TW201723451A - Optical superimposing measurement system using a low coherent light source as the system light source even if the sample needs high resolution sample slice, depth and thickness information detections - Google Patents

Abstract

The optical superimposing measurement system of the present invention basically comprises a system light source module, a lens module, a photosensitive module, a spectral module, and a control module. The parallel extended light beam of the system light source module is reflected by the spectral module to form two measurement light beams, and the two measurement light beams are superimposed to focus on the sample by the lens module. After the photosensitive module receives the interference signal superimposed by the light beams reflected by the sample, the control module obtains the numerical signal corresponding to the two-dimensional to three-dimensional structure appearance of the sample by calculation; In particular, the intensities of the light beams passing through and reflected from the spectral module are the same, which not only significantly reduces the measurement error, but can still use a low coherent light source as the system light source to achieve the measurement results with high longitudinal resolution, even if the sample needs high resolution sample slice, depth and thickness information detections.

Description

Optical coincidence measurement system

This creation relates to an optical measurement system, in particular to a relatively high-energy light illumination effect, which makes it possible to use a low-coherence light source as a system light source for high-resolution sample slice, depth and thickness information detection. Coincidence measurement system.

In many high-tech industries (such as semiconductors, flat panel displays, fiber optic communications, micro-electromechanics, biomedical and electronic packaging, etc.), the accuracy of the surface profile of the microstructure determines the performance and function of the product, so it needs to be in the process. The surface profile quality of the microstructure is monitored.

In terms of optical interference mechanism, when the two channels coincide, the optical path difference is within the coherence length of the light source to produce interference. It is known that low-coherence light sources (such as light-emitting diodes, halogen bulbs, etc.) can be used. The sample is subjected to subtle longitudinal depth measurement. The principle is to apply the low coherence characteristic of the light source as longitudinal information detection, and then obtain fine longitudinal depth information.

Generally, the McKinson interferometer for detecting non-transparent samples and the Mirau self-interference objective lens have a system structure that uses a single beam of light to illuminate the sample, and finally uses another reflected light as a reference light to generate an interference mechanism, which is not only large. The light energy that is irradiated on the sample is reduced, and the front and back distances of the mirror at the reference end must be controlled to achieve the interference effect, and the overall interference mechanism is relatively inconvenient.

Furthermore, in the case of a self-interference objective lens, although it is easy to interfere, in a non-transparent sample, the backscattered light of the sample must also be used to achieve the result of the interference detection, so the beam must be split by the beam splitter. After that, the reflected light of the sample is transmitted to the detecting end, and the intensity of the light irradiated to the sample must be lowered at this time. Therefore, when the sample slice, depth, and thickness information requiring high resolution are detected, the expected detection effect is often not achieved.

In view of this, the present invention provides an optical re-measurement measurement system that can obtain a relatively high energy light irradiation effect, and can utilize a low-coherence light source as a system light source that requires high-resolution sample slice, depth, and thickness information detection. For its main purpose.

The optical coincidence measuring system of the present invention basically comprises: a system light source module for generating parallel expanded beam light with preset energy after power-on; a lens module for receiving and generating the light source module of the system The two parallel measuring beams formed by the parallel beam expanding are superimposed and focused on a predetermined sample; and a photosensitive module is configured to receive the interference after the reflected beams of the two measuring beams are irradiated to the sample a light splitting module is disposed between the light source module of the system, the lens module and the photosensitive module for reflecting the parallel beam expanding light generated by the light source module of the system to form two shots into the lens The measuring beam of the module and the reflected beam from the sample are coincident into the photosensitive module; a control module is electrically connected to at least the light source module and the photosensitive module of the system for generating and controlling the light source module of the system The operation control signal is preloaded with at least one operation mode, and the plurality of interference signals respectively received by the photosensitive module are processed by the at least one operation mode Raw signal values.

Using the above structural features, the optical coincidence measuring system of the present invention can form two measuring beams of the lens module under the action of the beam splitting module, and then the two measuring beams of the lens module are coincidently focused by the lens module. On the sample, after receiving the interference signal of the sample reflected beam overlap by the photosensitive module, the control module can calculate the numerical signal corresponding to the two-dimensional to three-dimensional structure appearance of the sample; in particular, the penetration and reflection by the beam splitting module The beam intensity is the same, which not only can greatly reduce the measurement error, but even if the sample needs high-resolution sample slicing, depth and thickness information detection, the low-coherence light source can be used as the system light source to achieve the measurement result of high longitudinal resolution. .

