GB2292658A

GB2292658A - Compact X-ray diffraction micrograph device

Info

Publication number: GB2292658A
Application number: GB9517304A
Authority: GB
Inventors: Shigeru Kimura
Original assignee: NEC Corp
Current assignee: NEC Corp
Priority date: 1994-08-24
Filing date: 1995-08-24
Publication date: 1996-02-28
Also published as: GB9517304D0; JPH0862400A

Abstract

In an X-ray diffraction micrographic device which irradiates an X-ray beam onto a sample 104 and which records a diffracted X-ray obtained thereby on a photographic plate 106, the X-ray diffraction micrographic device includes a mechanism for moving the sample and the photographic plate in a vertical direction with the sample 104 and the photographic plate 106 being linked to each other. The device also incorporates a slit 108 placed just in front of the crystal sample 104 for restricting the X-ray beam in the vertical direction in addition to a slit placed between the sample and the photographic plate 106 which collimates the X-ray beam in the horizontal direction. The apparatus may be placed on a rotating table 115 with a detector placed on a rotating stand 114 and is useful for evaluating defects in large samples of crystalline materials e.g. semiconductors. <IMAGE>

Description

COMPACT X-RAY DIFFRACTION MICROGRAPHIC DEVICE This invention relates to an X-ray diffraction micrographic device which is for use in a crystallographic evaluation and, in partlcular, to an X-ray diffraction micrographic device which is capable of corresponding to a large diameter tendency of a sample crystal even though the X-ray diffraction micrographic device is not made large in size.

An X-ray diffraction micrographic device detects lattice strain as a sllppage of a diffraction position or a change of reflectance. It is quite an important problem to know a reliable information concerning a crystalline distribution of the lattice strain. An X-ray diffraction micrography is used as very effective testing or evaluating means compared with the other testing or evaluating method, since a rapid and non-destructive materials test is required particularly in the fleld of the present semiconductor industries in which materials having large areas are dealt with.The X-ray diffraction micrographic device includes all devices which record diffracted X-rays from samples on nuclear plates, or the like and which observe intensity of the diffracted X-rays and changes of diffraction directions by corresponding samples and photographles with each other one by one (Applied Physics, Vol. 36-2, p. 88, 1967).

However, the X-ray diffraction micrographic device inevitably becomes very large in size in order that a large sample crystal may be measured at a hlgh precision. Thus, it is difficult to provide an x-ray diffraction micrographic device which is capable of measuring a large sample crystal, even though the X-ray diffraction micrographic device is not made large in size.

It is therefore an object of the present invention to provide an X-ray diffraction micrographic device which is capable of measuring a large sample crystal, even though the X-ray diffraction micrographic device is not made large in size.

Other objects of this invention will become clear as the description proceeds.

According to this invention, the X-ray dlffrac tion micrographic device comprises irradiating means for irradiating an X-ray beam onto a sample to obtain a diffracted X-ray; recording means for recording the diffracted X-ray on a photographic plate; and moving means for moving the sample and the photographic plate in a vertical direction with the sample and the photographic plate being linked to each other.

The X-ray diffraction inicrographic device may have a slit for restricting a beam width of the X-ray beam in a vertical direction with the slit being positioned near the incident side of the sample.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. 1(A) is a plan view of a conventional X-ray diffraction micrographic device; Fig. 1(B) is a front view of the conventional X-ray diffraction micrographic device illustrated in Fig. 1(A); Fig. 2(A) is a plan view of an X-ray diffraction micrographic device according to an embodiment of this invention; and Fig. 2(B) is a front view of the X-ray diffraction micrographic device illustrated in Fig. 2(A).

Referring to Figs. 1(A) and l (B), a conventional X-ray diffraction micrographic device will first be described for a better understanding of this invention.

