KR102573768B1 - Swir hyper spectral imaging microscope system - Google Patents

Abstract

The present invention relates to a short wavelength infrared hyperspectral imaging microscope system, comprising: a base; a support stand upright from the base; a stage positioned on the base to place a subject; a lens barrel installed on the support and facing a subject disposed on the stage; a beam splitter installed inside the barrel; a light source installed outside the lens barrel to face the beam splitter and radiating light to the subject through the beam splitter; an optical module installed inside the lens barrel and obtaining short-wavelength infrared rays of 0.9 μm to 2.5 μm from the light of the light source reflected from the subject; and a detector for converting the short-wavelength infrared rays obtained by the optical module into a digital image signal and outputting the converted image signal.
According to the present invention, it is possible to obtain an image of a bonding portion inside silicon that cannot be seen with a conventional optical microscope by acquiring short-wavelength infrared rays having transmission characteristics of a material from a subject.

Description

Short wavelength infrared hyperspectral imaging microscope system {SWIR HYPER SPECTRAL IMAGING MICROSCOPE SYSTEM}

The present invention relates to a microscope system, and more particularly, to a short-wavelength infrared hyperspectral imaging microscope system capable of detecting bonds in silicon that cannot be seen with conventional optical microscopes.

Far infrared ray (LWIR) is light in a wavelength range of 8 to 13 μm, including infrared rays emitted by humans, and mid-infrared rays (MWIR) refers to infrared rays with a wavelength range of 3 to 5 μm.

A typical mid-infrared and far-infrared microscope system obtains an image of an object by radiant energy generated from the object in the infrared wavelength region. An image of an object obtained in a conventional infrared microscope system is obtained by receiving radiant energy in a wavelength band of mid-infrared or higher, and there is a limit to obtaining an image transmitted through a material.

As related prior art, there is Korean Patent Publication No. 10-2012-0006631 "Infrared Lens Microscope". The prior art obtains an image by transmitting only mid-infrared rays having a wavelength of 2 to 5 μm.

Korean Patent Publication No. 10-2012-0006631 "Infrared Lens Microscope"

An object of the present invention is to provide a short-wavelength infrared hyperspectral imaging microscope system capable of exploring bonds in silicon that cannot be seen with conventional optical microscopes.

The technical problems to be solved by the present invention are not limited to the above-mentioned technical problems, and other technical problems not mentioned will be clearly understood by those skilled in the art from the description below. You will be able to.

The present invention for achieving the above object is a base; a support stand upright from the base; a stage positioned on the base to place a subject; a lens barrel installed on the support and facing a subject disposed on the stage; a beam splitter installed inside the barrel; a light source installed outside the lens barrel to face the beam splitter and radiating light to the subject through the beam splitter; an optical module installed inside the lens barrel and obtaining short-wavelength infrared rays of 0.9 μm to 2.5 μm from the light of the light source reflected from the subject; and a detector installed in the lens barrel and converting the short-wavelength infrared rays obtained by the optical module into a digital image signal and outputting the converted image signal.

More specifically, moving means for moving the stage in X-axis, Y-axis, and Z-axis directions may be installed between the support and the stage.

The distance of the lens barrel from the stage may be adjusted.

According to the present invention, it is possible to obtain an image of a bonding portion inside silicon that cannot be seen with a conventional optical microscope.

1 is a diagram showing a short-wavelength infrared hyperspectral imaging microscope system of the present invention.
Figure 2 is a side view of Figure 1;
3 is a view showing an arrangement of an optical module and a beam splitter built into a lens barrel in the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Like elements in the drawings are indicated by like symbols wherever possible. In addition, detailed descriptions of well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted.

As shown in the figure, the short-wavelength infrared hyperspectral imaging microscope system of the present invention includes a base 11. The base 11 has a plate shape and can be stably placed on the floor. A support 13 is installed vertically on one side of the base 11, and the support 13 is integrated with the base 11 to form the body 10 of the microscope.

