JP2000097883A - Laminated structure inspection method, film formation control method, film formation apparatus, and magnetic recording / reproducing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate structure inspecting method to allow highly precise laminate structure evaluation using X-rays of two or more of wave lengths. SOLUTION: At least two kinds out of Kβ rays of two or more of elements constituting a laminate are used as X-rays incident into the laminate, in a laminate structure inspecting method wherein the X-rays are incident with low angles θ into the laminate with two or more layers of thin films formed on a substrate, X-ray reflectances from the laminate are measured, and the reflectances are analyzed to inspect layer structure of the laminate. The reflectances are measured using two kinds of wave lengths λ1, λ2 as X-ray wave lengths, the angles θ in the respective reflectances are converted into scattered spectra levels (q) (=4π sin θ/λ), then, the (q) dependency of reflectance ratio relating to the same level (q) is calculated, and the dependency is optimized to inspect the layer structure of the laminate.

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 the X-ray reflectivity of a thin film laminate having two or more layers formed on a substrate, analyzing the obtained reflection profile, and measuring the film thickness of each layer of the laminate. The present invention relates to a method for inspecting a laminated structure, a method for controlling film formation, and a device using the same, which are non-destructive and can be analyzed with high accuracy.

[0002]

2. Description of the Related Art In the fields of semiconductor integrated circuits, devices using them, magnetic files, etc., semiconductor layers, insulating layers, and metal layers are laminated to form elements by pattern formation.

[0003] The number of layers of films formed with the aim of increasing the functionality and performance of elements has been increasing as the thickness of the films has become extremely thin. Since the film thickness and density of such a laminated body greatly affect the characteristics of the element, a highly accurate laminated structure evaluation method is required along with the enhancement of film forming controllability.

[0004] The X-ray reflectivity method is an effective method capable of non-destructively analyzing the layer structure of a laminate. FIG. 10 shows a conventional reflectance measuring apparatus, and FIG. 11 shows an analysis method thereof. After the X-rays from the X-ray source 1 are separated by the crystal spectroscope 3, they are incident on the sample 6 at an oblique incident angle θ, and the reflected X-rays from the sample 6 are detected by the detector 10.
To detect.

The reflectance is measured from θ / 2θ scanning in which the rotary table 5 is driven by the control unit 11. The slits 2 and 4 limit incident X-rays, and the slits 7 and 9 limit reflected X-rays. In addition, the solar slit 8 is a reflection X
This is to increase the parallelism of the lines. The obtained reflectance is analyzed by the analysis device 12, and the results such as the density and the film thickness of each layer are output to the output device 13.

The analysis method shown in FIG. 11 is a method for optimizing the complex refractive index (proportional to the density), the film thickness, and the interface width of each layer by the least square method, and is an algorithm generally used.

[0007]

The X-ray reflectivity method is a method for analyzing a vibration structure (see FIG. 3) in a reflectivity profile caused by interference of X-rays reflected on the surface of a laminate and each interface. When the refractive index difference (density difference) between adjacent films is small, the intensity of the reflected X-rays at the interface becomes small, and the analysis becomes impossible depending on the analysis accuracy of each film or the material composition of the thin film. There was a problem.

To overcome this problem, the use of the X-ray refractive index anomalous dispersion effect by the constituent materials of the laminate is disclosed in Japanese Patent Laid-Open Publication No. Hei.
Although it is disclosed in Japanese Patent Application Laid-Open No. 0-38821, the number of laminated films is increased (5 layers or more), and the film itself is made extremely thin (several nm).
The problem that the analysis accuracy is reduced with the following) is inevitable.

Japanese Patent Application Laid-Open No. Sho 64-20405 reports a method of measuring the film thickness from the mutual phase of the reflection intensity modulation of X-rays of two or more wavelengths. Since the phase shift due to multiple scattering and absorption of X-rays in the above is not taken into account, there is a problem that the film thickness can be easily obtained but the accuracy is not sufficient. Furthermore, this method can be applied only to a single-layer film, and cannot be applied to a laminate having two or more layers.

An object of the present invention is to use X-rays of two or more wavelengths, calculate a reflectance based on a laminated structure model, and
By using an optimization method that minimizes the residual sum of squares with the ratio of the reflectance measured at each wavelength, etc., a laminated structure inspection method that can evaluate the laminated structure with higher accuracy than the conventional method and used it In providing the equipment.

