JP2004286855A - Stereoscopic microscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stereoscopic microscope capable of effectively utilizing illuminating light and enabling a user to stably observe a large sample with excellent operability. <P>SOLUTION: The stereoscopic microscope is provided with a stereoscopic microscope frame 21 consisting of a base 21a having a movable XY stage 22 for mounting a sample 23 thereon and a horizontal arm 21c extended from a barrel part 21b erected from the base 21a in parallel with the base 21a, an illuminating optical system 28 attached to the horizontal arm 21c and capable of irradiating the sample 23 mounted on the XY stage 22 with vertical illumination light, a half mirror 24 arranged in an optical path between the illuminating optical system 28 and the sample 23 and capable of separating the optical path into an illuminating optical path for transmitting the vertical illumination light from the illuminating optical system 28 and an observing optical path for reflecting light from the sample 23, and at least a zoom barrel and an eyepiece mirror barrel 40 arranged on the reflecting optical path side observing optical path of the half mirror 24. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a stereo microscope that is most suitable for observing a large sample.
[0002]
[Prior art]
As a large sample, there are a glass substrate of a flat panel display (FPD) and a semiconductor wafer.
[0003]
For example, in the FPD manufacturing process, in order to maintain the quality of the glass substrate in a stable manner, an inspection of the appearance of unevenness in the thickness of a resist or the like on the substrate, a pinhole on the ITO film, etc. Inspection of the appearance of dust and scratches attached to the surface has become extremely important. This is the same in the semiconductor wafer manufacturing process.
[0004]
Therefore, a stereoscopic microscope, which is optimal for the appearance inspection of such a large sample, has been put to practical use.
[0005]
FIG. 3 shows an example of a conventional stereo microscope. In the figure, reference numeral 1 denotes a mount for a stereomicroscope. The mount 1 for a stereomicroscope includes a base 1a arranged in a horizontal direction, a body 1b provided upright with respect to the base 1a, and a body An arm 1c is provided at the tip of 1b in parallel with the base 1a. An XY stage 2 that can hold a large sample 3 and move in the XY directions is provided on the base 1a. A zoom lens barrel 4 is supported at the tip of the arm 1c via a focusing mechanism including a rack and a pinion. An objective lens 5 is provided at the lower end of the zoom lens barrel 4, and is moved up and down along the optical axis 5a by operating a focusing dial 6 provided at the tip of the arm 1c. The magnification of the zoom lens barrel 4 can be changed by operating the zoom dial 7.
[0006]
At the upper end of the zoom lens barrel 4, a relay lens barrel 9 is provided horizontally via an illumination unit 8. The illumination unit 8 includes a polarizer 10, an analyzer 11, and a polarizing beam splitter (hereinafter, referred to as PBS) 12. Illumination light from a light source 13 passes through the polarizer 10 and is reflected by the PBS 12 so that the zoom lens barrel 4, the objective lens 5 , And λ / 4 plate 14 so that the reflected light from the sample 3 follows the above-described optical path in reverse, passes through the PBS 12 and the analyzer 11 and enters the relay barrel 9.
[0007]
The relay barrel 9 has a pair of bending mirrors 15 and 16 and a relay optical system 17, reflects reflected light from the sample 3 incident from the illumination unit 8 side by the bending mirror 15, and passes through the relay optical system 17. Further, the light is reflected by the bending mirror 16 and can be visually observed by an observer via the eyepiece 19 of the eyepiece tube 18.
[0008]
In this case, the relay optical system 17 functions to extend the optical path of the reflected light incident from the illumination unit 8 side to the specimen 3 surface and to the observer side. It is compatible with large specimens in which the distance on the observer side from the axis 5a to the eye point 20 on the eyepiece tube 18 is large. That is, when observing the deep part of the large sample 3 held on the XY stage 2, the XY stage 2 is drawn toward the user. At this time, in order to prevent the XY stage 2 from interfering with the observer, a distance L1 between the optical axis 5a of the objective lens 5 and the eye point 20 is ensured by extending the optical path by the relay optical system 17. Conversely, when observing the front part of the specimen 3 held on the XY stage 2, the XY stage 2 is pushed to the back. At this time, in order to prevent the XY stage 2 from interfering with the body 1b, the arm 1c of the stereoscopic microscope mount 1 is lengthened, and a distance L2 between the optical axis 5a of the objective lens 5 and the body 1b is also ensured. Like that.
