CN216208615U - Detection device - Google Patents

Abstract

The embodiment of the application discloses detection device for optical detection specifically includes: the light source is used for emitting detection light to a point to be measured of the sample, and the incident angle of the detection light is an acute angle; the detection light is reflected by the sample to form signal light, and the signal light is used for forming a signal light spot on a photosensitive surface of the detector; the detector is used for acquiring the detection height of the point to be detected along a measurement direction according to the position of the signal light spot on the photosensitive surface, and the measurement direction is perpendicular to the surface of the sample or has an acute included angle.

Description

Detection device

Technical Field

The embodiment of the application relates to the field of microscopic imaging, in particular to a detection device.

Background

The focusing technology is widely applied to the fields of scientific research, industrial detection and processing related to microscopic imaging, and high-precision and high-speed focusing is the direction of continuous improvement of the focusing technology. In recent years, with the rapid development of the semiconductor chip industry field, the demand for the throughput of the sample optical detection and measurement equipment is increasing.

Among them, the film thickness measuring apparatus based on the ellipsometer principle has been widely used in the field of microscopic imaging, and can perform optical detection and optical focusing on a sample.

SUMMERY OF THE UTILITY MODEL

The embodiment of the application provides a detection device for optical detection.

A detection device, comprising: a light source and a detector;

the light source is used for emitting detection light to a point to be detected of a sample, the incident angle of the detection light is an acute angle, and the sample is an article to be detected;

the detection light is reflected by the sample to form signal light, and the signal light is used for forming a signal light spot on a photosensitive surface of the detector;

the detector is used for acquiring the detection height of the point to be detected along a measurement direction according to the position of the signal light spot on the photosensitive surface, and the measurement direction is perpendicular to the surface of the sample or has an acute included angle.

Optionally, the device further comprises an incidence assembly;

the incident assembly is arranged on a light path from the light source to the sample and used for enabling the detection light to reach a point to be detected of the sample after being converged or collimated.

Optionally, the light source further comprises an exit component;

the emergent component is arranged on a light path from the sample to the detector and is used for converging or collimating the signal light to the detector.

Optionally, the system further comprises a control device and a detection module;

the control equipment is used for receiving the detection height sent by the detector, so as to control the movement of the sample stage in the vertical direction according to the difference between the detection height and a standard height, wherein the standard height is the height of the focal plane of the detection module.

Optionally, the incidence assembly includes a first incidence mirror group, and the first incidence mirror group is configured to collimate the detection light emitted by the light source;

when the detection device further comprises an emergent component, the emergent component comprises a first emergent mirror group, and the first emergent mirror group is used for collecting the signal light and collimating the signal light.

Optionally, the signal light is collimated by the first exit mirror group to form first parallel light, and the detector is configured to detect the first parallel light; or,

the emergent assembly further comprises a second emergent mirror group, the second emergent mirror group is used for enabling the signal light collimated by the first emergent mirror group to be converged to the detector, and the distance between the first emergent mirror group and the second emergent mirror group is adjustable.

Optionally, the detection light is collimated by the first incident mirror group to form second parallel light, and the second parallel light reaches the surface of the sample; or,

the incidence assembly further comprises a second incidence lens group used for converging the detection light collimated by the first incidence lens group to the surface of the sample.

Optionally, the incident angle of the detection light is greater than or equal to 45 °.

Optionally, the exit assembly includes an exit lens group, and the incident assembly includes an incident lens group; the distance between the outgoing mirror group and the detector is adjustable, and the distance between the incoming mirror group and the sample is adjustable.

Optionally, at least one of the first switching component and the second switching component is further included;

the first switching assembly is used for installing a plurality of first emergent mirror groups and switching different first emergent mirror groups to enter a light path, and the focal lengths of the plurality of first emergent mirror groups are different;

the second switching assembly is used for installing a plurality of second emergent mirror groups and switching different second emergent mirror groups to enter the light path, and the focal lengths of the plurality of second emergent mirror groups are different.

Optionally, the light source is a coherent light source or an incoherent light source, and the detector 103 is a charge coupled device image sensor module or a position sensitive sensor module.