Furthermore, a magnetoresistive sensor mounted on a magnetic recording / reproducing apparatus is composed of a magnetic and non-magnetic thin film laminate having a thickness of several nm, and the magnetic characteristics of the sensor strongly depend on the thickness of each layer.

Therefore, the next object of the present invention is to provide a film forming control method for controlling the film thickness with high accuracy by the present inspection method, and a magnetic recording / reproducing method using a magnetoresistive sensor having stable performance by the present control method. In providing the equipment.

[0013]

A feature of the laminated structure inspection method according to the present invention that achieves the above object is that X-rays are incident at a low angle θ on a laminate in which two or more thin films are formed on a substrate. In a laminate structure inspection method for measuring the X-ray reflectivity from a body and analyzing the reflectivity to inspect the layer structure of the laminate, two or more types of laminates that constitute X-rays incident on the laminate are included. It is to use two or more kinds of elemental Kβ rays.

Further, X-rays are incident on the thin film laminate formed on the substrate at a low angle θ, the X-ray reflectivity from the laminate is measured, and the reflectivity calculated based on an appropriate laminate structure model is obtained. By the optimization method that minimizes the residual sum of squares with the measured reflectance,
In a laminate structure inspection method for analyzing a layer structure of the laminate,
The reflectance is measured using two types of wavelengths λ ₁ and λ ₂ as the X-ray wavelength, and the angle θ of each reflectance is determined by the magnitude q of the scattering vector.
(= 4π sin θ / λ), the point is to inspect the layer structure of the stacked body by calculating the q dependence of the reflectance ratio with respect to the same q and optimizing the dependence.

Further, the X-ray wavelength has two or more wavelengths λi.
The reflectance using (i = i to n) is measured, and an optimization method for minimizing the sum of the residual squares of each wavelength χ ² i Σχ ² i is given by:
The purpose is to inspect the layer structure of the laminate.

The apparatus further comprises an X-ray source for generating at least two types of characteristic X-rays used for measurement, a spectroscope, a sample and a driving table for the detector, a detector and a control unit. X-rays that irradiate X-rays and measure reflected X-rays from the sample
The line reflectivity device includes a spectroscopic element that extracts only a specific characteristic X-ray by two reflections, a driving unit that rotates and translates the spectroscopic element, and a control unit that controls the driving unit by the control unit. And an X-ray reflectivity apparatus provided with an analyzing means for performing analysis based on the above-mentioned laminated structure inspection method.

Further, a feature of the film forming control method according to the present invention is that the film thickness of each film is reduced to 0.2 using the above-mentioned laminated structure inspection method.
The method is a film formation control method for controlling the surface roughness with an accuracy of 4 nm or less, the interface unevenness of 4 nm or less, and the density of 4% or less.

Further, in a film forming apparatus for forming two or more thin films on a substrate, an X-ray source for generating two or more types of characteristic X-rays used for measurement, a spectroscope, a sample and a drive table for a detector, A detector and a control unit, which irradiate the sample placed on the drive table with X-rays and measure reflected X-rays from the sample;
The line reflectivity device includes a spectroscopic element that extracts only a specific characteristic X-ray by two reflections, a driving unit that rotates and translates the spectroscopic element, and a control unit that controls the driving unit by the control unit. The X-ray reflectivity device described above, wherein the transport time of the stacked body between the X-ray reflectivity device and the film formation device by the control method is within 10 minutes. is there.

Further, a magnetic recording medium, a magnetoresistive sensor for reading a magnetic signal written on the medium, a write head for writing a magnetic signal, and a magnetic head mounted with the magnetoresistive sensor and the write head at the tip end, A magnetic recording / reproducing apparatus comprising: an arm that is driven in a radial direction of a recording medium; a control unit that controls a driving unit of the magnetic recording medium and the arm; and a signal processing unit that processes reading and writing signals of a magnetic signal. The magnetic recording / reproducing apparatus is characterized in that the thin film laminate of the magnetoresistive sensor is constituted by a magnetoresistive sensor formed by the film forming apparatus.

[0020]

According to the present invention, X of two or more wavelengths is used.
Since the reflectance based on the line is used, it is possible to evaluate the laminated structure with higher accuracy than the conventional one-wavelength reflectance.
Hereinafter, the reason will be described.

