Surface analyzing method and apparatus

• US 5,220,169 A
• Filed: 05/02/1990
• Issued: 06/15/1993
• Est. Priority Date: 09/01/1989
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Nishimatsu, Shigeru, Suzuki, Keizo, Ninomiya, Ken
• Primary Examiner(s): Hannaher, Constantine
• Assistant Examiner(s): Glick, Edward J.
• Application Number:
  US07/517,692
• Time in Patent Office: 1,140 Days
• Field of Search: 378/206, 250/358.1, 250/360.1, 250/372, 250/458.1, 250/459.1, 250/461.1, 250/491.1, 250/359.1
• US Class Current: 250/358.1
• CPC Class Codes: G01N 23/22 by measuring secondary emission from the material
• CPC Class Codes: G01N 23/2273 Measuring photoelectron spectrum, e.g. electron spectroscopy for chemical analysis [ESCA] or X-ray photoelectron spectroscopy [XPS]
• CPC Class Codes: G21K 1/06 using diffraction, refraction or reflection, e.g. monochromators G21K1/10, G21K7/00 take precedence
• CPC Class Codes: G21K 7/00 Gamma- or X-ray microscopes
• CPC Class Codes: H01J 49/16 using surface ionisation, e.g. field-, thermionic- or photo-emission

Abstract

A first beam of light having a wavelength ranging from a soft X-ray to a vacuum ultraviolet region is focused into a thin beam of light and irradiated upon a surface of a specimen, and physical information obtained as a result of such irradiation is detected to obtain information of the surface of the specimen. A second beam of light is focused into a thin beam of light and irradiated at the irradiation spot of the first beam of light upon the surface of the specimen, and the position of the irradiation spot of the second beam of light on the surface of the specimen is visually observed to located the position of the irradiation point of the first beam of light on the surface of the specimen.

Claims

1. A surface analyzing method, comprising the steps of:

focusing a first beam of light having a wavelength ranging from a soft x-ray to a vacuum ultraviolet region into a thin first beam of light;

irradiating the thin first beam of light upon a surface of a specimen to cause emissions at an irradiation spot;

detecting physical information from the emissions to obtain analysis information of the surface of the specimen;

focusing a second different beam of light into a thin second beam of light;

irradiating the thin second beam of light over an area including and wider than the irradiation spot of the thin first beam of light upon the surface of the specimen;

obtaining an enlarged image of a spot of the thin second beam of light on the surface of the specimen by an enlarging optical system; and

locating the position of the irradiation spot of the thin first beam of light on the surface of the specimen in accordance with the enlarged image.

2. A surface analyzing method according to claim 1, characterized in that the second beam of light is a beam of light having a wavelength in a visible light region.

3. A surface analyzing method according to claim 1, characterized in that the second beam of light is a beam of light having a wavelength in a wavelength region shorter than a visible light region.

4. A surface analyzing method according to claim 2, characterized in that the beam of light having a wavelength in a visible light region is a laser beam from a laser source.

5. A surface analyzing method according to any one of the preceding claims, characterized in that focusing of the first beam of light is effected using a focusing optical element which makes use of reflection of light.

6. A surface analyzing method according to any one of claims 1 to 4, characterized in that focusing of the second beam of light is effected using a focusing optical element which makes use of reflection of light.

7. A surface analyzing method according to any one of claims 1 to 4, characterized in that focusing of the first beam of light and focusing of the second beam of light are effected using a common focusing optical element.

8. A surface analyzing method, comprising the steps of:

focusing a first beam of light having a wavelength ranging from a soft x-ray to a vacuum ultraviolet region into a thin first beam of light;

irradiating the thin first beam of light upon a surface of a specimen to cause emissions at an irridiation spot;

detecting physical information from the emissions to obtain analysis information of the surface of the specimen;

focusing simultaneously with the irradiation of the first beam of light on the surface of the specimen, a second beam of light over an area including and wider than the irradiation spot of the first beam of light;

detecting fluorescent light produced from the surface of the specimen as a result of the irradiation of the first and second beams of light;

displaying an enlarged image of the surface of the specimen obtained by such detection of fluorescent light; and

locating the position of the irradiation spot of the first beam of light on the surface of the specimen from a difference in contrast in the enlarged image.

9. A surface analyzing method according to claim 8, characterized in that the first beam of light is a monochromatic beam of light.

10. A surface analyzing method according to claim 9, characterized in that the second beam of light is a monochromatic beam of light.

11. A surface analyzing method according to claim 8, characterized in that the irradiation intensity of the second beam of light on the surface of the specimen is variable.

12. A surface analyzing method, comprising the steps of:

focusing a first beam of light having a wavelength ranging from a soft x-ray to a vacuum ultraviolet region into a thin first beam of light;

irradiating the thin first beam of light upon a surface of a specimen to cause emissions at an irradiation spot;

detecting physical information from the emissions to obtain analysis information of the surface of the specimen;

locating the irradiation spot of the first beam of light on the surface of the specimen by;

(i) focusing simultaneously with the irradiation of the first beam of light on the surface of the specimen, a second beam of light over an area including and wider than the irradiation spot of the first beam of light;

(ii) detecting fluorescent light produced from the surface of the specimen as a result of the irradiation of the first and second beams of light;

(iii) displaying an enlarged image of the surface of the specimen obtained by such detection of fluorescent light; and

(iv) determining a position of the irradiation spot of the first beam of light on the surface of the specimen from a difference in contrast in the enlarged image; and

said step of detecting physical information being characterized in that irradiation of the second beam of light on the surface of the specimen is not performed while a surface analysis by irradiation of the first beam of light is being performed.

