JPH0587749A - Method for measuring angle-resolved spectrum of characteristic x-rays - Google Patents

Abstract

PURPOSE:To obtain the method by which the angle-resolved spectrum of characteristic X-rays from an object to be measured, such as a formed film, etc., can be easily measured in a short time. CONSTITUTION:In this method for detecting characteristic X-rays excited by irradiating an object to be measured with high-speed particles near their total reflection angle, a mobile slit 2 is arranged in front of a semiconductor detector 1 to which the characteristic X-rays are made incident. The intensity of the characteristic X-rays is measured at the position of the slit 2 by switching multi-channel analyzers 71, 72, 73,..., 7n to one to which detecting signals are inputted synchronously to the drive of the slit 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring an angle-resolved spectrum of characteristic X-rays, and particularly to a method for measuring an angle-resolved spectrum of characteristic X-rays used for analyzing the composition and surface properties of a formed film. Involved in

[0002]

2. Description of the Related Art Chemistry of an object to be measured (for example, a film coated on a substrate) using characteristic X-rays excited by irradiating the object to be measured with high-speed particles such as electron beams or X-rays. As a method for analyzing the composition, EPMA (electron probe micro area analysis method) has been conventionally used. However, such a method has a problem that it is not suitable for analysis of an extremely surface (100 angstroms or less from the surface) because the detection depth reaches several μm.

Therefore, by detecting the characteristic X-rays in the vicinity of the total reflection angle with respect to the coating film, the detection efficiency on the pole surface can be improved and at the same time, the characteristic X-rays from a deep portion can be blocked as compared with the pole surface. A total reflection X-ray analysis method has been developed that enables the analysis of the pole surface.

In the above-mentioned total reflection X-ray analysis method, the detection sensitivity of characteristic X-rays depends on the X-ray extraction angle (the angle between the substrate surface and the X-ray incident direction), and the X-ray wavelength and the physical properties of the coating material. It has a sharp peak near the total reflection angle (a small angle of 2 ° or less in most cases) determined by the value, and the intensity sharply decreases to zero below the total reflection angle. A relational diagram showing the X-ray intensity as a function of the extraction angle is called an angle-resolved spectrum. The angle-resolved spectrum sharply changes depending on the surface state of the coating, the state in which the corresponding coating is covered with another coating, or the like. By utilizing this phenomenon, it becomes possible to obtain information on the surface state of the coating film from the shape of the angle-resolved spectrum.

[0005] The angle-resolved spectrum is conventionally obtained when the film is being formed by interrupting the film formation to detect the semiconductor detector (or substrate).
Is moved to change the take-out angle (height), and the operation of measuring the energy dispersion spectrum of the X-ray and the like is repeated at that position.

[0006]

The semiconductor detector used for the measurement of the angle-resolved spectrum is small and light in itself, but it is considerably heavy because it needs to be cooled by liquid nitrogen before use. Therefore, it becomes difficult to move the semiconductor detector at high speed and with high accuracy when measuring the angle-resolved spectrum. As a result, there is a problem in that not only the precise movement and positioning operation become complicated, but also a long time is required and a substantial measurement time becomes long.

The present invention has been made in order to solve the above-mentioned conventional problems, and is to measure the angle-resolved spectrum of characteristic X-rays from an object to be measured such as a formed film in a simple and short time. Is to provide a possible method.

[0008]

A method for measuring an angle-resolved spectrum of characteristic X-rays according to the present invention is a characteristic X-ray excited by irradiating an object to be measured with high-speed particles such as electron beams, X-rays and ions. In the vicinity of the total reflection angle, a multi-channel analysis in which a movable slit is arranged in front of the semiconductor detector on which the characteristic X-ray is incident, and a detection signal is input in synchronization with the driving of the movable slit. The characteristic X-ray intensity at the slit position is measured by switching to the instrument.

Another characteristic X-ray angle-resolved spectrum measuring method according to the present invention is the method for detecting the characteristic X-rays excited by irradiating an object to be measured with high-speed particles in the vicinity of the total reflection angle. The slit position is arranged by arranging a movable slit in front of a semiconductor detector on which characteristic X-rays are incident, and switching to a counter in which a detection signal is input through at least one single-channel analyzer in synchronization with the driving of the movable slit. Is an angle-resolved spectrum measuring method for characteristic X-rays.

[0010]

According to the present invention, the characteristic X-rays excited by irradiating an object to be measured (eg, a film formed on a substrate) with high-speed particles such as electron beams, X-rays and ions are totally reflected. When detecting in the vicinity of a corner, a movable slit is arranged in front of the semiconductor detector on which the characteristic X-ray is incident, and is switched to a multi-channel analyzer in which a detection signal is input in synchronization with the driving of the movable slit, or Alternatively, by switching to a counter in which a detection signal is input through at least one single-channel analyzer in synchronization with the driving of the movable slit and measuring the characteristic X-ray intensity depending on the slit position, The angle-resolved spectrum can be measured easily and in a short time.