Consider an X-ray reflectivity from a laminate having an n-1 layer film formed on a substrate. Complex refractive index n = 1−δ−i
β, viewing angle θ of incident X-ray, X-ray wavelength λ, film thickness t, β
Using the approximation of ０0, θ ² >> 2δ, θ << 1, the reflectance R is expressed by the following equation.

[0022]

(Equation 1)

Γ in Equation 1 is a quantity representing the phase of the reflected X-ray, and is a function of the film thickness and the like. The first sum term in Equation 1 is the reflection from the surface and the interface, and information relating to the film thickness cannot be derived from this term.

On the other hand, the second sum term is caused by interference of X-rays reflected on the surface and the interface, and a vibration structure appears in the reflectance (see FIG. 3). This vibration structure contains information on the thickness and density of each film of the laminate.

Conventionally, the reflectance including the vibration structure measured at one wavelength is analyzed. As is apparent from Equation 1, since the reflectance is attenuated by θ to the -4th power, a slight difference in the vibration structure is analyzed. On the other hand, when Equation 1 is rewritten using the variable transformation of the scattering vector magnitude q = 4π sin θ / λ and ξ = (4π / λ) ² δ, the following equation is obtained.

[0026]

(Equation 2)

Since λ is not directly included in the above equation due to this variable change, the period of the reflectivity vibration structure measured at each wavelength becomes substantially the same (see FIG. 5).

Then, by taking the ratio of the reflectances R ₁ and R ₂ measured at the _two X-ray wavelengths λ ₁ and λ ₂ , the -4 power attenuation term is eliminated, and the vibration structure can be extracted. Therefore, accuracy is improved (see FIG. 6).

FIG. 1 shows an analysis algorithm according to the present invention. The reflectance measured at two wavelengths is the magnitude q of the scattering vector.
And the ratio is fitted by the least squares method to optimize the structure of each laminated film. In this case, the ratio of the reflectance at each wavelength is calculated using the X-ray scattering theoretical formula.

FIG. 2 shows another analysis algorithm of the present invention with improved analysis accuracy. The point of directly analyzing the reflectance measured at two wavelengths is the same as the conventional analysis of the reflectance measured at one wavelength. However, it differs from the conventional method in that the condition for optimization is determined by minimizing the sum of the residual square sums calculated at each wavelength. Since the refractive index is wavelength-dependent,
The amplitude of the vibrating structure is different for the two wavelength reflectances. In the present invention, the accuracy can be improved because the different vibration structures are analyzed together.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Example 1 First, it was confirmed by computer simulation that the accuracy of the inspection method according to the present invention was improved as compared with the conventional method. The structures of the laminate are three types shown in Table 1.

[0033]

[Table 1]

The calculation of the reflectance from the laminate is described in L. G. FIG.
Paratt (Phys. Rev. 95, 359 (195)
4)) and L. Nevot and P.S. Croce (Rev.
Phys. Appl, 15, 761 (1980)), and Cu-Kβ (0.13922 nm), which is a Kβ line of Cu and Co, which are constituent elements of the laminate, and Co
Calculation was performed at two wavelengths of -Kβ (0.16088 nm).

In the calculation, the complex refractive index of each layer is based on the literature value (S
Asaki, KEK Report, 88-14), and calculated with each interface width being 0.5 nm.

FIG. 3 shows the reflectance (Cu-K) from each laminate.
β). Solid lines, dotted lines, and broken lines indicate the laminates a, b, and c, respectively.
And there is only a slight difference in the reflectance of each laminate. It is clear that high-precision analysis is difficult to analyze the reflectance by the conventional method.

On the other hand, FIG. 4 shows the reflectance ratio at two wavelengths according to the present invention. The vertical axis is Co-Kβ reflectance / Cu-Kβ
The reflectivity and the horizontal axis are the magnitude q of the scattering vector. solid line,
The dotted line and the broken line are the laminates a, b, and c, respectively. In FIG.
The vibration part of the reflectance is extracted, and its amplitude is emphasized as compared with FIG.

Further, it can be clearly seen that the amplitude of the vibration differs depending on the laminated body. Since the vibration structure contains information on the layer structure, the inspection method according to the present invention (FIG. 1)
Obviously, the layer structure of the laminate can be analyzed with higher accuracy than before.

Example 2 It was confirmed by computer simulation that the accuracy of the analysis method according to the present invention was improved as compared with the conventional method. The configuration of the laminate is Co (4) /
In the Cu (2) / Co (4) / Ta (5) / Si substrate, the numerical value in parentheses is the film thickness (nm).

