JPH1114568A - Fluorescent x-ray analyzer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure the thickness of a thin film averaged in the circumferential direction at high speed by measuring the integrated intensity of fluorescent X-rays while turning a disc-like sample by one round or more at a fixed position in the radial direction. SOLUTION: A sample stage 7 is moved in the radial direction R and a sample 2 is irradiated with a first order X-rays B1 from an X-ray source 4 at a specified position. A spectrometer 5 is turned about an axis O2 and set at a position for receiving a fluorescent X-rays B2 from the sample 2 and analyzing the fluorescent X-rays B2 of specified wavelength to be measured. Intensity of fluorescent X-rays detected by a detector 6 when the sample 2 turns a round at the specified position is integrated and the intensity of fluorescent X-rays averaged in the circumferential direction 9 is determined. More specifically, the intensity of X-rays is integrated over a time corresponding to a round and divided by that time to determine an averaged intensity of X rays. Since the sample is not required to be moved or stopped repeatedly, the thickness of a thin film averaged in the circumferential direction or the content of an element can be measured at high speed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray fluorescence analyzer for analyzing a disk-shaped sample coated with a thin film.

[0002]

2. Description of the Related Art Conventionally, in order to analyze a disk-shaped sample coated with a thin film, an X-ray source irradiates the sample with primary X-rays, and a detector detects the intensity of fluorescent X-rays generated from the sample. An X-ray fluorescence analyzer that detects and measures the thickness or element content of a thin film is used. In this type of apparatus, generally, for one or more measurement points on a disk, a sample is fixed at each measurement point, and the film thickness or the element content is measured.

[0003] However, depending on the type of the sample, there is a case where the measurement is not limited to the above. For example, a thin disk sample (magnetic film) made of NiP is coated on an Al substrate shown in FIG. 5A, and a PSG film (insulating film) is coated on a Si wafer shown in FIG. 5B. This is the case for the sample that was obtained.

That is, in the case of FIG. 5A, a thin film is formed by, for example, coating a thin film while rotating a recording medium. In this case, the rotation changes the film thickness and element content in the circumferential direction. Is small and the change in the radial direction is large. Therefore, in the circumferential direction, it is necessary to measure the average value of the film thickness or the element content in the circumferential direction.

On the other hand, in the case of FIG. 5B, when a PSG film (insulating film) is formed on a Si wafer, the coating is performed without rotating the wafer, so that the circumferential film thickness and the element content change. Since it may be large, it is necessary to measure the film thickness or the element content in each of a predetermined angular range in the circumferential direction or a predetermined radial range in the radial direction.

In any of the above cases, conventionally, measurement is performed at a large number of measurement points in the radial direction and the circumferential direction of the sample, so that a predetermined angular range or the circumferential direction of the sample or the circumferential direction of the sample is obtained. The average film thickness or element content in a predetermined radial range in the radial direction has been determined.

[0007]

However, in the conventional apparatus, it is necessary to stop the sample at many measurement points to perform the measurement, and the measurement is repeatedly performed by moving and stopping the sample.
There was the problem of having a long time to complete all measurements.

The present invention solves the above-mentioned problems and provides a fluorescent X-ray analyzer capable of measuring an average film thickness or element content in a radial or circumferential direction of a disk-shaped sample at a high speed. It is intended to be.

[0009]

To achieve the above object, an X-ray fluorescence spectrometer according to one aspect of the present invention comprises a sample stage on which a disk-shaped sample coated with a thin film is concentrically mounted; An X-ray source for irradiating the sample with primary X-rays, a detector for detecting the intensity of fluorescent X-rays generated from the sample, rotating means for rotating the sample stage around its central axis, and The X-ray source and the detector are operated in a state where the sample stage is set at a predetermined position in the radial direction, and the fluorescent X-rays are rotated while rotating the sample stage one or more times. A control means for detecting the intensity of the X-rays, and an analysis for measuring the integral value of the intensity of the fluorescent X-rays from the detector during the rotation to determine the film thickness or element content of the thin film averaged in the circumferential direction. Means.

According to the above configuration, while rotating the disc-shaped sample at a predetermined position in the radial direction by one or more turns, the fluorescent X
Since the integrated value of the line intensity is measured, the fluorescent X-ray intensity averaged in the circumferential direction can be obtained. Since the measurement is not repeated by repeatedly moving and stopping the sample as in the conventional case, the average is obtained in the circumferential direction. The thickness or element content of the thin film obtained can be measured at high speed.