According to the technical scheme, the embodiment of the application has the following advantages:

after the light source emits detection light to a sample on the sample table, the detection light is reflected by the sample to form signal light, and the signal light forms a signal light spot on a photosensitive surface of the detector. And the detector acquires the detection height of the point to be detected along the measurement direction according to the position of the signal light spot. The detection height of the point to be detected along the measuring direction can be obtained by the position of the signal light spot on the photosensitive surface through the detector, so that optical detection is completed.

Drawings

FIG. 1 is a schematic view of a first embodiment of a detection apparatus in an embodiment of the present application;

FIG. 2 is a schematic diagram of a second embodiment of a detection device in an embodiment of the present application;

FIG. 3 is a schematic view of a third embodiment of the detecting device in the embodiment of the present application;

FIG. 4 is a schematic view of a fourth embodiment of the detecting device in the embodiment of the present application;

FIG. 5 is a schematic diagram of a fifth embodiment of a detecting device in the embodiment of the present application;

fig. 6 is a schematic diagram of a sixth embodiment of the detection device in the embodiment of the present application.

Detailed Description

The embodiment of the application provides a detection device for optical detection.

Focusing techniques have found wide application in the optical field. With the rapid development of the semiconductor chip industry, the demand for the productivity of the sample optical detection and measurement equipment is increasing. The detection device provided by the embodiment of the application can be applied to the field of microscopic imaging needing high-speed and high-precision focusing detection.

Referring to fig. 1, a first embodiment of a detection apparatus in an embodiment of the present application includes: a light source 101 and a detector 103;

the light source 101 is used for emitting detection light to a point to be measured of the sample 102, and the incident angle of the detection light is an acute angle;

the detection light is reflected by the sample 102 to form signal light, and the signal light is used for forming a signal light spot on a photosensitive surface of the detector 103;

the detector 103 is configured to obtain a detection height of the point to be detected along a measurement direction according to the position of the signal light spot on the photosensitive surface, where the measurement direction is perpendicular to the surface of the sample 102 or has an acute included angle.

In the embodiment of the present application, after the light source 101 emits the detection light to the sample 102 on the sample stage, the detection light is reflected by the sample 102 to form a signal light, and the signal light forms a signal light spot on the photosensitive surface of the detector 103. The detector 103 obtains the detection height of the point to be detected along the measurement direction according to the position of the signal light spot. The position of the signal light spot on the photosensitive surface can be obtained through the detector 103, and the detection height of the point to be detected along the measurement direction can be obtained, so that optical detection is completed.

For the sake of understanding, the detection device in the embodiment of the present application will be specifically described below.

Referring to fig. 2, a second embodiment of the detecting device in the embodiment of the present application includes: light source 101, detector 103, an incidence assembly, control device 106 and detection module 107. The incidence component is arranged on a light path from the light source 101 to the sample 102, and is used for converging or collimating the detection light to reach a point to be measured of the sample 102. The incident assembly in this embodiment includes a first incident lens group 105, and the first incident lens group 105 is used for collimating the detection light emitted from the light source 101. The detection device further comprises: a mirror 104.

The light source 101 is used for emitting detection light to the incident assembly. Specifically, in this embodiment, the incident assembly is disposed on the light path from the light source 101 to the sample 102 on the sample stage, and can collimate the detection light to the point to be measured of the sample 102 on the sample stage. And the detection light is collimated by the first incident mirror group to form second parallel light, and the second parallel light reaches the surface of the sample. Specifically, the detection light emitted by the light source 101 is reflected by the reflecting mirror 104 and then reaches the first incident mirror group 105, and the first incident mirror group 105 can collimate the detection light, so that the detection light is emitted to the surface of the sample 102 on the sample stage in parallel. The distance between the first incident lens group 105 and the sample 102 is adjustable to adjust the size of the light spot of the detection light on the surface of the sample 102.

In this embodiment, the first incident lens group 105 includes only lenses, and in another embodiment, the first incident lens group 105 may include one or more concave mirrors or convex mirrors. In other embodiments, the mirror 104 may not be included.

The parallel detection light is reflected by the sample 102 to form signal light, and the signal light is used for forming a signal light spot on a photosensitive surface of the detector 103. The detector 103 obtains the detection height of the sample 102 along the measuring direction according to the position of the signal light spot on the photosensitive surface of the detector 103. Wherein the measurement direction is perpendicular to the surface of the sample 102 or has an acute angle.

