Selective SiARC removal

Patent metadata

Field	Value
Publication number	US-10115591-B2
Application number	US-201715440604-A
Country	US
Kind code	B2
Filing date	Feb 23, 2017
Priority date	Feb 29, 2016
Publication date	Oct 30, 2018
Grant date	Oct 30, 2018

Abstract

Methods and systems for selective silicon anti-reflective coating (SiARC) removal are described. An embodiment of a method includes providing a substrate in a process chamber, the substrate comprising: a resist layer, a SiARC layer, a pattern transfer layer, and an underlying layer. Such a method may also include performing a pattern transfer process configured to remove the resist layer and create a structure on the substrate, the structure comprising portions of the SiARC layer and the pattern transfer layer. The method may additionally include performing a modification process on the SiARC layer of the structure, the modification converting the SiARC layer into a porous SiARC layer. Further, the method may include performing a removal process of the porous SiARC layer of the structure, wherein the modification and removal processes of the SiARC layer are configured to meet target integration objectives.

First claim

What we claim:

1. A method for an integration process of selectively removing a silicon-containing antireflective coating (SiARC) in a substrate, the method comprising:
providing a substrate in a process chamber, the substrate comprising:
a resist layer, a SiARC layer, a pattern transfer layer, and an underlying layer;

performing a pattern transfer process configured to remove the resist layer and create a structure on the substrate, the structure comprising portions of the SiARC layer and the pattern transfer layer;
performing a nitridation modification process on the SiARC layer of the structure, the nitridation modification process using a plasma of nitrogen ions and bombarding the SiARC layer to implant the nitrogen ions therein to an implantation depth, converting the SiARC layer into a nitrided SiARC layer having an increased nitrogen content; and
performing a removal process of the nitrided SiARC layer of the structure, wherein the increased nitrogen content increases percent removal of the SiARC layer and increases etch selectivity of the SiARC layer relative to the pattern transfer layer and/or the underlying layer.

2. The method of claim 1 wherein the pattern transfer layer comprises a carbon hard mask (CHM) layer, an organic dielectric layer (ODL), an amorphous silicon layer, and/or an oxide layer.

3. The method of claim 1 wherein the nitridation modification process further uses oxygen ions or hydrogen ions in the ionized plasma field.

4. The method of claim 1 wherein the removal process of the nitrided SiARC layer utilizes a dry etch process step and a wet etch process step.

5. The method of claim 4 wherein the dry etch process step utilizes an NF 3 or H 2 plasma.

6. The method of claim 4 wherein the wet etch process step utilizes a dilute HF or HCl.

7. The method of claim 1 wherein the removal process of the nitrided SiARC layer utilizes a dry etch process step and a second dry etch process step.

8. The method of claim 7 wherein the second dry etch process step utilizes an HF gas.

9. The method of claim 1 further comprising selecting and controlling one or more operating variables of the integration process in order to meet target integration objectives including the implantation depth being sufficient to remove substantially all of the SiARC layer.

10. The method of claim 9 wherein the one or more operating variables include plasma density, plasma ion energy, feed gas flow rates for gases used in the nitridation modification process and/or the removal process, etching time, etching rate, nitridation modification process pressure, nitridation modification process temperature, or bias power.

11. The method of claim 10 wherein target integration objectives further include percent removal of residue, etch selectivity of the SiARC layer relative to the pattern transfer layer, etch selectivity of the SiARC layer relative to the underlying layer, extent of damage to the underlying layer, and/or extent of damage to the pattern transfer layer.

12. The method of claim 11 wherein two or more of the operating variables of the nitridation modification and removal processes are controlled using a controller in order to meet the target integration objectives.

13. The method of claim 12 wherein the target integration objectives include the etch selectivity of the SiARC layer relative to the pattern transfer layer and/or the underlying layer in a range of 5:1 or higher.

14. The method of claim 13 wherein the nitridation modification process pressure is controlled in a range from 150 to 300 mTorr.

15. A method for an integration process of selectively removing a silicon-containing antireflective coating (SiARC) in a substrate, the method comprising:
providing a substrate in a process chamber, the substrate comprising a resist layer, a SiARC layer, a pattern transfer layer, and an underlying layer;
performing a pattern transfer process configured to remove the resist layer and create a structure on the substrate, the structure comprising portions of the SiARC layer and the pattern transfer layer;
concurrently with performing the pattern transfer process, nitriding the SiARC layer of the structure using a plasma of N 2 and H 2 to implant nitrogen ions to an implantation depth; and
removing the nitrided SiARC layer of the structure, wherein the implantation depth is sufficient to achieve substantially complete removal of the SiARC layer with an etch selectivity of the SiARC layer relative to the pattern transfer layer and/or the underlying layer of at least 5:1.

16. The method of claim 15 wherein removing the nitrided SiARC layer includes a dry etch process with NF 3 or H 2 plasma.

17. The method of claim 15 wherein removing the nitrided SiARC layer includes a wet etch process with dilute HF or HCl.

18. The method of claim 15 further comprising selecting and controlling one or more operating variables of the integration process in order to meet target integration objectives including the implantation depth being sufficient to achieve substantially complete removal of the SiARC layer and the etch selectivity of at least 5:1.

19. The method of claim 18 wherein the one or more operating variables include plasma density, plasma ion energy, N 2 and H 2 flow rates, etching time, etching rate, process pressure during nitriding, process temperature during nitriding, or bias power.

Assignees

• Tokyo Electron Ltd

Inventors

• Sridhar Shyam
• Wang Li
• Nolan Andrew
• Ohtake Hiroto
• Voronin Sergey
• Ranjan Alok

Classifications

• H10P30/40

  into insulating materials · CPC title

• H10P14/6524

  the substance being nitrogen · CPC title

• H10P76/2043

  using an anti-reflective coating · CPC title

• H10P76/405

  characterised by their composition, e.g. multilayer masks · CPC title

• H10P76/403

  for lift-off processes · CPC title