ETCH METHOD IN THE MANUFACTURE OF AN INTEGRATED CIRCUIT

• US 20110027999A1
• Filed: 08/16/2006
• Published: 02/03/2011
• Est. Priority Date: 08/16/2006
• Status: Abandoned Application

• Current Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Original Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Inventors: Shahid, Rauf, Sparks, Terry G.
• Application Number:
  US12/377,348
• Publication Number:
  US 20110027999A1
• Time in Patent Office: Days
• US Class Current: 438/712
• CPC Class Codes: C23F 4/00 Processes for removing metallic material from surfaces, not provided for in group C23F1/00 or C23F3/00
• CPC Class Codes: H01L 21/3065 Plasma etching; Reactive-ion etching
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/32136 using plasmas

Abstract

The present invention provides a method for etching a substrate in the manufacture of a semiconductor device, the method comprising contacting a surface of the substrate with ions extracted from a plasma formed from a gas comprising one or more of an oxygen-containing species, a nitrogen-containing species and an inert gas, and separately contacting the surface of the substrate with a plasma formed from a gas comprising a fluorine-containing species.

Claims

1. A method for etching a substrate in the manufacture of a semiconductor device, the method comprising:

contacting a surface of the substrate with ions extracted from a plasma formed from a gas comprising one or more of an oxygen-containing species, a nitrogen-containing species and an inert gas, and separately contacting the surface of the substrate with a plasma formed from a gas comprising a fluorine-containing species.

2. The method as claimed in claim 1, wherein the fluorine-containing species is a fluorocarbon.

3. The method according to claim 2, wherein the fluorine-containing species comprises one or more of CF₄, CHF₃, CH₂F₂, C₂F₆, C₄F₆, octafluorocyclobutane and C₅F₈.

4. The method according to claim 1, wherein the gas comprising the fluorine-containing species is essentially oxygen-free.

5. The method as claimed in claim 1, wherein the inert gas is a noble gas.

6. The method as claimed in claim 4, wherein the inert gas comprises one or more of helium, neon and argon.

7. The method as claimed in claim 1, wherein the oxygen-containing species comprises one or more of O₂, CO, CO₂, N₂O and H₂O.

8. The method as claimed in claim 1, wherein the nitrogen-containing species comprises N₂.

9. The method as claimed in claim 1, the method comprising:

(A) forming a first plasma from a first gas comprising an oxygen-containing species;

(B) extracting ions from the first plasma;

(C) contacting a surface of the substrate with the ions extracted from the first plasma;

(D) forming a second plasma from a second gas comprising a fluorine-containing species; and

(E) contacting the surface of the substrate with at least a portion of the second plasma.

10. The method according to claim 9, wherein the portion of the plasma contacting the surface of the substrate in step (C) and/or step (E) contains essentially only ions.

11. The method according to claim 10, wherein the ions contacting the surface of the substrate in step (C) and/or step (E) are positive ions.

12. The method according to claim 10, wherein the ions contacting the surface in step (C) and/or step (E) have an energy less than the physical sputtering threshold energy of the surface.

13. The method according to claim 9, wherein steps A to E are repeated until a pre-determined semiconductor depth has been etched.

14. The method according to claim 9, wherein the surface of the substrate comprises an oxidizable material.

15. The method according to claim 9, wherein the surface of the substrate comprises one or more of Si, Ge, Ru, Mo and W.

16. The method according to claim 9, wherein the temperature of the substrate in step (C) and/or step (E) is less than 300°

C.

17. A method according to claim 1, the method comprising:

(A) forming a first plasma from a first gas comprising a fluorocarbon;

(B) contacting the surface of the substrate with at least a portion of the first plasma;

(C) forming a second plasma from a second gas comprising one or more of an oxygen-containing species, a nitrogen-containing species and an inert gas;

(D) extracting ions from the second plasma; and

(E) contacting the surface of the substrate with the ions extracted from the second plasma.

18. The method according to claim 17, wherein the portion of the plasma contacting the surface of the substrate in step (B) and/or step (E) contains essentially only ions.

19. The method according to claim 18, wherein the ions contacting the surface in step (B) and/or step (E) of the substrate are positive ions.

20. The method according to either claim 18, wherein essentially all of the ions contacting the surface in step (B) and/or step (E) have an energy less than the physical sputtering threshold energy of the surface.

21. The method according to claim 17, wherein steps A to E are repeated until a pre-determined semiconductor depth has been etched.

22. The method according to claim 17, wherein the surface of the substrate comprises one or more of Si, Ge, Ru, Mo and W.

23. The method according to claim 17, wherein the temperature of the substrate in step (B) and/or step (E) is less than 300°

C.