Image processing apparatus, image processing method, and image processing program

• US 8,687,921 B2
• Filed: 03/25/2011
• Issued: 04/01/2014
• Est. Priority Date: 03/25/2010
• Status: Active Grant

• Current Assignee: Hitachi High-Tech Company Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi High-Technologies Corporation (Hitachi, Ltd.)
• Inventors: Shinoda, Shinichi, Toyoda, Yasutaka, Matsuoka, Ryoichi
• Primary Examiner(s): Bayat, Ali
• Application Number:
  US13/578,651
• Publication Number:
  US 20130011080A1
• Time in Patent Office: 1,103 Days
• Field of Search: 382/276, 382/282, 382/287, 382/289, 382/293, 382/296, 345/648, 345/649, 345/658, 345/659, 348/583
• US Class Current: 382/296
• CPC Class Codes: G06T 2207/10061 from scanning electron microscope
• CPC Class Codes: G06T 2207/30148 Semiconductor; IC; Wafer
• CPC Class Codes: G06T 7/001 using an image reference approach
• CPC Class Codes: G06T 7/74 involving reference images or patches

Abstract

It is an object of the present invention is to provide an image processing technique that can detect the rotation of an observation image of a specimen with high accuracy. An image processing apparatus according to the present invention indirectly corrects a rotation gap between measurement image data and reference image data through wide-angle image data including a measurement part of a specimen (FIG. 1).

Claims

1. An image processing apparatus for processing an observation image of a specimen, the apparatus comprising:

a measurement image data storage unit that stores measurement image data obtained by imaging a measurement part on a specimen;

a wide-angle image data storage unit that stores wide-angle image data obtained by imaging a wide angle region including the measurement part;

a reference image data storage unit that stores reference image data used as a reference to determine whether or not the measurement part has a desired pattern;

a rotation angle calculating unit that calculates a rotation angle of image data; and

a rotation correcting unit that performs rotation correction for image data,

wherein the rotation angle calculating unit calculates a rotation gap angle between the measurement image data, the wide-angle image data, and the reference image data, and

the rotation correcting unit corrects a rotation gap between the measurement image data and the reference image data using the rotation gap angle.

2. The image processing apparatus according to claim 1, wherein

the rotation angle calculating unit calculates:

a first rotation gap angle between the wide-angle image data and the reference image data;

a second rotation gap angle between the wide-angle image data and the measurement image data; and

a rotation gap angle between the reference image data and the measurement image data using the first rotation gap angle and the second rotation gap angle, and

the rotation correcting unit corrects a rotation gap of the measurement image data using the rotation gap angle.

3. The image processing apparatus according to claim 2, further comprising a magnification adjusting unit that enlarges or reduces image data, wherein

the magnification adjusting unit enlarges or reduces the measurement image data or the wide-angle image data to adjust magnifications, and

the rotation angle calculating unit calculates the second rotation gap angle using the magnification-adjusted wide-angle image data and the reference image data.

4. The image processing apparatus according to claim 1, wherein

the rotation angle calculating unit calculates:

a first rotation gap angle between the wide-angle image data and the reference image data;

a second rotation gap angle between the wide-angle image data and the measurement image data; and

a rotation gap angle between the measurement image data and the reference image data using the first rotation gap angle and the second rotation gap angle, and

the rotation correcting unit corrects a rotation gap of the reference image data using the rotation gap angle.

5. The image processing apparatus according to claim 4, further comprising a magnification adjusting unit that enlarges or reduces image data, wherein

the magnification adjusting unit enlarges or reduces the measurement image data or the wide-angle image data to adjust magnifications, and

the rotation angle calculating unit calculates the second rotation gap angle using the magnification-adjusted wide-angle image data and the reference image data.

6. The image processing apparatus according to claim 1, further comprising:

a first rotation gap angle detecting unit that calculates a first rotation gap angle between the wide-angle image data and the reference image data;

a first rotation gap correcting unit that corrects a rotation gap between the reference image data and the wide-angle image data using the first rotation gap angle;

a second rotation gap angle detecting unit that calculates a second rotation gap angle between the wide-angle image data corrected by the first rotation gap correcting unit and the measurement image data; and

a second rotation gap correcting unit that corrects a rotation gap between the wide-angle image data and the measurement image data using the second rotation gap angle,

wherein the rotation angle calculating unit includes the first rotation gap angle detecting unit and the second rotation gap angle detecting unit, and

the rotation correcting unit includes the first rotation gap correcting unit and the second rotation gap correcting unit.

