CN116263323A - Film thickness testing device and film thickness testing method - Google Patents

Abstract

The invention belongs to the technical field of film thickness testing, and particularly relates to a film thickness testing device and a film thickness testing method. The invention is used for solving the problem of lower efficiency of film thickness testing in the related technology. The film thickness testing device comprises a light guide device and processing equipment; the processing equipment is connected with the light guide device, the light guide device is provided with a plurality of collecting ends which are arranged towards different positions of the film to be detected, and the light guide device is used for guiding the reflected light received by each collecting end from the film to be detected to the processing equipment; the processing equipment is used for obtaining the thickness of the film to be detected corresponding to each collecting end according to the reflected light. And a plurality of reflected light rays reflected by the surface of the film to be tested are guided to processing equipment through the acquisition end, and the processing equipment acquires the film thicknesses of a plurality of points to be tested according to the plurality of reflected light rays, so that the testing efficiency is improved.

Description

Film thickness testing device and film thickness testing method

Technical Field

The invention relates to the technical field of film thickness testing, in particular to a film thickness testing device and a film thickness testing method.

Background

During thin film fabrication processes, the corresponding thin film materials are often formed by a deposition process. If the film thickness is uneven, the tensile strength and barrier properties of the film are affected everywhere, and the uneven film also affects subsequent processing. Therefore, in the thin film manufacturing process, it is often necessary to perform a film thickness test on the thin film.

The film thickness testing device in the related art is used for testing the film thickness of a single point, and in the testing process, the film to be tested needs to be scanned point by point, so that the film thickness information of each position is obtained, and the testing efficiency is low.

Disclosure of Invention

The embodiment of the invention provides a film thickness testing device and a film thickness testing method, which are used for solving the problem of lower film thickness testing efficiency in the related technology.

A first aspect of an embodiment of the present invention provides a film thickness testing apparatus, including: a light guide device and a processing apparatus; the processing equipment is connected with the light guide device, the light guide device is provided with a plurality of collecting ends which are arranged towards different positions of the film to be detected, and the light guide device is used for guiding the reflected light from the film to be detected received by each collecting end to the processing equipment; the processing equipment is used for obtaining the thickness of the film to be detected corresponding to each collecting end according to the reflected light.

In a possible implementation manner, the processing device includes an array spectrometer and an analysis device, the analysis device is connected with the array spectrometer, the array spectrometer is connected with the light guiding device, the array spectrometer is used for acquiring a plurality of corresponding interference images according to each reflected light ray, and the analysis device is used for calculating a corresponding film thickness according to the interference images.

In one possible implementation, the array spectrometer includes a spectroscopic device, a filter cavity assembly, and an imaging device, the filter cavity assembly being located between the spectroscopic device and the imaging device, the filter cavity assembly including a plurality of filter cavities for dispersing the reflected light into a plurality of dispersed light beams, each of the filter cavities for processing each of the dispersed light beams to form an output spectrum, the imaging device for acquiring the interference image from the output spectrum.

In one possible implementation, the filtering cavity includes a plurality of filtering units, the dispersed light beam having a plurality of dispersed lights therein, each of the filtering units for processing each of the dispersed lights to obtain the dispersed light of a corresponding wavelength.

In one possible implementation manner, the filtering cavity includes a first filtering cavity, the first filtering cavity is arranged in the filtering cavity assembly along a first preset direction, the first filtering cavity includes a plurality of filtering units arranged along a second preset direction, and each passband of the filtering units in the first filtering cavity is different, and the second preset direction is perpendicular to the first preset direction.

In one possible implementation, the light splitting device includes a cylindrical mirror.

In one possible implementation manner, the filtering cavity includes a second filtering cavity, the second filtering cavity is arranged in an array in the filtering cavity assembly, the second filtering cavity includes a plurality of filtering units arranged in an array, and pass bands of each filtering unit in the second filtering cavity are different.

In one possible implementation manner, the light splitting device includes a microlens array, where the microlens array includes a plurality of microlenses arranged in an array, and one side of each microlens corresponds to one of the reflected light rays, and the other side corresponds to one of the second filtering cavities.

In one possible implementation manner, the device further comprises a supporting frame, wherein the supporting frame comprises a supporting seat and a supporting rod which are connected with each other, the supporting rod is connected with the collecting ends, and the supporting seat is used for placing the film to be tested, so that each collecting end faces the film to be tested.

In one possible implementation manner, the supporting rod comprises a vertical rod connected with the supporting seat and a horizontal rod connected with the vertical rod, and a mounting hole for inserting the collecting end is formed in the horizontal rod.

In one possible implementation manner, the device further comprises a light source, and the light guide device is connected with the light source and is used for guiding incident light rays from the light source to each collecting end and guiding the incident light rays from the collecting ends to the film to be tested.

In one possible implementation, the light guide includes a Y-fiber having a first end connected to the light source, a second end, and a third end connected to the processing device, the second end including an acquisition end.

In one possible implementation, the light source comprises a halogen lamp and/or an LED array lamp.