The control device 106 is configured to receive the detection height sent by the detector 103, so as to control the movement of the sample stage in the vertical direction according to the difference between the detection height and a standard height, where the standard height is a height of a focal plane of the detection module 107. The control device 106 is used for receiving the detection height sent by the detector 103, and then the control device 106 controls the movement of the sample stage in the vertical direction according to the difference between the detection height and the standard height so as to drive the sample 102 to move in the vertical direction. The detection module 107 is configured to obtain a standard height, where the standard height is a height of a focal plane of the detection module 107, and may also refer to a preset height of a plane where a point to be measured of the sample 102 is located when the sample 102 is focused by detection light. For example, in the case of focusing, there is a spot position on the detector 103 (x0, y0) corresponding to stage height z0, if out of focus in the positive direction, the spot position on the detector 103 may be (x0+ Δ x, y0) and the stage height is z0+ Δ z, so that the control device 106 is required to control the stage to lower Δ z to focus the light on the surface of the sample 102. And vice versa for the negative direction.

The light source 101 is a coherent light source or an incoherent light source. It is understood that, in the case of high requirement for detection accuracy, the light source 101 may be a coherent light source, such as a laser or the like; in the case where the requirement for detection accuracy is not high, the light source 101 may be an incoherent light source, such as a light-emitting diode (LED), a plasma light source, or the like. The details are not limited herein.

For the detector 103, specifically, the detector 103 may be a charge coupled device image sensor module (CCD), or a sensor module with a focus frequency up to mhz, such as a position sensitive sensor module (PSD), and is not limited herein.

The incident angle of the detection light is an acute angle, and specifically, the incident angle of the detection light is greater than or equal to 45 °. The detection light is incident at an incident angle of more than or equal to 45 degrees and can be regarded as large-angle incidence, and when the detection light is incident at the large angle, the moving distance of a light spot formed on the photosensitive surface by the signal light when the height of a point to be detected of an object to be detected is changed is larger than the change amount of the height of the point to be detected, so that the detection sensitivity can be improved, and high-precision and high-speed focusing can be realized. Under the condition of not using a microscope objective lens with a large numerical aperture, the light enters the detection device at an incidence angle of more than or equal to 45 degrees, so that the detection device can achieve sub-wavelength focusing precision, and can realize high-precision high-speed focusing of 10 Hz. Specifically, the detection light incidence angle is 60 ° or 70 ° or 75 °.

Referring to fig. 3, a third embodiment of the detecting apparatus in the embodiment of the present application is similar to the second embodiment, except that the incident assembly of the third embodiment includes a first incident lens group 105 and a second incident lens group 108. The second incidence lens group is used for converging the detection light collimated by the first incidence lens group to the surface of the sample. The detection device in this embodiment further comprises a mirror 104.

The light source 101 is used for emitting detection light to the incident assembly. The incident component is arranged on a light path from the light source 101 to the sample 102 on the sample stage, and can collimate or converge the detection light to a point to be measured of the sample 102 on the sample stage. Specifically, in this embodiment, the incidence assembly collimates the detection light and then converges the detection light into a point on the sample surface. The detection light emitted from the light source 101 is reflected by the reflecting mirror 104 and then reaches the first incident mirror group 105, the first incident mirror group 105 can collimate the detection light, so that the detection light is emitted to the second incident mirror group 108 in parallel, and the second incident mirror group 108 converges the light emitted from the first incident mirror group 105 to the surface of the sample 102 on the sample stage. The distance between the first incident lens group 105 and the sample 102 is adjustable, and the distance between the second incident lens group 108 and the sample 102 is adjustable, so as to adjust the size of the light spot of the detection light on the surface of the sample 102.

In this embodiment, the second incident lens group 108 includes only lenses, and in another embodiment, the second incident lens group 108 may include one or more concave mirrors or convex mirrors. In other embodiments, the mirror 104 may not be included.

Referring to fig. 4, a fourth embodiment of the detecting device in the embodiment of the present application is similar to the second embodiment, except that the fourth embodiment includes an exit element and a first switching element 110. The exit assembly may include at least one of a lens group and a concave mirror, and in this embodiment, the exit assembly includes a first exit lens group 109 for collecting and collimating the signal light. The exit assembly is disposed on a light path from the sample 102 to the detector 103, and is configured to converge or collimate the signal light to the detector.