[0009]
[Patent Document 1]
JP-A-60-227214
[Problems to be solved by the invention]
However, when the zoom lens barrel 4 is arranged in a common optical path of the illumination optical system and the observation optical system, the zoom optical system generally uses a lens having a large radius of curvature, and the illumination light is reflected on the lens surface. As a result, a flare entering the eyepiece lens 19 occurs. To prevent this flare, a polarizer 10, an analyzer 11, a PBS and a λ / 4 plate 14 are required. The light amount is greatly reduced due to the transmission loss of light in the polarizer 10, the analyzer 11, and the PBS. Therefore, it is necessary to prepare a large light amount in advance as the light source 13, so that the light source 13 is expensive and large. Problem arises.
[0011]
In addition, since the zoom optical system is arranged in the optical path, the illumination field cannot be increased, so that the zoom magnification is only about 70% on the high magnification side, and there is a problem in that the zoom magnification decreases.
[0012]
Further, not only the expensive relay barrel 9 is required, but also the eyepiece barrel 18 is arranged far away from the focusing unit guide which determines the rigidity of the apparatus via the relay barrel 9, so that the eyepiece lens 19 is required. There is a problem that vibration is easily generated in the portion, and the observation image fluctuates during visual observation, making it difficult to observe.
[0013]
Further, since the focusing dial 6 and the zoom dial 7 are disposed far away from the observer due to the presence of the relay lens barrel 9, the operation is difficult, and the objective lens 5, the zoom lens barrel 4, the illumination unit 8 and Since the relay barrel 9 is configured to be stacked, there is also a problem that the position of the eye point 20 becomes high and it becomes difficult to observe.
[0014]
By the way, FIG. 6 of Patent Document 1 discloses an arrangement in which a variable magnification mirror unit and an objective lens are arranged in a horizontal direction so that a relay barrel is not required. In other words, in this publication, a horizontal bar is provided on a support provided upright on the gantry, and the variable magnification mirror is provided on the horizontal bar via a focusing operation unit. An objective lens is provided in the variable power mirror unit, and the operation of the focusing operation unit moves the variable power mirror unit together with the objective lens in the horizontal direction along the optical axis of the objective lens. It has become. In addition, a table is provided on the column together with the reflection mirror, and the sample is placed on the table, and the zooming operation with the zoom lens unit and the focusing operation with the focusing operation unit are performed. The light transmitted through is reflected by a reflection mirror, and can be visually observed by a binocular tube through an objective lens and a variable power mirror.
[0015]
However, in the stereo microscope configured as described above, since the transmitted illumination is used as the illumination method, the above-described polarizer, analyzer, PBS, and λ / 4 plate are not required. When an epi-illumination device is used as shown, a variable magnification mirror unit is arranged on a common optical path of the illumination optical system and the observation optical system, and a polarizer, an analyzer, and a PBS are required. Cause problems. Further, in FIG. 2 of Patent Document 1, since the table is configured to be supported by the tip of the column together with the reflecting mirror, an XY stage for holding a large sample cannot be mounted, and a slight external Vibration is also easily transmitted to the table and the reflection mirror, and there is a problem in that the image fluctuates during visual observation, making it difficult to observe.
[0016]
The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a stereoscopic microscope that can effectively use illumination light, has good operability, and can stably perform observation of a large sample. .