7. The image processing apparatus according to claim 6, further comprising a magnification adjusting unit that enlarges or reduces image data, wherein

the magnification adjusting unit enlarges or reduces the wide-angle image data corrected by the first rotation gap correcting unit or the measurement image data to adjust magnifications, and

the second rotation gap angle calculating unit calculates the second rotation gap angle using the magnification-adjusted wide-angle image data and the reference image data.

8. The image processing apparatus according to claim 1, further comprising:

a first rotation gap angle detecting unit that calculates a first rotation gap angle between the wide-angle image data and the measurement image data;

a first rotation gap correcting unit that corrects a rotation gap between the measurement image data and the wide-angle image data using the first rotation gap angle;

a second rotation gap angle detecting unit that calculates a second rotation gap angle between the wide-angle image data corrected by the first rotation gap correcting unit and the reference image data; and

a second rotation gap correcting unit that corrects a rotation gap between the wide-angle image data and the reference image data using the second rotation gap angle,

wherein the rotation angle calculating unit includes the first rotation gap angle detecting unit and the second rotation gap angle detecting unit, and

the rotation correcting unit includes the first rotation gap correcting unit and the second rotation gap correcting unit.

9. The image processing apparatus according to claim 8, further comprising a magnification adjusting unit that enlarges or reduces image data, wherein

the magnification adjusting unit enlarges or reduces the measurement image data or the wide-angle image data to adjust magnifications, and

the first rotation gap angle calculating unit calculates the first rotation gap angle using the magnification-adjusted wide-angle image data and the measurement image data.

10. The image processing apparatus according to claim 1, wherein

the measurement image data, the wide-angle image data, and the reference image data are image data extracted in outline extracting processing.

11. The image processing apparatus according to claim 1, further comprising an outputting unit that outputs a calculation result from the rotation angle calculating unit.

12. The image processing apparatus according to claim 1, wherein the wide-angle image data is image data created in panoramic combining processing.

13. The image processing apparatus according to claim 1, wherein the rotation correcting unit detects a position discrepancy between rotation-corrected image data items and corrects the position discrepancy.

14. The image processing apparatus according to claim 1, further comprising an imaging unit that images the wide angle region to obtain the wide-angle image data, wherein

the imaging unit determines an imaging position so that density of patterns included in the wide angle region is equal to or higher than a predetermined threshold.

15. The image processing apparatus according to claim 1, further comprising an imaging unit that images the wide angle region to obtain the wide-angle image data, wherein

the imaging unit determines an imaging magnification so that density of patterns included in the wide angle region is equal to or higher than a predetermined threshold.

16. An image processing method for processing an observation image of a specimen, the method comprising the steps of:

obtaining measurement image data obtained by imaging a measurement part on a specimen;

obtaining wide-angle image data obtained by imaging a wide angle region including the measurement part;

obtaining reference image data used as a reference to determine whether or not the measurement part has a desired pattern;

calculating a rotation angle of image data; and

performing rotation correction for image data,

wherein the calculating a rotation angle calculates a rotation gap angle between the measurement image data, the wide-angle image data, and the reference image data, and

the performing rotation correction corrects a rotation gap between the measurement image data and the reference image data using the rotation gap angle.

17. An image processing program embodied on a non-transitory computer-readable medium that causes a computer to execute an image processing method comprising:

obtaining measurement image data obtained by imaging a measurement part on a specimen;

obtaining wide-angle image data obtained by imaging a wide angle region including the measurement part;

obtaining reference image data used as a reference to determine whether or not the measurement part has a desired pattern;

calculating a rotation angle of image data; and

performing rotation correction for image data,

wherein the calculating a rotation angle calculates a rotation gap angle between the measurement image data, the wide-angle image data, and the reference image data, and

the performing rotation correction corrects a rotation gap between the measurement image data and the reference image data using the rotation gap angle.