KR102083239B1 - Measuring method of thin film thickness by secondary ion mass spectrometry - Google Patents

Abstract

The present invention relates to a method for calculating a thin film thickness by combining a composition profile such as secondary ion mass spectrometry (SIMS) and other methods such as a stylus profile Peter etc. Provided is the method for accurately, quickly, and easily measuring the thin film thickness for various specimens.

Description

Measuring method of thin film thickness using secondary ion mass spectrometer {Measuring method of thin film thickness by secondary ion mass spectrometry}

The present invention relates to a method for measuring the thickness of a thin film by combining a composition profile such as secondary ion mass spectrometry (SIMS) and other methods.

Accurate measurement of film thickness is one of the most important measurement problems in the manufacture of advanced electronic devices. The thickness of the thin film is X-ray reflectivity (XRR), spectroscopic ellipsometry (SE), X-ray photoelectron spectroscopy (XPS), Rutherford backscattering spectroscopy (RBS)) and transmission electron microscopy (TEM). However, the measurement of various thin film thicknesses by this method requires complex and special prerequisites.

In the pilot study P-38 of the surface analysis working group (SAWG) of the consultative committee for amount of substance (CCQM), Si (100) and (111) with XRR, SE, RBS and TEM The thickness of the nanometer SiO ₂ film on the substrate was measured, and the thickness measurement of the multilayer film was carried out by the SC6 (SIMS) division of ISO / TC-201 (Surface Chemical Analysis). It has also been investigated in the international round robin test, but no absolute surface analysis method for accurate thickness measurement of thin films has yet been reported.

Although SIMS is a useful technique for analyzing the depth distribution of various thin film materials, thickness measurement by SIMS has a limitation that it is difficult to determine the position of the interface. In particular, the abnormal change in the intensity of a particular ion at the interface at which the medium changes due to the matrix effect is a problem to be considered in the thickness measurement of thin film material by SIMS depth profiling.

Republic of Korea Patent Publication No. 10-1061163

The present invention has been made to solve the problems of the prior art as described above, for the purpose of providing a method for measuring the thickness of the thin film accurately, quickly and simply for a variety of specimens.

The thin film thickness measuring method of the present invention comprises the steps of: preparing a film including a first layer which is a thin film and a second layer in contact with one surface of the first layer; Two or more craters are formed from the other surface of the first layer to the second layer of the thin film, and for each crater, the depth from the interface between the first and second layers of the crater Calculating D _total ); Measuring a depth D _subst from the other surface of the first layer of each formed crater by a method other than the composition profile; And determining a _total of D when the crater from the respective D and D _{total subst, subst} D is 0 with a thickness of the first layer; and a.

In one aspect of the present invention, the thickness of the first layer may be determined by further reflecting a correction value in D _total when D _subst becomes zero.

In one aspect of the invention, the correction value may be one in which an error due to crater topography is compensated.

In one aspect of the invention, the composition profile according to the depth can be obtained through secondary ion mass spectrometry (SIMS).

In one embodiment of the present invention, the composition profile according to the depth may be obtained through secondary ion mass spectrometry (SIMS) using cesium (Cs) cluster ions.

In one aspect of the invention, the depth measurement method other than the composition profile may be by a stylus profile meter and / or an optical interferometer.

In one aspect of the present invention, D _total when the D _subst becomes 0 may be determined through linear regression analysis.

In one embodiment of the present invention, the first layer and the second layer may each include any one or two or more of a single element material, an alloy, and a compound including a metal.

The present invention provides a method for measuring the thickness of a thin film accurately, quickly and simply for various specimens.

The present invention also provides a method for measuring thin film thickness that can be easily used by non-experts.

The invention also provides an accurate thin film thickness that reflects the topography of the material surface.

