阅读说明：本技术 一种正交偏振分选光学采集装置及其应用 (Orthogonal polarization sorting optical acquisition device and application thereof ) 是由 赵丽 雷自力 于 2020-11-26 设计创作，主要内容包括：本发明属于表面形貌测量领域,并公开了一种正交偏振分选光学采集装置及其应用。该装置中宽带线偏振光射入消偏振分光棱镜并产生反射光和透射光；反射光通过第一显微镜、反光镜和消偏振分光棱镜形成参考光；透射光通过第二显微镜投射到待测样品表面形成出射光并进入第二显微镜,然后通过消偏振分光透镜反射形成测量光；测量光中与宽带线偏振光偏振方向正交的偏振分量被第一成像面采集,为待测样品表面的散射信号；测量光中与宽带线偏振光偏振方向相同的偏振分量与参考光在第二成像面上发生干涉,并被该第二成像面采集,为待测样品表面的反射信号。本发明能够同步分选采集表面的反射、散射两种光学特性信息,适用于多光学特性微纳结构表面形貌测量。(The invention belongs to the field of surface topography measurement, and discloses an orthogonal polarization sorting optical acquisition device and application thereof. In the device, broadband linearly polarized light is emitted into a depolarization beam splitter prism and generates reflected light and transmitted light; the reflected light forms reference light through a first microscope, a reflector and a depolarization beam splitter prism; the transmitted light is projected to the surface of a sample to be measured through a second microscope to form emergent light, enters the second microscope, and is reflected through a depolarization beam splitting lens to form measuring light; the polarization component orthogonal to the polarization direction of the broadband linearly polarized light in the measuring light is collected by the first imaging surface and is a scattering signal of the surface of the sample to be measured; and the polarization component in the measurement light, which has the same polarization direction as the broadband linearly polarized light, interferes with the reference light on the second imaging surface, and is collected by the second imaging surface and is a reflection signal of the surface of the sample to be measured. The method can synchronously sort and collect two kinds of optical characteristic information of reflection and scattering of the surface, and is suitable for measuring the surface appearance of the multi-optical characteristic micro-nano structure.)

1. An orthogonal polarization sorting optical collection device, comprising a broadband point light source (101), a collimating lens (102), a polarizer (103), a first mirror (104), a second mirror (105), a depolarizing beam-splitting prism (106), a first microscope (107), a reflective mirror (108), a second microscope (109), a polarizing beam-splitting prism (111), a first imaging plane (113), a first lens (112), a second imaging plane (115), a second lens (114), wherein:

the broadband point light source (101), the collimating lens (102) and the polarizer (103) are sequentially arranged in the transmission direction of emergent light of the broadband point light source (101) and are used for generating broadband linearly polarized light;

the broadband linearly polarized light is reflected by the first reflecting mirror (104) and the second reflecting mirror (105) in sequence and then enters the depolarizing beam-splitting prism (106) to generate reflected light and transmitted light;

the first microscope (107) and the reflective mirror (108) are arranged along the propagation direction of the reflected light, the reflected light is projected on the reflective mirror (108) through the first microscope (107), re-enters the first microscope (107) after being reflected, and is transmitted through the depolarization light splitting prism (106) to form reference light;

the second microscope (109) is arranged along the transmission direction of the transmitted light, the transmitted light is projected to the surface of a sample to be measured through the second microscope (109) to form emergent light, enters the second microscope (109), and is reflected through the depolarization light splitting lens (106) to form measuring light;

polarization components in the measuring light, which are 90 degrees orthogonal to the polarization direction of the broadband linearly polarized light, pass through the first lens (112) and then are collected by the first imaging surface (113) and are scattering signals of the surface of a sample to be measured;

the polarization component in the measurement light, which is the same as the polarization direction of the broadband linearly polarized light, and the reference light pass through the second lens (114) and then interfere on the second imaging surface (115), and the interference is collected by the second imaging surface (115) and is a reflection signal of the surface of the sample to be measured, so that the synchronous collection work of the reflection signal and the scattering signal of the surface of the sample to be measured is realized.

