CN118089564A - Film thickness testing method based on white light interferometer - Google Patents
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Abstract
The invention discloses a film thickness testing method based on a white light interferometer, which comprises the following steps: step 1, preparing a plurality of standard sample films; step 2, placing one standard sample film in the step 1 on an objective table of a white light interferometer, and placing medium microspheres on the surface of the standard sample film; step 3, obtaining an interference fringe pattern on the upper surface of the standard sample film; step 4, obtaining an interference fringe pattern of the lower surface of the standard sample film; step 5, calculating interference fringe contrast delta; step 6, calculating the change delta of the contrast of the lower surface of the standard sample film relative to the upper surface; step 7, constructing a relation curve of the variation of the contrast of the interference fringes of the sample film and the film thickness d of the corresponding sample film; and 8, obtaining the film thickness d of the sample to be detected according to the relation curve of the step 7. The method has the advantages that the film with the thickness smaller than one wavelength can be tested; the operation is simple and convenient; the sample is not damaged; the cost is very low.
Description
Technical Field
The invention relates to the field of semiconductor processing detection, in particular to a film thickness testing method based on a white light interferometer.
Background
When the white light interferometer is used for testing the thickness of the film, the coherent peak detection algorithm is adopted to respectively position the zero optical path difference positions of the upper surface and the lower surface, the distance between the two positions represents the optical thickness of the film, and the ratio of the optical thickness to the refractive index of the film is the actual thickness. When the film thickness is thin, there is an overlapping portion of the interference peaks between the upper and lower surfaces, which is difficult to distinguish, and the film thickness is difficult to test.
Disclosure of Invention
The invention aims to solve the technical problems that the thickness of a film is thinner, the interference peaks between the upper surface and the lower surface have overlapped parts, the resolution is difficult, and the thickness of the film is difficult to test. The invention provides a film thickness testing method based on a white light interferometer, which is used for testing films with thickness smaller than one wavelength.
The method of the invention is based on the following principle: the medium microsphere is a transparent microsphere made of barium carbonate or silicon dioxide and other materials. Evanescent waves carrying high-frequency information on the surface of the object can be collected and transmitted back to the optical system. The evanescent wave is a near-field diffraction wave, and has a distance relation with an object as follows: er 1/r 2, in the far field, decays very fast to 0. (r is the propagation distance of the evanescent wave). Therefore, when the distance between the medium microsphere and the surface of the object is changed, the evanescent wave collected by the medium microsphere is reduced, and the contrast of stripes is changed.
The technical scheme is as follows:
A film thickness testing method based on a white light interferometer comprises the following steps:
Step 1, preparing a plurality of standard sample films, wherein the film thickness d of each standard sample film is known;
step 2, placing one standard sample film in the step 1 on an objective table of a white light interferometer, and placing medium microspheres on the surface of the standard sample film;
step 3, driving an interference objective lens to move by piezoelectric ceramics of a white light interferometer to obtain an interference fringe pattern on the upper surface of the standard sample film;
step 4, driving an interference objective lens to move by piezoelectric ceramics of a white light interferometer to obtain an interference fringe pattern on the lower surface of the standard sample film;
Step 5, calculating the interference fringe contrast delta in the two interference fringe patterns in the step 3 and the step 4, wherein the interference fringe contrast of the interference fringe pattern on the upper surface is delta 1, and the interference fringe contrast of the interference fringe pattern on the lower surface is delta 2;
step 6, calculating the change delta of the contrast of the lower surface of the standard sample film relative to the upper surface;
Step 7, repeating the steps 2-6, and constructing a relation curve of the variation of the contrast of the interference fringes of the sample film and the film thickness d of the corresponding sample film;
Step 8, placing the sample to be detected on an objective table of a white light interferometer, and placing medium microspheres on the surface of the sample to be detected; repeating the steps 3-6 to obtain the variation of the contrast of the lower surface of the sample to be tested relative to the upper surface; and (3) obtaining the film thickness d of the sample to be detected according to the relation curve of the step (7).
The method of the invention can test the film with the thickness smaller than one wavelength; the operation is simple and convenient; the sample is not damaged; the cost is very low.