The second aspect of the embodiment of the invention provides a film thickness testing method, which comprises the following steps: a plurality of collecting ends of the light guide device face to a plurality of to-be-measured points of the film to be measured respectively, and the light guide device is connected with processing equipment; and receiving reflected light rays from the film to be detected through processing equipment, and acquiring the film thickness of the corresponding point to be detected according to the reflected light rays.

In one possible implementation manner, obtaining the film thickness of the to-be-measured point according to the reflected light includes: acquiring a corresponding interference image according to the reflected light; and calculating the film thickness of the corresponding point to be detected according to the interference image.

In one possible implementation, acquiring a corresponding interference image according to the reflected light includes: dispersing the reflected light into a beam of light; arranging the scattered light beams according to a certain wavelength rule to form an output spectrum; and acquiring the corresponding interference image according to the output spectrum.

The embodiment of the invention provides a film thickness testing device and a film thickness testing method, wherein the film thickness testing device comprises a light guide device and processing equipment; the processing equipment is connected with the light guide device, the light guide device is provided with a plurality of collecting ends which are arranged towards different positions of the film to be detected, and the light guide device is used for guiding the reflected light received by each collecting end from the film to be detected to the processing equipment; the processing equipment is used for obtaining the thickness of the film to be detected corresponding to each collecting end according to the reflected light. And a plurality of reflected light rays reflected by the surface of the film to be tested are guided to processing equipment through the acquisition end, and the processing equipment acquires the film thicknesses of a plurality of points to be tested according to the plurality of reflected light rays, so that the testing efficiency is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a film thickness testing apparatus according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of an LED array lamp according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of an array spectrometer according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of the filter cavity assembly of FIG. 3;

FIG. 5 is a schematic diagram of a second embodiment of the present invention;

FIG. 6 is a schematic diagram of the second filtering cavity in FIG. 5;

fig. 7 is a flowchart illustrating steps of a film thickness testing method according to an embodiment of the present invention.

Reference numerals illustrate:

10. a light source;

11. an LED element;

20. a processing device;

21. an array spectrometer;

211. a cylindrical mirror;

212. a microlens array;

213. a filter cavity assembly;

2131. a first filtering cavity;

2132. a second filtering cavity;

21311. a filtering unit;

214. an imaging device;

22. an analysis device;

30. a support frame;

31. a horizontal bar;

32. a vertical rod;

33. a support base;

40. y-type optical fiber;

41. a first end;

42. a second end;

421. a collection end;

43. a third end;

50. a film to be measured;

51. and (5) waiting for measuring points.

Detailed Description

For a clear understanding of the technical solutions of the present application, first, related technical solutions will be described in detail.

During the thin film manufacturing process, it is often necessary to perform a film thickness test on the thin film. In the related art, the method of testing the film thickness includes an optical measurement method, which generally calculates the film thickness based on a spectroscopic method. Generally, it is required to emit incident light to the film to be measured, the incident light is reflected on the upper and lower surfaces of the film after being incident to the film to be measured, the reflected light is interfered, the reflected light is represented as a plurality of peaks and valleys in a spectrum, and the film thickness can be calculated according to the peak position distribution in the spectrum. However, the film thickness testing device in the related art performs a single-point film thickness test on the film, and in the testing process, the film to be tested needs to be scanned point by point, so that the film thickness information of each position is obtained, and the testing efficiency is low.

In view of this, an embodiment of the present invention provides a film thickness testing device, including: the device comprises a light guide device and processing equipment, wherein the light guide device is provided with a plurality of acquisition ends which are arranged towards different positions of the film to be measured, and the processing equipment is used for acquiring film thicknesses of a plurality of points to be measured according to a plurality of reflected light rays. Through the structure, a plurality of to-be-measured points of the film to be measured can be subjected to film thickness test simultaneously, so that the test efficiency is improved.

Referring to fig. 1, the film thickness testing apparatus includes a light guiding device and a processing device 20. The processing device 20 is connected to the film 50 to be tested by a light guiding device, the light guiding device has a plurality of collecting ends 421 disposed towards different positions of the film 50 to be tested, and the light guiding device is used for guiding the reflected light from the film 50 to be tested received by each collecting end 421 to the processing device 20. The processing device 20 is configured to obtain the thickness of the film 50 to be measured corresponding to each collecting end 421 according to the reflected light.

In some embodiments, the film 50 to be tested may include a self-luminescent film layer structure, such as a panel. The panel comprises a backlight and a film layer structure arranged on the backlight, incident light rays emitted by the backlight are reflected on the surface of the film layer structure to form reflected light rays, and the reflected light rays are guided to the processing equipment 20 by the light guide device, so that the thickness of the film 50 to be detected is obtained.

In the embodiment where the film 50 to be tested has a film layer structure without a light emitting function, the film thickness testing device further includes the light source 10. As shown in fig. 1, the light source 10 is connected to a light guide so that the light source 10 guides incident light to the collection terminal 421 through the light guide. The Light source 10 may include, for example, an LED array lamp (Light-Emitting Diode, simply referred to as LED), which may include a plurality of LED elements 11 distributed in an array. Alternatively, the light source 10 may also comprise, for example, a halogen lamp, in order to be applied to different spectral ranges. Of course, in some examples, the light source 10 may also be used in combination with a halogen lamp and an LED array lamp. Further, the light source 10 may also include one or more of a fluorescent lamp, a tunable wavelength laser, a xenon lamp, and a high intensity LED lamp.