2. The orthogonal polarization sorting optical collection device according to claim 1, further comprising a linearly polarized ring light source (110) disposed outside the second microscope (109), wherein the polarization direction of the linearly polarized ring light source (110) is the same as the polarization direction of the broadband linearly polarized light for use as a supplementary light source.

3. Use of the cross-polarization sorting optical acquisition device of claim 1 or 2 for constructing a multi-optical property surface topography micro-measurement system, wherein the measurement system comprises an optical acquisition device (10), a support device, a servo drive device, a laser interferometry device and a master control device (40), wherein:

the optical acquisition device (10) adopts the orthogonal polarization sorting optical acquisition device;

the supporting device is used for providing a supporting function and placing a sample to be measured;

the servo driving device is connected with the optical acquisition device (10) and is used for driving the optical acquisition device (10) to move along the direction vertical to the sample to be detected;

the laser interference measuring device is arranged above the optical acquisition device (10) and used for monitoring the displacement of the optical acquisition device (10) in the vertical direction in real time and synchronously triggering the first imaging surface (113) and the second imaging surface (115) when the optical acquisition device (10) reaches a preset displacement distance;

the main control device (40) is used for controlling the movement of the servo driving device and simultaneously acquiring optical characteristic signals of the first imaging plane (113) and the second imaging plane (115) and displacement information acquired by the laser interference measuring device.

4. The system for microscopic measurement of surface topography with multiple optical properties according to claim 3, wherein the servo driving means comprises a motor (302), a decelerator (303), a displacement stage (304) and a servo controller (301), wherein the motor (302) is connected to the displacement stage (304) through the decelerator (303), and the displacement stage (304) is connected to the optical pickup device (10) to move the optical pickup device (10) in a vertical direction by the motor (302); the servo controller (301) is used for controlling the motor (302) so as to adjust the position of the optical acquisition device (10).

5. The system for microscopic measurement of surface topography with multiple optical characteristics according to claim 3, wherein the laser interference measuring device comprises a laser interference generator (201) and a conical mirror (202), wherein the laser interference generator (201) is disposed above the conical mirror (202), laser emitted by the laser interference generator (201) is reflected by the conical mirror (202) and then received by the laser interference generator (201), and the interference signal is used to monitor the displacement of the optical acquisition device (10) in the vertical direction in real time.

6. The multi-optical property surface topography microscopy measurement system according to claim 3 wherein the laser interference generator (201) emits laser light with an optical axis coinciding with the optical axis of the second microscope (109).

7. The system for microscopic measurement of surface topography with multiple optical properties according to any of the claims 3 to 6, wherein the supporting device comprises a stage (501) and a vertical mounting bracket, the stage (501) is arranged directly below the second microscope (109) for placing the sample to be measured; the vertical mounting bracket is used for mounting the measuring system.

8. A method for measurement using the multi-optical property surface topography microscopic measurement system according to any one of claims 3 to 7, the method comprising the steps of:

s1, adjusting the placement angle of a polarizer (103) to enable the polarization direction of a broadband line light source to be the same as the polarization direction of e light of a polarization beam splitter prism (111) and to be orthogonal to the polarization direction of o light of the polarization beam splitter prism (111) at 90 degrees, and then placing a sample to be measured on the supporting device;

s2, the servo driving device drives the optical acquisition device (10) to perform continuous vertical scanning movement under the control of the main control device (40), when the optical acquisition device (10) reaches a preset displacement distance of the main control device (40), the interference metering device synchronously triggers the first imaging surface (113) and the second imaging surface (115), and the main control device (40) respectively acquires two optical characteristic signals of the sample to be detected;

s3, repeating the step S2 to enable each measuring point of the sample to be measured to enter the focal depth range of the second microscope (109) in sequence until all the measuring points exit, and thus completing vertical scanning;

s4, analyzing and resolving the two optical characteristic signals respectively by adopting a reflection characteristic surface topography recovery algorithm and a scattering characteristic surface topography recovery algorithm, and recombining to obtain the topography measurement data of the sample to be measured.

Technical Field

The invention belongs to the field of surface topography measurement, and particularly relates to an orthogonal polarization sorting optical acquisition device and application thereof.

