying a second gas including dilution gas to a first gas inlet to introduce the second gas through a first region containing a central portion of the upper electrode into the plasma generation region;

feeding a first gas including etchant gas to a second gas inlet to introduce the first gas through a second region of the upper electrode provided at an outside of the first region along its radial direction into the plasma generation region; and

supplying the second gas including dilution gas to a third gas inlet to introduce the second gas through a third region of the upper electrode provided at an outside of the second region along its radial direction into the plasma generation region.

18. The plasma etching method of claim 17, wherein the first gas inlet has a first gas injection portion provided in the first region of the upper electrode, and the second gas is injected through the first gas injection portion toward the plasma generation region, and

wherein the first gas inlet has a first gas supply line for supplying the second gas toward the first gas injection portion and a first gas buffer space for accumulating the second gas supplied through the first gas supply line in front of the first gas injection portion.

19. The plasma etching method of claim 17, wherein the second gas inlet has a second gas injection portion provided in the second region of the upper electrode, and the first gas is injected through the second gas injection portion toward the plasma generation region, and

wherein the second gas inlet has a second gas supply line for supplying the first gas toward the second gas injection portion and a second gas buffer space for accumulating the first gas supplied through the second gas supply line in front of the second gas injection portion.

20. The plasma etching method of claim 17, wherein the third gas inlet has a third gas injection portion provided in the third region of the upper electrode, and the second gas is injected through the third gas injection portion toward the plasma generation region.

21. The plasma etching method of claim 20, wherein the third gas injection portion is made of a material selected from a group consisting of Si, SiC and quartz.

22. The plasma etching method of claim 20, wherein the third gas inlet has a third gas supply line for supplying the second gas toward the third gas injection portion and a third gas buffer space for accumulating the second gas supplied through the third gas supply line in front of the third gas injection portion.

23. The plasma etching method of claim 17, further comprising a flow rate ratio control unit for controlling a flow rate ratio of the second gas depending on processes.

24. The plasma etching method of claim 17, wherein the second gas contains all or most of an additive gas.

25. The plasma etching method of claim 17, wherein first gas contains all or most of an additive gas.