An X-ray fluorescence spectrometer according to another aspect of the present invention comprises a sample stage on which a disk-shaped sample coated with a thin film is concentrically mounted, and an X-ray for irradiating the sample with primary X-rays.
A radiation source, a detector for detecting the intensity of the fluorescent X-rays generated from the sample, a rotating unit for rotating the sample stage around its central axis, and a radial moving unit for moving the sample stage in the radial direction; Activating the X-ray source and the detector in a state where the sample stage is set at a predetermined position in the radial direction, and while rotating the sample stage, the intensity of the fluorescent X-rays for each predetermined angle range of 180 ° or less. Measuring control means for detecting, and the film thickness or element content of the thin film averaged for each angular range in the circumferential direction by measuring the integrated value of the fluorescent X-ray intensity from the detector for each of the predetermined angular ranges And analysis means for determining

According to the above arrangement, while rotating the disk-shaped sample at a predetermined position in the radial direction, the integrated value of the fluorescent X-ray intensity for each predetermined angle range of 180 ° or less is measured. The averaged fluorescent X-ray intensity is obtained and the measurement is not repeated by moving and stopping the sample as in the past, so that the film thickness or element content of the thin film averaged for each angle range can be increased quickly. Can be measured.

Preferably, the measurement control means detects the intensity of the fluorescent X-ray at a plurality of predetermined positions in a radial direction. Therefore, the change in the radial direction of the film thickness or element content of the thin film averaged in the circumferential direction can be measured at high speed.

According to another aspect of the present invention, there is provided an X-ray fluorescence analyzer comprising: a sample stage on which a disk-shaped sample coated with a thin film is concentrically mounted; and an X-ray irradiating the sample with primary X-rays. A source, a detector for detecting the intensity of fluorescent X-rays generated from the sample, a rotating unit for rotating the sample stage around its central axis, and a radial moving unit for radially moving the sample stage, With the sample stage set at a predetermined angular position in the circumferential direction, the X-ray source and the detector are operated, and while the sample stage is moved in the radial direction, the fluorescence X
Measurement control means for detecting the intensity of the line, and measuring the integral value of the fluorescent X-ray intensity for each of the predetermined radial ranges from the detector while moving in the radial direction, thereby measuring each of the predetermined radial ranges in the radial direction. Analysis means for determining the film thickness or element content of the thin film averaged for each time.

According to the above arrangement, while the disk sample is moved in the radial direction at the predetermined angular position, the integrated value of the fluorescent X-ray intensity during the movement in each predetermined radial direction range is measured. The fluorescent X-ray intensity averaged for each predetermined radial range is obtained, and measurement is not repeated by repeatedly moving and stopping the sample as in the conventional method. Therefore, the thin film averaged for each predetermined radial range in the radial direction is used. Can be measured at high speed.

Preferably, the measurement control means detects the intensity of the fluorescent X-ray at a plurality of predetermined angular positions in a circumferential direction. Therefore, the change in the radial direction of the film thickness or element content of the thin film averaged in the circumferential direction can be measured at high speed.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a side view of an X-ray fluorescence analyzer according to the first embodiment of the present invention. This device is a thin film 2
a sample table 7 on which a disk-shaped sample 2 coated with a is concentrically mounted, an X-ray source 4 for irradiating the sample 2 with primary X-rays B1, and a fluorescent X-ray B2 generated from the sample 2
And a spectroscope 5 rotatably provided to split the fluorescent X-rays B2 of a specific wavelength to be measured.
And a detector 6 for detecting the intensity of the fluorescent X-rays B3 separated from the light. The spectroscope 5 and the detector 6 are attached to a goniometer (not shown), and rotate the detector 6 to detect the fluorescent X-rays B3 from the spectroscope 5 in accordance with the rotation of the spectroscope 5.

The sample stage 7 is fixed to an upper portion 8a of a rotary stage (rotating means) 8 thereunder. The upper portion 8a of the rotary stage 8 can rotate the sample stage 7 in the circumferential direction θ around its center axis O1 by rotation of the motor M with respect to the lower portion 8b. A lower portion 8b of the rotary stage is fixed to an upper portion 9a of a radial moving stage (radial moving means) 9. The upper part 9a of the moving stage 9 is installed movably in the radial direction R with respect to the lower part 9b by an XY moving mechanism 11 which is a two-dimensional driving means. The lower portion 9b is provided with a height adjusting means (not shown) that moves up and down,
It is installed on a base via an incident angle adjusting means for adjusting the incident angle of the primary X-ray B1 to the sample 2 by tilting.