The technical scheme of the invention is further improved, and the calculation method in the step 5 is as follows: the maximum gray level in the interference fringe is denoted as Imax, the minimum gray level is denoted as Imin, and the contrast δ=imax/Imin. The contrast delta can represent the change of the contrast of the lower surface relative to the upper surface, the contrast delta=imax/Imin, the calculation mode is simple, and the data is easy to process.
Further improvement of the technical scheme of the invention is that the contrast of the lower surface of the standard sample film in the step 6 relative to the upper surface changes delta=δ2/δ1. The change delta can represent the change of the contrast of the lower surface relative to the upper surface, the change delta=δ2/δ1, and the slope of the fitted relation curve between the contrast change delta and the film thickness d is larger, so that the method is suitable for the scene with larger film thickness change range of the sample to be measured.
Further improvement of the technical scheme of the invention is that the contrast of the lower surface of the standard sample film in the step 6 relative to the upper surface changes delta=δ2- δ1. The change delta can represent the change of the contrast of the lower surface relative to the upper surface, the change delta=δ2- δ1, the slope of a fitted relation curve between the contrast change delta and the film thickness d is smaller, and the mode is more suitable when the film thickness change range of the sample to be detected is smaller.
The method for constructing the relation curve in the step 7 is further improved by the technical scheme of the invention, and comprises the following steps: the method comprises the steps of taking the film thickness d of a standard sample film as a y coordinate, taking the variation delta of the interference fringe contrast of the standard sample film as an x coordinate, obtaining a plurality of groups of values (delta 1, d1; delta 2, d2; delta 3, d3 …), drawing the values in an xy coordinate axis, and fitting a curve according to the numerical values, wherein the curve is a relation curve of the variation delta of the interference fringe contrast of the standard sample film and the film thickness d.
According to the technical scheme, the film thickness of each standard sample film is different.
The invention also provides a film thickness testing method based on the white light interferometer, which comprises the following steps:
s1, preparing a plurality of standard sample films, wherein the film thickness d of each standard sample film is known;
s2, placing one standard sample film in the S1 on an objective table of a white light interferometer, and placing medium microspheres on the surface of the standard sample film;
S3, driving an interference objective lens to move by piezoelectric ceramics of the white light interferometer to obtain an interference fringe pattern on the upper surface of the standard sample film;
S4, driving an interference objective lens to move by piezoelectric ceramics of the white light interferometer to obtain an interference fringe pattern on the lower surface of the standard sample film;
S5, calculating the MTF of the interference fringe modulation transfer function in the two interference fringe patterns in S3 and S4; the transfer function of the interference fringe modulation of the interference fringe pattern on the upper surface is recorded as MTF1, and the transfer function of the interference fringe modulation of the interference fringe pattern on the lower surface is recorded as MTF2;
S6, calculating the variation delta=MTF2/MTF1 of the modulation transfer function of the lower surface of the standard sample film relative to the upper surface;
S7, repeating the steps S2-S6, and constructing a relation curve of the variation delta of the sample film interference fringe modulation transfer function and the film thickness d;
S8, placing a sample to be detected on an objective table of a white light interferometer, and placing medium microspheres on the surface of the sample to be detected; repeating the steps S3-S6 to obtain the variation of the modulation transfer function of the lower surface relative to the upper surface of the sample to be detected; and (3) obtaining the film thickness d of the sample to be detected according to the relation curve of S7.
The method has the advantages that: 1. a film that can be tested for thickness less than one wavelength; 2. the operation is simple and convenient; 3. the sample is not damaged; 4. the cost is very low.
Further preferably, the film thickness of each standard film is different.
Further preferably, the calculation method in S5 is as follows: the maximum gray level in the interference fringe is denoted as Imax, the minimum gray level is denoted as Imin, and the modulation transfer function mtf= (Imax-Imin)/(imax+imin). The data is normalized, and the stripe MTF values are all between (0 and 1), so that the variation of stripes on the upper surface and the lower surface of different film thicknesses can be reflected more clearly.
Further preferably, the construction method of the relation curve of S7 comprises the following steps: and taking the film thickness d of the standard sample film as a y coordinate, taking the variation delta of the interference fringe modulation transfer function of the standard sample film as an x coordinate, obtaining a plurality of groups of values (delta 1, d1; delta 2, d2; delta 3, d3 …), drawing the values in an xy coordinate axis, and fitting a curve according to the values, wherein the curve is a relation curve of the variation delta of the interference fringe modulation transfer function of the standard sample film and the film thickness d.