FIG. 5 shows Cu-Kα (0.1406 nm).
And the reflectivity calculated at the wavelength of Cu-Kβ are shown by solid and dotted lines, respectively. By changing the wavelength, a slight but distinct difference in the reflectivity is observed. In the conventional method, this reflectance is individually analyzed.

On the other hand, according to the present invention, an algorithm for minimizing the sum of the residual square sums calculated at each wavelength (see FIG. 2)
Is used, optimization is performed while maintaining the consistency of the oscillating portion of the reflectance measured at each wavelength, thereby improving analysis accuracy.

That is, in the reflectance at each wavelength, the film thickness and interface width of each layer are common, and the complex variables (film thickness, interface width) are used in order to optimize the wavelength-dependent complex refractive index at each wavelength.
Can be maintained. For this reason, it became clear that the accuracy of the analysis method according to the present invention was improved as compared with the conventional method.

FIG. 6 shows Cu-Kβ reflectance / Cu-
The reflectance ratio of the Kα reflectance is also shown. The vibration part of the reflectance is extracted, and its period and amplitude indicate a complicated shape. This is in sharp contrast to the reflectance shown in FIG. 5, and it can be seen that a slight difference in reflectance is more emphasized. That is, it shows that the analysis method based on the reflectance ratio according to the present invention is also effective.

[Embodiment 3] FIG. 7 shows an embodiment of X of the present invention.
It is a lineblock diagram of a line reflectivity device. X-rays having two or more types of wavelengths from the X-ray source 1 are extracted from the X-ray having a specific wavelength by the crystal spectroscope 3 and then incident on the sample 6. Reflected X-rays from the sample 6 are slits 7 and 9 and a solar slit 8
After shaping and collimating in, measurement is performed by the detector 10.

Next, individual functions will be described. In the X-ray composite target 20, a rotating anti-cathode using a pure metal of Co and Cu was used for a rotating part irradiated with an electron beam from the filament 21.

The operating conditions of the X-ray source are a tube voltage of 45 kV and a tube current of 200 mA. From this X-ray source, Co-Kα,
Characteristic X-rays of Kβ and Cu-Kα, Kβ are emitted.
At this time, the intensities of Co-Kβ, Cu-Kα, and Cu-Kβ are about 500 kcps, about 6000 kcps, and about 100 kcps, respectively.
It was 0 kcps. The crystal spectroscope 3 has Si (111)
Channel cut type crystal was used. The control unit 11 has a function of rotating and translating the crystal.

In order to extract X-rays of the Co-Kβ wavelength from the X-ray source 1, the viewing angle of the X-ray with respect to the crystal is set to 14.98.
The sample 6 was irradiated with X-rays which were set to ゜, and the position of the slit 4 was adjusted and spectrally separated.

The X-ray of the Cu-Kβ wavelength from the X-ray source 1
In order to extract the X-ray, the viewing angle of the X-ray crystal
The angle was set to 2.83 °, and the crystal was driven to translate so that the slit 4 previously set was adjusted so that spectral X-rays would pass therethrough.

As a result, the incident angle and the irradiation position of the X-ray of each wavelength on the sample could be matched. The rotary table 5 is composed of two axes θ and 2θ, and the sample holding table provided on the θ table is driven by the control unit 11 so that the sample enters the X axis.
Can be aligned parallel to the line. As the detector 10, a scintillation counter having an opening diameter of 1 inch was used. Each drive unit can be controlled by the control unit 11.

Next, the measurement and analysis procedure will be described. First, the sample is retracted from the optical axis, the crystal spectroscope 3 is adjusted so that X-rays of each wavelength can be extracted, and the set angle and the translation position are recorded.

Next, the sample 6 is returned to the optical axis, and the sample is aligned so as to be parallel to the X-ray. Then, the sample is rotated to a set angle (θ) and the 2θ arm is set to a predetermined angle (2θ). Rotate.

In the measurement, the reflected X-ray intensity is measured by θ-2θ scanning at a step angle of 0.01 ° of the sample. First C
The reflectance was measured at the o-Kβ wavelength.

Next, the sample and the detector were returned to the initial set values, and the crystal spectroscope 3 was set to the Cu-Kβ wavelength, and the reflectance was measured. The scan angle range of the sample is 0.15 ° to 3.
0 °.