Background

With the development of scientific and advanced manufacturing technology, the fineness and complexity of the surface features of the micro-nano structure are continuously improved, and the surface with multiple optical characteristics of reflection and scattering continuously appears in various novel parts. These novel surfaces with multiple optical characteristics exhibit a state in which two types of reflection-scattering optical characteristic regions coexist alternately.

The existing optical surface topography measuring method can only collect one specific optical characteristic information of reflection and scattering to restore the surface topography, so that the overall effective precise measurement is difficult to realize. Therefore, the research on the micro-measurement system and the method suitable for the reflection-scattering multi-optical characteristic surface morphology solves the problem of related surface measurement analysis requirements, and has important practical significance.

Disclosure of Invention

Aiming at the defects or improvement requirements of the prior art, the invention provides an orthogonal polarization sorting optical acquisition device and application thereof, wherein the device can synchronously sort and collect two types of surface optical characteristic information of reflection and scattering by optimizing the composition and the position of an optical component of the device, so that the device is particularly suitable for application occasions of surface characterization of a micro-nano structure.

To achieve the above object, according to one aspect of the present invention, there is provided an orthogonal polarization sorting optical pickup apparatus including a broadband point light source, a collimating lens, a polarizer, a first mirror, a second mirror, a depolarizing beam splitter prism, a first microscope, a reflective mirror, a second microscope, a polarization beam splitter prism, a first imaging plane, a first lens, a second imaging plane, and a second lens, wherein:

the broadband point light source, the collimating lens and the polarizer are sequentially arranged in the transmission direction of emergent light of the broadband point light source and are used for generating broadband linearly polarized light;

the broadband linearly polarized light is reflected by the first reflecting mirror and the second reflecting mirror in sequence and then enters the depolarizing beam splitter prism to generate reflected light and transmitted light;

the first microscope and the reflector are arranged along the propagation direction of the reflected light, the reflected light is projected on the reflector through the first microscope, re-enters the first microscope after being reflected, and is transmitted through the depolarization beam splitter prism to form reference light;

the second microscope is arranged along the transmission direction of the transmitted light, the transmitted light is projected to the surface of a sample to be measured through the second microscope to form emergent light and enters the second microscope, and then the emergent light is reflected through the depolarization light splitting lens to form measuring light;

polarization components in the measuring light, which are 90 degrees orthogonal to the polarization direction of the broadband linearly polarized light, pass through the first lens and are collected by the first imaging surface, and the polarization components are scattering signals on the surface of a sample to be measured;

and the polarization component in the measurement light, which is the same as the polarization direction of the broadband linearly polarized light, and the reference light are interfered on a second imaging surface after passing through the second lens and are collected by the second imaging surface to be a reflection signal of the surface of the sample to be detected, so that the synchronous collection work of the reflection signal and the scattering signal of the surface of the sample to be detected is realized.

Preferably, the orthogonal polarization sorting optical acquisition device further comprises a linear polarization annular light source sleeved outside the second microscope, and the polarization direction of the linear polarization annular light source is consistent with the polarization direction of the broadband linearly polarized light and is used as a supplementary light source.

According to another aspect of the present invention, there is provided a multi-optical characteristic surface topography microscopic measuring system, the measuring system comprising an optical collecting device, a supporting device, a servo driving device, a laser interference measuring device and a main control device, wherein:

the optical acquisition device adopts the orthogonal polarization sorting optical acquisition device;

the supporting device is used for providing a supporting function and placing a sample to be measured;

the servo driving device is connected with the optical acquisition device and is used for driving the optical acquisition device to move along a direction vertical to the sample to be detected;

the laser interference measuring device is arranged above the optical acquisition device and used for monitoring the displacement of the optical acquisition device in the vertical direction in real time and synchronously triggering the first imaging surface and the second imaging surface when the optical acquisition device reaches a preset displacement distance;

the main control device is used for controlling the servo driving device to move and simultaneously acquiring optical characteristic signals of the first imaging surface and the second imaging surface and displacement information acquired by the laser interference measuring device.

