STANDARD REFERENCE COMPONENT FOR CALIBRATION, FABRICATION METHOD FOR THE SAME, AND SCANNING ELECTRON MICROSCOPE USING THE SAME

• US 20080121791A1
• Filed: 11/14/2007
• Published: 05/29/2008
• Est. Priority Date: 11/27/2006
• Status: Active Grant

• Current Assignee: Hitachi High-Tech Company Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi High-Technologies Corporation (Hitachi, Ltd.)
• Inventors: Nakayama, Yoshinori, Hitomi, Keiichiro, Sohda, Yasunari, Koyanagi, Hajime
• Granted Patent: US 7,612,334 B2
• Time in Patent Office: Days
• US Class Current: 250/252.1
• CPC Class Codes: H01J 2237/24578 Spatial variables, e.g. position, distance
• CPC Class Codes: H01J 2237/2816 Length
• CPC Class Codes: H01J 2237/2823 Resolution
• CPC Class Codes: H01J 2237/2826 Calibration for object processing apparatus H01J2237/30433
• CPC Class Codes: H01J 2237/30433 System calibration for microscopes H01J2237/2826
• CPC Class Codes: H01J 2237/3142 Ion plating
• CPC Class Codes: H01J 2237/31732 Depositing thin layers on selected microareas ion plating H01J2237/3142
• CPC Class Codes: H01J 37/244 Detectors; Associated components or circuits therefor
• CPC Class Codes: H01J 37/263 Contrast, resolution or power of penetration
• CPC Class Codes: H01J 37/28 with scanning beams H01J37/268, H01J37/292, H01J37/2955 take precedence

Abstract

The present invention provides a standard reference component for calibration for performing magnification calibration used in the scanning electron microscope with high precision, and provides a scanning electron microscope technique using it. Provided is a standard reference component for calibration for calibrating a scanning electron microscope that measures a length of a pattern in an observation area from information on the intensity of secondary electrons or reflected electrons generated by scanning an incident electron beam in the observation area on a measuring sample, having: a first substrate on which a multiple-layer is laminated and a second substrate with a recess for holding the first substrate, wherein the first substrate is held in the recess of the second substrate so that a normal direction of the multiple-layer surface may be roughly perpendicular to a normal direction of the second substrate surface, and the multiple-layer has a multiple-layer structure of a film containing silicon and a film containing molybdenum.

Claims

1. A standard reference component for calibration for calibrating a scanning electron microscope that measures a pattern in an observation area from information on the intensity of secondary electrons or reflected electrons generated by scanning an incident electron beam in the observation area on a measuring sample, comprising:

a first substrate on which a multiple-layer is laminated; and

a second substrate with a recess for holding the first substrate on its surface,

wherein the first substrate is held in the recess of the second substrate so that a normal direction of the multiple-layer surface may be roughly perpendicular to a normal direction of the second substrate, and

the multiple-layer has a multiple-layer structure of a film containing silicon and a film containing molybdenum.

2. The standard reference component for calibration according to claim 1,

wherein the multiple-layer is fabricated to have a lamination structure in which a film containing silicon and a film containing molybdenum are alternately arranged periodically at a fixed pitch and a pitch size is obtained in advance by light- or X-ray diffraction.

3. The standard reference component for calibration according to claim 1,

wherein the second substrate has the form of a silicon wafer and has a structure in which the multiple-layer is implanted in a silicon wafer so that a cross-section of the multiple-layer held in the recess of the second substrate may become substantially the same plane as the surface of the silicon wafer.

4. The standard reference component for calibration according to claim 1,

wherein the multiple-layer structure is a periodic convex pattern of the molybdenum films or the silicon films.

5. The standard reference component for calibration according to claim 2,

wherein the second substrate has the form of a silicon wafer, and the multiple-layer is implanted in the silicon wafer so that the cross-section of the multiple-layer held in the recess of the second substrate may become substantially the same plane as the surface of the silicon wafer.

6. The standard reference component for calibration according to claim 2,

wherein the multiple-layer structure is a periodic convex pattern of the molybdenum films or the silicon films.

7. The standard reference component for calibration according to claim 3,

wherein the multiple-layer structure is a periodic convex pattern of the molybdenum films or the silicon films.

8. A fabrication method for a standard reference component for calibration, comprising the steps of:

forming a multiple-layer structure of a silicon film and a molybdenum film by alternately arranging the two films periodically at a fixed pitch;

implanting a crystal cross-section of the multiple-layer structure in a recess formed on the surface of a silicon wafer with an electroconductive adhesive;

polishing the surface of the silicon wafer in which a crystal cross-section of the multiple-layer structure is implanted; and

conducting material selecting etching on the crystal cross-section of the multiple-layer structure after the polishing step and forming it into a pattern form of a one-dimensional diffraction grating.

9. The fabrication method for a standard reference component for calibration according to claim 8,

wherein the multiple-layer structure is a periodic convex pattern of the molybdenum films or the silicon films.

10. A scanning electron microscope, comprising:

a sample stage for holding a sample;

an irradiation optical system for scanning an electron beam in the sample on the sample stage;

a detector for detecting secondary electrons or reflected electrons generated by electron beam scanning;

signal processing means for measuring a length of the sample by processing an electronic signal obtained from the detector;

display means for displaying the length measurement result; and

a standard reference component for calibration used for performing magnification calibration of the irradiation optical system,

wherein the standard reference component for calibration substantially consists of a first substrate on which a multiple-layer is laminated and a second substrate with a recess for holding the first substrate on its surface,

the first substrate is held in the recess of the second substrate so that a normal direction of the multiple-layer surface may be roughly perpendicular to a normal direction of the second substrate, and

the multiple-layer has a multiple-layer structure of a film containing silicon and a film containing molybdenum.

11. The scanning electron microscope according to claim 10,

wherein the multiple-layer has a lamination structure in which a film containing silicon and a film containing molybdenum are alternately arranged periodically at a fixed pitch and the pitch size is obtained in advance by light- or X-ray diffraction.

12. The scanning electron microscope according to claim 10,

wherein the standard reference component for calibration is mounted on the sample stage.

13. The scanning electron microscope according to claim 11,

wherein the standard reference component for calibration is mounted on the sample stage.

14. The scanning electron microscope according to claim 11,

wherein a pitch size of either one of films obtained by the signal processing means and a pitch size that is obtained in advance by the light- or X-ray diffraction are compared and magnification calibration of the irradiation optical system is performed so that the difference may become substantially zero.

15. The scanning electron microscope according to claim 14,

wherein the standard reference component for calibration is mounted on the sample stage.