PULSED PLASMA ETCHING METHOD AND APPARATUS

• US 20080081483A1
• Filed: 12/29/2006
• Published: 04/03/2008
• Est. Priority Date: 09/30/2006
• Status: Abandoned Application

• Current Assignee: Semiconductor Manufacturing International (Shanghai) Corporation (Semiconductor Manufacturing International Corporation)
• Original Assignee: Semiconductor Manufacturing International (Shanghai) Corporation (Semiconductor Manufacturing International Corporation)
• Inventors: Wu, Hanming
• Application Number:
  US11/618,504
• Publication Number:
  US 20080081483A1
• Time in Patent Office: Days
• US Class Current: 438/714
• CPC Class Codes: H01J 37/32137 controlling of the discharge by modulation of energy
• CPC Class Codes: H01J 37/32357 Generation remote from the workpiece, e.g. down-stream
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/31122 of layers not containing Si, e.g. PZT, Al2O3
• CPC Class Codes: H01L 21/32136 using plasmas
• CPC Class Codes: H01L 21/32137 of silicon-containing layers

Abstract

A plasma etching method includes preparing in a reaction chamber a semiconductor substrate on which a material layer to be etched is provided; and injecting an etching gas into the reaction chamber, the etching gas being ionized through an RF (Radio Frequency) power source to generate a plasma, wherein the RF power source outputs RF power in a pulse output mode. The plasma etching apparatus includes a reaction chamber adapted to contain an etching gas; and an RF power source adapted to output RF power for excitation of the etching gas to generate plasma, wherein the apparatus further include a pulse control circuit adapted to control the RF power source to output RF power in a pulse output mode. With the invention, the plasma for etching can be generated in a pulse output mode, thus improving a precision of an endpoint where the etching can be disabled.

Claims

1. A plasma etching method comprising:

preparing in a reaction chamber a semiconductor substrate on which a material layer to be etched is provided; and

injecting an etching gas into the reaction chamber, the etching gas being ionized through an RF (Radio Frequency) power source to generate plasma, wherein;

the RF power source outputs RF power in a pulse output mode.

2. The method according to claim 1, wherein the RF power source outputs RF power ranging from 100 to 2200 W.

3. The method according to claim 1, wherein a time range for the RF power source to output RF power is of 5% to 90% relative to a whole etching time range.

4. The method according to claim 3, wherein a pressure in the reaction chamber ranges from 3 to 500 mTorr.

5. The method according to claim 1, wherein a temperature of the semiconductor substrate ranges from 20 to 180°

C.

6. The method according to claim 1, wherein the material layer is a photoresist layer, a metal layer or a medium layer.

7. The method according to claim 6, wherein the metal layer is one of copper, titanium, tungsten, tantalum, nickel and cobalt.

8. The method according to claim 6, wherein the medium layer is one of silicon oxide, silicon nitride, silicon oxynitride, polysilicon, hafnium oxide, hafnium silicon oxide and hafnium silicon oxynitride.

9. The method according to claim 1, wherein the etching gas is one of O₂, N₂, Ar, He, Ne, Cl₂, O₂—

He, HBr and a fluorine-containing gas.

10. The method according to claim 9, wherein the fluorine-containing gas is one of CF₄, CH₂F₂, CHF₃ and SF₆.

22. The method according to claim 2, wherein a time range for the RF power source to output RF power is of 5% to 90% relative to a whole etching time range.

23. The method according to claim 22, wherein a pressure in the reaction chamber ranges from 3 to 500 mTorr.

11. A plasma etching apparatus comprising:

a reaction chamber adapted to contain an etching gas;

an RF (Radio Frequency) power source adapted to output RF power for excitation of the etching gas to generate plasma; and

a pulse control circuit adapted to control the RF power source to output RF power in a pulse output mode.

12. The apparatus according to claim 11, wherein the RF power source outputs RF power ranging from 100 to 2200 W.

13. The apparatus according to claim 11, wherein a time range for the RF power source to output RF power is of 5% to 90% relative to a whole etching time range.

14. The apparatus according to claim 11, wherein a pressure in the reaction chamber ranges from 3 to 500 mTorr.

15. The device according to claim 11, wherein a wafer temperature ranges from 20 to 180°

C.

24. The apparatus according to claim 12, wherein a time range for the RF power source to output RF power is of 5% to 90% relative to a whole etching time range.

16. A plasma etching apparatus comprising:

an RF power source adapted to output RF (Radio Frequency) power;

a pulse control circuit adapted to control the RF power source to output RF power; and

a first reaction chamber and a second reaction chamber, wherein;

the first reaction chamber contains an etching gas, the RF power source outputs RF power in a pulse output mode through the pulse control circuit, and an etching gas is ionized in the first reaction chamber to generate plasma entering the second reaction chamber to etch a material layer on a wafer surface.

17. The apparatus according to claim 16, wherein the RF power source outputs RF power ranging from 100 to 2200 W.

18. The apparatus according to claim 16, wherein a time range for the RF power source to output RF power is from 5% to 90% relative to a whole etching time range.

19. The apparatus according to claim 16, wherein a pressure in the first reaction chamber ranges from 3 to 500 mTorr.

20. The apparatus according to claim 16, wherein a temperature of the wafer ranges from 20 to 180°

C.

21. The apparatus according to claim 16, wherein the etching gas comprises oxygen and water vapor.

25. The apparatus according to claim 17, wherein a time range for the RF power source to output RF power is from 5% to 90% relative to a whole etching time range.