[0017]
[Means for Solving the Problems]
The present invention provides a stereo microscope comprising a base having a movable XY stage on which a sample is placed, and a horizontal arm extending parallel to the base from a body provided upright with respect to the base. And a illuminating means provided on the horizontal arm for irradiating the specimen mounted on the XY stage with incident illumination light; and an illuminating means disposed on an optical path between the illuminating means and the specimen. An optical element that separates into an illumination optical path that transmits incident illumination light and an observation optical path that reflects light from the sample, at least a zoom lens barrel and an eyepiece cylinder that are disposed in the observation optical path on the reflection optical path side of the optical element; And a microscope main body comprising:
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0019]
(First Embodiment)
FIG. 1 shows a schematic configuration of a Galileo-type stereo microscope according to a first embodiment of the present invention.
[0020]
In FIG. 1, reference numeral 21 denotes a mount for a stereoscopic microscope. The mount 21 for a stereoscopic microscope includes a base 21a arranged in a horizontal direction, a body 21b provided upright with respect to the base 21a, and a body 21b. An arm 21c is provided at the end of the portion 21b in parallel with the base 21a. An XY stage 22 that holds a large substrate plate such as an FPD glass substrate or a semiconductor wafer as a specimen 23 and is movable in the XY directions is provided on the base 21a. In this case, the moving space of the XY stage 22 in the X direction and the Y direction requires twice the size of the sample 23, and the depth of the base 21a mounted on the XY stage 22 is twice the size of the XY stage 22. Requires space.
[0021]
The horizontal arm 21c of the stereomicroscope mount 21 extends above a substantially central portion of the base 21a (substantially the central portion of the movement area of the XY stage). A half mirror 24 as an optical element for separating the optical illumination optical path and the observation optical path is inclined at a predetermined angle (45 °) at the distal end of the horizontal arm 21c. The half mirror 24 bends an optical axis 36a of an objective lens 36 described later vertically on the surface of the sample 23. A microscope main body support portion 29 is integrally formed at the tip of the horizontal arm portion 21c. A mirror 25 is arranged on the microscope main body support portion 29 at a predetermined angle (45 °) above the half mirror 24. An illumination optical system 28 including a light projecting lens 26 and a light source 27 for epi-illumination is arranged on the horizontal optical axis of the mirror 25. The illumination light from the light source 27 passes through the light projecting lens 26, is reflected by the mirror 25, passes through the half mirror 24, and is emitted perpendicularly to the surface of the sample 23. The reflected light from the sample 23 is reflected by the half mirror 24 and is deflected in the horizontal direction.
[0022]
A shaft 30 extending parallel to the XY stage 22 is fixed to an upper portion of the microscope main body support portion 29 by a fixing screw 31a.
[0023]
A fixed portion 32 is provided on the shaft 30. The fixing portion 32 has a guide through-hole 32a having a diameter equal to the diameter of the shaft 30, and the shaft 30 is inserted through the through-hole 32a, and is fixed by a fixing screw 31b. The fixing part 32 is horizontally moved along a convex guide formed on the shaft 30 so as not to rotate, and can be moved to an arbitrary position and fixed by tightening the fixing screw 31b. .
[0024]
On the lower surface of the fixed part 32, a microscope main body composed of a zoom lens barrel 35, an objective lens 36, a mirror box 38, and an eyepiece cylinder 40 constituting an observation optical system via a focusing part 33 composed of a rack and a pinion. Supported.
[0025]
The zoom lens barrel 35 and the objective lens 36 are arranged side by side on the optical axis 36a, which is the horizontal optical path of the half mirror 24 parallel to the XY stage 22, in the direction along the shaft 30. A zoom lens barrel 35 is connected to the fixed part 32 via a focusing part 33, and the microscope body is moved along the fixed part 32 by operating the focusing dial 34 so that the focal point of the objective lens 36 with respect to the specimen 23. Are combined. The magnification of the zoom lens barrel 35 can be changed by operating the zoom dial 37.
[0026]
The objective lens 36 used here is a lens having a large WD (working distance), for example, a lens having a size of about 0.5 × and a WD of about 180 mm which is prepared as a standard in a general stereo microscope.
[0027]
A mirror box 38 is provided at an end of the zoom lens barrel 35 opposite to the objective lens 36. The mirror box 38 is provided with a mirror 39. The mirror 39 bends the optical axis of the zoom lens barrel 35 upward. Further, an eyepiece tube 40 having an eyepiece 41 with its optical axis aligned is arranged in the mirror box 38.