With continued reference to fig. 1, the light guiding device may specifically include a Y-shaped optical fiber 40, where the Y-shaped optical fiber 40 may include a first end 41, a second end 42, and a third end 43, where the first end 41 is connected to the light source 10, as shown in fig. 2, and in an embodiment where the light source 10 is an LED array lamp, the Y-shaped optical fiber 40 includes a plurality of optical fibers, and the collecting end 421 may be, for example, an optical fiber port of the Y-shaped optical fiber 40. When the LED array lamp is connected to the first end 41 of the Y-shaped optical fiber 40, a plurality of optical fibers in the first end 41 may be made to correspond one-to-one to the LED elements 11 so that the first end 41 can receive the incident light emitted from each LED element 11. The second end 42 of the Y-shaped optical fiber 40 has a plurality of collection ends 421 disposed toward different positions of the film 50 to be measured, and the collection ends 421 may be, for example, fiber ports of the Y-shaped optical fiber 40. The collecting end 421 is opposite to the plurality of points 51 to be measured of the film 50, and the collecting end 421 is configured to collect a plurality of reflected light generated after the light source 10 is incident to the points 51 to be measured, so as to measure the film thickness through the reflected light. The third end 43 of the Y-shaped optical fiber 40 is connected to the array spectrometer 21 in the processing apparatus 20, and the light guiding device guides the incident light from the light source 10 to each collecting end 421 and to the film 50 to be tested by the collecting ends 421, and is further used for guiding the reflected light from the film 50 to be tested received by each collecting end 421 to the processing apparatus 20.

As shown in fig. 1, the first end 41 of the Y-fiber 40 is located at the right end in the illustrated position and the second end 42 is located at the lower end in the illustrated position; the third end 43 is located at the left end in the illustrated position. The light source 10 is transmitted from the first end 41 to the second end 42 of the Y-shaped optical fiber 40, and then the collection end 421 guides the incident light to the film 50 to be measured, the incident light is reflected by the surface of the film 50 to be measured and then transmitted to the collection end 421, and the reflected light is guided from the second end 42 to the third end 43 of the Y-shaped optical fiber 40, and then guided into the array spectrometer 21.

In some other examples, the light guide may also include other types of optical fibers, and the present embodiment is not specifically limited herein.

In a specific implementation, the device further comprises a support 30, and the plurality of collection ends 421 are connected to the support 30. The support 30 may include, for example, a support base 33 and a support rod, where the support base 33 is used for placing the film 50 to be tested, and the support rod includes a vertical rod 32 connected to the support base 33 and a horizontal rod 31 connected to the vertical rod 32, where an extending direction of the horizontal rod 31 is parallel to a surface of the support base 33, and a plurality of mounting holes for inserting the collection end 421 are provided on the horizontal rod 31. The plurality of collection terminals 421 may be disposed along a direction perpendicular to the horizontal direction, and an end of each collection terminal 421 near the supporting seat 33 faces the corresponding point 51 to be measured. It should be noted that, when other points 51 of the film 50 to be measured need to be measured, the film 50 to be measured can be moved horizontally, and the corresponding positions of the collecting end 421 and the film 50 to be measured can be changed.

As shown in fig. 1, the processing apparatus 20 is connected to the light guiding device, and the processing apparatus 20 is configured to obtain film thicknesses of the plurality of to-be-measured points 51 according to the plurality of reflected light beams, so as to implement a multi-point film thickness test on the to-be-measured thin film 50. The processing device 20 may comprise an array spectrometer 21 and an analysis device 22, the array spectrometer 21 being connected to the analysis device 22. Wherein the array spectrometer 21 is configured to obtain a plurality of interference images based on the plurality of reflected light rays, and the analysis device 22 is configured to calculate a film thickness based on the interference images.

It should be noted that the array spectrometer 21 may perform spectroscopy to split, filter and image each reflected light, so that the reflected light forms a corresponding interference image after passing through the array spectrometer 21. Referring to fig. 3 and 5, the array spectrometer 21 may include a spectroscopic device, a filter cavity assembly 213, and an imaging device 214, the filter cavity assembly 213 being located between the spectroscopic device and the imaging device 214, the filter cavity assembly 213 including a plurality of filter cavities therein, each filter cavity including a plurality of filter units 21311 therein. The path of the reflected light at the array spectrometer 21 is as follows: the reflected light passes through the beam splitting device, then passes through the filtering cavity assembly 213, and finally enters the imaging device 214. Specifically, each reflected light beam enters the array spectrometer 21 and then passes through the beam splitting device, the beam splitting device splits the reflected light beam into light beams, so that each split light beam is split into a corresponding filtering cavity in the filtering cavity assembly 213, each split light beam includes a plurality of split lights, when each split light beam passes through the filtering cavity assembly 213, the corresponding filtering unit 21311 performs filtering processing, then the reflected light beam after the filtering processing forms an output spectrum on the imaging device 214, and the imaging device 214 converts the output spectrum into an interference image.

