Method for Sealing Pores at Surface of Dielectric Layer by UV Light-Assisted CVD

• US 20110159202A1
• Filed: 11/24/2010
• Published: 06/30/2011
• Est. Priority Date: 12/29/2009
• Status: Abandoned Application

• Current Assignee: ASM Japan K.K. (ASM International NV)
• Original Assignee: ASM Japan K.K. (ASM International NV)
• Inventors: Matsushita, Kiyohiro, Kimura, Yosuke, Yanagisawa, Ippei
• Application Number:
  US12/953,870
• Publication Number:
  US 20110159202A1
• Time in Patent Office: Days
• US Class Current: 427/509
• CPC Class Codes: B05D 1/60 Deposition of organic layers from vapour phase vapour phase deposition in general C23C14/00, C23C16/00
• CPC Class Codes: B05D 3/061 using U.V.
• CPC Class Codes: B05D 7/22 to internal surfaces, e.g. of tubes
• CPC Class Codes: H01L 21/02126 the material containing Si, O, and at least one of H, N, C, F, or other non-metal elements, e.g. SiOC, SiOC:H or SiONC
• CPC Class Codes: H01L 21/02167 the material being a silicon carbide not containing oxygen, e.g. SiC, SiC:H or silicon carbonitrides H01L21/02126 and H01L21/0214 take precedence
• CPC Class Codes: H01L 21/02203 the layer being porous
• CPC Class Codes: H01L 21/3105 After-treatment
• CPC Class Codes: H01L 21/67115 mainly by radiation
• CPC Class Codes: H01L 21/76825 by exposing the layer to particle radiation, e.g. ion implantation, irradiation with UV light or electrons etc. plasma treatment H01L21/76826
• CPC Class Codes: H01L 21/76826 by contacting the layer with gases, liquids or plasmas
• CPC Class Codes: H01L 21/76831 in via holes or trenches, e.g. non-conductive sidewall liners

Abstract

A method for sealing pores at a surface of a dielectric layer formed on a substrate, includes: providing a substrate on which a dielectric layer having a porous surface is formed as an outermost layer; placing the substrate in an evacuatable chamber; irradiating the substrate with UV light in an atmosphere of hydrocarbon and/or oxy-hydrocarbon gas; sealing pores at the porous surface of the dielectric layer as a result of the irradiation; and continuously irradiating the substrate with UV light in the atmosphere of hydrocarbon and/or oxy-hydrocarbon gas until a protective film having a desired thickness is formed on the dielectric layer as a result of the irradiation.

Claims

1. A method for sealing pores at a surface of a dielectric layer formed on a substrate, comprising:

providing a substrate on which a dielectric layer having a porous surface is formed as an outermost layer;

placing the substrate in an evacuatable chamber;

irradiating the substrate with UV light in an atmosphere of hydrocarbon and/or oxy-hydrocarbon gas to seal pores at the porous surface of the dielectric layer; and

continuously irradiating the substrate with UV light in the atmosphere of hydrocarbon and/or oxy-hydrocarbon gas to form a protective film or layer having a desired thickness on the dielectric layer.

2. The method according to claim 1, wherein the step of irradiating the substrate with UV light to seal the pores is performed to restore a surface layer of the substrate while forming substantially no film thereon.

3. The method according to claim 2, wherein the surface layer of the substrate is restored at a depth of about 5 nm to about 50 nm where the pores are sealed with carbon and hydrogen derived from the hydrocarbon and/or oxy-hydrocarbon gas.

4. The method according to claim 1, wherein the protective film or layer has a thickness of about 0.1 nm to about 6 nm.

5. The method according to claim 1, wherein the porous surface of the dielectric layer receives chemical degradation prior to the step of sealing the pores.

6. The method according to claim 5, wherein the chemical degradation is etching, ashing, or cleaning.

7. The method according to claim 1, wherein the atmosphere of hydrocarbon and/or oxy-hydrocarbon gas is established by introducing a hydrocarbon and/or oxy-hydrocarbon gas without including silicon-containing gas into the evacuatable chamber.

8. The method according to claim 7, wherein the hydrocarbon and/or oxy-hydrocarbon gas consists of hydrogen and carbon.

9. The method according to claim 8, wherein the hydrocarbon and/or oxy-hydrocarbon gas is a mixture of hydrocarbon gas and oxy hydrocarbon gas.

10. The method according to claim 7, wherein the hydrocarbon and/or oxy-hydrocarbon gas is introduced with an inert gas saturated with hydrocarbon and/or oxy-hydrocarbon gas.

11. The method according to claim 10, wherein the saturated inert gas is introduced at a flow rate of 500 sccm to 10,000 sccm.

12. The method according to claim 1, wherein the UV light has a wavelength of 200 nm or higher.

13. The method according to claim 1, further comprising annealing the substrate after the protective film or layer is formed by the UV light irradiation.

14. The method according to claim 1, wherein the protective film or layer is formed on a top surface and side surfaces of the dielectric layer.

15. The method according to claim 1, wherein the dielectric layer is a SiCO film.

16. The method according to claim 1, wherein the dielectric layer has a dielectric constant of lower than 2.5.

17. The method according to claim 16, wherein the protective film or layer and the dielectric layer together have a dielectric constant which is substantially the same as that of the dielectric layer.

18. The method according to claim 1, wherein the substrate is irradiated with UV light through a transmission window which is made of synthetic quartz.

19. The method according to claim 18, further comprising cleaning the evacuatable chamber by using a cleaning gas containing no fluorine after the protective film or layer is formed.