According to the above structural feature, the lens module has a first plane mirror and a second plane mirror arranged in parallel, and a first concentrating lens is disposed between the first plane mirror and the second plane mirror; The module has a beam splitter for reflecting the parallel beam expanding light generated by the light source module of the system to the first plane mirror and the second plane mirror, and for the reflected light from the sample to penetrate into the photosensitive module A second concentrating lens is disposed between the beam splitter and the photosensitive module.

According to the above structural feature, the lens module has a first plane mirror and a second plane mirror arranged in parallel, and a first collecting lens is disposed between the first plane mirror and the second plane mirror. a plane mirror, the second plane mirror and the first concentrating lens are fixed on a frame that can be reciprocally displaced relative to the beam splitting module; the beam splitting module has a light source module for generating the system Parallel beam expanding light is respectively reflected to the first plane mirror and the second plane mirror, and the reflected light from the sample penetrates into the beam splitter of the photosensitive module, and another section is disposed between the beam splitter and the photosensitive module Diphoto lens.

The light source module of the system has a photoelectric element for generating a low-coherence light source, and a spatial filter and a parallel beam expander lens group are sequentially disposed at the light exit of the photoelectric element.

The parallel beam expander lens group described above is provided with two lenses in sequence.

The photocell may be one of a light emitting diode, a xenon lamp, a halogen bulb, or a pulsed laser.

The photosensitive module is provided with at least one photosensitive coupled device (CCD).

The photosensitive module is provided with at least one complementary metal-oxide semiconductor (CMOS).

The optical coincidence measuring system disclosed in the present invention mainly utilizes the optical double combining mechanism generated by the above structural design to achieve the standard of interference generation, and can be widely applied to IC panel yield detection, wafer yield detection, various optical film layers. Measurement, various biological tissues, non-invasive medical tests, and related inspections using optical interference; in particular, the beam intensity transmitted and reflected by the beam splitting module is the same, which not only greatly reduces the measurement error, but even the sample needs When high-resolution sample slice, depth, and thickness information is detected, a low-coherence light source can be selected as the system light source to achieve a high longitudinal resolution capability measurement result.

This creation mainly provides a light irradiation effect that can obtain relatively high energy, so that a low-coherence light source can be used as an optical coincidence measurement system for a system light source requiring high-resolution sample slice, depth, and thickness information detection, as shown in FIG. As shown in Figure 3, the optical coincidence measurement system of the present invention basically includes:

A system light source module 10 is configured to generate a parallel beam of light having a predetermined energy after being energized; in the embodiment, the system light source module 10 has a photovoltaic element 11 for generating a low-coherence light source. A spatial filter 12 and a parallel beam expander lens group 13 are sequentially disposed at the light exit of the photoelectric element 11. In practice, the photoelectric element 11 can be a light emitting diode, a xenon lamp, or a halogen bulb. Or one of the pulsed lasers; as for the set of parallel beam expander lens groups 13, two lenses 131 are sequentially disposed, which can be reduced or enlarged by changing the focal length of the lens 131 of the parallel beam expander lens group 13. The size of the spot that is parallel expanded.

a lens module 20 for receiving and superimposing two measurement beams formed by reflection of the parallel beam expanding light generated by the system light source module 10 on a preset sample S; in the present embodiment, the lens The module 20 has a first plane mirror 21 and a second plane mirror 22 arranged in parallel, and a first collecting lens 23 is disposed between the first plane mirror 21 and the second plane mirror 22.

a photosensitive module 30 for receiving an interference signal after the reflected beams of the two measuring beams are incident on the sample S; in practice, the photosensitive module is provided with at least one photosensitive coupling element ( Charge Coupled Device (CCD), or at least one complementary metal-oxide semiconductor (CMOS).

A splitting module 40 is disposed between the system light source module 10, the lens module 20 and the photosensitive module 30 for reflecting the parallel beam expanding light generated by the system light source module 10 to form two shots. The measuring beam entering the lens module 20 and the reflected beam from the sample S are coincident into the photosensitive module 30.

A control module 50 is electrically connected to at least the system light source module 10 and the photosensitive module 30 for generating a control signal for controlling operation of the system light source module 10, and preloading at least one operation mode, and corresponding to each The numerical signal generated after the interference signals received by the photosensitive module 30 are processed by the at least one operation mode.