1 is a fitting method for calculating a thin film thickness from D _total and D _subst according to an aspect of the present invention.
Figure 2 is a profile conversion process according to an aspect of the present invention, (a) is the SIMS secondary ion intensity (Intensity) according to the sputtering time, (b) is the normalized SIMS secondary ion strength according to the sputtering depth, (c) is SIMS secondary ion strength ratio with sputtering depth.
3 is a conceptual diagram of a crater bottom having a fine surface shape in nm, in which depth is measured with a stylus after sputtering according to one aspect of the present invention.
4 is a calibration curve of a stylus for measuring crater depth in accordance with an aspect of the present invention.
5 shows different crater depths ((a) 182.7 nm, (b) 208.6 nm, (c) 246.9 nm, (d) 290.2 nm, (e) 367.8 nm, and (f) 429.4 according to one aspect of the present invention. nm) sputtering time-SIMS secondary ion intensity profile and crater depth-SIMS secondary ion intensity ratio profile of the Fe _0.4 Ni _0.6 alloy film forming.
6 shows (a) Ge (50 nm) / Si (100), (b) Ge (100 nm) / Si (100) and (c) Ni (200) obtained from MCs ₂ ⁺ SIMS according to one aspect of the present invention. nm) / Si (100) film is the result of calculating the depth profile and film thickness.
7 shows (a) 5 × (Ta / Ta ₂ O ₅ ) / Si (100), (b) 5 × (Si / Ge) / Si (100) obtained from MCs ₂ ⁺ SIMS according to one aspect of the present invention. (c) sputtering time-SIMS secondary ion intensity profile of 5 × (Cr / Ni) / Si (100), and (d) 5 × (Ta / Ta ₂ O ₅ ) / Si (100), (e) 5 Crater depth-SIMS secondary ion intensity ratio profile of (Si / Ge) / Si (100), (f) 5x (Cr / Ni) / Si (100).
8 is a transmission electron microscope for the cross section after sputtering of (a) Ni, (b) 5 × (Cr / Ni), and (c) 5 × (Ta / Ta ₂ O ₅ ) membranes according to one aspect of the present invention. electron microscopy (TEM) image.
9 shows the thickness T _TEM obtained from a TEM image for each of (a) the thickness T _SIMS obtained from _SIMS and (b) the compensated thickness T _SIMS + ΔI / 2, according to one aspect of the present invention. The fitting result.

Hereinafter, the present invention will be described in detail. The embodiments and drawings introduced below are provided as examples to sufficiently convey the spirit of the present invention to those skilled in the art. Accordingly, the present invention is not limited to the embodiments and drawings presented below, but may be embodied in other forms. At this time, if there is no other definitions in the technical terms and scientific terms used, those having ordinary skill in the technical field to which the present invention has a meaning commonly understood, the gist of the present invention in the following description and the accompanying drawings. Descriptions of well-known functions and configurations that may be unnecessarily blurred are omitted.

In the present invention, the thin film thickness measuring method,

Preparing a thin film including a first layer and a second layer in contact with one surface of the first layer;

Two or more craters are formed from the other surface of the first layer of the thin film to the second layer, and in each crater, the interface between the first and second layers of the crater from the SIMS composition profile according to the depth. Calculating a depth D _total from the;

Measuring a depth D _subst from the other surface of the first layer of each formed crater by a method other than the composition profile; And

Determining a _total D of the case from the crater of each of D and D _{total subst, subst} D is zero in which the thickness of the first layer; It includes.

Thin film used in the present invention means a film having a thickness in nanometers, for example, may have a thickness of less than 1 ㎛, especially applicable to a thickness of less than 500 nm, even thinner 300 Accurate thickness calculation is possible even with a thickness of less than nm and a thickness of less than 100 nm.

In the present invention, the first layer and the second layer may be a two-dimensional structure having a planar and / or curved surface, and when any one side of the first layer is referred to as one side, the opposite side corresponding to the one side is turned into the other side. Refers to.

In the present invention, the second layer is in contact with one surface of the first layer, not only the surface of the second layer and the first layer are in physical contact with each other, but also the components constituting the first layer and / or the second layer. It is also included that some of the parts are unilaterally or interspersed at the interface. If so interspersed, the interface may not be clearly distinguishable at the atomic scale.

In one aspect of the invention, the second layer may be a substrate on which the first layer is formed. In this case, the first layer may be formed by evaporation, and examples of such evaporation methods include ion beam sputter deposition and thermal evaporation. ) Is not limited to the formation method.

In one aspect of the invention, the first layer and the second layer may each comprise any one or two or more of a monoelement material, an alloy, and a compound comprising a metal. In one aspect of the present invention, the compound may be any one or more selected from oxides, nitrides, and carbides of metals. In one embodiment of the present invention, the metal may be any one or more selected from Ge, Si, Fe, Ni, and Ta.

In one aspect of the invention, the first layer may comprise any one or two or more of a single metal layer, an alloy layer, and a metal compound deposited on a second layer, which is a Si substrate.

In one aspect of the invention, compounds such as oxides, nitrides, carbides of metals may be formed by forming a reaction gas atmosphere during metal deposition, wherein the reaction gas is oxygen, nitrogen, hydrocarbons, or the like, or mixtures or reactants thereof Can be.