The base 11 is mounted with a moving means 30 for moving the stage 20 on which a subject is placed in the X-axis, Y-axis, and Z-axis. The moving means 30 includes a fixed base 31, an X-axis moving base 32, a Y-axis moving base 33, a Z-axis moving base 34, an X-axis knob 35, and a Y-axis knob (36) and the Z-axis knob 37.

The fixing table 31 has a plate shape and is placed on the upper surface of the base 11 and fixedly installed. move in the axial direction. The X-axis knob 35 is located between the fixing base 31 and the X-axis moving base 32, one side is coupled to the fixing base 31 and the other side is coupled to the X-axis moving base 32, so that the X-axis moving base ( 32) is moved in the X-axis direction parallel to the plane of the fixing table 31.

The plate-shaped Y-axis moving table 33 is placed on the upper surface of the X-axis moving table 32 and moves in the Y-axis direction parallel to the plane of the fixing table 31 and is orthogonal to the X-axis of the X-axis moving table 32. . The Y-axis knob 36 is located between the X-axis moving table 32 and the Y-axis moving table 33, and one side is coupled to the X-axis moving table 32 and the other side is coupled to the Y-axis moving table 33. and moves the Y-axis moving table 32 in the Y-axis direction parallel to the plane of the fixing table 31.

A quadrangular Z-axis moving table 34 supporting the stage 20 is placed on the upper surface of the Y-axis moving table 33 and moves in the Z-axis direction perpendicular to the plane of the fixed table 31 . For example, the Z-axis moving unit 34 may move in the Z-axis direction from the plane of the fixed unit 31 using a rack and a pinion.

A U-shaped holder 38 having a groove is installed on the upper surface of the Y-axis moving table 33, and the Z-axis moving table 34 is inserted into the groove of the holder 38 and supported by the holder 38. It can slide in the Z-axis direction.

Between the holder 38 and the Y-axis mover 33, a fixing plate 39 is installed and fixed on the upper surface of the Y-axis mover 33, and the fixing plate 39 and the Z-axis mover 34 have A fixing means 40 for fixing the position of the Z-axis moving table 34 may be installed.

The fixing means 40 includes a length member 41 having a length in which one end is fixed to the Z-axis moving table 34 and the other end is fixed to the fixing plate 39, and a slot formed along the length of the length member 41 ( 43), a fixing hole (not shown) formed in the Z-axis moving table 34 and corresponding to the slot 43, and a fixing bolt 45 that passes through the slot 43 and is screwed into the fixing hole. there is.

The Z-axis moving table 34 moves along the length of the slot 43 in a state in which the fixing bolt 45 is loosely released from the fixing hole, and when the fixing bolt 45 is firmly screwed into the fixing hole, the Z axis The moving table 34 is fixed to the length member 41 so that its position is fixed.

In this way, the fixing means 40 firmly fixes the Z-axis mover 34 adjusted to the position by the fine adjustment of the Z-axis knob 37 so that it does not move any more.

A pinion is formed on the Z-axis knob 36 coupled to the Z-axis moving table 34 through the wall of the holder 38, and a rack engaged with the pinion is formed on the Z-axis moving table 34 so that the Z-axis is The copper stage 34 can move in the Z-axis direction.

The X-axis knob 35, Y-axis knob 36, and Z-axis knob 37 finely control the movement of the X-axis mover 32, Y-axis mover 33, and Z-axis mover 34. It may be a micrometer so that Preferably, the stage 20 on which the object is placed can be finely adjusted in the X-axis, Y-axis, and Z-axis directions by using a micrometer with a driving accuracy of 1 μm or less.

A first rail is formed on the upper surface of the fixing table 31, and a first rail groove is formed on the lower surface of the X-axis moving table 32 to be fitted in correspondence with the first rail, so that the X-axis moving table 32 is It can move precisely along the rail.

In addition, a second rail is formed on the upper surface of the X-axis mover 32, and a second rail groove is formed on the lower surface of the Y-axis mover 33 to correspond to the second rail, and the Y-axis mover (33) 33) can precisely move along the second rail.