As a further preferred option, the servo driving device includes a motor, a speed reducer, a displacement table and a servo controller, wherein the motor is connected to the displacement table through the speed reducer, and the displacement table is connected to the optical pickup device so as to drive the optical pickup device to move in a vertical direction by the motor; the servo controller is used for controlling the motor and further adjusting the position of the optical acquisition device.

Preferably, the laser interference measuring device includes a laser interference generator and a conical mirror, wherein the laser interference generator is disposed above the conical mirror, laser emitted by the laser interference generator is reflected by the conical mirror and then received by the laser interference generator, and the interference signal is used to monitor the displacement of the optical acquisition device in the vertical direction in real time.

As a further preference, the optical axis of the laser interference generator emitting laser light coincides with the optical axis of the second microscope.

Preferably, the supporting device comprises a carrying platform and a vertical mounting bracket, wherein the carrying platform is arranged right below the second microscope and used for placing a sample to be tested; the vertical mounting bracket is used for mounting the measuring system.

According to another aspect of the present invention, there is provided a method for measuring by using the multi-optical characteristic surface topography microscopic measuring system, the method specifically comprises the following steps:

s1, adjusting the placement angle of the polarizer to enable the polarization direction of the broadband line light source to be the same as the polarization direction of the e light of the polarization beam splitter prism and to be orthogonal to the polarization direction of the o light of the polarization beam splitter prism at 90 degrees, and then placing the sample to be measured on the supporting device;

s2, the servo driving device drives the optical acquisition device to perform continuous vertical scanning movement under the control of the main control device, when the optical acquisition device reaches a preset displacement distance of the main control device, the interference metering device synchronously triggers a first imaging surface and a second imaging surface, and the main control device respectively acquires two optical characteristic signals of the sample to be measured;

s3, repeating the step S2 to enable each measuring point of the sample to be measured to enter the focal depth range of the second microscope in sequence until all measuring points exit, and thus completing vertical scanning;

s4, analyzing and resolving the two optical characteristic signals respectively by adopting a reflection characteristic surface topography recovery algorithm and a scattering characteristic surface topography recovery algorithm, and recombining to obtain the topography measurement data of the sample to be measured.

Generally, compared with the prior art, the above technical solution conceived by the present invention mainly has the following technical advantages:

1. the invention provides an orthogonal polarization sorting optical acquisition device, which correspondingly designs a first imaging surface and a second imaging surface aiming at a sample to be detected with two optical characteristic areas of reflection and scattering on the surface, optimizes the arrangement mode of each optical assembly, enables a polarization component in measurement light, which is the same as the polarization direction of a light source, to interfere with reference light and be acquired by the second imaging surface as a reflection signal of the sample to be detected, and simultaneously enables a polarization component in the measurement light, which is 90 degrees orthogonal to the polarization direction of the light source, to be acquired by the first imaging surface as a scattering signal of the sample to be detected, thereby realizing synchronous acquisition of optical characteristic information of the two surfaces of reflection and scattering;

2. particularly, the invention provides a multi-optical characteristic surface topography microscopic measurement system, which adopts the orthogonal polarization sorting optical acquisition device and moves along the vertical direction under the drive of a servo driving device, so that each measurement point of a sample to be measured sequentially enters the focal depth range of a second microscope, thereby realizing one-time high-precision measurement of the overall topography of the multi-optical characteristic surface and meeting the requirements of micro-nano structure surface topography detection and quality assurance.

Drawings

FIG. 1 is a schematic diagram of an orthogonal polarization sorting optical acquisition device constructed in accordance with a preferred embodiment of the present invention;

FIG. 2 is a schematic diagram of a multi-optical property surface topography micro-measurement system constructed in accordance with a preferred embodiment of the present invention.

