Method for selectively etching areas of a substrate using a gas cluster ion beam

• US 8,202,435 B2
• Filed: 08/01/2008
• Issued: 06/19/2012
• Est. Priority Date: 08/01/2008
• Status: Active Grant

• Current Assignee: TEL Manufacturing and Engineering of America, Inc.
• Original Assignee: TEL Epion Inc. (Tokyo Electron Limited)
• Inventors: Tabat, Martin D.
• Primary Examiner(s): ALANKO, ANITA KAREN
• Application Number:
  US12/184,517
• Publication Number:
  US 20100025365A1
• Time in Patent Office: 1,418 Days
• Field of Search: None
• US Class Current: 216/13
• CPC Class Codes: C23C 16/04 Coating on selected surface areas, e.g. using masks
• CPC Class Codes: C23C 16/30 Deposition of compounds, mixtures or solid solutions, e.g. borides, carbides, nitrides
• CPC Class Codes: C23C 16/513 using plasma jets
• CPC Class Codes: H01J 2237/0812 Ionized cluster beam [ICB] sources
• CPC Class Codes: H01L 21/3065 Plasma etching; Reactive-ion etching
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/76802 by forming openings in dielectrics
• CPC Class Codes: H01L 21/76829 characterised by the formation of thin functional dielectric layers, e.g. dielectric etch-stop, barrier, capping or liner layers
• CPC Class Codes: H01L 21/76832 Multiple layers

Abstract

A method for selectively etching areas of a substrate is described. The method includes providing in a process chamber a substrate containing a first material having a film deposition surface and a second material having an etch surface. The method further includes forming a gas cluster ion beam (GCIB) from a pressurized gas containing a deposition-etch gas, and exposing the substrate to the GCIB to remove at least a portion of the second material from the etch surface and deposit a thin film on the film deposition surface of the first material. According to some embodiments, the deposition-etch gas may contain silicon (Si) and carbon (C), and it may possess a Si—C bond.

Claims

1. A method for selectively etching an area of a substrate, comprising:

providing in a process chamber a substrate containing a first material having a film deposition surface and a second material having an etch surface;

forming a gas cluster ion beam (GCIB) from a pressurized gas comprising a deposition-etch gas; and

exposing the substrate to the GCIB to remove at least a portion of the second material from the etch surface and to deposit a thin film on the film deposition surface of the first material, wherein the gas clusters of the GCIB are accelerated by an acceleration voltage less than 30 keV.

2. The method of claim 1, wherein the first material comprises a SiCOH-containing dielectric material and the second material comprises a non-SiCOH material.

3. The method of claim 2, wherein the first material comprises a SiCOH material or a F-doped SiCOH material.

4. The method of claim 2, wherein the second material comprises single crystal silicon, polycrystalline silicon, amorphous silicon, silicon nitride, silicon carbide, or silicon carbonitride.

10. The method of claim 1, wherein the pressurized gas further comprises a nitrogen-containing gas.

11. The method of claim 1, wherein the pressurized gas further comprises N₂, NH₃, NF₃, NO, N₂O, or NO₂, or a combination of two or more thereof.

12. The method of claim 1, wherein the pressurized gas further comprises a noble gas.

14. The method of claim 1, further comprising a recessed feature in the first material having a bottom and a sidewall, wherein the etch surface of the second material is located at the bottom of the recessed feature.

15. The method of claim 1, further comprising:

removing the thin film by wet processing or dry processing, the dry processing comprising a thermal process, a plasma-excited process, or a GCIB process.

5. A method for selectively etching an area of a substrate, comprising:

providing in a process chamber a substrate containing a first material having a film deposition surface and a second material having an etch surface;

forming a gas cluster ion beam (GCIB) from a pressurized gas comprising a deposition-etch gas; and

exposing the substrate to the GCIB to remove at least a portion of the second material from the etch surface and to deposit a thin film on the film deposition surface of the first material, wherein the deposition-etch gas and the thin film each comprise silicon (Si) and carbon (C).

6. The method of claim 5, wherein the deposition-etch gas comprises a Si—

C bond.

7. The method of claim 6, wherein the deposition-etch gas comprises an alkyl silane, an alkane silane, an alkene silane, or an alkyne silane.

8. The method of claim 6, wherein the deposition-etch gas comprises methylsilane, dimethylsilane, trimethylsilane, tetramethylsilane, ethylsilane, diethylsilane, triethylsilane, or tetraethylsilane.

9. The method of claim 6, wherein the deposition-etch gas consists of methylsilane.

13. The method of claim 5, wherein the deposition-etch gas further comprises an additional carbon-containing gas selected from CO, CO₂, a hydrocarbon-containing gas, a fluorocarbon-containing gas, or a hydrofluorocarbon-containing gas, or any combination of two or more thereof.

22. The method of claim 5, wherein the first material comprises a SiCOH-containing dielectric material and the second material comprises a non-SiCOH material.

23. The method of claim 22, wherein the second material comprises single crystal silicon, polycrystalline silicon, amorphous silicon, silicon nitride, silicon carbide, or silicon carbonitride.

16. A method for selectively etching areas of a substrate, comprising:

providing in a process chamber a substrate containing a SiCOH-containing dielectric material having a film deposition surface and a second material having an etch surface, the second material containing single crystal silicon, polycrystalline silicon, amorphous silicon, silicon nitride, silicon carbide, or silicon carbonitride;

forming a gas cluster ion beam (GCIB) from a pressurized gas comprising a deposition-etch gas containing silicon (Si), carbon (C), and a Si—

C bond, wherein gas clusters in the GCIB are accelerated by an acceleration voltage less than 30 keV;

exposing the substrate to the GCIB to remove at least a portion of the second material from the etch surface and to deposit a thin film containing silicon and carbon on the film deposition surface of the dielectric material.

17. The method of claim 16, wherein the deposition-etch gas comprises methylsilane, dimethylsilane, trimethylsilane, tetramethylsilane, ethylsilane, diethylsilane, triethylsilane, or tetraethylsilane.

18. A method for selectively etching areas on a patterned substrate, comprising:

providing in a process chamber a patterned substrate containing a recessed feature having a bottom and a sidewall formed in a first material having a film deposition surface and a second material containing an etch surface at the bottom of the recessed feature;

forming a gas cluster ion beam (GCIB) from a pressurized gas comprising a deposition-etch gas containing silicon (Si) and carbon (C); and

exposing the patterned substrate to the GCIB to etch the second material from the etch surface and to deposit a thin film containing silicon and carbon on the film deposition surface.

19. A method for processing a substrate, comprising:

providing in a process chamber a substrate containing a first material having a film deposition surface and a second material having an etch surface;

selecting first gas cluster ion beam (GCIB) processing parameters for selectively etching the etch surface and for depositing a first film on the film deposition surface;

forming a first GCIB from a pressurized gas comprising a deposition-etch gas using the first GCIB processing parameters;

exposing the substrate to the first GCIB using the first GCIB processing parameters to remove at least a portion of the second material from the etch surface and to deposit the first film on the film deposition surface of the first material;

selecting second GCIB processing parameters for non-selectively depositing an additional film on the substrate;

forming a second GCIB using the second GCIB processing parameters; and

exposing the substrate to the second GCIB using the second GCIB processing parameters to deposit the additional film on the substrate,

wherein the deposition-etch gas, the first film, and the additional film each comprise silicon (Si) and carbon (C).

20. The method of claim 19, wherein the first material comprises a SiCOH-containing dielectric material and the second material comprises a non-SiCOH material.

21. The method of claim 19, further comprising:

prior to exposing the substrate to the second GCIB, removing the first film from the film deposition surface.