A barrel 50 is installed on the support 13 . The barrel 50 may be installed on the support 13 to enable working distance from the stage 20 . The barrel 50 is installed and fixed to the U-shaped bracket 60, and the distance of the barrel 50 from the stage 20 can be adjusted by moving the bracket 60 up and down.

For example, it is possible to adjust the distance of the barrel 50 from the stage 20 by installing a distance adjusting bar 70 having a length facing the vertical part 61 of the bracket 60 on the top of the support 13. there is. The barrel 50 passes through the horizontal portions 63 of the bracket 60 and is fixedly installed.

In the distance control table 70, a plurality of distance control holes 71 are formed at a distance from each other in the vertical direction (Z-axis direction), and the distance control holes 71 and the distance control holes 71 are formed in the vertical part 61 of the bracket 60 Corresponding holes (not shown) may be formed.

The bracket 60 is moved up and down along the length of the distance adjusting table 70 so that the hole coincides with one of the distance adjusting holes 71 and adjusts the distance between the matched hole. The distance of the barrel 50 from the stage 20 can be adjusted by fixing the fixture 73 into the hole 71 . In this way, the adjustment of the distance of the lens barrel 50 from the stage 20 is determined according to the volume of the subject.

The distance adjustment holes 71 are arranged in two rows along the length of the distance adjustment table 70 so that the bracket 60 is firmly fixed to the distance control table 70, so that the distance-adjusted barrel 50 is stably fixed. And, the fixture 73 may be a pin or bolt that can be inserted and detached from the hole and the distance adjusting hole 71.

A guide groove 75 is formed on the distance control rod 70, and a guide protrusion (not shown) fitted in correspondence with the guide groove 75 is formed on the vertical portion 61 of the bracket 60. It is possible to guide the bracket 60 moving up and down along the length of (70).

An optical module for receiving and condensing light reflected from a subject placed on the stage 20 is installed inside the lens barrel 50 . The optical module may include first and second lenses 81 and 83.

The first lens 81 is installed on the lower end of the lens barrel 50, the second lens 83 is installed on the upper end of the lens barrel 50, and, if necessary, between the first and second lenses 81 and 83 More lenses may be installed. Each of the first and second lenses 81 and 83 may be configured as a lens group.

The first lens 81 installed at the lower end of the lens barrel 50 functions as an objective lens for capturing an image by receiving infrared rays reflected from a subject, and the second lens 83 installed at the upper end of the lens barrel 50. ) performs the function of a condensing lens for condensing light traveling in parallel by the first lens 81.

An optical module composed of first and second lenses 81 and 83 receives and condenses short-wavelength infrared (SWIR) in a wavelength range of 0.9 μm to 2.5 μm reflected from a subject. Short-wavelength infrared rays of 0.9 μm to 2.5 μm have fog and material penetration characteristics.

A detector 90 is installed at the upper end of the barrel 50 . The detector 90 converts the short-wavelength infrared energy collected by the optical module into a digital image signal and outputs it. The detector 90 acquires the short-wavelength infrared energy of the object condensed by the optical module, converts the obtained short-wavelength infrared energy into a digital image signal, and outputs the converted image signal.

For example, when the detector 90 has a 640×512 array, the optical module composed of the first and second lenses 81 and 83 has a 4x (4×) to secure a horizontal field of view (FOV) of 2.5 mm. ), and the resolution is optimized to have a value of 4 μm or less. Further, the optical module may have a 6x (6x), 10x (10x) arrangement, and the like, and the arrangement of the detector 90 may be changed accordingly.

A light source 110 is installed in the barrel 50 . The light source 110 may be built into the housing and installed orthogonally in the middle of the barrel 50 . The light source 110 radiates light to a subject through the lens barrel 50 to secure short-wavelength infrared light.