In the present invention, the crater is a recessed structure formed in the boundary direction between the first layer and the second layer from the other surface of the first layer, and the crater is a recessed structure extending through the first layer to the second layer. In one aspect of the invention the craters may be formed in the process of obtaining a composition profile. That is, as an example, a composition profile through SIMS may be obtained, and the composition profile may be obtained by sensing secondary ions generated as craters are formed in the thin film by the irradiated ions. In one aspect of the invention, the irradiated (sputtered) ions of the SIMS may be cesium (Cs) cluster ions, where the secondary ions are in the form of MCs ₂ ⁺ (M is an element included in the first and second layers) and secondary Ionization of the ions is governed by Cs atoms having the property of being easily ionized with cations, which can lead to a reduction in medium effect.

In one aspect of the invention, the depth measurement method other than the composition profile may be by a stylus profilometer and / or an optical interferometer. That is, for a crater formed with a composition profile obtained (sputtered), the depth of the crater can be measured using a probe or via optical means. The craters should be formed to have two or more different depths, and in order to obtain reliable results of the depth-composition relationship, the conditions under which composition profiles such as current density of sputtering ions are obtained need to be kept uniform.

In one aspect of the present invention, the thickness of the thin film (first layer) may be determined as D _total when D _subst becomes 0, which may be determined through linear regression analysis. That is, the actual thickness of the thin film is determined from an offset (intercept) value of crater depth determined by extrapolation in a linear plot of substrate (second layer) depth (horizontal coordinate) and crater depth (vertical coordinate) as shown in FIG. Can be determined. In this case, the slope m value means the ratio of the sputtering speed with respect to the first layer and the sputtering speed with respect to the substrate (second layer). A slope greater than 1 means that the sputtering rate for the first layer is faster than the sputtering rate for the substrate (second layer).

In one aspect of the invention, in compositional element analysis with respect to the depth of a thin film by a method such as a surface analysis method, the intensity of ions sputtered and released from the thin film material is generally at half the maximum value of the plateau portion. At the decreasing point the location of the interface (eg the interface between the first and second layers) is determined. In order to realize this method, the value measured in sputtering time-ion intensity must be converted into a relative ratio of ionic strength according to the sputtered depth (crater depth).

In one aspect of the invention, this is converted by the following three step process.

In the first step, the scale of abscissa must be converted from time (seconds) to depth (nm) in order to calculate the crater depth. Total crater depth can be measured using a mechanical stylus profile meter or an optical interferometer, which is a common method of calibrating SIMS depth.

In the second step, the secondary ion strength of each layer (first layer and second layer) is normalized by dividing the secondary ion intensity ( i _F ^raw , i _S ^raw ) by the average intensity ( I _F ^plateau ) at the ^plateau . Converted to normalized intensities i _F ^norm and i _S ^norm .

i _F ^norm  = i _F ^raw  / I _F ^plateau

i _S ^norm  = i _S ^raw  / I _S ^plateau

In the third step, the normalized ionic strengths i _F ^norm and i _S ^norm are converted into the relative ionic strength ratios of the first layer (thin film) and the second layer (substrate) from the following relationship.

r _F  = i _F ^norm  / (i _F ^norm  + i _S ^norm ) × 100%

r _S  = i _S ^norm  / (i _F ^norm  + i _S ^norm ) × 100%

From the normalized ionic strength ratio according to the converted depth, the interface position of the first layer and the second layer can be clearly determined as the position where the normalized ionic strength ratio of both layers becomes 50% (FIG. 2).

In one aspect of the present invention, the thickness of the first layer may be determined by further reflecting a correction value in D _total when D _subst becomes 0, where the correction value is compensated for an error due to crater topography. It may have been. That is, the crater depth measurement by a stylus profile meter is determined in the peak region along the shape of the crater bottom (FIG. 3). If the stylus tip is round and large in diameter, it becomes difficult to profile the valleys in small surface shapes in the nanometer range, and consequently the level of the crater bottom is determined at the highest point of the fine surface shape. Therefore, the thickness of the thin film measured by the stylus profile meter is calculated to be thinner than the actual thickness within the difference between the actual interface and the measured crater bottom. The thin film thickness thus calculated thinner than the actual thickness can be compensated from the width of the interface, which is directly related to the development of the surface shape as described above. The interface width ΔI is then derived from the resolution of the interface determined in the depth range from plateau to 84-16% in the depth-composition profile of the membrane material. The thin film thickness is compensated by adding the half value ΔI / 2 of the interface width ΔI to the thin film thickness T _SIMS calculated by _SIMS .

