JP2012073133A - Observation device and observation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image formation type observation device and an observation method capable of simultaneously capturing images of positioning marks for a first object plane and a second object plane with different heights without varying magnification.SOLUTION: A observation device 1A includes: partial reflection mirrors 2, 3 arranged coaxially; and an optical microscope 19 for detecting light beams emitted from object points on a hologram surface 21a and a photodetector surface 22a through the partial reflection mirrors 2, 3. The optical microscope 19 observes a photodetector surface 22a (first object plane) by transmitted light from the partial reflection mirrors 2, 3 and observes the hologram surface 21a (second object plane) by transmitted light after reciprocating between the partial reflection mirror 2 and the partial reflection mirror 3. Thus, the observation device 1A can simultaneously optically observe the photodetector surface 22a (first object plane) and the hologram surface 21a (second object plane) which are arranged coaxially and have different heights.

Description

  The present invention relates to an observation apparatus and an observation method, and more specifically, an observation apparatus and an observation method for observing optically simultaneously in order to relatively align alignment marks of two objects having different heights. About.

  As an alignment method, there is a method of forming an image of an alignment mark on an image pickup device such as a CCD (Charge Coupled Device) using a microscope and detecting the position of the alignment mark using an image processing method. It has been put into practical use and is widely used. Furthermore, as a case of aligning two objects having different heights, a method using a bifocal lens and a method using a separation optical system have been proposed.

  The bifocal lens is formed by concentrically forming lenses having different focal lengths. In the method using a bifocal lens, the difference between the two focal lengths is made equal to the gap between the first object surface and the second object surface. Thereby, the alignment mark on the first object surface and the alignment mark on the second object surface are simultaneously imaged on the same image surface to perform alignment. A bifocal lens is disclosed in Patent Document 1 in which the difference between two focal lengths is variable.

  Non-Patent Document 1 describes a method using a separation optical system. Here, it demonstrates using FIG.

FIG. 7 is a diagram showing a configuration of a conventional observation apparatus 100 using a separation optical system.
Referring to FIG. 7, the observation apparatus 100 includes a light source 60, objective lenses 61, 63, 65, half mirrors 62, 67, and prisms 64, 66. The observation apparatus 100 is provided with two optical systems having different optical paths in a microscope barrel. The first optical system includes a half mirror 62, an objective lens 63, and a prism 64. The second optical system includes a half mirror 67, an objective lens 65, and a prism 66.

  The observation apparatus 100 condenses the light emitted from the light source 60 on an object point on the first object surface 68 and an object point on the second object surface 69. Thereafter, in the observation apparatus 100, the positions of the objective lens 63 provided in the first optical system and the objective lens 65 provided in the second optical system are adjusted. As a result, the alignment mark on the first object surface 68 and the alignment mark on the second object surface 69 are simultaneously imaged on the same image plane 70.

Japanese Patent Laid-Open No. 6-224101 (released on August 12, 1994)

Jongstrom "Bifocal Optics" <URL: http://www.g-angstrom.com/products/goptics.php>

  In the method using a bifocal lens, a special lens such as a bifocal lens is required, so that the optical system becomes expensive. In addition, the method using the separation optical system requires a plurality of independent optical systems, which complicates the optical system. In either case, the microscope itself needs to be modified.

  In any method, the magnification of the optical system differs between the optical system that observes the first object surface and the optical system that observes the second object surface. Therefore, even if the alignment mark on the first object surface and the alignment mark on the second object surface are the same, the size of each alignment mark is different on the image surface. As a result, there is a problem that even if the alignment is performed accurately on the image plane, there is a problem that the alignment is misaligned, which is not suitable for precise alignment.

  SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an imaging type observation apparatus and an observation method capable of capturing alignment mark images of first and second object surfaces having different heights at the same time without changing the magnification. That is.