Compared with the prior art, the invention has the following beneficial effects:
The method of the invention is simple and easy to operate, and has low implementation cost.
The method of the invention tests the film thickness smaller than one wavelength under the condition of not damaging the sample, and expands the testing and analyzing means of the film thickness.
The method provided by the invention has high instantaneity, the strip variation and the film thickness are tested after the relation curve of the strip variation and the film thickness is obtained, and the film thickness can be directly obtained after the strip variation is measured, so that the method has high instantaneity and high speed, and is beneficial to a high-speed test system.
The method of the invention can test the film with the thickness smaller than one wavelength; the operation is simple and convenient; the sample is not damaged; the cost is very low.
Drawings
Fig. 1 is a schematic diagram of a test method (white light interferometer, medium microsphere, and sample to be tested) according to the present embodiment;
FIG. 2 is an interference fringe pattern of the upper surface of a sample film obtained by the method of example 1;
FIG. 3 is an interference fringe pattern of the lower surface of the sample film obtained by the method of example 1;
fig. 4 is a graph showing the relationship between the film thickness d and the contrast variation δ obtained by the method for the interference fringe contrast variation Δ=δ2/δ1 in the specific application example of example 1;
Fig. 5 is a graph showing the relationship between the film thickness d and the contrast variation δ obtained by the method for the interference fringe contrast variation Δ=δ2- δ1 in the specific application example of example 1;
Fig. 6 is a graph showing the relationship between the film thickness d and the contrast variation δ obtained by the interference fringe contrast variation Δ=mtf2/mtf1 method in the specific application example of example 2.
Wherein: white light interferometer 1, medium microsphere 2, sample 3 to be measured.
Detailed Description
The technical scheme of the present invention is described in detail below, but the scope of the present invention is not limited to the embodiments.
In order to make the contents of the present invention more comprehensible, the present invention is further described with reference to fig. 1 to 6 and the detailed description below.
The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.
Example 1
The embodiment is a film thickness testing method based on a white light interferometer, comprising the following steps:
Step 1, preparing a plurality of standard sample films, wherein the film thickness d of each standard sample film is known; the film thickness of each of the standard films was different.
Step 2, placing one standard sample film in the step 1 on an objective table of the white light interferometer 1, and placing medium microspheres 2 on the surface of the standard sample film;
Step 3, driving an interference objective lens to move by piezoelectric ceramics of a white light interferometer to obtain an interference fringe pattern on the upper surface of the standard sample film; as shown in fig. 2.
Step 4, driving an interference objective lens to move by piezoelectric ceramics of a white light interferometer to obtain an interference fringe pattern on the lower surface of the standard sample film; as shown in fig. 3.
Step 5, calculating the interference fringe contrast delta in the two interference fringe patterns in the step 3 and the step 4, wherein the interference fringe contrast of the interference fringe pattern on the upper surface is delta 1, and the interference fringe contrast of the interference fringe pattern on the lower surface is delta 2;
step 6, calculating the change delta of the contrast of the lower surface of the standard sample film relative to the upper surface;
Step 7, repeating the steps 2-6, and constructing a relation curve of the variation of the contrast of the interference fringes of the sample film and the film thickness d of the corresponding sample film;
Step 8, placing the sample 3 to be measured on an objective table of a white light interferometer, and placing medium microspheres on the surface of the sample to be measured; repeating the steps 3-6 to obtain the variation of the contrast of the lower surface of the sample to be tested relative to the upper surface; and (3) obtaining the film thickness d of the sample to be detected according to the relation curve of the step (7).
In the method of this embodiment, the white light interferometer 1 is a known product, known to those skilled in the art. In the method of this embodiment, in step 3 and step 4, the piezoelectric ceramic of the white light interferometer drives the interference objective lens to move, so as to obtain two interference fringe patterns of the upper surface and two interference fringe patterns of the lower surface with different brightness, which are known techniques by those skilled in the art, and this embodiment is not described in detail.
In the method of the embodiment, the calculation method of step 5 is as follows: the maximum gray level in the interference fringe is denoted as Imax, the minimum gray level is denoted as Imin, and the contrast δ=imax/Imin.