13. A surface analyzing apparatus, comprising:

a first light source for producing a first beam of light having a wavelength ranging from a soft X-ray to a vacuum ultraviolet region;

first focusing means for focusing the first beam of light from said first light source into a thin beam of light and irradiating the first beam of light upon a surface of a specimen at an irradiation spot;

detecting means for detecting physical information obtained from an irradiation spot of the first beam of light on the surface of the specimen;

a second light source for producing a second beam of light having a different wavelength from that of the first beam of light;

second focusing means for focusing the second beam of light from the second light source into a thin beam of light and irradiating the second beam of light over an area including and wider than the irradiation spot of the first beam of light on the surface of the specimen; and

means for observing the position of an irradiation spot of the second beam of light on the surface of the specimen.

14. A surface analyzing apparatus according to claim 13, characterized in that said second light source is a light source which produces a beam of light of a wavelength in a visible light region as the second beam of light.

15. A surface analyzing apparatus according to claim 13, characterized in that said second light source is a light source which produces a beam of light of a wavelength region shorter than a visible light region as the second beam of light.

16. A surface analyzing apparatus according to any one of claims 13 to 15, characterized in that said detecting means detects charged particles, photons or neutral particles radiated from the irradiation spot of the first beam of light.

17. A surface analyzing apparatus according to any one of claims 13 to 15, characterized in that said detecting means includes means for detecting energy of electrons or photons radiated from the irradiation spot of the first beam of light.

18. A surface analyzing apparatus according to any one of claims 13 and 14, characterized in that said second light source is a laser source which produces a laser beam of a wavelength in a visible light region as the second beam of light.

19. A surface analyzing apparatus according to any one of claims 13 to 15, characterized in that said first focusing means is constituted from a focusing optical system which makes use of reflection of light.

20. A surface analyzing apparatus according to claim 13, characterized in that said second focusing means is constituted from a focusing optical system which makes use of reflection of light.

21. A surface analyzing apparatus according to claim 13, characterized in that said first and second focusing means are constituted from a single focusing optical system.

22. A surface analyzing apparatus according to claim 21, characterized in that it further comprises light source moving means for alternately positioning said first and second light sources to a predetermined light source position with respect to said single focusing optical system.

23. A surface analyzing apparatus according to claim 21, characterized in that it further comprises means for introducing the first beam of light from said first light source and the second beam of light from said second light source simultaneously into said single focusing optical system.

24. A surface analyzing apparatus according to claim 13, characterized in that it further comprises scanning means for causing the positions of the irradiation spots of the first and second beams of light to two-dimensionally scan the surface of the specimen.

25. A surface analyzing apparatus according to claim 24, characterized in that said scanning means includes means for finely moving the specimen with respect to the first and second beams of light.

26. A surface analyzing apparatus according to claim 24, characterized in that said scanning means includes means for deflecting the first and second beams of light to scan the surface of the specimen.

27. A surface analyzing apparatus according to claim 26, characterized in that the deflecting scanning means includes a reflecting mirror for reflecting the first and second beams of light and introducing the same to the surface of the specimen, and a mechanism for changing the angles of said reflecting mirror with respect to the first and second beams of light.

28. A surface analyzing apparatus according to claim 24, characterized in that said scanning means includes means for finely moving a focusing optical system or systems which constitute said first and second focusing means.

29. A surface analyzing apparatus according to claim 15, characterized in that said means for observing the position of the irradiation spot of the second beam of light on the surface of the specimen includes a member in the form of a thin plate disposed proximate the surface of the specimen for receiving irradiation of the second beam of light and emitting fluorescent light therefrom.

30. A surface analyzing apparatus, comprising:

a first light source for producing a first beam of light having a wavelength ranging from a soft X-ray to a vacuum ultraviolet region;

first focusing means for focusing the first beam of light from said first light source into a thin beam of light and irradiating the first beam of light upon a surface of a specimen at an irradiation spot;

a second light light source for producing a second beam of light;

means for irradiating the second beam of light from said second light source over an area including and wider than the irradiation spot of the first beam of light; and

means for detecting fluorescent light emitted from the surface of the specimen as a result of the irradiation of the first and second beams of light and displaying an enlarged image of the surface of the specimen obtained by such detection of fluorescent light.

31. A surface analyzing apparatus according to claim 30, characterized in that said first light source produces a beam of monochromatic light.

32. A surface analyzing apparatus according to claim 30, characterized in that it further comprises monochromatic light forming means for changing the beam of light from said first light source into a beam of monochromatic light.

33. A surface analyzing apparatus according to claim 31 or 32, characterized in that said second light source produces a beam of monochromatic light.

34. A surface analyzing apparatus according to claim 31 or 32, characterized in that it further comprises monochromatic light forming means for changing the beam of light from said second light source into a beam of monochromatic light.

35. A surface analyzing apparatus according to claim 31 or 32, characterized in that the wavelength of the second beam of light is equal to the wavelength of the first beam of light.

36. A surface analyzing apparatus according to claim 30, characterized in that said detecting means detects electrons radiated from the irradiation spot of the first beam of light.

37. A surface analyzing apparatus according to claim 36, characterized in that said detecting means includes energy analyzing means for analyzing energy of electrons radiated from the irradiation spot of the first beam of light.

38. A surface analyzing apparatus according to claim 30, characterized in that it further comprises scanning means for causing the position of the irradiation spot of the first beam of light to two-dimensionally scan the surface of the specimen.

39. A surface analyzing apparatus according to claim 30, characterized in that it further comprises means for preventing irradiation of the second beam of light upon the surface of the specimen when said detecting means operates.

40. A surface analyzing apparatus according to claim 30, characterized in that it further comprises means for varying the irradiation intensity of the second beam of light upon the surface of the specimen.