Example

[Preparation of Thin Films]

Three Ge films with thicknesses of 50 nm, 100 nm and 200 nm were grown on 6 inch Si (100) wafers by ion beam sputter deposition. The Ge target is sputtered by 1 keV Ar ⁺ ion beam and deposited on the Si (100) substrate at room temperature. The substrate was rotated about 30 times per minute to improve the homogeneity of the film thickness.

Meanwhile, an Si _0.5 Ge _0.5 alloy film was grown on a 6 inch Si (100) substrate by co-deposition of Si and Ge targets. This film was produced as a reference for determining the position of the Ge / Si interface. The atomic fraction of the Si _0.5 Ge _0.5 alloy film was measured by RBS (EAG, USA).

In addition, a Fe _x Ni _1-x alloy film was grown on a Si (100) substrate by co-deposition of Fe and Ni targets. The composition of the Fe—Ni alloy film was controlled by changing the relative sputtering regions of two adjacent target materials using a movable target holder. After confirming the correct position for the desired alloy composition, the alloy film was grown on a 150 mm Si wafer under the same conditions. Five Fe _x Ni _1-x alloy films having different compositions were prepared, and their atomic fractions were analyzed by coupled plasma atomic emission spectroscopy.

In addition, a Si / Ge multilayer film having Si and Ge layers which were repeated five times by ion beam sputter deposition was grown. Si and Ge wafer targets were sputtered alternately and deposited on a Si (100) substrate at room temperature. Relative film thickness was controlled by the growth rate of Si and Ge calibrated by high resolution transmission electron microscopy (HR-TEM) measurements.

In addition, a Ta ₂ O ₅ / Ta multilayer film having Ta ₂ O ₅ and Ta layers repeated five times was grown by ion beam sputter deposition of a Ta target. Ta and Ta ₂ O ₅ layers were optionally deposited on a 6 inch Si (100) wafer by sputtering the Ta target, respectively, with or without oxygen gas flow with a 1 keV Ar ion beam.

[SIMS Depth-Composition Profiling Analysis]

SIMS depth-composition analysis of the thin films was performed by magnetic sector SIMS (IMS-7f, Cameca, France). MCs ₂ ⁺ receive less because the data distortion due to matrix effects, and using cesium ion as a primary ion source. In order to determine the thickness of the thin film, two or more craters with different depths passing through the thin film and the substrate interface are required.

[Measurement of film thickness by HR-TEM]

The thickness of the thin film was measured by HR-TEM. The crystal lattice plane of the Si (100) substrate was used as an internal reference for the scale calibration of the TEM to measure the absolute value of the film thickness. The lattice distance between the Si (110) planes in the cross-sectional TEM image is 0.543 nm. In the TEM measurement, the combined standard uncertainty u _c is calculated from the equation u _c ² = u _m ² + u _r ² . Where u _m is the standard uncertainty of the thickness measurement in the TEM image and u _r is the standard uncertainty of the periodic Si (110) lattice plane.

[Measurement of Crater Depth]

The depth of the series of craters formed sputtered following depth-composition profiling by SIMS was measured by a stylus profile meter (Alpha Step IQ, KLA-Tencor, USA).

The vertical scale of the stylus profile meter was calibrated over a wide range of step-height using a series of step-height certified reference materials (CRM). 4 shows an example of a calibration curve for step height measurement using four step-height CRMs. This is derived by linearly fitting the measured step height H _meas to the authentication value H _{CRM of CRM} . In the linear fitting equation of this example (H _meas = mH _CRM + c), the slope (m) of 1.006 and the offset of 1.15 nm (H _meas value when H _CRM is 0) ensure that the measured height is within the given uncertainty. It is linearly proportional to the value.

The uncertainty of the step height measurement was determined by the equation U _c ² = U _r ² + U _m ² . U _r is then the standard uncertainty in the calibration of the vertical scale of the stylus profile meter and is calculated from the average reference uncertainty of the step height repeatedly measured for CRM, combined with the standard uncertainty of CRM. In this example, the largest standard uncertainty in the four CRMs is used as the standard uncertainty of the CRM. U _m is the measurement uncertainty of the crater depth, which is the standard deviation (S _m ) divided by the square root of the number of measurements.