The method for calculating the interference fringe contrast delta 1 of the interference fringe pattern of the upper surface of one sample film comprises the following steps: the maximum gray level of the interference fringes of the interference fringe pattern on the upper surface is denoted as Imax1, the minimum gray level is denoted as Imin1, and the contrast δ1=imax1/Imin 1. The method for calculating the interference fringe contrast delta 2 of the interference fringe pattern of the lower surface comprises the following steps: the maximum gray level of the interference fringes of the interference fringe pattern on the upper surface is denoted as Imax2, the minimum gray level is denoted as Imin2, and the contrast δ2=imax2/Imin 2.
In the method of this embodiment, the contrast of the lower surface of the sample film with respect to the upper surface may be changed by not only a ratio but also a difference. Therefore, in the method of this embodiment, there are two calculation methods for the change amount Δ of the contrast of the lower surface of the standard film with respect to the upper surface in step 6, namely, the change amount Δ=δ2/δ1 of the contrast of the lower surface of the standard film with respect to the upper surface and the change amount Δ=δ2- δ1 of the contrast of the lower surface of the standard film with respect to the upper surface.
In the method of the embodiment, the construction method of the relation curve in the step 7 is as follows: the method comprises the steps of taking the film thickness d of a standard sample film as a y coordinate, taking the variation delta of the interference fringe contrast of the standard sample film as an x coordinate, obtaining a plurality of groups of values (delta 1, d1; delta 2, d2; delta 3, d3 …), drawing the values in an xy coordinate axis, and fitting a curve according to the numerical values, wherein the curve is a relation curve of the variation delta of the interference fringe contrast of the standard sample film and the film thickness d.
In the method of this embodiment, a plurality of sets of values (Δ1, d1; Δ2, d2; Δ3, d3 …) are obtained, wherein Δ1, d1 is calculated from steps 2-6 for the first sample film, Δ2, d2 is calculated from steps 2-6 for the second sample film, and so on to obtain a plurality of sets of values (Δ1, d1; Δ2, d2; Δ3, d3 …).
Specific application example 1
A group of sample films with the thickness of (1; 2;3; 4), and calibrating the method to obtain the maximum value and the minimum value of the interference fringe gray scale of the upper surface of (80, 10) respectively; (80, 10); (80, 10); (80, 10); the maximum value and the minimum value of the interference fringe gray scale of the lower surface are respectively (70, 15); (65, 20); (50, 25); (40, 30).
The interference fringe contrast delta=imax/Imin, the interference fringe gray scale contrast of the upper surface is δ1_1=δ1_2=δ1_3=δ1_4=8 for films of different thicknesses; the interference fringe gray contrast of the lower surface is δ2—1=4.67; δ2_2=3.25; δ2_3=2; δ2_4=1.33.
The method for interference fringe contrast variation delta=δ2/δ1: Δ1=0.584; Δ2=0.41; Δ3=0.25; Δ4=0.17 gives the interference fringe contrast variation Δas a function of film thickness d (0.584, 1;0.41,2;0.25,3;0.17, 4). As shown in fig. 4.
The method for the interference fringe contrast variation delta=δ2- δ1 is Δ1= -3.33; Δ2= -4.75; Δ3= -6; Δ4= -6.67; the relationship between the contrast variation of interference fringes (delta) and the film thickness (d) was obtained (-3.33,1; 4.75,2; 6,3; 6.67,4). As shown in fig. 5.
Example 2
The embodiment is a film thickness testing method based on a white light interferometer, comprising the following steps:
S1, preparing a plurality of standard sample films, wherein the film thickness d of each standard sample film is known; the film thickness of each of the standard films was different.