The lens module 20 has a first plane mirror 21 and a second plane mirror 22 arranged in parallel, and a first collecting lens is disposed between the first plane mirror 21 and the second plane mirror 22. In the structure of 23, the beam splitting module 40 has a parallel beam expanding light generated by the system light source module 10 and reflected to the first plane mirror 21 and the second plane mirror 22 respectively for the sample. The reflected light of S penetrates into the beam splitter 41 of the photosensitive module 30, and a second collecting lens 42 is disposed between the beam splitter 41 and the photosensitive module 30.

In principle, the optical coincidence measuring system of the present invention, when used, the light beam emitted from the photoelectric element 11 in the system light source module 10 passes through the spatial filter 12, and a Gaussian distributed beam is generated, and the Gaussian distributed beam passes through The parallel beam expanding lens group 13 forms a parallel beam expanding light, and the parallel beam expanding light forms two measuring beams that are incident on the lens module 20 via the beam splitting module 40, and then the two lenses are measured by the lens module 20. The beam coincidence is focused on the sample S, and after receiving the interference signal after the reflected beam of the sample S is reflected by the photosensitive module 30, the control module 50 can calculate the numerical signal corresponding to the two-dimensional to three-dimensional structure appearance of the sample S.

Using the optical double-coupling mechanism generated by the optical coincidence measurement system of the present invention to achieve the standard of interference generation, it can be widely used in IC panel yield detection, wafer yield detection, various optical film measurement, various biological tissues. Non-invasive medical testing, and related optical recording and other testing operations; in particular, the beam intensity transmitted and reflected by the beam splitting module 40 is the same, which not only greatly reduces the measurement error, but even the sample requires high-resolution sample slices. When the depth and thickness information is detected, the low-coherence light source can still be used as the system light source to achieve the measurement result of high longitudinal resolution.

Furthermore, in the optical coincidence measuring system of the present invention, the lens module 20 is provided with a first plane mirror 21 and a second plane mirror 22 arranged in parallel, and the first plane mirror 21 and the second The first planar mirror 21, the second planar mirror 22, and the first concentrating lens 23 can be fixed to each other as shown in FIG. 4, and the first concentrating lens 23 is disposed between the planes 22 and the first concentrating lens 23. The beam splitting module 40 is relatively reciprocally displaced on the frame 24.

Similarly, the beam splitting module 40 has a parallel beam expanding light generated by the system light source module 10 to be reflected to the first plane mirror 21 and the second plane mirror 22 respectively, and the reflected light from the sample S is reflected. A second condensing lens 42 is disposed between the beam splitter 41 and the photosensitive module 30.

In the embodiment shown in FIG. 4 , the first plane mirror 21 , the second plane mirror 22 and the first concentrating lens 23 are mainly fixed to a frame 24 that can be reciprocally displaced relative to the beam splitting module 40 . The structural design is such that a lens that can be adjusted or even three-dimensionally turned can quickly fine-tune the coincidence position of the measuring beam by simply changing the relative position of the lens module 20 and the beam splitting module 40. The interference mechanism required for the measurement work corresponding to different samples; further, the beam splitter 41 can also be disposed on the frame 24 for synchronous displacement.

Compared with traditional conventional technology, the optical coincidence measurement system disclosed in the present invention mainly utilizes the optical double-coupling mechanism generated by the above structural design to achieve the standard of interference generation, and can be widely applied to IC panel yield detection and wafer good. Rate detection, various optical film measurements, various biological tissues, non-invasive medical tests, and related optical interference tests; in particular, the beam intensity transmitted through the splitting module is the same, not only can be greatly reduced Measurement error, even if the sample needs high-resolution sample slice, depth, thickness information detection, you can still use low-coherence light source as the system light source to achieve high vertical resolution capability measurement results.

The embodiments described above are only for explaining the technical idea and characteristics of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement them according to the scope of the patent. That is, the equivalent changes or modifications made by the people in accordance with the spirit revealed by this creation should still be covered by the scope of the patent of this creation.

