US 7,680,246 B2Granted

Method and device for judging polarity of single crystal sample

AssigneeRigaku Corporation

InventorKatsuhiko Inaba

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Abstract

Wavelength dependence of diffraction X-ray intensity of a single crystal sample is measured using an X-ray incident optical system of simple structure so that the polarity of the single crystal sample can be judged. When the polarity of the {111} face of a GaAs single crystal sample (18) is judged, for example, an X-ray source (10) which can generate X-rays in a predetermined wavelength range including in the middle the wavelength at the K absorption end of Ga, i.e. an X-ray source of Au target, is employed. An X-ray beam (12) emitted from that X-ray source is reflected on a paraboloidal multilayer film mirror (14) to form a parallel beam (16) including an X-ray in a predetermined wavelength range. The sample (18) is irradiated with the parallel beam and the intensity of a diffraction X-ray therefrom is detected by an X-ray detector (22). Wavelength dependence of diffraction X-ray intensity is measured in the wavelength range including the wavelength at the absorption end by performing 2θ/ω scanning. Polarity is judged by determining the ratio of diffraction X-ray intensity on the shorter wavelength side than the absorption end to diffraction X-ray intensity on the longer wavelength side than the absorption on end.

Claims12

Dependent claims

A method for judging a polarity of a single crystal sample, the method comprising the step of:

(a) preparing a single crystal sample (18), which consists of plural elements and has a polarity;
(b) preparing an X-ray source (10), which can generate X-rays in a predetermined wavelength range including an absorption edge of any one of the plural elements;
(c) allowing a divergent X-ray beam (12) emitted from the X-ray source to be reflected by a parabolic multilayer mirror (14) to make a parallel beam that includes the X-rays in the predetermined wavelength range;
(d) allowing the parallel beam, which is used as an incident X-ray beam, to be incident on the single crystal sample, and thereafter detecting an intensity of a diffracted X-ray beam (20) coming from the single crystal sample with an X-ray detector (22);
(e) measuring a wavelength dependence of the intensity of diffracted X-ray beam in the wavelength range including the absorption edge of any one of the plural elements by synchronously scanning a rotation on angle ω of the single crystal sample to the incident X-ray beam and an angle 2θ between the incident X-ray beam and the diffracted X-ray beam with an angular speed ratio of 1 to 2;
and
(f) acquiring a ratio of the intensity of diffracted X-ray beam shorter in wavelength than the absorption edge to the intensity of diffracted X-ray beam longer in wavelength than the absorption edge, and thereafter judging the polarity on a basis of a value of the ratio of intensity.

4 more elements

An apparatus for judging a polarity of a single crystal sample, the apparatus comprising:

(a) an X-ray tube (10) having a target, which is made of a predetermined material;
(b) a parabolic multilayer mirror (14), which reflects X-rays (12) emitted from the X-ray tube to convert it to a parallel beam (16);
(c) a sample holder for holding a single crystal sample (18), which consists of plural elements and has a polarity;
(d) an X-ray detector (22) for detecting a diffracted X-ray beam (20) coming from the single crystal sample;
(e) a control device for synchronously scanning a rotation on angle ω of the single crystal sample to the parallel beam and an angle 2θ between the parallel beam and the X-ray detector;
(f) measurement instructing means for allowing the parallel beam, which is used as an incident X-ray beam, to be incident on the single crystal sample, and thereafter detecting an intensity of diffracted X-ray beam coming from the single crystal sample with an X-ray detector, and further measuring a wavelength dependence of the intensity of diffracted X-ray beam in a wavelength range including an absorption edge of any one of the plural elements by synchronously scanning the angle ω and the angle 2θ with an angular speed ratio of 1 to 2;
and
(g) judging means for acquiring a ratio of the intensity of diffracted X-ray beam shorter in wavelength than the absorption edge to the intensity of diffracted X-ray beam longer in wavelength than the absorption edge, and thereafter judging the polarity on a basis of a value of the ratio of intensity.

5 more elements

Dependencies are inferred from the claim text.