The same reference numbers will be used throughout the drawings to refer to the same or like elements or structures, wherein:

10-an optical acquisition device, 101-a broadband point light source, 102-a collimating lens, 103-a polarizer, 104-a first reflector, 105-a second reflector, 106-a depolarizing beam splitter prism, 107-a first microscope, 108-a reflector, 109-a second microscope, 110-a linear polarized annular light source, 111-a polarizing beam splitter prism, 112-a first lens, 113-a first imaging plane, 114-a second lens, 115-a second imaging plane, 201-a laser interference generator, 202-a conical mirror, 301-a servo controller, 302-a motor, 303-a speed reducer, 304-a displacement workbench, 40-a main control device and 501-a loading platform.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

As shown in fig. 1, an orthogonal polarization sorting optical collecting apparatus according to an embodiment of the present invention includes a broadband point light source 101, a collimating lens 102, a polarizer 103, a first mirror 104, a second mirror 105, a depolarizing beam splitter 106, a first microscope 107, a reflective mirror 108, a second microscope 109, a polarization beam splitter 111, a first imaging plane 113, a first lens 112, a second imaging plane 115, and a second lens 114, where:

the broadband point light source 101, the collimating lens 102 and the polarizer 103 are sequentially arranged in the transmission direction of emergent light of the broadband point light source 101, the broadband point light source 101 is placed at the focus of one side of the collimating lens 102, and the polarizer 103 is placed at the other side of the collimating lens 102 to form broadband linearly polarized light which is collimated and emitted by the optical collecting device;

a first reflector 104 is arranged in the direction of collimation and propagation of broadband linearly polarized light, a second reflector 105 is arranged in the direction of emergent light of the first reflector 104, a depolarizing beam splitter 106 is arranged in the direction of emergent light of the second reflector 105, and the broadband linearly polarized light is reflected by the first reflector 104 and the second reflector 105 in sequence and then enters the depolarizing beam splitter 106 to generate reflected light and transmitted light;

the first microscope 107 and the reflective mirror 108 are arranged along the propagation direction of the reflected light, the reflected light is projected on the reflective mirror 108 arranged in the direction vertical to the optical axis of the reflected light through the first microscope 107, and then enters the first microscope 107 again after being reflected and is transmitted through the depolarizing beam splitter prism 106 to form reference light, and the reflecting surface of the reflective mirror 108 is coincided with the focal plane of the first microscope 107;

the second microscope 109 is arranged along the transmission direction of the transmission light, the transmission light is projected to the surface of a sample to be measured through the second microscope 109 to form emergent light and enters the second microscope 109, then the emergent light is reflected through the depolarization light splitting lens 106 to form measuring light, and the first microscope 107 and the second microscope 109 adopt small-focus-depth microscopes;

polarization components in the measurement light, which are 90 degrees orthogonal to the polarization direction of the broadband linearly polarized light, pass through the first lens 112 and are collected by the first imaging surface 113, and the polarization components are scattering signals on the surface of a sample to be measured;

the polarization component in the measurement light, which has the same polarization direction as the broadband linearly polarized light, and the reference light pass through the second lens 114 and then interfere with each other on the second imaging surface 115, and are collected by the second imaging surface 115 to be the reflection signal of the surface of the sample to be measured, so that the synchronous collection of the reflection signal and the scattering signal of the surface of the sample to be measured is realized.

Further, the orthogonal polarization sorting optical collecting device further includes a linear polarization annular light source 110 sleeved outside the second microscope 109, and the linear polarization annular light source 110 is installed on the optical axis vertical plane of the second microscope 109, so that the focusing plane of the linear polarization annular light source coincides with the focal plane of the second microscope 109, and the polarization direction of the linear polarization annular light source 110 is consistent with the polarization direction of the broadband linearly polarized light, and is used as a supplementary light source.

According to another aspect of the present invention, there is provided a multi-optical characteristic surface topography microscopic measuring system, the measuring system comprising an optical collecting device 10, a supporting device, a servo driving device, a laser interferometry device and a main control device 40, wherein:

the optical acquisition device 10 adopts the orthogonal polarization sorting optical acquisition device;

the supporting device is used for providing a supporting function and placing a sample to be tested, and comprises an object carrying platform 501 and a vertical mounting bracket, wherein the object carrying platform 501 is arranged right below the second microscope 109 and used for placing the sample to be tested; the vertical mounting bracket is used for mounting the measuring system;