The light source 110 may be any light source capable of radiating light, and is not limited thereto. Preferably, the light source 110 is preferably a halogen lamp that can satisfy all wavelength bands, and if the light source 110 is a halogen lamp, it is preferable that the ballast 111 is electrically connected to secure the stability of discharge.

A beam splitter 120 is installed inside the barrel 50 . The beam splitter 120 is built into the barrel 50 to face the light source 110 and reflects a part of the light emitted from the light source 110 and transmits the other part. The light reflected by the beam splitter 120 is reflected from the subject, returns to the beam splitter 120, and is transmitted to the detector 90 so that an image can be seen.

A filter 130 may be mounted at a lower end of the barrel 50 . The filter 130 selectively transmits light reflected from a subject and blocks the remaining light. The filter 130 is preferably a narrowband optical filter that transmits short-wavelength infrared (SWIR) in a narrow wavelength band of 0.9 μm to 2.5 μm and blocks other light.

The narrowband optical filter constituting the filter 130 makes it possible to obtain a hyperspectral image in the short-wavelength infrared region, and at this time, a wavelength band width of 30 nanometers or less may be applied in the short-wavelength infrared region. A narrowband optical filter is a hyperspectral filter.

When light is irradiated from the light source 110, the light is reflected from the beam splitter 120 along the lens barrel 50 toward a subject placed on the stage 20. The beam splitter 120 reflects only a part of the light, and the reflected light passes through the first lens 81 and the filter 130 and is irradiated to the subject.

The light irradiated to the subject is reflected and passes through the filter 130, and the filter 130 transmits short-wavelength infrared (SWIR) in a narrow wavelength band of 0.9 μm to 2.5 μm and blocks the remaining light. Short-wavelength infrared rays transmitted through the filter 130 are received by the first lens 81 , and short-wavelength infrared rays received by the first lens 81 and propagated as parallel light are transmitted through the beam splitter 120 . The beam splitter 120 transmits only short-wavelength infrared rays transmitted through the lens 81 .

The short-wavelength infrared rays passing through the beam splitter 120 and traveling as parallel light are collected by the second lens 83, and the collected short-wavelength infrared rays are transmitted to the detector 90 located above the lens barrel 50. The detector 90 acquires the short-wavelength infrared energy of the subject condensed through the second lens 83, converts the obtained short-wavelength infrared energy into a digital image signal (electrical signal), and outputs it.

A display device 140 such as a monitor is electrically connected to the detector 90, and the digital image signal output from the detector 90 is displayed as an image on the display device 140, and the image is displayed in the short-wavelength infrared wavelength region. It is a hyperspectral image.

The hyperspectral image divides the wavelength band into small pieces to obtain an image in which the intensity of light reflected from a subject is different according to each wavelength characteristic. In this case, it is possible to secure an image having characteristics of a subject that cannot be seen in the entire wavelength band.

The light source 110 may use a halogen lamp, LED light, laser, or the like. The halogen lamp illuminates the entire short-wavelength infrared wavelength band to the subject. Therefore, it is possible to secure an image of rays reflected from a subject for all short-wavelength infrared wavelength bands. After illumination with a halogen lamp, when the narrowband optical filter 130 is inserted between the microscope and the subject, a hyperspectral image for a specific wavelength region, that is, a short-wavelength infrared region is obtained.

Even when LED light or laser light is used as the light source 110, a hyperspectral image in the short-wavelength infrared wavelength region can be obtained. The wavelength resolution of the hyperspectral image can be realized below 20 nm.

The detector 90 may be electrically connected to a computer means for controlling an image output of the display device 140 . A computer means such as a laptop or PC stores the digital image signal output from the detector 90, controls the output to the display device 140, and analyzes the image output to the display device 140.

A visible light microscope, a well-known technique, is a microscope that can enlarge and view the size of an object using a wavelength band visible to the naked eye, and secures an image of the object using reflected light.

An infrared microscope is a microscope that can enlarge and view the size of an object using a wavelength band invisible to the naked eye.