The detection light is reflected by the sample 102 and then emitted to the exit assembly. In this embodiment, the exit assembly is disposed on the optical path from the sample 102 to the detector 103, and is used to collimate the light reflected from the sample 102 to the detector 103. The signal light is collimated by the first exit mirror set 109 to form a first parallel light, and the detector 103 is configured to detect the first parallel light. Specifically, after the light reflected from the sample 102 is collimated by the first exit mirror group 109, the parallel signal light forms a signal light spot on the photosensitive surface of the detector 103. The detector 103 obtains the detection height of the sample 102 along the measuring direction according to the position of the signal light spot on the photosensitive surface of the detector 103. The measurement direction is perpendicular to the surface of sample 102 or has an acute angle. The distance between the first exit mirror set 109 and the detector 103 is adjustable. The first switching element 110 is used for installing a plurality of first exit lens sets 109 and switching different first exit lens sets 109 to enter the light path, and the focal lengths of the plurality of first exit lens sets 109 are different. In other embodiments, the first switching component 110 may not be included.

In this embodiment, the first exit lens group 109 includes only lenses, and in another embodiment, the first exit lens group 109 may include one or more concave mirrors or convex mirrors. In other embodiments, the mirror 104 may not be included.

Referring to fig. 5, a fifth embodiment of the detecting device in the embodiment of the present application is similar to the third embodiment, except that the fifth embodiment includes an exit element and a first switching element 110. The exit assembly includes at least one of a lens group and a concave mirror, and in this embodiment, the exit assembly includes a first exit lens group 109 for collecting and collimating the signal light. The exit assembly is disposed on a light path from the sample 102 to the detector 103, and is configured to converge or collimate the signal light to the detector.

The detection light is reflected by the sample 102 and then emitted to the exit assembly. The exit assembly is disposed on an optical path from the sample 102 to the detector 103, and is configured to collimate light reflected from the sample 102 to the detector 103. The signal light is collimated by the first exit mirror set 109 to form a first parallel light, and the detector 103 is configured to detect the first parallel light. Specifically, after the light reflected from the sample 102 is collimated by the first exit mirror group 109, the parallel signal light forms a signal light spot on the photosensitive surface of the detector 103. The detector 103 obtains the detection height of the sample 102 along the measuring direction according to the position of the signal light spot on the photosensitive surface of the detector 103. The measurement direction is perpendicular to the surface of sample 102 or has an acute angle. The distance between the first exit mirror set 109 and the detector 103 is adjustable. The first switching element 110 is used for installing a plurality of first exit lens sets 109 and switching different first exit lens sets 109 to enter the light path, and the focal lengths of the plurality of first exit lens sets 109 are different. In other embodiments, the first switching component 110 may not be included.

In this embodiment, the first exit lens group 109 includes only lenses, and in another embodiment, the first exit lens group 109 may include one or more concave mirrors or convex mirrors.

Referring to fig. 6, a sixth embodiment of the detecting device in the embodiment of the present application is similar to the fifth embodiment, except that the sixth embodiment includes an exit element and one or a combination of the first switching element 110 and the second switching element 112. The exit assembly in this embodiment includes a first exit lens group 109 and a second exit lens group 111. The second exit lens group 111 of the exit assembly is used for converging the signal light collimated by the first exit lens group 109 to the detector 103.

The detection light is reflected by the sample 102 and then emitted to the exit assembly. In this embodiment, the exit assembly is disposed on the optical path from the sample 102 to the detector 103, and is used to collimate the light reflected from the sample 102 to the detector 103. Specifically, after the light reflected from the sample 102 is collimated by the first exit mirror group 109, the parallel light enters the second exit mirror group 111, and the second exit mirror group 111 converges the parallel light on the photosensitive surface of the detector 103. The detector 103 obtains the detection height of the sample 102 along the measuring direction according to the position of the convergent point on the photosensitive surface of the detector 103. The measurement direction is perpendicular to the surface of sample 102 or has an acute angle.