the servo driving device is arranged in the middle of the vertical mounting bracket, is connected with the optical acquisition device 10 and is used for driving the optical acquisition device 10 to move along the direction vertical to a sample to be detected, and comprises a motor 302, a speed reducer 303, a displacement workbench 304 and a servo controller 301, wherein the motor 302 is connected with the displacement workbench 304 through the speed reducer 303, and the movable plane of the displacement workbench 304 is connected with the optical acquisition device 10 so as to drive the optical acquisition device 10 to move along the vertical direction by utilizing the motor 302; the servo controller 301 is used for controlling the motor 302 so as to adjust the position of the optical acquisition device 10;

the laser interference measuring device is arranged on the upper part of the vertical mounting bracket, is arranged above the optical acquisition device 10, and is used for monitoring the displacement of the optical acquisition device 10 in the vertical direction in real time and synchronously triggering the first imaging surface 113 and the second imaging surface 115 when the optical acquisition device 10 reaches a preset displacement distance;

the main control device 40 is in control connection with the servo driving device and the laser interference measuring device, meanwhile, external trigger interfaces of the first imaging plane 113 and the second imaging plane 115 are connected with the laser interference measuring device, an image transmission interface of the main control device is connected with the main control device 40, and the main control device 40 is used for controlling the movement of the servo driving device and simultaneously collecting optical characteristic signals of the first imaging plane 113 and the second imaging plane 115 and displacement information collected by the laser interference measuring device.

Further, the laser interference measuring device comprises a laser interference generator 201 and a conical mirror 202, wherein the laser interference generator 201 is arranged above the conical mirror 202, laser emitted by the laser interference generator 201 is reflected by the conical mirror 202 and then received by the laser interference generator 201, and the interference signal is utilized to monitor the displacement of the optical acquisition device 10 in the vertical direction in real time; the optical axis of the laser interference generator 201 emitting laser light coincides with the optical axis of the second microscope 109.

According to another aspect of the present invention, there is provided a method for measuring by using the multi-optical characteristic surface topography microscopic measuring system, the method specifically comprises the following steps:

s1, adjusting the optical acquisition device 10 to ensure that the sorted reflection and scattering characteristic signals are obtained synchronously, firstly adjusting the placement angle of the polarizer 103 in a plane perpendicular to the transmission optical axis to ensure that the polarization direction of the broadband linear light source is the same as the polarization direction of e light of the polarization beam splitter prism 111 and is 90-degree orthogonal to the polarization direction of o light of the polarization beam splitter prism 111, then adjusting the polarization direction of emergent light of the linear polarization annular light source 110 to ensure that the emergent light of the linear polarization annular light source is consistent with the polarization direction of the broadband linear polarization light, and finally placing a sample to be detected on a supporting device;

s2 the polarization component part of the emergent light on the surface of the sample to be measured, which has the same polarization direction with the two light sources, interferes with the reference light at the second imaging surface 115, and is collected by the second imaging surface 115 and is the reflection characteristic signal of the sample to be measured; polarization components which are orthogonal to the polarization directions of the two light sources at 90 degrees in emergent light on the surface of the sample to be detected are collected by the first imaging surface 113 and are scattering characteristic signals of the sample to be detected; the servo driving device drives the optical acquisition device 10 to perform continuous vertical scanning movement under the control of the main control device 40, the laser interference metering device monitors the displacement amount of the optical acquisition device 10 in the treatment direction in real time in the process, when the optical acquisition device 10 reaches the preset displacement distance of the main control device 40, the interference metering device synchronously triggers the first imaging surface 113 and the second imaging surface 115, and the main control device 40 respectively acquires two optical characteristic signals of a sample to be detected;

s3, repeating the step S2 to enable each measuring point of the sample to be measured to enter the focal depth range of the second microscope 109 in sequence until all the measuring points exit, and thus completing vertical scanning;

s4, analyzing and resolving the two optical characteristic signals respectively by adopting a reflection characteristic surface topography recovery algorithm and a scattering characteristic surface topography recovery algorithm, and recombining to obtain the topography measurement data of the sample to be measured.

It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.