The imaging device 214 may include a CMOS camera (CMOS, complementary Metal Oxide Semiconductor, complementary metal oxide semiconductor) and a CCD camera (CCD, charge coupled device, charge coupled device). After the scattered light passing through the filtering unit 21311 enters the CMOS camera or the CCD camera, a light sensing sensor in the CMOS camera or the CCD camera converts the light signal into an electrical signal, and further converts the electrical signal into a digital signal through an analog-to-digital converter in the CMOS camera or the CCD camera, and then transmits the digital signal to an image processor in the CMOS camera or the CCD camera to obtain an interference image.

The analysis device 22 is configured to calculate a corresponding film thickness from the interference image, and specifically, the analysis device 22 may determine an original spectrum from the interference image using one or more signal reconstruction techniques, and further obtain the thickness of the point 51 to be measured in the film 50 through fourier transform. The signal reconstruction technique may include, for example, a compressive sensing technique. It is worth noting that the analysis device 22 may be presented in the form of a functional unit. "unit" is to be understood herein in the broadest possible sense, and the objects used to implement the functions described by the various "units" may be, for example, a processor (shared, dedicated, or chipset) and memory for executing one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality. The form of the hardware carrier of the analysis device 22 in this embodiment may specifically be a computer device.

The embodiment of the invention provides a film thickness testing device, which comprises a light guide device and processing equipment 20, wherein the light guide device is provided with a plurality of collecting ends 421 which are arranged towards different positions of a film 50 to be tested, the processing equipment 20 is connected with the light guide device, and the light guide device is also used for guiding reflected light received by each collecting end 421 from the film 50 to be tested to the processing equipment 20; the processing device 20 is configured to obtain the thickness of the film 50 to be measured corresponding to each collecting end 421 according to the reflected light. The multiple reflected light rays reflected by the surface of the film 50 to be tested are guided to the processing device 20 through the collecting end 421, and the processing device 20 obtains the film thicknesses of the multiple points 51 to be tested according to the multiple reflected light rays, so that the testing efficiency is improved.

Further, the film thickness testing device provided by the embodiment of the invention can also monitor the film thickness of the film 50 to be tested in real time, thereby being beneficial to ensuring the production quality of the film and improving the working performance of the film.

Referring to fig. 3 and 4, fig. 3 illustrates a structure of the array spectrometer 21 in one implementation, and fig. 4 is a schematic diagram of the filter cavity assembly 213 in fig. 3. In the illustration, the X-axis direction is a first preset direction, and the Y-axis direction is a second preset direction.

As shown in fig. 3, in the illustrated position, the optical fiber is the uppermost, and the spectroscopic device, the filter cavity assembly 213, and the imaging device 214 are located below the optical fiber in that order. It should be noted that, the optical fiber in the drawing is the third end 43 of the Y-shaped optical fiber 40, and it can be seen that the third end 43 of the Y-shaped optical fiber 40 is connected to the spectroscopic device. The spectroscopic device may comprise a cylindrical mirror 211, the curved surface of the cylindrical mirror 211 being located on the side close to the filter cavity assembly 213, and the projection of the cylindrical mirror 211 on the horizontal plane being able to cover the projection of the filter cavity assembly 213 on the horizontal plane, so that the spectroscopic device disperses the reflected light onto the filter cavity assembly 213.

The filter cavity assembly 213 includes a plurality of first filter cavities 2131 arranged along a first preset direction, the first filter cavities 2131 include a plurality of filter units 21311 arranged along a second preset direction, and pass bands of each filter unit 21311 in the first filter cavities 2131 are different, and the second preset direction is perpendicular to the first preset direction.

It is worth noting that the filter unit 21311 may be configured with a specific passband, and as reflected light passes through the filter unit 21311, the filter unit 21311 may attenuate at least one wavelength (or portion of the spectrum) that is outside the passband of the filter unit 21311 while allowing transmission of at least one other wavelength (or portion of the spectrum) that is within the passband of the filter unit 21311. Since the pass bands of each of the filter units 21311 in the first filter cavity 2131 are different, the wavelengths of the output light of each of the filter units 21311 in the first filter cavity 2131 are different after the reflected light passes through the filter units 21311 in the first filter cavity 2131. When the filter units 21311 in the first filter cavity 2131 are arranged according to a certain passband rule, the output light of the first filter cavity 2131 is also arranged according to a corresponding wavelength rule, that is, an output spectrum is formed.

Referring to fig. 4, the plurality of filter units 21311 in the first filter cavity 2131 have a thickness variation, and pass bands corresponding to the filter units 21311 having different thicknesses are also different. As shown, the filter units 21311 in the filter cavity assembly 213 may be, for example, distributed in a grid shape of nine times nine, where the filter cavity assembly 213 may include nine identical first filter cavities 2131 arranged along the first direction, each first filter cavity 2131 may include nine filter units 21311 arranged along the second preset direction, and the thicknesses of the filter units 21311 in each first filter cavity 2131 are all arranged in a step shape. It can be seen that when the filtering cavity assembly 213 is used for filtering, the wavelengths of the output scattered light beams are arranged in an increasing or decreasing manner in the second preset direction, and the wavelengths of the output scattered light beams are the same in the same first preset direction. In this embodiment, the arrangement rule of the filter units 21311 in each first filter cavity 2131 is not limited, and a desired output spectrum can be formed.