[0011]

EXAMPLES Examples of the present invention will be described in detail below. Example 1

FIG. 1 is a schematic diagram showing an angle-resolved spectrum measuring apparatus for characteristic X-rays used in the first embodiment.
1 in the figure is a semiconductor detector (S for detecting a characteristic X-ray).
SD). A movable slit 2 is arranged on the front surface of the semiconductor detector 1 which is a characteristic X-ray incident surface. The movable slit 2 is driven by a slit driving mechanism 3. A high-voltage power supply 4 is connected to the electrode of the semiconductor detector 1 on the characteristic X-ray incident surface side, and a detection signal from the electrode is connected to an amplifier 5. An electrode located on the opposite side of the electrode of the semiconductor detector 1 is grounded. The amplifier 5 is connected to the A / D converter 6. The A / D converter 6 is connected to a switch 8 for switching the detection signal to a plurality of multi-channel analyzers 7 ₁ , 7 ₂ , 7 _3, ... 7 _n . The plurality of multi-channel analyzers 7
₁ , 7 ₂ , 7 ₃ ... 7 _n are connected to the personal computer 10 through the interface 9. The personal computer 10 is connected to a CRT 11 for displaying a predetermined image. Reference numeral 12 in the figure is a controller for synchronously driving the slit driving mechanism 3 and switching the switching device 8. The controller 12 is connected to the A / D converter 5. Next, a method of measuring the same spectrum using the angle-resolved spectrum measuring apparatus will be described with reference to FIGS.

[0013] First, by irradiating an electron beam 15 in the coating 14 which is deposited on the substrate 13 as shown in FIG. 2, the movable slit excited characteristic X-ray 16 at a predetermined take-out angle (theta _t) It is incident on the semiconductor detector 1 through 2. In addition,
L in FIG. 2 is the distance between the X-ray generation position and the movable slit 2, h
Indicates the height of the slit 2 from the surface of the coating film 14. When a characteristic X-ray is incident on the semiconductor detector 1, it is converted into an electric signal (detection signal; pulse) by the detector 1, and its peak value is A / D converted by an A / D converter 6 and switched. Output to the container 8. At this time, the controller 12 synchronizes the drive of the slit driving mechanism 3 and the switching of the switch 8 to synchronize the drive of the movable slit 2 with the signal after the A / D conversion through the switch 8. Switching to a predetermined multi-channel analyzer (for example, 7 ₁ ), the multi-channel analyzer 7 ₁ obtains an energy dispersion spectrum corresponding to a predetermined slit position. The signal from the multi-channel analyzer is displayed on the CRT 11 through the interface 9 and the personal computer 10 as the angle-resolved spectrum of the characteristic X-ray based on the energy dispersion spectrum.

By sequentially driving the movable slit 2 and switching the multi-channel analyzer by the switch 8 synchronized with this, a characteristic diagram showing the relationship between the slit drive position and the time diagram shown in FIG. 3 is obtained. Be done. Further, the slit position, the multi-channel analyzer (MCA) switching command pulse, the MCAn open and the data transfer command from the MCA to the personal computer in the portion A of FIG. 3 are made in accordance with the timing chart shown in FIG. When the length is 3 mm, the analysis time at each slit position is 2.8 seconds.

Based on the angle-resolved spectrum of the characteristic X-ray obtained by the above-mentioned measurement, a characteristic diagram showing the relationship between the slit displacement amount and the characteristic X-ray count shown in FIG. 5 is obtained. 14 compositions and surface states are evaluated.

Therefore, according to the first embodiment, since the movable slit can be made small and lightweight, high speed operation (for example, several tens Hz) becomes possible. Therefore, each multi-channel analyzer can measure the characteristic X-rays at each position of the slit, that is, at each extraction angle, substantially simultaneously by time division. The time required for measurement becomes dominant when the number of incident particles is obtained for X-rays required to form a meaningful spectrum, and the time required for position change control can be substantially ignored. If the time is sufficiently short, it is possible to perform online measurement without interrupting film formation. Example 2

FIG. 6 is a schematic diagram showing an angle-resolved spectrum measuring apparatus for characteristic X-rays used in the second embodiment.
The same members as those in FIG. 1 described above are designated by the same reference numerals and the description thereof is omitted.

The amplifier 5 comprises a plurality of single channel analyzers 1.
7 ₁ , 17 ₂ , ... 17 _m are connected. Each of the single-channel analyzers 17 ₁ , 17 ₂ , ... 17 _m outputs the detection signal to a plurality of counters 18 ₁₁ ... 18 _1n , 18 _m1 ... 18 _mn.
7 _m for switching the analyzers 17 ₁ , 17 ₂ ... 7 _m for switching to each of the switching devices 19 ₁ , ... 19 _m . The counters 18 ₁₁ ... 18 _1n , 18 _m1 ... 18 _mn are
Personal computer 1 through interface 9
0, connected to a CRT 11 for displaying a predetermined image. Further, reference numeral 12 in the drawing is a controller for synchronously driving the slit drive mechanism 3 and switching the switching devices 19 ₁ , ..., 19 _m . The switching device 19
_1, ... 19 _m are switching operation at the same time each is performed by the controller 12. The controller 12 is connected to the single channel analyzers 17 ₁ , 17 ₂ , ... 17 _m .