[Measurement of film thickness]

FIG. 5 shows an example of measuring thickness by SIMS depth-composition profiling for a Fe _0.5 Ni _0.5 alloy film on a Si (100) substrate. Six SIMS profiles were obtained using a 10 keV Cs ⁺ ion beam as the base ion source. This is due to the 5 keV impact energy of the ion beam and the sample voltage of 5 keV. ⁵⁸ to avoid the effect of the medium in order to minimize interference by mass (mass interference) Ni ₂ ^{+ 133} Cs, and ¹³³ Cs ²⁸ Si ⁺ ₂ tracked as secondary ions. SIMS depth-composition analysis shows that the media effect is not severe at the interface region.

The secondary ionic strength ratio profile to depth shows that the six craters that pass through the interlayer (between thin and substrate) interfaces are well formed. The total depth of the six craters was measured by a stylus profile meter and the depth of the dug into the second layer substrate was determined by subtracting the thin film thickness measured in SIMS from the total crater depth. The actual thickness of the thin film is determined from the offset value of the crater depth determined by extrapolation in a linear plot of the substrate depth (horizontal coordinate) and the total crater depth (vertical coordinate) as shown in FIG. 1, that is, the crater depth when the substrate depth is zero. do.

In this case, the slope (m) value means the ratio of the sputtering speed in the thin film and the sputtering speed in the substrate. A slope greater than 1 means that the sputtering rate in the thin film material is faster than the sputtering rate in the substrate, and an m value of 1.057 means that the sputtering rate in the Fe _0.5 Ni _0.5 alloy film is 1.057 times faster than in the Si substrate. .

[Measurement of thickness of various thin films]

In order to confirm the validity of the thickness measuring method according to an aspect of the present invention, the thin film thicknesses of various thin films measured by MCs ₂ ⁺ SIMS were compared with the thin film thickness measured by HR-TEM. Si (100) substrates were selected to infer silicon lattice spacing by TEM. Ge and Ni are examples of semiconductor and metal materials for comparing SIMS and TEM film thicknesses. SIMS depth-composition profiles of Ge films (50, 100 nm) and Ni films (200 nm) grown on Si (100) substrates were obtained by MCs ₂ ⁺ SIMS under the same experimental conditions, and ⁷⁴ Ge ¹³³ Cs ₂ ⁺ , ⁵⁸ Ni ¹³³ Cs ₂ ^+, Cs ₂ ⁺ and ²⁸ Si ¹³³ were monitored, as shown in FIG.

The film thicknesses of the various multilayers obtained by MCs ₂ ⁺ SIMS are compared with those measured by HR-TEM. 7 shows sputtering times for 5 × (Ta / Ta ₂ O ₅ ) / Si (100), 5 × (Si / Ge) / Si (100), and 5 × (Cr / Ni) / Si (100). Shows the secondary ion strength profile according to and the ratio profile of secondary ion strength according to crater depth (5 × means the layer is repeated five times)

Since _{5 × (Ta / Ta 2 O} 5) / Si (100) In the case of multilayer film, ¹⁸¹ Ta ¹³³ Cs ₂ ⁺ is too small, strength, ¹⁸¹ Ta ¹³³ Cs ₂ ⁺ Ta ¹³³ instead of ¹⁸¹ Cs ⁺ intensity was monitored. However, ²⁸ Si ^133, because the intensity of Cs ⁺ is to indicate a bad virtual image surface ^{(interface artifact), 28 Si 133} Cs 2 + Si intensity is ^{28 133} Cs ⁺ was monitored instead. For 5 × (Si / Ge) / Si (100) and 5 × (Cr / Ni) / Si (100) films, the film thickness is ⁷⁴ Ge ¹³³ Cs ⁺ , ⁵⁴ Cr ¹³³ Cs ₂ ⁺ , ⁵⁸ Ni ¹³³ Cs ₂ ⁺ use, and ¹³³ Cs ²⁸ Si ₂ ⁺ was measured by the method MCs ₂ ^+.