The measurement control means 12 controls the operation of the motor M and the XY moving mechanism 11, and rotates and moves the sample stage 7 so as to irradiate a predetermined position of the thin film 2a of the sample with the primary X-ray B1. The measurement control means 12 operates the X-ray source 4, the spectroscope 5 and the detector 6 with the sample stage 7 set at a predetermined position in the radial direction by operating the moving stage 9 to operate the rotary stage 8. While rotating the sample stage 7 once, the intensity of the fluorescent X-ray is detected. The analyzing means 14 detects the fluorescence X from the detector 6 during the one rotation.
The film thickness or element content averaged in the circumferential direction is determined by measuring the integral value of the line intensity.

Next, the operation of the apparatus according to the first embodiment having the above configuration will be described. In the first embodiment, an average film thickness or element content on a circumference at a predetermined position in a radial direction R of a disk-shaped sample 2 coated with a thin film is measured. FIG. 2 shows an operation state of the donut-shaped sample 2 mounted on the sample stage 7 in the first embodiment. First, the integrated value of the fluorescent X-ray intensity is measured for each element of the thin film layer forming the thin film 2a of the sample 2.

By controlling the XY moving mechanism 11 shown in FIG. 1, the moving stage 9 is operated to move the sample table 7 in the radial direction R.
To irradiate the sample 2 with the primary X-rays B1 from the X-ray source 4 at a predetermined position Q (radius r, see FIG. 2), and rotate the spectroscope 5 around the axis O2. Then, the fluorescent X-ray B2 from the sample 2 is incident, and is set at a position where the fluorescent X-ray B2 of a specific wavelength to be measured is separated. In this state, by controlling the motor M, the rotating stage 8 is operated to rotate the sample stage 7 once in the circumferential direction θ (see FIG. 2), and the fluorescent X-rays B3 Is detected. Next, the fluorescence X-ray intensity averaged in the circumferential direction θ is obtained by measuring the integral value of the fluorescence X-ray intensity from the detector 6 during one rotation of the sample 2 at the predetermined position Q. . That is, the X-ray intensity is integrated over a time T corresponding to one round, and the integrated value is divided by the time T to obtain an averaged X-ray intensity. This corresponds to integrating and averaging the X-ray intensity over one circumference.

Thus, the predetermined position Q in the radial direction R of the sample 2 is
Since the integral value of the fluorescent X-ray intensity during one rotation of is measured, the fluorescent X-ray intensity averaged in the circumferential direction θ can be measured at high speed.

The sample table 7 is rotated a plurality of times, and the integrated value of the intensity of the fluorescent X-rays from the detector 6 during the plurality of rotations is measured to obtain a more accurate value. Is also good.

Next, using the measured intensity of the fluorescent X-rays averaged in the circumferential direction θ, for example, a fundamental parameter (F
The film thickness and element content of the thin film averaged in the circumferential direction θ are obtained by the P) method.

That is, first, the initial value of the content of the element in the sample 2 is set, then the theoretical X-ray intensity is calculated, and then the content of the element is determined from the comparison between the measured intensity and the theoretical intensity. Is repeated several times. Then, the n-th and (n-
1) The convergence value is determined as the element content ratio by checking whether the rate of change of the difference for the first time is smaller than a specified value (convergence). The film thickness is determined by changing the incident angle to the sample 2 by the incident angle adjusting means for the same element and measuring the fluorescent X-ray intensity. Hereinafter, similarly, for other elements, the fluorescent X
The integral value of the line intensity is measured, and the film thickness and the element content of the thin film layer are obtained.

As described above, the fluorescent X-ray intensity averaged in the circumferential direction θ is measured by measuring the integrated value of the fluorescent X-ray intensity during one or more rotations at the predetermined position Q in the radial direction R of the sample 2. Is measured, so that the sample is not repeatedly measured by repeatedly rotating and stopping, so that the film thickness and the element content of the sample 2 can be measured at high speed.

It should be noted that, instead of the FP method as described above, a calibration curve method, which is also a well-known method, in which a standard sample is prepared,
The thickness and the element content of the sample 2 may be determined.

Further, in this embodiment, the film thickness and the element content of the sample 2 are measured at the same time, but either one may be measured.