The driving of the turntable 5 was controlled by the control unit 11, and signals from the detector 10 were sequentially recorded in the analysis device 12 via the control unit 11. The sample was Ta
(30) / CrMnPt (300) / Co (30) / C
u (23) / Co (10) / NiFe (50) / Ta
(50) / The value in parentheses in the substrate is the designed film thickness (Å).

As the wavelength of the incident X-ray, Kβ rays of Co and Cu, which are constituent elements of the sample, were used. The analysis uses a calculation code based on the algorithm shown in FIG.
The above was performed, and the result was output to the output device 13.

The layer structure model used in the analysis is an oxide layer / T
a / CrMnPt / Co / Cu / Co / NiFe / reaction layer / Ta / interface layer / working layer / substrate;
The film thickness and interface width were optimized.

FIG. 8 shows the reflectance measured at each wavelength. In this analysis, an algorithm that minimizes the sum of the reflectance measured at each wavelength and the calculated reflectance was used. For comparison, Co
Only the reflectance at -Kβ was analyzed using a normal algorithm.

FIG. 9 shows the ratio (χ ² / χ) of the residual sum of squares χ ^{2 to} the minimum value when the film thickness of Co on the substrate side is fixed to a value shifted from the optimum value and other variables are optimized again. ² shows the results of analyzing ² min) at two wavelengths and one wavelength.

[0059] chi ² distribution by one wavelength it can be seen that substantially difficult to converge to the minimum value in the flat. On the other hand, at two wavelengths
It can be seen that the ^two distributions have a downward convex shape and easily converge to the minimum value in the optimization. From this, it was found that the accuracy was improved when the analysis was performed at two wavelengths.

Next, errors including measurement and analysis by the two-wavelength method were examined. The above sample was treated with Co-Kβ
And the reflectance data measured twice with Cu-Kβ were combined and analyzed using an algorithm that minimizes the sum of the measured reflectance and the calculated reflectance at each wavelength. as a result,
Table 2 summarizes the average value and dispersion of Δ, the refractive index was changed, the film thickness d, and the interface width σ.

From this, the refractive index (proportional to the density) is about 0.4%, and the thickness of Cu is about 0.2０ (= 0.02n).
m), about 0.4 ° (= 0.04n) in CrMnPt interface width
It was found that the analysis could be performed with the accuracy of m).

[0062]

[Table 2]

[Embodiment 4] Next, a film forming control method and a magnetoresistive sensor will be described. An RF sputtering apparatus was used as a film forming apparatus, and CrMnPt, Co, Cu,
The sputtering rate of each target of NiFe and Ta was calibrated.

First, using the sputter rate built into the control unit of the sputtering apparatus, 1, 2,.
Films were formed at a designed thickness of 4.8 nm. For CrMnPt, films were formed at a design thickness of 10, 20, 40, and 80 nm.

Next, these calibration laminates were measured and analyzed using the X-ray reflectometer of Example 3 to analyze the thickness of each layer. From the analyzed film thickness and film formation time, the sputter rate of each target was fitted by linear regression and calibrated. In this operation, the sputtering rate was calibrated under each of the film forming conditions in which the RF power of the RF sputtering apparatus and the pressure in the chamber were changed.

By these operations, the film thickness is 0.2 nm or less,
It has become possible to control the interface unevenness with an accuracy of 0.4 nm or less and a density of 4% or less. That is, since the two-wavelength reflectance method according to the present invention has sufficiently high analysis accuracy, the film formation can be controlled with the above accuracy.

The film forming apparatus and the reflectivity apparatus were installed in a clean room, and the transport time of the calibration laminate was 1 hour.
Within 0 minutes. Since the transport time is short, the calibration of the sputtering device can be performed quickly, and the effect of the oxide layer formed on the surface is small, and highly accurate analysis can be performed.

Next, several magnetoresistive sensors were manufactured using the calibrated film forming apparatus described above. The film configuration is Ta (3)
/CrMnPt(30)/Co(3)/Cu(2.3)
The value in parentheses in / Co (1) / NiFe (5) / Ta (5) is the designed film thickness (nm).

After the film formation, the film thickness of each sensor was measured and evaluated by an X-ray reflectometer, and as a result, the film thickness was 0.2 nm or less, which coincided with the designed film thickness. Since the film thickness of each sensor is controlled with sufficient accuracy, the sensitivities of the sensors are almost the same.