The near-infrared microscope uses a CCD sensor or CMOS sensor that detects visible light to secure an image from the light reflected from the subject, and the short-wavelength infrared microscope uses an InGAS (Indium Gallium Arsenide) sensor that detects short-wavelength infrared light to obtain an image from the reflected light from the subject. Obtain an image from the rays.

Mid-infrared and far-infrared microscopes secure images by detecting radiated energy rather than detecting rays reflected from a subject. The image that can be seen by radiant energy has the advantage that it can be seen even when there is no light at all because the temperature distribution of the subject is expressed as an image, but it has the disadvantage that it is not expressed in the image when there is no temperature difference.

In general, since visible light does not pass through an object, it is impossible to know whether there is a crack or damage inside the object. However, since short-wavelength infrared rays penetrate the object, internal cracks or damage can be inspected non-destructively. However, even in the case of mid-infrared and far-infrared rays, you can see the inside because they penetrate through the object, but you cannot see if there is no temperature difference between the crack or damaged area and the surrounding area. Therefore, it is most preferable to use short-wavelength infrared light to inspect cracks or damage inside an object.

For example, it is most preferable to use short-wavelength infrared rays to inspect internal cracks or damages of silicon wafers, which are key components used in semiconductor processing. Near-infrared rays have a wavelength range of 0.7um to 1.0um, which is shorter than the wavelength range of short-wavelength infrared rays, which is 0.9um to 2.5um, so they hardly penetrate silicon wafers.

As described above, according to the present invention, it is possible to obtain an image of a bonding portion inside silicon that cannot be seen with a conventional optical microscope by acquiring short-wavelength infrared rays having transmission characteristics of a material from a subject.

The present invention has been examined with a focus on preferred embodiments, and those skilled in the art can implement embodiments of a different form from the detailed description of the present invention within the essential technical scope of the present invention. You will be able to. Here, the essential technical scope of the present invention is shown in the claims, and all differences within the equivalent range should be construed as being included in the present invention.

10: body 11: base
13: support 20: stage
30: means of transportation 31: fixed stand
32: X-axis moving table 33: Y-axis moving table
34: Z-axis shifter 35: X-axis knob
36: Y-axis knob 37: Z-axis knob
38: holder 39: fixing plate
40: fixing means 41: length member
43: slot 45: fixing bolt
50: body tube 60: bracket
61: vertical part 63: horizontal part
70: distance control table 71: distance control hole
73: fixture 75: guide groove
81: first lens 83: second lens
90: detector 110: light source
111: ballast 120: beam splitter
130: filter 140: display device

Claims (3)

Base;
a support stand upright from the base;
a stage positioned on the base to place a subject;
a lens barrel installed on the support and facing a subject disposed on the stage;
a beam splitter installed inside the barrel;
a light source installed outside the lens barrel to face the beam splitter and radiating light to the subject through the beam splitter;
an optical module installed inside the lens barrel and obtaining short-wavelength infrared rays of 0.9 μm to 2.5 μm from the light of the light source reflected from the subject; and
A detector installed in the lens barrel and converting short-wavelength infrared rays of 0.9 μm to 2.5 μm acquired by the optical module into a digital image signal and outputting it,
A filter installed at a lower end of the lens barrel and transmitting only short-wavelength infrared rays of 0.9 μm to 2.5 μm from the light of the light source reflected from the subject,
A distance adjuster is installed on the upper part of the support, and the vertical portion of the U-shaped bracket for fixing the barrel faces the distance adjuster, and the bracket moves up and down along the distance adjuster, and the vertical portion of the bracket The formed hole matches one of the distance adjusting holes formed in the distance adjusting table, and a fixture is installed in the matched hole and the distance adjusting hole, so that the distance of the barrel from the stage is adjusted. short-wavelength infrared hyperspectral imaging microscopy system.
According to claim 1,
A short-wavelength infrared hyperspectral imaging microscope system in which moving means for moving the stage in X-axis, Y-axis, and Z-axis directions are installed between the support and the stage.
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