Further, when the sample 2 has a large change in the film thickness and element content in the radial direction R, not only the predetermined position Q in the radial direction R but also a plurality of predetermined positions in the radial direction R. The fluorescent X-ray intensity may be detected at Q1, Q2, etc. (see FIG. 2) and integrated over one or more rounds. Thereby, at a plurality of predetermined positions in the radial direction R, the circumferential direction θ
Can be measured at high speed.

Next, the description will proceed to the second embodiment. In the second embodiment, the disk-shaped sample 2 to be measured has a circumferential direction θ.
It is applied when the change of the film thickness and the element content of is large. FIG. 3 shows a sample stage 7 according to the second embodiment.
The operation state of the sample 2 attached on the top is shown.

In this apparatus, the X-ray source 4, the spectroscope 5 and the detector 6 are operated while the measurement control means 12 of FIG. 1 sets the sample stage 7 at a predetermined position Q in the radial direction R (see FIG. 3). Activate,
While rotating the sample stage 7, the intensity of the fluorescent X-ray B3 is detected for each predetermined angle range such as 45 ° in the circumferential direction θ (see FIG. 3). The analysis means 14 measures the integrated value of the fluorescent X-ray intensity from the detector 6 for each range of 45 °, thereby measuring the fluorescent X-ray intensity averaged for each range, and averaging the fluorescent X-ray intensity for each range. The film thickness or element content of Sample 2 is determined. Other configurations are the same as in the first embodiment. In addition,
If the predetermined angle range is 180 ° or less, 30 °,
It may be 60 °, 90 °, or the like.

Thus, while rotating the disk-shaped sample 2 at a predetermined position in the radial direction R in the circumferential direction θ, the integrated value of the fluorescent X-ray intensity for each predetermined angle range is measured. Since the sample is not repeatedly measured by rotating and stopping, the film thickness or the element content of the sample 2 averaged over a predetermined angle range can be measured at high speed.

When the sample 2 has a large change in the film thickness and the element content in the radial direction R, not only the predetermined position Q in the radial direction R but also a plurality of predetermined positions in the radial direction R. , The fluorescent X-ray intensity may be detected. Thereby, at a plurality of predetermined positions in the radial direction R, the fluorescent X-ray intensity averaged for each range in the circumferential direction θ can be measured at high speed, so that the film thickness or element content in the radial direction R can be quickly obtained. Can be

Next, the description will proceed to the third embodiment. The third embodiment is applied to a case where the disk-shaped sample 2 to be measured has a large change in film thickness and element content along the radial direction R. FIG. 4 shows an operation state of the sample 2 mounted on the sample stage 7 in the third embodiment.

In the present apparatus, the X-ray source 4, the spectroscope 5 and the detector 6 are operated while the measurement control means 12 of FIG. 1 sets the sample stage 7 at a predetermined angular position such as 0 ° in the circumferential direction. By operating the sample table 7 in the radial direction R (see FIG. 4), the intensity of the fluorescent X-ray is detected. Then, the analysis means 14 measures the integral value of the fluorescent X-ray intensity from the detector 6 during the movement in each of the predetermined radial ranges in the radial direction R, thereby averaging the values for each of the predetermined radial ranges. Sample 2
The film thickness or the element content of is determined.

As a result, while the disk-shaped sample 2 is moved in the radial direction R at the predetermined angular position, the integrated value of the fluorescent X-ray intensity during the movement in each predetermined radial direction range is measured.
Since there is no need to repeatedly move and stop the sample in the radial direction R as in the conventional measurement, the thickness or element content of the thin film averaged for each predetermined radial range in the radial direction R can be measured at high speed. .

When the sample 2 has a large change in the film thickness and element content in the circumferential direction θ, not only the predetermined angular position 0 ° but also a plurality of predetermined angles in the circumferential direction θ. At positions θ1 and θ2 (see FIG. 4), the intensity of the fluorescent X-ray may be detected while moving the sample 2 in the radial direction R. Thereby, at a plurality of predetermined angular positions in the circumferential direction θ, the film thickness or the element content of the sample 2 averaged for each predetermined radial direction range in the radial direction R can be measured at high speed.

[0038]

As described above, according to one embodiment of the present invention, the integral value of the fluorescent X-ray intensity is measured while rotating the disc-shaped sample at a predetermined position in the radial direction one or more rounds. Therefore, the fluorescent X-ray intensity averaged in the circumferential direction can be obtained, and the measurement is not repeated by repeatedly moving and stopping the sample as in the conventional method. The rate can be measured at high speed.