S2, placing one standard sample film in the S1 on an objective table of a white light interferometer, and placing medium microspheres on the surface of the standard sample film;
S3, driving an interference objective lens to move by piezoelectric ceramics of the white light interferometer to obtain an interference fringe pattern on the upper surface of the standard sample film;
S4, driving an interference objective lens to move by piezoelectric ceramics of the white light interferometer to obtain an interference fringe pattern on the lower surface of the standard sample film;
S5, calculating the MTF of the interference fringe modulation transfer function in the two interference fringe patterns in S3 and S4; the transfer function of the interference fringe modulation of the interference fringe pattern on the upper surface is recorded as MTF1, and the transfer function of the interference fringe modulation of the interference fringe pattern on the lower surface is recorded as MTF2;
S6, calculating the variation delta=MTF2/MTF1 of the modulation transfer function of the lower surface of the standard sample film relative to the upper surface;
S7, repeating the steps S2-S6, and constructing a relation curve of the variation delta of the sample film interference fringe modulation transfer function and the film thickness d;
S8, placing a sample to be detected on an objective table of a white light interferometer, and placing medium microspheres on the surface of the sample to be detected; repeating the steps S3-S6 to obtain the variation of the modulation transfer function of the lower surface relative to the upper surface of the sample to be detected; and (3) obtaining the film thickness d of the sample to be detected according to the relation curve of S7.
In the method of the embodiment, the calculation method of S5 is as follows: the maximum gray level in the interference fringe is denoted as Imax, the minimum gray level is denoted as Imin, and the modulation transfer function mtf= (Imax-Imin)/(imax+imin).
The method for calculating the interference fringe modulation transfer function MTF1 of the interference fringe pattern of the upper surface of one sample film is as follows: the maximum gray level of the interference fringes of the interference fringe pattern on the upper surface is denoted as Imax1, the minimum gray level is denoted as Imin1, and the modulation transfer function mtf1= (Imax 1-Imin 1)/(imax1+imin 1). The maximum gray level in the interference fringes of the interference fringe pattern on the lower surface is calculated and is denoted as Imax2, the minimum gray level is denoted as Imin2, and the modulation transfer function mtf2= (Imax 2-Imin 2)/(imax2+imin 2).
In the method of the embodiment, the construction method of the relation curve of S7 is as follows: and taking the film thickness d of the standard sample film as a y coordinate, taking the variation delta of the interference fringe modulation transfer function of the standard sample film as an x coordinate, obtaining a plurality of groups of values (delta 1, d1; delta 2, d2; delta 3, d3 …), drawing the values in an xy coordinate axis, and fitting a curve according to the values, wherein the curve is a relation curve of the variation delta of the interference fringe modulation transfer function of the standard sample film and the film thickness d.
In the method of this embodiment, a plurality of sets of values (Δ1, d1; Δ2, d2; Δ3, d3 …) are obtained, wherein Δ1, d1 is calculated from steps 2-6 for the first sample film, Δ2, d2 is calculated from steps 2-6 for the second sample film, and so on to obtain a plurality of sets of values (Δ1, d1; Δ2, d2; Δ3, d3 …).
Specific application example 2
A group of sample films with the thickness of (1; 2;3; 4), and calibrating the method to obtain the maximum value and the minimum value of the interference fringe gray scale of the upper surface of (80, 10) respectively; (80, 10); (80, 10); (80, 10); the maximum value and the minimum value of the interference fringe gray scale of the lower surface are respectively (70, 15); (65, 20); (50, 25); (40, 30); the modulation transfer function MTF of the upper and lower surfaces is: mtf= (Imax-Imin)/(imax+imin), resulting in a modulation transfer function mtf1_1=mtf1_2=mtf1_3=mtf1_4=0.78 for films of different thickness; the lower surface modulation transfer function MTF is mtf2—1=0.65; mtf2—2=0.53; mtf2—3=0.33; mtf2—4=0.14.
The interference fringe contrast variation Δ=mtf2/mtf1 is Δ1=0.83; Δ2=0.68; Δ3=0.42; Δ4=0.18; the interference fringe contrast variation delta was obtained as a function of film thickness d (0.83, 1;0.68,2;0.42,3;0.18, 4). As shown in fig. 6.
The above embodiments are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited thereto, and any modification made on the basis of the technical scheme according to the technical idea of the present invention falls within the protection scope of the present invention.
