X-ray diffraction apparatus and method for measuring X-ray rocking curves

• US 6,385,289 B1
• Filed: 04/10/2000
• Issued: 05/07/2002
• Est. Priority Date: 04/12/1999
• Status: Active Grant

• Current Assignee: Rigaku Corporation
• Original Assignee: Rigaku Corporation
• Inventors: Kikuchi, Tetsuo
• Primary Examiner(s): Kim, Robert H.
• Assistant Examiner(s): Barber, Therese
• Application Number:
  US09/546,890
• Time in Patent Office: 757 Days
• Field of Search: 378/70, 378/71, 378/79
• US Class Current: 378/79
• CPC Class Codes: G01N 23/20 by using diffraction of the radiation by the materials, e.g. for investigating crystal structure; by using scattering of the radiation by the materials, e.g. for investigating non-crystalline materials; by using reflection of the radiation by the materials

Abstract

A two-dimensional position-sensitive X-ray detector is used for the precision measurement of lattice constants so that a plurality of X-ray rocking curves can be measured at the same time for the respective points on a sample and an area map, on the sample, of the lattice constants can be obtained in a short time. X-rays from an X-ray source pass through the first slit and are then incident on a crystal collimator. X-rays reflected by the crystal collimator are incident on the sample. X-rays diffracted at the sample are detected by the two-dimensional position-sensitive X-ray detector. The diffracted X-rays from the respective points on the sample are detected separately at respective points on the X-ray detector. X-ray intensities which are detected at respective points on the detecting surface of the X-ray detector are recorded, at the same time, at every rotation angle with a predetermined pitch of angle during sample rotation, so that a plurality of rocking curves for said respective points of the sample can be obtained at the same time.

Claims

1. An X-ray diffraction apparatus comprising:

(a) an X-ray source;

(b) a sample holder for holding a sample having a surface, said sample holder being rotatable around an ω

-axis which is parallel to the surface of said sample;

(c) a crystal collimator system for reflecting, towards said sample, X-rays having a predetermined wavelength out of X-rays generated by said X-ray source;

(d) a two-dimensional position-sensitive X-ray detector having a detecting surface for detecting diffracted X-rays from said sample; and

(e) means for simultaneously recording X-ray intensities detected at respective points on said detecting surface of said X-ray detector at rotation angles with a predetermined pitch of angle during rotation of the sample around said ω

-axis, to thereby obtain rocking curves for said respective points.

2. X-ray diffraction apparatus according to claim 1, wherein said X-ray detector comprises an X-ray CCD camera.

3. X-ray diffraction apparatus according to claim 1, wherein said crystal collimator system effects asymmetric reflection so that a width of an X-ray beam which is reflected by said crystal collimator system can be larger than a width of an X-ray beam which is incident on said crystal collimator system.

4. X-ray diffraction apparatus according to claim 1, wherein said X-ray detector is rotatable around said ω

-axis.

5. X-ray diffraction apparatus according to claim 1, wherein an X-ray irradiated region on said sample has an approximately rectangular shape.

6. X-ray diffraction apparatus according to claim 1, wherein an analyzer crystal is arranged between said sample and said X-ray detector.

7. X-ray diffraction apparatus according to claim 1, wherein said crystal collimator system comprises a plurality of crystal collimators.

8. X-ray diffraction apparatus according to claim 7, wherein said crystal collimator system comprises a symmetric-reflection crystal collimator and an asymmetric-reflection crystal collimator which are set in (+,+) arrangement.

9. A method for measuring X-ray rocking curves comprising:

(a) reflecting X-rays having a predetermined wavelength out of X-rays generated by an X-ray source by using a crystal collimator system;

(b) irradiating a sample with X-rays which are reflected by said crystal collimator system;

(c) rotating said sample around a ω

-axis which is parallel to a surface of said sample;

(d) detecting intensities of diffracted X-rays from said sample using a detecting surface of an X-ray detector; and

(e) simultaneously recording X-ray intensities detected at respective points on the detecting surface of the X-ray detector at rotation angles with a predetermined pitch of angle during rotation of said sample around said ω

-axis, to thereby obtain rocking curves for said respective points.

10. A method according to claim 9, wherein said sample comprises at least one epitaxial thin film deposited on a single crystal substrate.

11. A method according to claim 9, further comprising taking out, as two-dimensional X-ray intensity information, detected X-ray intensities for respective points on said detecting surface of said X-ray detector at a certain angle of rotation of said sample around said ω

-axis, to thereby obtain an X-ray topographic image of said sample.