In Figs. 1(A) and 1 (El) illustrated is a Lang camera as an example of the conventional X-ray ditfrac- ion micrographic devices. The Lang camera comprises a 2 rotating stand 114 attached with a detector 110 and a slit 105, and a 6 rotating stand 115 on which a sample horizontally scanning stand 109 is mounted. A photoraphic plate 106 for recording diffracted X-rays from a sample crystal 104 and a photographic plate holder 107 for fixing the photographic plate 106 thereon are mounted on the sample horizontally scanning stand 109. In order to use this device, first, the 28 rotating stand 114 is rotated to set the detector 110 In the direction of a diffracted X-ray 113.An X-ray beam 102 produced from an X-ray source 101 is adjusted to have an angle 8 B in which only a Ka 1 ray is diffracted within the sample crystal 104 through the slit 103, as shown by the arrow mark, by rotating the 8 rotating stand 115. At this time, a distance L between the X-ray source 101 and the sample crystal 104 must be L > e /a , a6 shown in Fig.

1 (B) , in order to acquire a diffraction from all surfaces of the sample crystal, provided that a divergence angle in a vertical direction of the X-ray beam 102 is deflned as a radian and that a length in a vertical direction of the sample crystal 104 is defined as a . Second, a transmitted x-ray beam 112 which has transmitted through the sample crystal 104 is slit by the slit 105, only the diffracted X-ray beam 113 is thereby led to the photographic plate 106 fixed on the photographic plate holder 107 which is located perpendicular to the diffracted xray beam 113. In this state, the incident X-ray beam 102 is expanded over the area called "wave fun" which is shown by the marks, A, B and C within the sample crystal 104.Herein, the sample horizontally scanning stand 109, on which the sample crystal 104 and the photographic plate holder 107 are mounted, is reciprocated in parallel to the surfaces of the sample crystal 104 with this diffraction condition being kept. A diffracted image of the wide area of the sample crystal 104 is thereby obtained. The diffracted image is called a "Lang diffraction micrograph (Lang topograph)".

With the use of the X-ray diffraction micrographic device mentioned above, when a large sample crystal is measured, it is requlred that the distance L shown in Fig. 1(A) is kept large. As a result, the X-ray diffraction micrographic device inevitably becomes very large in size.

Referring now to Figs. 2(A) and 2(B), description will proceed to an X-ray diffraction micrographic device according to an embodiment of this invention.

The x-ray diffraction micrographic device according to the embodiment has a structure similar to the conventional X-ray diffraction micrographic device shown in Figs. 1(A) and 1(B) except that the X-ray diffraction micrographic device has a mechanism for moving a sample and a photographic plate in a vertical direction with the sample and the photographic plate being linked to each other. Similar portions are designated by like reference numerals.

In Figs. 2(A) and 2(B), like the conventional x-ray diffraction micrographic device shown in Figs. 1(A) and 1(B), the X-ray diffraction micrographic device according to this embodiment comprises a 26 rotating stand 114 attached with a detector 110 and a slit 105, and a 8 rotating stand 115 on which a sample horizontally scanning stand 109 is mounted, and a photographic plate 106 for recording diffracted X-rays from a sample crystal 104 and a photographic plate holder 107 for fixing the photographic plate 106 thereon are mounted on the sample horizontally scanning stand 109.

In this embodiment, a sample vertical scanning mechanism 111 for moving the sample crystal 104 and the photographic plate holder 107 in a vertical direction is provided on the sample horizontally scanning stand 109.

Further, a slit 108 for restricting a beam width of the Xray beam in a vertical direction is located near the sample crystal 104 In the incident side of the X-ray beam. In the measurement, the sample crystal 104 is moved in a horlzontal direction by the sample horizontally scanning stand 109 and in a vertical direction by the sample vertical scanning mechanism 111.

With this structure, a diffracted image of the sample crystal having a large diameter is thereby obtained.

Description is hereinunder made about an example of the result of the measurement of the samples by the use of the X-ray diffraction micrographic device according to this embodiment. Ka l rays of molybdenum (wavelength: 0.07093 nm) are used as incident x-rays. A width of the slit 10a was determined to be 10 cm with respect to a substrate sample of silicon single crystal having a diameter of 20 cm. First, the sample crystal is horizontally reciprocated on the condition shown in Pig.