Claims (10)
1. A film thickness testing method based on a white light interferometer is characterized by comprising the following steps:
Step 1, preparing a plurality of standard sample films, wherein the film thickness d of each standard sample film is known;
step 2, placing one standard sample film in the step 1 on an objective table of a white light interferometer, and placing medium microspheres on the surface of the standard sample film;
step 3, driving an interference objective lens to move by piezoelectric ceramics of a white light interferometer to obtain an interference fringe pattern on the upper surface of the standard sample film;
step 4, driving an interference objective lens to move by piezoelectric ceramics of a white light interferometer to obtain an interference fringe pattern on the lower surface of the standard sample film;
Step 5, calculating the interference fringe contrast delta in the two interference fringe patterns in the step 3 and the step 4, wherein the interference fringe contrast of the interference fringe pattern on the upper surface is delta 1, and the interference fringe contrast of the interference fringe pattern on the lower surface is delta 2;
step 6, calculating the change delta of the contrast of the lower surface of the standard sample film relative to the upper surface;
Step 7, repeating the steps 2-6, and constructing a relation curve of the variation of the contrast of the interference fringes of the sample film and the film thickness d of the corresponding sample film;
Step 8, placing the sample to be detected on an objective table of a white light interferometer, and placing medium microspheres on the surface of the sample to be detected; repeating the steps 3-6 to obtain the variation of the contrast of the lower surface of the sample to be tested relative to the upper surface; and (3) obtaining the film thickness d of the sample to be detected according to the relation curve of the step (7).
2. The method according to claim 1, characterized in that: the calculation method in the step 5 is as follows: the maximum gray level in the interference fringe is denoted as Imax, the minimum gray level is denoted as Imin, and the contrast δ=imax/Imin.
3. The method according to claim 2, characterized in that: the contrast change of the lower surface of the standard film of step 6 relative to the upper surface is delta=δ2/δ1.
4. The method according to claim 2, characterized in that: the contrast change of the lower surface of the standard film of step 6 relative to the upper surface is delta=δ2- δ1.
5. A method according to claim 3 or 4, characterized in that: the construction method of the relation curve in the step 7 comprises the following steps: the method comprises the steps of taking the film thickness d of a standard sample film as a y coordinate, taking the variation delta of the interference fringe contrast of the standard sample film as an x coordinate, obtaining a plurality of groups of values (delta 1, d1; delta 2, d2; delta 3, d3 …), drawing the values in an xy coordinate axis, and fitting a curve according to the numerical values, wherein the curve is a relation curve of the variation delta of the interference fringe contrast of the standard sample film and the film thickness d.
6. The method according to claim 1, characterized in that: the film thickness of each of the standard films was different.
7. A film thickness testing method based on a white light interferometer is characterized by comprising the following steps:
s1, preparing a plurality of standard sample films, wherein the film thickness d of each standard sample film is known;
s2, placing one standard sample film in the S1 on an objective table of a white light interferometer, and placing medium microspheres on the surface of the standard sample film;
S3, driving an interference objective lens to move by piezoelectric ceramics of the white light interferometer to obtain an interference fringe pattern on the upper surface of the standard sample film;
S4, driving an interference objective lens to move by piezoelectric ceramics of the white light interferometer to obtain an interference fringe pattern on the lower surface of the standard sample film;
S5, calculating the MTF of the interference fringe modulation transfer function in the two interference fringe patterns in S3 and S4; the transfer function of the interference fringe modulation of the interference fringe pattern on the upper surface is recorded as MTF1, and the transfer function of the interference fringe modulation of the interference fringe pattern on the lower surface is recorded as MTF2;
S6, calculating the variation delta=MTF2/MTF1 of the modulation transfer function of the lower surface of the standard sample film relative to the upper surface;
S7, repeating the steps S2-S6, and constructing a relation curve of the variation delta of the sample film interference fringe modulation transfer function and the film thickness d;
S8, placing a sample to be detected on an objective table of a white light interferometer, and placing medium microspheres on the surface of the sample to be detected; repeating the steps S3-S6 to obtain the variation of the modulation transfer function of the lower surface relative to the upper surface of the sample to be detected; and (3) obtaining the film thickness d of the sample to be detected according to the relation curve of S7.
8. The method according to claim 7, wherein: the film thickness of each of the standard films was different.
9. The method according to claim 7, wherein: the calculation method in S5 is as follows: the maximum gray level in the interference fringe is denoted as Imax, the minimum gray level is denoted as Imin, and the modulation transfer function mtf= (Imax-Imin)/(imax+imin).