[0028]
In such a configuration, when the illumination light is emitted from the light source 27 of the illumination optical system 28, the illumination light passes through the light projecting lens 26, is reflected by the mirror 25, passes through the half mirror 24, and passes on the XY stage 22. Is irradiated perpendicularly to the specimen 23 of.
[0029]
The reflected light from the specimen 23 is reflected by the half mirror 24 in the direction of the optical axis 36a of the objective lens 36, reflected by the mirror 39 of the mirror box 38 via the objective lens 36 and the zoom lens barrel 35, and reflected by the eyepiece barrel 40. The image is visually observed by an observer through the eyepiece 41 as an observation image.
[0030]
In this case, the user operates the zoom dial 37 to select a desired zoom magnification of the zoom lens barrel 35, and operates the focusing dial 34 to horizontally move the microscope main body along the optical axis 36a, thereby attaching the microscope body to the optical path. The focusing of the objective lens 36 is performed. Thereby, it is possible to visually observe through the eyepiece lens 41 in a state where the part to be observed on the specimen 23 is enlarged.
[0031]
Therefore, according to this configuration, the illumination light from the light source 27 of the illumination optical system 28 is irradiated to the sample 23 without passing through the zoom lens barrel 35, and the zoom lens barrel 35 is removed from the illumination optical path. This can prevent flare caused by the zoom lens, which has been a problem in the epi-illumination stereo microscope. This eliminates the need for the polarizer, analyzer, and PBS required by conventional epi-illumination stereomicroscopes. Light can be used effectively. Further, it is not necessary to prepare a light source having a particularly large light amount, so that a low-priced light source can be used. In addition, by separating the zoom lens barrel 35 from the illumination optical path, a large illumination field can be obtained, and there is no restriction on the zoom magnification, so that the zoom magnification range can be widened.
[0032]
In addition, the shaft 30 extends horizontally from the tip of the arm portion 21c, supports the microscope body via the focusing portion 32, and shortens the distance from the fixed portion 32 to the eyepiece 41. And the effect of vibration can be reduced. . Further, if the position close to the center of gravity of the microscope main body is supported with respect to the fixing portion 32, the microscope main body can be reliably and stably supported without applying excessive force to the microscope main body. A stable speculum can always be realized without blurring.
[0033]
Furthermore, the eye point 48 does not move in the height direction with respect to the observer because it moves only slightly in the front-rear direction for focusing the objective lens 36, and does not impair the operability of the operator. Absent. Further, since the focusing dial 34 and the zoom dial 37 can be arranged near the observer side, the operability can be improved.
[0034]
Furthermore, by arranging the zoom lens barrel 35 and the objective lens 36 constituting the microscope main body in a horizontal direction in parallel with the sample mounting surface of the sample mounting surface 22, the sample can be sampled without using a conventional relay lens barrel. The distance from the optical axis 36a of the objective lens 36 perpendicular to the 23 surfaces to the eye point 48 on the eyepiece tube 40 side can be made large, and it can sufficiently cope with a large sample. In this case, the half mirror 24 and the mirror box 38 are required instead of the relay barrel, but these are cheaper than the relay barrel and can be economically advantageous.
[0035]
Furthermore, since the half mirror 24 is provided directly at the tip of the arm portion 21c, it is possible to prevent external vibration from being transmitted to the half mirror 24, and to reflect the reflected light from the sample 23 to the light of the objective lens 36. Since the light can be stably reflected in the direction of the axis 36a, there is no deviation of the optical axis on the microscope main body side, and a stable sample image can always be observed.
[0036]
(Second embodiment)
Next, a second embodiment of the present invention will be described.
[0037]
FIG. 2 shows a schematic configuration of a second embodiment of the present invention, and the same parts as those in FIG. 1 are denoted by the same reference numerals.