As shown in fig. 3, the number of first filter cavities 2131 in the filter cavity assembly 213 should be set according to the number of optical fibers, e.g. nine optical fibers may be provided in fig. 3, and accordingly, nine first filter cavities 2131 are included in the filter cavity assembly 213. It should be noted that the filtering units 21311 in the filtering cavity assembly 213 may also be distributed in a grid shape of M times N, where N and M may be the same or different arbitrary positive integers.

The principle of operation of the array spectrometer 21 of the present embodiment is illustrated by the transmission of light from the second fiber labeled a from the left in the figure: the reflected light beam enters the cylindrical mirror 211 after being output by the optical fiber, and is dispersed into a component light beam by the cylindrical mirror 211, and the dispersed light beam passes through the corresponding first filter cavity 2131. And, the scattered light beam includes nine equal parts of scattered light, each of the scattered light enters the corresponding filter unit 21311 in the first filter cavity 2131, and then 9 parts of the scattered light with different wavelengths are output on the surface of the imaging device 214 after being filtered by the filter units 21311 with different passbands, that is, an output spectrum is formed, and the projection of the output spectrum on the horizontal plane coincides with the projection of the corresponding first filter cavity 2131 on the horizontal plane. And so on, after the reflected light rays emitted by other optical fibers are dispersed by the cylindrical mirror 211, corresponding output spectrums are also output on the surface of the imaging device 214 through the corresponding first filtering cavities 2131. The imaging device 214 converts each output spectrum into a corresponding interference image so as to obtain the film thickness of the point 51 to be measured corresponding to the optical fiber according to the interference image.

In this embodiment, the optical fiber can receive the reflected light from the corresponding point 51 to be measured and guide the reflected light to the array spectrometer 21 at the same time. Through the one-to-one correspondence between the optical fibers and the first filtering cavities 2131, each reflected light ray can be simultaneously converted into a corresponding interference image by the array spectrometer 21, and the analysis equipment 22 can simultaneously calculate the thickness of the corresponding point 51 to be tested according to each interference image, so that the effect of simultaneously testing the film thickness of a plurality of points 51 to be tested is realized, and the testing efficiency of the film thickness is improved.

Referring to fig. 5 and 6, fig. 5 shows a structure of an array spectrometer 21 in another implementation, and fig. 6 is a schematic structural diagram of a second filter cavity 2132 in the filter cavity assembly 213 in fig. 5. In the illustration, the X-axis direction is a first preset direction, and the Y-axis direction is a second preset direction.

As shown in fig. 5, in the illustrated position, the optical fiber is located at the top, and the spectroscopic device, the filter cavity assembly 213, and the imaging device 214 are located below the optical fiber in that order. It should be noted that the optical fiber in the drawing is the third end 43 of the Y-shaped optical fiber 40, and it can be seen that the third end 43 of the Y-shaped optical fiber 40 is connected to the filter cavity assembly 213. The beam splitting means may comprise a microlens array 212, the microlens array 212 being an array of clear aperture and micro-scale relief depth lenses. As shown in the figure, the number of the microlenses in the microlens array 212 should be set correspondingly according to the number of the optical fibers, for example, the third end 43 of the Y-shaped optical fiber 40 may include nine optical fibers, and the microlens array 212 may also include nine microlenses arranged in an array, accordingly, the third end 43 of the Y-shaped optical fiber 40 is also arranged in an array, and each microlens in the microlens array 212 faces the third end 43 of the corresponding Y-shaped optical fiber 40, so that each microlens corresponds to the reflected light emitted by one optical fiber, and further each microlens distributes the reflected light emitted by the corresponding optical fiber onto the filtering cavity assembly 213. It should be noted that, the manufacturing cost of the microlens array 212 is low, which is beneficial to further reducing the production cost.

The filter cavity assembly 213 includes a plurality of second filter cavities 2132 arranged in an array, the second filter cavities 2132 include a plurality of filter units 21311 arranged in an array, and each filter unit 21311 in the second filter cavity 2132 has a passband different from that of the other filter units 21311. The structure and the working principle of the filtering unit 21311 are the same as those of the filtering unit 21311 in the above embodiment, and are not described herein. Also, since each filter unit 21311 within the second filter cavity 2132 is different from the pass bands of the other filter units 21311, after the scattered light beams pass through the filter units 21311 in the second filter cavity 2132, the wavelengths of the scattered light beams output by each filter unit 21311 in the second filter cavity 2132 are different. When the filter units 21311 in the second filter cavity 2132 are arranged according to a certain passband rule, the scattered light beams output by the second filter cavity 2132 are also arranged according to a corresponding wavelength rule, that is, an output spectrum is formed. Further, each microlens corresponds to one second filtering cavity 2132, and the projection of each microlens on the horizontal plane can cover the projection of the corresponding second filtering cavity 2132 on the horizontal plane, so that the reflected light emitted by the optical fiber is dispersed by the corresponding microlens and enters the filtering unit 21311 of the corresponding second filtering cavity 2132. In this embodiment, the arrangement rule of the filter units 21311 in each second filter cavity 2132 is not limited, and a desired output spectrum can be formed.