In the second embodiment, instead of the A / D converter described in the first embodiment, a plurality of single channel analyzers 17 ₁ , 17 ₂ , ... 17 _m are used, and each of the single channel analyzers 17 is used. _A counter 18 outputs the output of ₁ , 17 ₂ , ... 17 _m
It is possible to measure with ₁₁ ... 18 _1n , 18 _m1 ... 18 _mn . Each switch 19 is synchronized with the driving of the movable slit 2.
₁ , ... 19 _{m The} counter 18 ₁₁ ... 18 _1n , 18
Switch to _m1 … 18 _mn , counter 18 ₁₁ … 18 _1n , 18
_The characteristic X-ray corresponding to each position of the slit, that is, each extraction angle is measured with _m1 ... 18 _mn . In this case, by setting the settings of the single-channel analyzers 17 ₁ , 17 ₂ , ... 17 _{m in} the vicinity of the peak energy of the characteristic X-ray of the specific element to be analyzed, the angle of the specific X-ray of the specific element is set. A decomposition spectrum is obtained, and based on the angle decomposition spectrum, a characteristic diagram showing the relationship between the slit displacement amount and the characteristic X-ray coefficient shown in FIG. 5 similar to that described in the first embodiment is obtained. It is possible to evaluate the composition and surface condition of the coating from.

[0020]

As described above in detail, according to the present invention, of the measurement time of the angle-resolved spectrum, the time required for the movement and position adjustment of the semiconductor detector can be omitted, so that the total measurement time can be shortened. You can As a result, the time can be shortened in the film forming process in which the film forming control is performed based on the angle resolved spectrum. Further, since the angle-resolved spectrum can be detected online without interrupting the film formation, the film formation can be controlled.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an angle-resolved spectrum measuring apparatus for characteristic X-rays used in Example 1 of the present invention.

FIG. 2 is a schematic diagram for explaining a measurement operation of Example 1.

FIG. 3 is a characteristic diagram showing a relationship between a slit driving position and a time diagram in the first embodiment.

FIG. 4 is a timing chart showing slit positions, multi-channel analyzer (MCA) switching command pulses, MCAn open, and a data transfer command from MCA to a personal computer in the first embodiment.

FIG. 5 is a characteristic diagram showing the relationship between the slit displacement amount and the characteristic X-ray count in the first embodiment.

FIG. 6 is a schematic view showing a characteristic X-ray angle resolved spectrum measurement apparatus used in Example 2 of the present invention.

[Explanation of symbols]

1 ... Semiconductor detector (SSD), 2 ... Movable slit, 3 ...
Slit drive mechanism, 6 ... A / D converter, 8, 19 ₁ ... 1
9 _m ... Switching device, 7 ₁ , 7 ₂ , 7 ₃ ... 7 _n ... Multi-channel analyzer, 10 ... Personal computer, 11 ... CR
T, 12 ... Controller, 13 ... Substrate, 14 ... Coating, 15 ... Electron beam, 16 ... Characteristic X-ray, 17 ₁ , 17 ₂ , ... 17 _m ... Single channel analyzer, 18 ₁₁ ... 18 _1n , 18 _{m 1} ... 18 _mn ...
counter.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Keiji Mashita, 1-7-2 Nishishinbashi, Minato-ku, Tokyo Within Rhymes, Inc. (72) Inventor Ryuji Yonemoto 1-7-2 Nishishinbashi, Minato-ku, Tokyo No. 72, Limez Co., Ltd. (72) Junzo Takahashi, 1-7-2 Nishishinbashi, Minato-ku, Tokyo Within Limez, Co., Ltd. (72) Ao Miyagawa 1-2-7, Nishi-Shimbashi, Minato-ku, Tokyo Stock company Limes

Claims (2)

[Claims] 1. A method for detecting a characteristic X-ray excited by irradiating an object to be measured with high-speed particles in the vicinity of a total reflection angle thereof, wherein a movable slit is provided in front of a semiconductor detector on which the characteristic X-ray is incident. And the characteristic X-ray intensity according to the slit position is measured by switching to a multi-channel analyzer in which a detection signal is input in synchronization with the driving of the movable slit. Measuring method. 2. A method for detecting a characteristic X-ray excited by irradiating an object to be measured with high-speed particles in the vicinity of a total reflection angle thereof, wherein a movable slit is provided in front of a semiconductor detector on which the characteristic X-ray is incident. And a characteristic X-ray intensity according to the slit position is measured by switching to a counter in which a detection signal is input through at least one single channel analyzer in synchronization with the driving of the movable slit. Angle-resolved spectrum measurement method for lines.