  According to an aspect of the present invention, there is provided an observation apparatus for optically observing first and second objects having different heights arranged on the same axis at the same time, the first being arranged on the same axis. And a second partial reflection mirror, and an optical observation system for detecting light from the first and second objects via the first and second partial reflection mirrors, The first object is observed by the transmitted light of the first and second partial reflection mirrors, and the second object is reciprocated between the first partial reflection mirror and the second partial reflection mirror. Observe with transmitted light.

  Preferably, the ratio between the reflectance and the transmittance of the first and second partial reflection mirrors is 1: 1.

  Preferably, the first partial reflection mirror has a circular outer shape, and the second partial reflection mirror has an annular shape.

  Preferably, the first partial reflection mirror has a circular mirror surface, and the second partial reflection mirror has an annular dichroic beam splitter surface.

  Preferably, the first object is observed with blue observation light transmitted through the dichroic beam splitter surface, and the second object is observed with red observation light reflected on the dichroic beam splitter surface.

  Preferably, the optical observation system includes an objective lens that collects light from the first and second objects, and an image sensor that receives the collected light, and is disposed between the objective lens and the image sensor. The distance is fixed.

  Preferably, the optical observation system includes an objective lens that collects light from the first and second objects, and the distance between the objective lens and the first and second partial reflection mirrors is fixed. ing.

  Preferably, the first object is a photodetector of the photodetector unit, and the second object is a hologram element of the photodetector unit.

  According to another aspect of the present invention, there is provided an observation method for simultaneously and optically observing first and second objects having different heights arranged on the same axis, wherein the first and second objects are arranged on the same axis. Observing the first object with the transmitted light of the first and second partially reflecting mirrors, and the second object with the transmitted light after reciprocating between the first partially reflecting mirror and the second partially reflecting mirror. Observing an object.

  According to the embodiment of the present invention, alignment mark images of the first object surface and the second object surface having different heights can be taken in simultaneously without changing the magnification.

It is the schematic for demonstrating the structure of 1 A of observation apparatuses by Embodiment 1 of this invention. It is sectional drawing which showed the schematic structure of the 3 wavelength optical pick-up apparatus 30 adjusted and fixed by 1 A of observation apparatuses of FIG. 3 is a cross-sectional view showing a configuration of a photodetector unit 29. FIG. 3 is a front view showing a configuration of a hologram element 21. FIG. 3 is a front view showing a configuration of a photodetector 22. FIG. It is the schematic for demonstrating the structure of the observation apparatus 1B by Embodiment 2 of this invention. It is the figure which showed the structure of the conventional observation apparatus 100 using a separation optical system.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

[Embodiment 1]
FIG. 1 is a schematic diagram for explaining the structure of an observation apparatus 1A according to Embodiment 1 of the present invention.

  With reference to FIG. 1, the observation apparatus 1 </ b> A of the first embodiment includes partial reflection mirrors 2 and 3, a mirror holding holder 4, a dichroic beam splitter 10, and an optical microscope 19. The optical microscope 19 includes an objective lens 5, a beam splitter 7, an image sensor 8, and an illumination light source 9. The dichroic beam splitter 10 guides the emitted light from the autocollimator 6 to the observation apparatus 1A. The optical microscope 19 does not need to be unique to the observation apparatus 1A, and may be a commercially available one, for example.

  The partial reflection mirror 2 is provided with a partial reflection mirror surface 2a on one surface of a transparent flat plate. Similarly, the partial reflection mirror 3 is provided with a partial reflection mirror surface 3a on one surface of a transparent flat plate. The partial reflection mirror surfaces 2 a and 3 a are arranged in parallel so that both mirror surfaces are orthogonal to the optical axis (Z axis) of the objective lens 5. The interval between the partial reflection mirror surfaces 2a and 3a can be adjusted. The ratio between the transmittance and the reflectance of the partial reflection mirror surfaces 2a and 3a is almost 1: 1.

  1 A of observation apparatuses are used for the assembly adjustment of the photodetector unit 29, for example. The photodetector unit 29 includes a hologram element 21, a photodetector 22, a hologram holder 23, and an adhesive layer 24. The photodetector unit 29 is mounted on an optical pickup device. The hologram element 21 is provided with a hologram surface 21a on one surface. The light detector 22 is provided with a light detector surface 22a on one surface.