Referring to fig. 6, the plurality of filter units 21311 in the second filter cavity 2132 have a thickness variation, and pass bands corresponding to the filter units 21311 having different thicknesses are also different. As shown in the figure, the filter cavity assembly 213 may include nine second filter cavities 2132 arranged in an array, where the filter units 21311 in each second filter cavity 2132 may be, for example, in a grid distribution of five times five, and the thicknesses of the filter units 21311 in the second filter cavities 2132 are different, the filter units 21311 are arranged in a step along a first preset direction, and the filter units 21311 are also arranged in a step along a second preset direction.

The working principle of the array spectrometer 21 of the present embodiment is described by taking the transmission process of light emitted from the optical fiber labeled B in the drawing as an example: the reflected light is output from the optical fiber, enters the microlens array 212, and is dispersed into a light beam by the corresponding microlens, and the dispersed light beam passes through the second filter cavity 2132 at an intermediate position in the filter cavity assembly 213. And, the scattered light beam includes twenty-five equal parts of scattered light, each of the scattered light enters the corresponding filter unit 21311 in the second filter cavity 2132, and then twenty-five parts of scattered light with different wavelengths are output on the surface of the imaging device 214 after being filtered by the filter units 21311 with different passbands, that is, an output spectrum is formed, and the projection of the output spectrum on the horizontal plane coincides with the projection of the corresponding second filter cavity 2132 on the horizontal plane. And so on, after the reflected light rays emitted by other optical fibers are dispersed by the corresponding microlenses, corresponding output spectrums are also output on the surface of the imaging device 214 through the corresponding second filter cavities 2132. The imaging device 214 converts each output spectrum into a corresponding interference image so as to obtain the film thickness of the point 51 to be measured corresponding to the optical fiber according to the interference image.

In this embodiment, the optical fiber can receive the reflected light from the corresponding point 51 to be measured and guide the reflected light to the array spectrometer 21 at the same time. By making the optical fibers correspond to the second filter cavities 2132 one by one, making the optical fibers correspond to the micro lenses in the micro lens array 212 one by one, so that each reflected light ray can be simultaneously converted into a corresponding interference image by the array spectrometer 21, the analysis device 22 can simultaneously calculate the thickness of the corresponding point 51 to be tested according to each interference image, thereby realizing the effect of simultaneously testing the film thickness of a plurality of points 51 to be tested and improving the testing efficiency of the film thickness. It should be noted that, the number of optical fibers in the Y-shaped optical fiber 40, the number of the collection ends 421 and the structure of the corresponding array spectrometer 21 can be adjusted, so as to be used for measuring different numbers of points 51 to be measured adaptively, which is beneficial to reducing the production cost.

The embodiment of the invention also provides a film thickness testing method implemented by the film thickness testing device in the embodiment, referring to fig. 7, the steps include:

step S101, a plurality of collecting ends of the light guide device face to a plurality of to-be-measured points of the film to be measured respectively, and the light guide device is connected with processing equipment.

Referring to fig. 1, when the film thickness testing apparatus is used, a film 50 to be tested may be first placed on the supporting base 33, and the distance between the collecting end 421 and the film 50 to be tested may be adjusted, for example, the distance between the collecting end 421 and the film 50 to be tested may be 5cm, so that the collecting end 421 sends and receives optical signals to and from the film 50 to be tested. In order to accurately acquire the film thickness of the point 51 to be measured on the film 50 to be measured, each acquisition end 421 needs to be in one-to-one correspondence with its corresponding point 51 to be measured. It should be noted that, after the film thickness value of the to-be-measured point 51 is obtained, if the film thickness of the to-be-measured film 50 is still required to be collected, the to-be-measured film 50 may be horizontally moved, and the position of the collection end 421 facing the to-be-measured film 50 may be changed.

Step S102, receiving reflected light from the film to be tested through processing equipment, and obtaining the thickness of the film to be tested according to the reflected light.

In this embodiment, the method further includes transmitting incident light to the film to be tested by the light source. Referring to fig. 2, the light source 10 may include, for example, an LED array lamp. Alternatively, the light source 10 may also comprise, for example, a halogen lamp, in order to be applied to different spectral ranges. Of course, in some examples, the light source 10 may also be used in combination with a halogen lamp and an LED array lamp. Further, the light source 10 may also include one or more of a fluorescent lamp, a tunable wavelength laser, a xenon lamp, and a high intensity LED lamp.

It should be noted that, after entering the film 50 to be measured, the incident light is reflected by the upper and lower surfaces of the film 50 to be measured, so as to form two reflected light beams with interference, so as to obtain the thickness of the film 50 to be measured according to the reflected light beams.

Referring to fig. 3 to 6, reflected light of the thin film 50 to be measured is received by the array spectrometer 21 in the processing apparatus 20. In this embodiment, the step of obtaining the thickness of the film 50 to be measured according to the reflected light includes: and acquiring a corresponding interference image according to the reflected light.

As shown in fig. 3 and 5, the array spectrometer 21 may include a spectroscopic device, a filter cavity assembly 213, and an imaging device 214, where the filter cavity assembly 213 is located between the spectroscopic device and the imaging device 214, and the path of the reflected light in the array spectrometer 21 is as follows: first through the beam splitting device, then through the filter cavity assembly 213, and finally into the imaging device 214.