FIG. 12 is a schematic diagram of a magnetic recording / reproducing apparatus incorporating the above-mentioned sensor. FIG. 12A shows an arm on which a magnetic recording medium on which information is written, a magnetoresistive sensor for reading a magnetic signal, and a write head for writing a magnetic signal are mounted at the distal end. Information can be recorded and reproduced at all locations on the magnetic recording medium by using a magnetic recording medium that rotates around the center of the disk and an arm that is driven in the radial direction of the disk.

FIG. 12 (b) shows the structure of the magnetoresistive sensor and the write head. A portion surrounded by a triangle indicates the magnetoresistive sensor, and this surface is close to the surface of the magnetic recording medium. Read the recording signal.

FIG. 12C shows a film structure of the magnetoresistive sensor. This is a structure in which a magnetization signal is read out by a change in electric resistance between electrodes due to a leakage magnetic field of magnetization written in a magnetic recording medium. Each magnetic recording / reproducing apparatus incorporating this sensor has a small variation in output signal because the sensitivity of each sensor is well matched, and shows a good yield as a recording apparatus.

According to the present invention, the film thickness of the laminated body, which is the main element of the magnetoresistive sensor, can be controlled with high accuracy, so that the performance of each sensor can be suppressed to within an allowable range, and the performance of each magnetic sensor can be stabilized. It is possible to produce a recording / reproducing device with a steel yield.

[0074]

According to the thin-film laminate analysis method of the present invention, it is possible to extract a vibrating portion by taking the ratio of the reflectance measured at two or more wavelengths, and to calculate the sum of the residual square sum at each wavelength. Since the algorithm for minimizing the size is used, there is an excellent effect that the inspection of the laminated structure can be performed with higher accuracy than the conventional one.

Further, according to the control method of the present invention, the thickness of the laminated body, which is the main element of the magnetoresistive sensor, can be controlled with high accuracy, so that the performance of each sensor can be suppressed within an allowable range. A magnetic recording / reproducing apparatus with stable performance can be produced with high yield.

[Brief description of the drawings]

FIG. 1 is a diagram showing an analysis algorithm according to the present invention.

FIG. 2 is a diagram showing an analysis algorithm according to the present invention.

FIG. 3 shows the calculated reflectance (C) from the laminate shown in Table 1.
FIG. 3 is a diagram showing u-Kb wavelength).

FIG. 4 is a graph showing Co—Kb reflectance /
It is the figure which calculated the ratio of Cu-Kb reflectance.

FIG. 5 is a diagram showing reflectances calculated at wavelengths of Cu-Kα and Cu-Kb from a Co / Cu / Co / Ta / Si substrate laminate.

FIG. 6 shows the reflectance ratio (Cu-Kb reflectance / C) shown in FIG.
FIG. 4 is a diagram showing calculated u-Kα reflectance).

FIG. 7 is a configuration diagram of an X-ray reflectivity device of one embodiment according to the present invention.

FIG. 8: Ta / CrMnPt / Co / Cu / Co / Ni
Co-Kb and Cu- from Fe / Ta / substrate laminate
It is a figure which shows the reflectance measured at the wavelength of Kb.

FIG. 9 is a graph showing the C on the substrate side in the analysis of the laminate shown in FIG. 8;
FIG. 11 is a diagram showing a result of analyzing the distribution of the residual sum of squares χ ² with respect to the film thickness by a two-wavelength method and a conventional one-wavelength method.

FIG. 10 is a configuration diagram of a conventional X-ray reflectivity device.

FIG. 11 is a diagram illustrating an analysis algorithm according to the related art.

FIG. 12 is a schematic diagram showing a configuration of a magnetic recording / reproducing apparatus of the present invention.