S sample
10‧‧‧System Light Source Module
11‧‧‧Optoelectronic components
12‧‧‧ Spatial Filter
13‧‧‧Parallel Beam Expanding Lens
131‧‧‧ lens
20‧‧‧Lens module
21‧‧‧ first plane mirror
22‧‧‧Second plane mirror
23‧‧‧First Concentrating Lens
24‧‧‧ frames
30‧‧‧Photosensitive module
40‧‧‧Distribution Module
41‧‧‧beam splitter
42‧‧‧Second condenser lens
50‧‧‧Control module

FIG. 1 is a schematic diagram showing the basic composition of the optical coincidence measuring system of the first embodiment of the present invention. The second picture is a schematic diagram of the structure of the lens module and the beam splitting module in the present creation. The third figure is a schematic diagram of the structure of the system light source module in the present creation. Figure 4 is a schematic view showing the structure of the lens module of the second embodiment of the present invention.

S‧‧‧ sample

10‧‧‧System Light Source Module

11‧‧‧Optoelectronic components

12‧‧‧ Spatial Filter

13‧‧‧Parallel Beam Expanding Lens

131‧‧‧ lens

20‧‧‧Lens module

21‧‧‧ first plane mirror

22‧‧‧Second plane mirror

23‧‧‧First Concentrating Lens

30‧‧‧Photosensitive module

40‧‧‧Distribution Module

41‧‧‧beam splitter

42‧‧‧Second condenser lens

50‧‧‧Control module

Claims (8)

An optical coincidence measuring system comprises: a system light source module (10) for generating a parallel beam expanding light with preset energy after being energized; a lens module (20) for receiving the light source module of the system (10) The two parallel measuring beams generated by the parallel expansion beam are recombined and focused on a predetermined sample (S); a photosensitive module (30) for receiving the two measuring beams is irradiated An interference signal after the reflected beam of the sample (S) is superposed; a light splitting module (40) is oppositely disposed on the light source module (10), the lens module (20) and the photosensitive module (30) Between the two, the parallel beam expanding light generated by the system light source module (10) is reflected to form two measuring beams incident on the lens module (20), and the reflected beam from the sample (S) Coincidentally enters the photosensitive module (30); a control module (50) is electrically connected at least to the system light source module (10) and the photosensitive module (30) for generating and controlling the system light source module (10) Operating the control signal, and preloading at least one of the operational modes, and the plurality of signals respectively corresponding to the receiving by the photosensitive module (30) Each of the interference signal signal value calculation mode by the at least one generated after processing. The optical overlap measurement system of claim 1, wherein the lens module (20) has a first plane mirror (21) and a second plane mirror (22) arranged in parallel, and the first A first concentrating lens (23) is disposed between the plane mirror (21) and the second plane mirror (22); the beam splitting module (40) has a parallel expansion for the light source module (10) of the system. Beam light is respectively reflected to the first plane mirror (21) and the second plane mirror (22) and the reflected light from the sample (S) penetrates into the beam splitter (41) of the photosensitive module (30), and A second collecting lens (42) is disposed between the beam splitter (41) and the photosensitive module (30). The optical overlap measurement system of claim 1, wherein the lens module (20) has a first plane mirror (21) and a second plane mirror (22) arranged in parallel, and the first A first concentrating lens (23) is disposed between the plane mirror (21) and the second plane mirror (22), and the first plane mirror (21), the second plane mirror (22) and the first concentrating lens (23) are fastened. The lens assembly (40) is disposed on a frame (24) that is reciprocally displaceable relative to the beam splitting module (40); the beam splitting module (40) has a parallel expansion beam generated by the light source module (10) of the system. Light is respectively reflected to the first plane mirror (21) and the second plane mirror (22) and the reflected light from the sample (S) penetrates into the beam splitter (41) of the photosensitive module (30), and A second collecting lens (42) is disposed between the beam splitter (41) and the photosensitive module (30). The optical coincidence measuring system according to any one of claims 1 to 4, wherein the system light source module (10) has a photoelectric element (11) for generating a low-coherence light source, and the photoelectric element (11) 11) A spatial filter (12) and a parallel beam expander lens group (13) are sequentially arranged at the light exit. The optical coincidence measuring system according to claim 4, wherein the parallel beam expanding lens group (13) is provided with two lenses (131) in sequence. The optical coincidence measuring system of claim 4, wherein the photovoltaic element (11) is one of a light emitting diode, a xenon lamp, a halogen bulb, or a pulsed laser. The optical coincidence measuring system according to any one of claims 1 to 4, wherein the photosensitive module is provided with at least one photosensitive coupled device (CCD). The optical overlap measurement system according to any one of claims 1 to 4, wherein the photosensitive module is provided with at least one complementary metal-oxide semiconductor (CMOS).