10. The method according to claim 9, wherein: the construction method of the relation curve of S7 comprises the following steps: and taking the film thickness d of the standard sample film as a y coordinate, taking the variation delta of the interference fringe modulation transfer function of the standard sample film as an x coordinate, obtaining a plurality of groups of values (delta 1, d1; delta 2, d2; delta 3, d3 …), drawing the values in an xy coordinate axis, and fitting a curve according to the values, wherein the curve is a relation curve of the variation delta of the interference fringe modulation transfer function of the standard sample film and the film thickness d.
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Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20050088663A1 (en) * | 2003-10-27 | 2005-04-28 | De Groot Peter J. | Scanning interferometry for thin film thickness and surface measurements |
| US20050280829A1 (en) * | 2004-06-16 | 2005-12-22 | Unruh Paul R | Film thickness and boundary characterization by interferometric profilometry |
| US20080180685A1 (en) * | 2007-01-31 | 2008-07-31 | Zygo Corporation | Interferometry for lateral metrology |
| US20090296099A1 (en) * | 2005-09-22 | 2009-12-03 | Kurt Burger | Interferometric Layer Thickness Determination |
| CN106370133A (en) * | 2015-07-24 | 2017-02-01 | 中国科学院大连化学物理研究所 | Method of characterizing hydrogel microsphere surface morphology in wet in-situ condition |
| CN107121080A (en) * | 2017-06-16 | 2017-09-01 | 东南大学 | A kind of method for measuring ordered porous nano film thickness |
| CN107388984A (en) * | 2017-07-11 | 2017-11-24 | 中国科学院光电技术研究所 | Micro-nano structure super-resolution three-dimensional appearance testing method based on structure light Yu medium microsphere combined modulation |
| CN108779976A (en) * | 2015-12-11 | 2018-11-09 | 赫尔辛基大学 | The property on the surface and sub-surface structure of white light interference is carried out using photon jet stream |
| US20200103224A1 (en) * | 2017-04-11 | 2020-04-02 | Universite De Strasbourg | System and method for super-resolution full-field optical metrology on the far-field nanometre scale |
| CN117788547A (en) * | 2024-02-26 | 2024-03-29 | 南京埃米仪器科技有限公司 | White light interference image super-resolution three-dimensional reconstruction method based on medium microspheres |
-
2024
- 2024-04-18 CN CN202410467443.5A patent/CN118089564A/en active Pending
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20050088663A1 (en) * | 2003-10-27 | 2005-04-28 | De Groot Peter J. | Scanning interferometry for thin film thickness and surface measurements |
| US20050280829A1 (en) * | 2004-06-16 | 2005-12-22 | Unruh Paul R | Film thickness and boundary characterization by interferometric profilometry |
| US20090296099A1 (en) * | 2005-09-22 | 2009-12-03 | Kurt Burger | Interferometric Layer Thickness Determination |
| US20080180685A1 (en) * | 2007-01-31 | 2008-07-31 | Zygo Corporation | Interferometry for lateral metrology |
| CN106370133A (en) * | 2015-07-24 | 2017-02-01 | 中国科学院大连化学物理研究所 | Method of characterizing hydrogel microsphere surface morphology in wet in-situ condition |
| CN108779976A (en) * | 2015-12-11 | 2018-11-09 | 赫尔辛基大学 | The property on the surface and sub-surface structure of white light interference is carried out using photon jet stream |
| US20200103224A1 (en) * | 2017-04-11 | 2020-04-02 | Universite De Strasbourg | System and method for super-resolution full-field optical metrology on the far-field nanometre scale |
| CN107121080A (en) * | 2017-06-16 | 2017-09-01 | 东南大学 | A kind of method for measuring ordered porous nano film thickness |
| CN107388984A (en) * | 2017-07-11 | 2017-11-24 | 中国科学院光电技术研究所 | Micro-nano structure super-resolution three-dimensional appearance testing method based on structure light Yu medium microsphere combined modulation |
| CN117788547A (en) * | 2024-02-26 | 2024-03-29 | 南京埃米仪器科技有限公司 | White light interference image super-resolution three-dimensional reconstruction method based on medium microspheres |
Non-Patent Citations (1)
| Title |
|---|
| 薛晖 等: "基于白光干涉的光学薄膜物理厚度测量方法", 光学学报, vol. 29, no. 07, 15 July 2009 (2009-07-15), pages 1877 - 1880 * |
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