According to another configuration of the present invention, the disk-shaped sample is rotated at a predetermined position in the radial direction by 180 °.
Since the integrated value of the fluorescent X-ray intensity for each of the following predetermined angle ranges is measured, the fluorescent X-ray intensity averaged for each angle range can be obtained. Since there is no thickness, the film thickness or element content of the thin film averaged for each angle range can be measured at high speed.

According to still another configuration of the present invention, while the disk sample is moved in the radial direction at the predetermined angular position, the integral of the fluorescent X-ray intensity during the movement in each predetermined radial range is obtained. Since the value is measured, the fluorescent X-ray intensity averaged for each predetermined radial direction range is obtained, and the measurement is not repeated by repeatedly moving and stopping the sample as in the conventional method. The thickness or element content of the thin film averaged for each time can be measured at high speed.

[Brief description of the drawings]

FIG. 1 is a side view showing an X-ray fluorescence spectrometer according to a first embodiment of the present invention.

FIG. 2 is a plan view showing the operation of the device.

FIG. 3 is a plan view showing the operation of the X-ray fluorescence spectrometer according to the second embodiment.

FIG. 4 is a plan view showing the operation of the X-ray fluorescence analyzer according to the third embodiment.

5A and 5B are cross-sectional views showing different examples of the structure of the sample.

[Explanation of symbols]

2 ... disc-shaped sample, 4 ... X-ray source, 5 ... spectroscope, 6 ... detector, 7 ... sample stand, 8 ... rotation means, 9 ... radial movement means,
12: measurement control means, 14: analysis means, B1: primary X
Line, B2: X-ray fluorescence, B3: X-ray fluorescence separated.

Claims (5)

[Claims] 1. A sample stage on which a disk-shaped sample coated with a thin film is concentrically mounted, an X-ray source for irradiating the sample with primary X-rays, and detecting the intensity of fluorescent X-rays generated from the sample. A detector that rotates the sample stage around its central axis, a radial moving unit that moves the sample stage in the radial direction, and a state in which the sample stage is set at a predetermined position in the radial direction. X
A measurement control unit for detecting the intensity of the fluorescent X-rays while operating the source and the detector and rotating the sample stage one or more turns; and integrating the intensity of the fluorescent X-rays from the detector during the rotation. An X-ray fluorescence analyzer comprising: analysis means for determining a film thickness or an element content of a thin film averaged in a circumferential direction by measuring a value. 2. A sample stage on which a disk-shaped sample coated with a thin film is concentrically mounted, an X-ray source for irradiating the sample with primary X-rays, and detecting the intensity of fluorescent X-rays generated from the sample. A detector that rotates the sample stage around its central axis, a radial moving unit that moves the sample stage in the radial direction, and a state in which the sample stage is set at a predetermined position in the radial direction. X
Activating a radiation source and a detector, for each predetermined angle range of 180 ° or less while rotating the sample stage, measurement control means for detecting the intensity of the fluorescent X-rays, from the detector for each predetermined angle range X-ray fluorescence analyzer comprising: an analyzer for measuring the integrated value of the X-ray fluorescence intensity of the above to obtain the film thickness or element content of the thin film averaged for each angular range in the circumferential direction. 3. The X-ray fluorescence analyzer according to claim 1, wherein the measurement control unit detects the intensity of the X-ray fluorescence at a plurality of predetermined positions in a radial direction. 4. A sample stage on which a disk-shaped sample coated with a thin film is concentrically mounted, an X-ray source for irradiating the sample with primary X-rays, and detecting the intensity of fluorescent X-rays generated from the sample. Detector, rotating means for rotating the sample stage around its center axis, radial moving means for radially moving the sample stage, and a state in which the sample stage is set at a predetermined angular position in the circumferential direction. Activating the X-ray source and the detector at the same time, while moving the sample stage in the radial direction, measurement control means for detecting the intensity of the fluorescent X-rays, from the detector while moving in the radial direction An X-ray fluorescence analyzer comprising: analysis means for measuring the integrated value of X-ray fluorescence intensity to determine the film thickness or element content of the thin film averaged for each predetermined radial direction range. 5. The X-ray fluorescence analyzer according to claim 4, wherein the measurement control unit detects the intensity of the X-ray fluorescence at a plurality of predetermined angular positions in a circumferential direction.