Specifically, in this embodiment, the step of acquiring the corresponding interference image according to the reflected light includes: the reflected light is dispersed into a dispersed light beam.

The reflected light enters the array spectrometer 21 and then passes through a beam splitting device, where the beam splitting device is configured to uniformly split the reflected light into a split beam, where the split beam includes a plurality of split lights, so as to split the plurality of split lights onto a plurality of filter units 21311 in the filter cavity assembly 213. The spectroscopic means may comprise, for example, a cylindrical mirror 211 in fig. 3 and a microlens array 212 in fig. 5. In fig. 5, in order to make the microlenses in the microlens array 212 correspond to the reflected light rays emitted from the optical fibers one by one, the optical fibers are also arranged in an array.

In this embodiment, in the step of acquiring the corresponding interference image according to the reflected light, after dispersing the reflected light into the light beams, the method further includes: the scattered light beams are regularly arranged with a certain wavelength to form an output spectrum.

After the reflected light is dispersed into the split light beams, the split light beams pass through the filter cavity assembly 213, are filtered by the plurality of filter units 21311, and are then filtered to form an output spectrum on the imaging device 214.

As shown in fig. 3, in the filter cavity assembly 213, the filter cavity assembly 213 includes a plurality of first filter cavities 2131 arranged along a first preset direction, the first filter cavities 2131 include a plurality of filter units 21311 arranged along a second preset direction, and pass bands of each filter unit 21311 in the first filter cavities 2131 are different, and the second preset direction is perpendicular to the first preset direction. The plurality of filter units 21311 in the first filter cavity 2131 have thickness variations, and pass bands corresponding to the filter units 21311 with different thicknesses are also different. It can be seen that, when the filtering cavity assembly 213 is used for filtering, the wavelengths of the output light are arranged in an increasing or decreasing manner in the second preset direction, and the wavelengths of the output light are the same in the same first preset direction. That is, the scattered light beams, which are scattered by the reflected light, form output spectra in a second predetermined direction, and each of the output spectra is arranged along the first predetermined direction.

As shown in fig. 5, in the illustrated filter cavity assembly 213, the filter cavity assembly 213 includes a plurality of second filter cavities 2132 arranged in an array, the second filter cavities 2132 include a plurality of filter units 21311 arranged in an array, and pass bands of each filter unit 21311 in the second filter cavities 2132 are different. When the filter units 21311 in the second filter cavity 2132 are arranged according to a certain passband rule, the output light of the second filter cavity 2132 is also arranged according to a corresponding wavelength rule, that is, an output spectrum is formed. That is, each output spectrum is arranged in an array.

In this embodiment, in the step of obtaining the corresponding interference image according to the reflected light, after the plurality of scattered light beams are arranged according to a certain wavelength rule to form the output spectrum, the method further includes: and acquiring a corresponding interference image according to the output spectrum.

The present embodiment converts a spectrum into an interference image by an imaging device. The imaging device 214 may include a CMOS camera (CMOS, complementary Metal Oxide Semiconductor, complementary metal oxide semiconductor) and a CCD camera (CCD, charge coupled device, charge coupled device). After the scattered light beams passing through the filtering unit 21311 enter the CMOS camera or the CCD camera, the light sensing sensor in the CMOS camera or the CCD camera converts the light signals into electrical signals, and further converts the electrical signals into digital signals through the analog-to-digital converter in the CMOS camera or the CCD camera, and then transmits the digital signals to the image processor in the CMOS camera or the CCD camera to obtain interference images.

It should be noted that, in order to further improve the imaging quality of the array spectrometer 21, the gray value of the imaging device 214 may be adjusted, for example, the gray value may be adjusted to be more than 500, so that the interference image formed by the imaging device 214 has sufficient brightness.

In this embodiment, in the step of obtaining the thickness of the film 50 to be measured according to the reflected light, after obtaining the corresponding interference image according to the reflected light, the method further includes: the film thickness of the corresponding point 51 to be measured is calculated from the interference image.

In this embodiment, the corresponding film thickness may be calculated by the analysis device 22 according to the interference image, specifically, the analysis device 22 may determine an original spectrum according to the interference image by using one or more signal reconstruction techniques, and may obtain an interference curve from the original spectrum, and further obtain the thickness of the point 51 to be measured in the film 50 to be measured through fourier transformation. The signal reconstruction technique may include, for example, a compressive sensing technique.

The embodiment of the invention provides a film thickness testing method, which comprises the steps of respectively enabling a plurality of collecting ends 421 of a light guide device to face a plurality of to-be-tested points 51 of a film 50 to be tested; the reflected light from the thin film 50 to be measured is received by the processing apparatus 20, and the film thickness of the corresponding point 51 to be measured is obtained from the reflected light. The multiple reflected light rays reflected by the surface of the film 50 to be tested are transmitted to the processing device 20 through the collecting end 421, and the processing device 20 obtains the film thicknesses of the multiple points 51 to be tested according to the multiple reflected light rays, so that the testing efficiency is improved.