Table 1 shows the film thicknesses measured for six membranes by SIMS (T _SIMS ) and HR-TEM (T _TEM ). The thickness measured by SIMS is thinner than the thickness measured by HR-TEM in the 2.0 to 16.5 nm range. In the Ni (200 nm), 5x (Cr / Ni) multilayer film containing a Ni layer especially, the difference between the thickness measured by both means is large. This is related to the broadening of the interface in the SIMS depth-composition profiling analysis due to the development of surface topography by ion beam sputtering. In general, the development of surface shape is serious in polycrystalline metal films. Surface shapes were investigated by cross-sectional TEM studies. 8 shows cross-sectional TEM images of Ni (200 nm), 5 × (Cr / Ni) multilayer film, and 5 × (Ta ₂ O ₅ / Ta) / Si (100) multilayer film after sputtering to the last interface. Serious surface shapes of about 40 nm were developed in Ni and 5x (Cr / Ni) multilayers containing Ni layers, but such surface profile development was negligible in 5x (Ta ₂ O ₅ / Ta) / Si (100) multilayers. It was small enough to be.

membrane Thickness (nm) T _TEM T _SIMS T _TEM -T _SIMS ΔI / 2 T _SIMS + ΔI / 2 Ge (50 nm) / Si 50.7 47.8 2.9 5.9 53.7 Ge (100 nm) / Si 101.4 99.4 2.0 5.9 105.3 Ni (200 nm) / Si 210.7 197.8 12.9 8.2 206.1 Cr / Ni ML 257.9 244.9 13.0 8.0 252.9 Ta / Ta ₂ O ₅ ML 252 249.6 2.4 1.6 251.2 Si / Ge ML 397.1 392.2 4.9 5.4 397.6 m - 0.988 - - 0.985 c - -3.829 - - 2.479

These results indicate that the respective thickness differences obtained by SIMS and TEM are related to surface shape development during SIMS depth-composition profiling analysis.

Figure 9 shows the linear fitting results of the film thickness measured by SIMS and TEM. The ideal values for the slope m and the offset (intercept) are 1 and 0, respectively, but the slope m = 0.987 means that there is a 1.3% difference in the length unit between the stylus and the TEM.

Looking at Table 1, large thickness differences in the thin films (50 nm Ge, 100 nm Ge and 200 nm Ni) are observed, but this can be compensated by reflecting the shape of the crater bottom as described above. Comparing (a) and (b) before such compensation, it can be seen that the slope has substantially changed but the offset value has decreased.

Claims (8)

Preparing a specimen including a first layer, which is a thin film, and a substrate in contact with a bottom surface of the first layer;
Composition depth distribution according to the depth is formed to form two or more craters from the top surface of the first layer to the substrate, for each crater, the depth (D _total ) from the top surface of the first layer to the bottom of the crater composition depth Measuring by methods other than distribution analysis;
For each formed crater, determining a depth D _subst from the bottom of the first layer to the bottom of the crater in the composition depth distribution;
Determining a _total D of the case from the crater of each of D and D _{total subst, subst} D is zero in which the thickness of the first layer; And
And determining the thickness of the first layer by adding a correction value to D _total when D _subst becomes zero.
delete The method of claim 1, wherein the correction value is compensated for an error due to crater topography.
The method of claim 1, wherein the composition depth distribution according to the depth is obtained through secondary ion mass spectrometry (SIMS).
Preparing a specimen including a first layer, which is a thin film, and a substrate in contact with a bottom surface of the first layer;
Composition depth distribution according to the depth is formed to form two or more craters from the top of the first layer to the substrate, for each crater, the depth (D _total ) from the top of the first layer to the bottom of the crater is formed depth Measuring by methods other than distribution analysis;
For each formed crater, determining a depth D _subst from the bottom of the first layer to the bottom of the crater in the composition depth distribution; And
From the crater of each of D and D _{total subst,} determining a _total D of the case is D _subst becomes zero as the thickness of the first layer, and including,
The composition depth distribution according to the depth is obtained through secondary ion mass spectrometry (SIMS) using cesium (Cs) cluster ions, thin film thickness measuring method.
The method of claim 1, wherein the depth measurement method other than the composition depth distribution analysis is by a stylus profile meter and / or an optical interferometer.
Preparing a specimen including a first layer, which is a thin film, and a substrate in contact with a bottom surface of the first layer;
Composition depth distribution according to the depth is formed to form two or more craters from the top surface of the first layer to the substrate, for each crater, the depth (D _total ) from the top surface of the first layer to the bottom of the crater composition depth Measuring by methods other than distribution analysis;
For each formed crater, determining a depth D _subst from the bottom of the first layer to the bottom of the crater in the composition depth distribution; And
From the crater of each of D and D _{total subst,} determining a _total D of the case is D _subst becomes zero as the thickness of the first layer, and including,
D _total when the D _subst becomes 0 is determined by linear regression, thin film thickness measuring method.
The method of claim 1, wherein the first layer and the substrate each include any one or two or more of a single element material, an alloy, and a compound including a metal.

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