[Explanation of symbols]

1 X-ray source, 2, 4, 7, 9 slit, 3 spectroscope,
5 ... rotary table, 6 ... sample, 8 ... solar slit,
10 detector, 11 controller, 12 analyzer, 13
Output device, 15: spectroscope driving unit, 20: X-ray composite target, 21: filament.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroyuki Hoshiya 1-280 Higashi Koigabo, Kokubunji-shi, Tokyo Inside the Central Research Laboratory, Hitachi, Ltd. Storage System Division (72) Inventor Kazuhiro Ueda 1-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture F-term in Hitachi Research Laboratory, Hitachi Ltd. 2F067 AA27 BB04 BB16 CC15 HH04 JJ03 KK02 KK08 LL02 MM01 RR33 SS11 2G001 AA01 BA15 CA01 EA01 EA09 FA01 GA13 JA01 JA15 KA01 KA11 MA05 SA01 SA02 2G017 AD54 AD63 AD65 5D034 BA02 BB12 BB14 DA04

Claims (7)

[Claims] An X-ray is incident at a low angle θ on a laminate in which two or more thin films are formed on a substrate, X-ray reflectance from the laminate is measured, and the reflectance is analyzed to obtain a laminate. A laminated structure inspection method for inspecting a layer structure of a body, wherein two or more kinds of Kβ rays of two or more elements constituting the laminated body are used as X-rays incident on the laminated body. 2. An X-ray is incident on a laminate having two or more thin films formed on a substrate at a low angle θ, and the X-ray reflectivity from the laminate is measured, and based on an appropriate laminate structure model. In a laminate structure inspection method for inspecting the layer structure of the laminate by an optimization method that minimizes the residual sum of squares of the calculated reflectance and the measured reflectance, two types of X-ray wavelengths, λ ₁ and λ, are used. _After measuring the reflectance using ₂ and converting the angle θ of each reflectance into the magnitude q of the scattering vector (= 4π sin θ / λ), the q dependency of the reflectance ratio with respect to the same q is calculated, A method for inspecting a laminated structure, wherein the layer structure of the laminated body is inspected by optimizing the dependency. 3. An X-ray is incident on a laminate having two or more thin films formed on a substrate at a low angle θ, and the X-ray reflectivity from the laminate is measured, and based on an appropriate laminate structure model. In a laminate structure inspection method for inspecting the layer structure of the laminate by an optimization method that minimizes the residual sum of squares of the calculated reflectance and the measured reflectance, two or more wavelengths λi (i = I ~ n)
Measuring the reflectance with, the optimization method that minimizes the sum Σχ ² i of SSD chi ² i of each wavelength, the laminated structure is characterized by examining the layer structure of the laminate test Law. 4. An X-ray source for generating two or more types of characteristic X-rays used for measurement, a spectroscope, a sample and a drive table for a detector,
An X-ray reflectivity device comprising a detector and a control unit, which irradiates a sample placed on the drive table with X-rays and measures reflected X-rays from the sample, wherein only specific characteristic X-rays are reflected twice. X, comprising: a driving unit that includes a spectral element to be taken out, rotates and translates the spectral element, and control means that controls the driving unit by the control unit.
An X-ray reflectivity device, comprising: an analysis unit for performing analysis based on the laminated structure inspection method according to claim 1, 2, or 3. 5. A film forming control method for forming one or more thin films on a substrate, wherein the film thickness of each film is 0.2 nm or less by using the laminated structure inspection method according to claim 1, 2, or 3. A film forming control method characterized by controlling interface roughness with an accuracy of 0.4 nm or less and a density of 4% or less. 6. A film forming apparatus for forming two or more layers of thin films on a substrate, an X-ray source for generating two or more types of characteristic X-rays used for measurement, a spectroscope, a sample and a driving table for a detector,
An X-ray reflectivity device that includes a detector and a control unit, irradiates a sample installed on the drive table with X-rays, and measures reflected X-rays from the sample. 5. An X-ray reflection apparatus comprising: the X-ray reflectivity device according to claim 4, further comprising: a driving unit configured to rotate and translate the spectroscopic element, and a control unit configured to control the driving unit by the control unit. A film forming apparatus, wherein a transport time of the stacked body between the reflectivity apparatus and the film forming apparatus according to the film forming control method according to claim 5 is within 10 minutes. 7. A magnetic recording medium, a magnetoresistive sensor for reading a magnetic signal written on the medium, a write head for writing a magnetic signal, and the magnetic recording by mounting the magnetoresistive sensor and the write head on a tip portion. A magnetic recording / reproducing apparatus comprising: an arm that is driven in a radial direction of a medium; a control unit that controls a driving unit of the magnetic recording medium and the arm; and a signal processing unit that processes a read signal and a write signal of a magnetic signal. A magnetic recording / reproducing apparatus, wherein the thin film laminate of the resistance sensor is constituted by a magnetoresistive sensor formed by the film forming apparatus according to claim 6.