PRE AND POST CLEANING OF MASK, WAFER, OPTICAL SURFACES FOR PREVENTION OF CONTAMINATION PRIOR TO AND AFTER INSPECTION

• US 20120274924A1
• Filed: 04/19/2012
• Published: 11/01/2012
• Est. Priority Date: 04/26/2011
• Status: Active Grant

• Current Assignee: KLA-Tencor Corporation
• Original Assignee: KLA-Tencor Corporation
• Inventors: Delgado, Gildardo
• Granted Patent: US 9,335,279 B2
• Time in Patent Office: Days
• US Class Current: 356/72
• CPC Class Codes: B08B 7/0035 by radiant energy, e.g. UV, laser, light beam or the like
• CPC Class Codes: B08B 7/005 by infrared radiation
• CPC Class Codes: B08B 7/0057 by ultraviolet radiation
• CPC Class Codes: G01N 21/94 Investigating contamination, e.g. dust G01N21/85 takes precedence
• CPC Class Codes: G01N 21/956 Inspecting patterns on the surface of objects contactless testing of electronic circuits G01R31/308; testing currency G07D; manufacturing processes per se of semiconductor devices implementing a measuring step H01L22/10
• CPC Class Codes: G03F 1/82 Auxiliary processes, e.g. cleaning or inspecting
• CPC Class Codes: G03F 1/84 Inspecting
• CPC Class Codes: G03F 7/70908 Hygiene, e.g. preventing apparatus pollution, mitigating effect of pollution or removing pollutants from apparatus

Abstract

A method and apparatus for preventing or minimizing contamination on a critical surface is disclosed. The method and apparatus for preventing or minimizing contamination on the critical surface may be an integrated component of an inspection system, and the cleaning process may be applied prior to the inspection process (may be referred to as pre-cleaning) which may greatly reduce photon-induced contamination. In addition, the cleaning process in accordance with the present disclosure may also be applied upon completion of the inspection process (may be referred to as post-cleaning).

Claims

1. An inspection specimen cleaning system, comprising:

a light source, the light source configured for providing photons towards a surface of the inspection specimen; and

a gas source, the gas source configured for providing a mixture of gases towards the surface of the inspection specimen;

wherein the photons in combination with the mixture of gases form reactive free radicals to dissociate contaminate compounds on the surface of the inspection specimen.

2. The inspection specimen cleaning system of claim 1, wherein the light source is at least one of:

an extreme ultraviolet (EUV) light source, a vacuum ultraviolet (VUV) light source, a deep ultraviolet (DUV) light source, an ultraviolet (UV) light source, a visible light source or an infrared (IR) light source.

3. The inspection specimen cleaning system of claim 1, wherein the gas source further comprises:

a gas input module, the gas input module configured for providing the mixture of gases including at least one of;

H₂, N₂, He, Ar, Xe, H₂O, O₂, O₃, CO₂ in gas form; and

a gas purification module, the gas purification module configured for purifying the mixture of gases prior to directing the mixture of gases towards the surface of the inspection specimen.

4. The inspection specimen cleaning system of claim 1, further comprising:

a gas ionizer, the gas ionizer configured for ionizing the mixture of gases prior to directing the mixture of gases towards the surface of the inspection specimen.

5. The inspection specimen cleaning system of claim 1, wherein the inspection specimen cleaning system is an integrated component of an inspection system, and wherein the cleaning system is utilized prior to an inspection process.

6. The inspection specimen cleaning system of claim 1, wherein the inspection specimen cleaning system is an integrated component of an inspection system, and wherein the cleaning system is utilized prior to and upon completion of an inspection process.

7. A method for reducing contamination on a surface of an inspection specimen, the method comprising:

providing photons towards the surface of the inspection specimen prior to an inspection process; and

providing a mixture of gases towards the surface of the inspection specimen prior to the inspection process, wherein the photons in combination with the mixture of gases form reactive free radicals to dissociate contaminate compounds on the surface of the inspection specimen.

8. The method of claim 7, wherein the photons include at least one of:

extreme ultraviolet (EUV) photons, vacuum ultraviolet (VUV) photons, deep ultraviolet (DUV) photons, ultraviolet (UV) photons, visible light photons or infrared (IR) photons.

9. The method of claim 7, wherein the mixture of gases include at least one of:

H₂, N₂, He, Ar, Xe, H₂O, O₂, O₃, CO₂ in gas form.

10. The method of claim 7, further comprising:

purifying the mixture of gases prior to directing the mixture of gases towards the surface of the inspection specimen.

11. The method of claim 7, further comprising:

ionizing the mixture of gases prior to directing the mixture of gases towards the surface of the inspection specimen.

12. The method of claim 7, further comprising:

providing a second mixture of gases towards the surface of the inspection specimen upon completion of the inspection process, wherein the photons in combination with the second mixture of gases form reactive free radicals to dissociate contaminate compounds on the surface of the inspection specimen.

13. The method of claim 12, wherein the second mixture of gases include at least one of:

H₂, N₂, He, Ar, Xe, H₂O, O₂, O₃, CO₂ in gas form.

14. A method for inspecting an inspection specimen, the method comprising:

pre-cleaning a surface of the inspection specimen prior to inspecting the inspection specimen, said pre-cleaning further comprising;

providing photons towards the surface of the inspection specimen;

providing a mixture of inner gases or ionized gases towards the surface of the inspection specimen, wherein the photons in combination with the mixture of gases form reactive free radicals to dissociate contaminate compounds on the surface of the inspection specimen; and

inspecting the inspection specimen upon completion of said pre-cleaning the surface of the inspection specimen.

15. The method of claim 14, wherein the photons include at least one of:

extreme ultraviolet (EUV) photons, vacuum ultraviolet (VUV) photons, deep ultraviolet (DUV) photons or infrared (IR) photons.

16. The method of claim 14, wherein the mixture of gases include at least one of:

H₂, N2, He, Ar, Xe, H₂O, O₂, O₃, CO₂ in gas form.

17. The method of claim 14, further comprising:

purifying the mixture of gases prior to directing the mixture of gases towards the surface of the inspection specimen.

18. The method of claim 14, further comprising:

ionizing the mixture of gases prior to directing the mixture of gases towards the surface of the inspection specimen.

19. The method of claim 14, further comprising:

post-cleaning the surface of the inspection specimen upon completion of said inspecting the inspection specimen, said post-cleaning further comprising;

providing photons towards the surface of the inspection specimen;

providing a second mixture of gases towards the surface of the inspection specimen, wherein the photons in combination with the second mixture of gases form reactive free radicals to dissociate contaminate compounds on the surface of the inspection specimen.

20. The method of claim 14, wherein the second mixture of gases include at least one of:

H₂, N₂, He, Ar, Xe, H₂O, O₂, O₃, CO₂ in gas form.