It should be noted that, when the film thickness testing device provided in the embodiment of the present invention is used for testing the film thickness, an optical substrate without a film may be placed on the supporting seat 33, after the optical substrate without a film is measured, the optical substrate with a film being coated may be placed on the supporting seat 33, and then the testing is performed by using the testing method described above, where the film coated on the optical substrate is the film 50 to be tested. By testing the optical substrates which are not coated and are coated respectively, the influence of the optical substrates in the film thickness testing process can be removed, and the reliability of the film thickness testing is further improved.

It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-described division of the functional modules is illustrated, and in practical application, the above-described functional allocation may be performed by different functional modules according to needs, i.e. the internal structure of the apparatus is divided into different functional modules to perform all or part of the functions described above. The specific working process of the above-described device may refer to the corresponding process in the foregoing method embodiment, which is not described herein again.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the invention.

Claims (16)

1. A film thickness testing apparatus, comprising: a light guide device and a processing apparatus; the processing equipment is connected with the light guide device, the light guide device is provided with a plurality of collecting ends which are arranged towards different positions of the film to be detected, and the light guide device is used for guiding the reflected light from the film to be detected received by each collecting end to the processing equipment; the processing equipment is used for obtaining the thickness of the film to be detected corresponding to each collecting end according to the reflected light.

2. The film thickness testing apparatus according to claim 1, wherein the processing device includes an array spectrometer and an analysis device, the analysis device is connected to the array spectrometer, the array spectrometer is connected to the light guide device, the array spectrometer is configured to obtain a corresponding plurality of interference images from each of the reflected light rays, and the analysis device is configured to calculate a corresponding film thickness from the interference images.

3. The film thickness testing apparatus according to claim 2, wherein the array spectrometer comprises a spectroscopic apparatus, a filter cavity assembly and an imaging apparatus, the filter cavity assembly being located between the spectroscopic apparatus and the imaging apparatus, the filter cavity assembly comprising a plurality of filter cavities, the spectroscopic apparatus being configured to disperse the reflected light into a plurality of dispersed light beams, each of the filter cavities being configured to process each of the dispersed light beams to form an output spectrum, the imaging apparatus being configured to acquire the interference image from the output spectrum.

4. A film thickness testing apparatus according to claim 3, wherein said filter cavity comprises a plurality of filter units having a plurality of dispersed lights therein, each of said filter units for processing each of said dispersed lights to obtain said dispersed lights of a corresponding wavelength.

5. The film thickness testing device of claim 4, wherein the filter cavity comprises a first filter cavity, the first filter cavity is arranged in the filter cavity assembly along a first preset direction, the first filter cavity comprises a plurality of filter units arranged along a second preset direction, the pass bands of each filter unit in the first filter cavity are different, and the second preset direction is perpendicular to the first preset direction.

6. The apparatus according to claim 5, wherein the spectroscopic device comprises a cylindrical mirror.

7. The film thickness testing device of claim 4, wherein the filter cavity further comprises a second filter cavity, the second filter cavity is arranged in an array in the filter cavity assembly, the second filter cavity comprises a plurality of filter units arranged in an array, and pass bands of the filter units in the second filter cavity are different.

8. The apparatus according to claim 7, wherein the spectroscopic apparatus comprises a microlens array including a plurality of microlenses arranged in an array, one side of each microlens corresponding to one of the reflected light rays, and the other side corresponding to one of the second filter cavities.

9. The apparatus according to claim 1, further comprising a supporting frame including a supporting seat and a supporting rod connected to each other, the supporting rod being connected to the collecting ends, the supporting seat being configured to place the thin film to be measured so that each collecting end faces the thin film to be measured.

10. The film thickness testing apparatus according to claim 9, wherein the support rod comprises a vertical rod connected to the support base and a horizontal rod connected to the vertical rod, and the horizontal rod is provided with a mounting hole for inserting the collecting end.

11. The apparatus according to claim 1, further comprising a light source, wherein the light guide is connected to the light source, and the light guide is configured to guide incident light from the light source to each of the collection terminals and from the collection terminal to the thin film to be measured.

12. The film thickness testing apparatus of claim 11, wherein the light guide comprises a Y-fiber having a first end coupled to the light source, a second end, and a third end coupled to the processing device, the second end comprising a collection end.

13. The film thickness testing apparatus according to claim 11, wherein the light source comprises a halogen lamp and/or an LED array lamp.

14. A film thickness testing method based on the film thickness testing device according to claim 1, wherein,

a plurality of collecting ends of the light guide device face to a plurality of to-be-measured points of the film to be measured respectively, and the light guide device is connected with processing equipment;

and receiving reflected light rays from the thin film to be detected through the processing equipment, and acquiring the film thickness of the corresponding point to be detected according to the reflected light rays.

15. The method according to claim 14, wherein obtaining the film thickness of the point to be measured from the reflected light includes:

acquiring a corresponding interference image according to the reflected light;

and calculating the film thickness of the corresponding point to be detected according to the interference image.

16. The method according to claim 15, wherein acquiring the corresponding interference image from the reflected light includes:

dispersing the reflected light into a beam of light;

arranging the scattered light beams according to a certain wavelength rule to form an output spectrum;

and acquiring the corresponding interference image according to the output spectrum.

Images