[0038]
In the first embodiment, an example is described in which a standard specification having a relatively large WD is used as the objective lens 36. However, in the second embodiment, the objective lens 43 having a short WD can be used. ing.
[0039]
In this case, an objective lens 43 is arranged in an optical path between the half mirror 24 and the sample 23. The objective lens 43 is supported at the distal end of the arm 21c via a focusing unit 44. The focusing unit 44 includes, for example, a rack and a pinion, and is provided with a focusing dial 45 connected to the pinion. By operating the focusing dial 45, the objective lens 43 moves in a direction perpendicular to the surface of the specimen 23. It can be moved up and down.
[0040]
The illumination optical system 28 includes a half mirror 46 instead of the mirror 25. In addition, a CCD camera 47 is disposed as an imaging unit above the tip of the arm 21c, and a part of the reflected light from the sample 23 passes through the half mirror 24 and further passes through the half mirror 46 of the illumination device 28. Thus, an image is formed on the imaging surface of the CCD camera 47 via the imaging lens 49 so that an observation image of the sample 23 can be captured.
[0041]
With such a configuration, by allowing only the objective lens 43 to move up and down along the optical axis 43a, it can be applied to an objective lens with a short WD.
[0042]
Further, since the objective lens 43 is moved up and down in the optical path between the half mirror 24 and the sample 23, the eye point 48 does not move at all, so that the operability can be further improved.
[0043]
In addition, the present invention is not limited to the above-described embodiment, and can be variously modified in an implementation stage without departing from the spirit of the invention.
[0044]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a stereomicroscope that can effectively use illumination light and that can stably observe a large sample with good operability.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of a first embodiment of a stereomicroscope according to the present invention.
FIG. 2 is a diagram showing a schematic configuration of a second embodiment of the stereomicroscope according to the present invention.
FIG. 3 is a diagram showing a schematic configuration of a conventional stereo microscope.
[Explanation of symbols]
Reference numeral 21: Stereo microscope mount 21a Base 21b Body 21c Arm 22 XY stage 23 Sample 24 Half mirror 25 Mirror 26 Light projecting lens 27 Light source 28 Illumination optical system 29 Microscope body support Part 30: Shafts 31a, 31b: Fixing screw 32 ... Fixing part 32a ... Through hole 33 ... Focusing part 34 ... Focusing dial 35 ... Zoom lens barrel 36 ... Objective lens 36a ... Optical axis 37 ... Zoom dial 38 ... Mirror box 39 Mirror 40 Eyepiece tube 41 Eyepiece 43 Objective lens 43a Optical axis 44 Focusing unit 45 Focusing dial 46 Half mirror 47 CCD camera 48 Eye point 49 Imaging lens

Claims (4)

A stereo microscope base including a base having a movable XY stage on which a sample is mounted, and a horizontal arm extending in parallel with the base from a body provided upright with respect to the base,
Illuminating means provided on the horizontal arm for irradiating the specimen mounted on the XY stage with incident illumination light;
An optical element disposed in an optical path between the illumination unit and the sample, and an optical element for separating an illumination optical path that transmits incident illumination light from the illumination unit and an observation optical path that reflects light from the sample,
A microscope body comprising at least a zoom lens barrel and an eyepiece tube arranged in the observation optical path on the reflection optical path side of the optical element,
A stereo microscope characterized by comprising: The microscope body is integrally connected to an objective lens, a zoom lens barrel, and an eyepiece barrel. The microscope body is supported on a shaft extending from the horizontal arm portion and is arranged on the reflection-side observation optical path. The stereo microscope according to claim 1, wherein: The microscope body is formed by integrally connecting a zoom lens barrel and an eyepiece barrel. The microscope body is supported on a shaft extending from the horizontal arm, and is disposed in the observation optical path on the reflection side. 2. The stereo microscope according to claim 1, wherein the stereo microscope is disposed on a common optical path on the side. 4. The objective lens according to claim 3, wherein the objective lens is provided on a common optical path between an illumination optical path and an observation optical path between the optical element and the sample so as to be movable in a direction perpendicular to the sample mounting surface. Stereo microscope.

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