2(B). Thereafter, the sample crystal 104 and the photographic plate holder 107 are moved by 10 cm in the direction shown by the arrow marks of Fig. 2(B). At the position, horizontal reciprocations were carried out the same number of times as carried out at the previous position. A good diffracted micrograph from all over the sample crystal is obtained, although the distance between the X-ray source 101 and the sample crystal 104 was 1 m at this time. As a comparative example, the same sample was measured by the conventional Lang camera. As a result, such a diffracted micrograph from all over the sample crystal could not be obtained until a distance between the sample crystal and the photographic plate became 2 m.

According to the above embodiment of the present invention, since the X-ray diffraction micrographic device has the sample vertical scanning mechanism 111 for moving the sample crystal 104 and the photographic plate 106 in a vertical direction with the sample crystal 104 and the photographic plate 106 being linked to each other, a horizontal reciprocation can be carried out by a plurality of separated parts in a vertical direction.

Consequently, even when a large sample crystal is measured, it becomes unnecessary that the distance between the X-ray source 101 and the sample crystal 104 is kept large in length. Accordingly, it can be prevented that the X-ray diffraction micrographic device becomes large in size.

As mentioned above according to the present invention, it becomes possible that a good diffracted micrograph from wide areas of the sample crystal is obtained while it can be avoided that the X-ray diffraction micrographic device becomes large in size due to a tendency of a large sample crystal. Namely, a sample of a large diameter can be measured, even though the X-ray diffraction micrographic device is not made large in size. It brings great effects to a test and an evaluation, and the like for materials having large diameters. The economical effects of the present invention is so great.

While this invention has thus far been descrlbed in conjunction with only a preferred embodiment thereof, it will readily be possible for those skilled in the art to put this invention into practice in various other manners.

For example, in the preferred embodiment, description is made only about Lang camera. However, the present invention can be applied not only to Lang camera but also to all of the X-ray diffraction micrographic devices in which a crystal of a large diameter is used as a sample.

Moreover, the device used in this embodiment is such a device that horizontal reciprocations are carried out by two separated parts in a vertical direction.

However, the horizontal reciprocations may alternatively be carried out by more than three separated parts in a vertical direction dependent on a size of a sample, and so on. Namely, the number of the separated parts is not restricted to two.

Claims

CLAIMS:

1. An X-ray diffraction micrographic device comprising: irradiating means for irradiating an X-ray beam onto a sample to obtain a diffracted X-ray; recording means for recording said diffracted X-ray on a photographic plate; and moving means for moving said sample and said photographic plate in a vertical direction with said sample and said photographic plate being linked to each other.

2. An X-ray diffraction micrographic device as claimed in claim 1, wherein said X-ray diffraction micrographic device has a slit for restricting a beam width of said X-ray beam in a vertical direction, said slit being positioned near the incident side of said sample

3. An X-ray diffraction micrographic device comprising: a 26 rotating stand which has a detector and a slit; a sample horizontally scanning stand for moving a sample in a horizontal direction; a 6 rotating stand on which said sample horizontally scanning stand is mounted; a photographic plate which records diffracted X-rays from said example; a photographic plate holder which is mounted on said sample horizontally scanning stand and which fixes said photographic plate thereon; and a sample vertical scanning mechanism which is provlded on said sample horizontally scanning stand and which moves said sample and said photographic plate holder in a vertical direction with said sample and said photographic plate being linked to each other.

4. An X-ray diffraction micrographic device as claimed in claim 3, further comprising a slit which is located near said sample crystal in the incident side of said X-ray beam and which restricts a beam width of said X-ray beam in a vertical direction.

S. An X-ray diffraction micrographic device which irradiates an X-ray beam onto a sample and which records a diffracted X-ray obtained thereby on a photographic plate, said X-ray diffraction micrographic device comprising: a mechanism for moving said sample and said photographic plate in a vertical direction with said sample and said photographic plate being linked to each other.

6. An X-ray diffraction device substantially as hereinbefore described with reference to and as shown in Figures 2A and 2B of the accompanying drawings.