METHOD FOR ETCHING WITH HARDMASK

Abstract

Methods are provided for processing a substrate by depositing a hardmask material on a surface of the substrate, depositing an anti-reflective coating on the hardmask material, depositing a resist material on the anti-reflective coating, patterning the resist material to form a first resist features having a first width to expose the anti-reflective coating, etching the anti-reflective coating and a first portion of the hardmask material, and trimming the resist material to form a second resist feature having a second width less than the first width.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above features of the invention are attained and can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.

FIGS. 1A-1D are cross sectional views showing a prior art hardmasks opening sequence;

FIG. 2 is a flow chart of one embodiment of a hardmasks opening sequence of the invention; and

FIGS. 3A-3F are cross sectional views showing one embodiment of a hardmasks opening sequence of the invention.

Claims

1. A method of processing a substrate, comprising: depositing a hardmask material on a surface of the substrate;depositing an anti-reflective coating on the hardmask material;depositing a resist material on the anti-reflective coating;patterning the resist material to form a first resist feature having a first width to expose the anti-reflective coating;etching the anti-reflective coating and a first portion of the hardmask material; andtrimming the resist material to form a second resist feature having a second width less than the first width.

2. The method of claim 1, further comprising: etching a second portion of the hardmask material to the surface of the substrate; andremoving the resist material.

3. The method of claim 1, wherein the patterning the resist material to form the first resist features having the first width comprises: patterning the resist material to form resist features having an initial width to expose the anti-reflective coating; andtrimming the resist material to form the first resist features having the first width.

4. The method of claim 1, wherein the hardmask material is selected from the group comprising silicon nitride, silicon oxynitride, and silicon oxide.

5. The method of claim 1, wherein the anti-reflective coating has a thickness between about 300 Å and about 3000 Å.

6. The method of claim 1, wherein the resist material has a thickness between about 4000 Å to about 6000 Å.

7. The method of claim 1, wherein the trimming the resist material to form a second resist feature having a second width less than the first width is performed for a time period between about 20 seconds to about 180 seconds.

8. The method of claim 1, wherein etching the anti-reflective coating and a first portion of the hardmask material comprises etching between about 5% and about 50% of a thickness of the hardmask material.

9. The method of claim 1, further comprising repeating the steps of etching the anti-reflective coating and a first portion of the hardmask material and trimming the resist material to form a second resist feature having a second width less than the first width until a desired width of the second resist is achieved.

10. The method of claim 1, wherein the resist material is a photoresist material.

11. The method of claim 1, wherein trimming the resist material to form a second resist feature having a second width less than the first width comprises forming a plasma comprising hydrogen bromide at a flow rate of 3 sccm to 200 sccm, oxygen at a flow rate of 5 sccm to 100 sccm, carbon tetrafluoride, and argon at a flow rate of 10 to 200 sccm.

12. A method of processing a substrate, comprising: depositing a hardmask material on a surface of the substrate;depositing a resist material on the hardmask material;patterning the resist material to form a first resist feature having a first width to expose the hardmask material;etching the anti-reflective coating and a first portion of the hardmask material;trimming the resist material to form a second resist feature having a second width between 10% and 30% less than the first width;etching a second portion of the hardmask material to the surface of the substrate; andremoving the resist material.

13. The method of claim 12, wherein the hardmask material is selected from the group comprising silicon nitride, silicon oxynitride, and silicon oxide.

14. The method of claim 12, wherein the anti-reflective coating has a thickness between about 300 Å and about 3000 Å.

15. The method of claim 12, wherein the resist material has a thickness between about 4000 Å to about 6000 Å.

16. The method of claim 12, wherein the trimming the resist material to form a second resist feature having a second width less than the first width is performed for a time period between about 20 seconds to about 180 seconds.

17. The method of claim 12, wherein etching the anti-reflective coating and a first portion of the hardmask material comprises etching between about 5% and about 50% of a thickness of the hardmask material.

18. The method of claim 12, further comprising repeating the steps of etching the anti-reflective coating and a first portion of the hardmask material and trimming the resist material to form a second resist feature having a second width less than the first width until a desired width of the second resist is achieved.

19. The method of claim 12, wherein the resist material is a photoresist material.

20. The method of claim 12, wherein trimming the resist material to form a second resist feature having a second width less than the first width comprises forming a plasma comprising hydrogen bromide at a flow rate of 3 sccm to 200 sccm, oxygen at a flow rate of 5 sccm to 100 sccm, carbon tetrafluoride, and argon at a flow rate of 10 to 200 sccm.