The distance between the exit mirror group and the detector 103 is adjustable, and the distance between the first exit mirror group 109 and the second exit mirror group 111 is adjustable. The first switching element 110 is used for installing a plurality of first exit lens sets 109 and switching different first exit lens sets 109 to enter the light path, and the focal length of each first exit lens set 109 is different. The second switching assembly 112 is configured to mount a plurality of second exit lens sets 111 and is configured to switch different second exit lens sets 111 to enter the light path, and a focal length of each second exit lens set 111 is different. The above structure can adjust the optical magnification of the detector 103 for the difference between the detection height and the standard height, which is determined by the distance from the exit lens group to the detector 103, the focal length of the first exit lens group 109 and the focal length of the second exit lens group 111. Because the distance and the focal length are both adjustable, the optical magnification can be selectively adjusted to be as large as possible, so that when the sample stage moves for a section of fixed height, the larger the change of the position of the light spot on the detector 103 is, the stronger the capability of distinguishing the minimum height change is, and the detection precision of the detection device is improved.

In this embodiment, the second exit lens group 111 only includes lenses, and in another embodiment, the second exit lens group 111 may include one or more concave mirrors or convex mirrors.

The above description of the present application with reference to specific embodiments is not intended to limit the present application to these embodiments. For those skilled in the art to which the present application pertains, several changes and substitutions may be made without departing from the spirit of the present application, and these changes and substitutions should be considered to fall within the scope of the present application.

Claims (11)

1. A detection device, comprising: a light source and a detector;

the light source is used for emitting detection light to a point to be detected of a sample, the incident angle of the detection light is an acute angle, and the sample is an article to be detected;

the detection light is reflected by the sample to form signal light, and the signal light is used for forming a signal light spot on a photosensitive surface of the detector;

the detector is used for acquiring the detection height of the point to be detected along a measurement direction according to the position of the signal light spot on the photosensitive surface, and the measurement direction is perpendicular to the surface of the sample or has an acute included angle.

2. The detection device of claim 1, further comprising an incident assembly;

the incident assembly is arranged on a light path from the light source to the sample and used for enabling the detection light to reach a point to be detected of the sample after being converged or collimated.

3. The detection device of claim 2, further comprising an exit assembly;

the emergent component is arranged on a light path from the sample to the detector and is used for converging or collimating the signal light to the detector.

4. The detection apparatus according to claim 3, further comprising a control device and a detection module;

the control equipment is used for receiving the detection height sent by the detector, so as to control the movement of the sample stage in the vertical direction according to the difference between the detection height and a standard height, wherein the standard height is the height of the focal plane of the detection module.

5. The detection apparatus according to claim 3, wherein the incident assembly comprises a first incident lens group for collimating the detection light emitted from the light source;

when the detection device further comprises an emergent component, the emergent component comprises a first emergent mirror group, and the first emergent mirror group is used for collecting the signal light and collimating the signal light.

6. The detecting device according to claim 5, wherein the signal light is collimated by the first exit mirror group to form a first parallel light, and the detector is configured to detect the first parallel light; or,

the emergent assembly further comprises a second emergent mirror group, the second emergent mirror group is used for enabling the signal light collimated by the first emergent mirror group to be converged to the detector, and the distance between the first emergent mirror group and the second emergent mirror group is adjustable.

7. The detection device according to claim 5, wherein the detection light is collimated by the first incident mirror group to form a second parallel light, and the second parallel light reaches the surface of the sample; or,

the incidence assembly further comprises a second incidence lens group used for enabling the detection light collimated by the first incidence lens group to be converged to the surface of the sample.

8. The detecting device according to claim 1, wherein an incident angle of the detecting light is greater than or equal to 45 °.

9. The detection apparatus according to claim 3, wherein the exit assembly comprises a set of exit mirrors and the entrance assembly comprises a set of entrance mirrors;

the distance between the outgoing mirror group and the detector is adjustable, and the distance between the incoming mirror group and the sample is adjustable.

10. The detection device of claim 4, further comprising one or a combination of the first switching component and the second switching component;

the first switching assembly is used for installing a plurality of first emergent mirror groups and switching different first emergent mirror groups to enter a light path, and the focal lengths of the plurality of first emergent mirror groups are different;

the second switching assembly is used for installing a plurality of second emergent mirror groups and switching different second emergent mirror groups to enter the light path, and the focal lengths of the plurality of second emergent mirror groups are different.

11. The apparatus of any one of claims 1 to 2, wherein the light source is a coherent light source or an incoherent light source, and the detector is a CCD image sensor module or a position-sensitive sensor module.

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