  By using the observation apparatus 1A for assembling and adjusting the photodetector unit 29, the hologram surface 21a and the photodetector surface 22a can be observed simultaneously. As a result, it is possible to perform alignment by simultaneously forming the alignment marks formed on the respective surfaces on the same image plane.

  Next, a mechanism for enabling observation of the hologram surface 21a and the photodetector surface 22a simultaneously will be described. For example, the light beam from the illumination light source 9 is reflected by the beam splitter 7, passes through the objective lens 5 and the dichroic beam splitter 10, and is collected on the hologram surface 21 a and the photodetector surface 22 a. This condensing point is referred to as an “object point”. The light beam emitted from the object point corresponds to the reflected light from the condensing point. Here, the photodetector surface 22a corresponds to the first object surface, and the hologram surface 21a corresponds to the second object surface.

  Light rays (solid lines) emitted from an object point on the photodetector surface 22a are transmitted through the partial reflection mirror surfaces 2a and 3a. Thereafter, the light beam passes through the dichroic beam splitter 10, the objective lens 5, and the beam splitter 7, and is condensed on the image sensor 8 located on the image plane. The distance between the photodetector surface 22a and the objective lens 5 is adjusted by moving the entire lens barrel of the optical microscope 19. Thereby, control is performed so that an image of the photodetector surface 22a (first object surface) is formed on the image sensor 8 (image surface).

  Rays (broken lines) emitted from object points on the hologram surface 21a are transmitted through the partial reflection mirror surface 3a and reflected by the partial reflection mirror surface 2a. Next, the reflected light is reflected by the partial reflection mirror surface 3a and passes through the partial reflection mirror surface 2a. After that, the light ray follows a path similar to the object point on the photodetector surface 22a and is condensed on the image sensor 8 located on the image plane.

  Here, the partial reflection mirror surfaces 2a and 3a are set such that the optical path length of the light beam emitted from the object point on the photodetector surface 22a is the same as the optical path length of the light beam emitted from the object point on the hologram surface 21a. Adjust the interval. Thereby, in the image sensor 8 located on the image plane, the image of the photodetector surface 22a (first object surface) and the image of the hologram surface 21a (second object surface) are simultaneously formed. As a result, the alignment mark on the photodetector surface 22a and the alignment mark on the hologram surface 21a can be aligned.

  In the adjustment of the optical path length, the interval between the partial reflection mirror surfaces 2a and 3a is set so that the optical distance is half of the optical distance between the light detector surface 22a to be observed and the hologram surface 21a. The The optical distance is defined by the actual distance × the refractive index of the medium. The light detector surface 22 a (first object surface) and the hologram surface 21 a (second object surface) are irradiated with a light beam emitted from the illumination light source 9.

  Assuming that the transmittances of the partial reflection mirror surfaces 2a and 3a are T1 and T2, respectively, the ratio Ra of the amount of light from the object point on the photodetector surface 22a to the image sensor 8 is expressed as follows.

Ra = T1 ・ T2
On the other hand, the ratio Rb of the amount of light from the object point on the hologram surface 21a to the image sensor 8 is expressed as follows.

Rb = T1, T2, (1-T1), (1-T2)
In order to observe the hologram surface 21a and the photodetector surface 22a with sufficient brightness, it is preferable to set both the reflectance / transmittance ratios of the partial reflection mirror surfaces 2a and 3a in the vicinity of 1: 1. At this time, 25% of the light beam from the photodetector surface 22a (first object surface) reaches the image sensor 8, and about 6% of the light beam from the hologram surface 21a (second object surface) reaches the image sensor 8. To do.

  As described above, since the distance between the objective lens 5 and the imaging element 8 is fixed in the optical microscope 19 in the observation apparatus 1A of the first embodiment, the observation magnification of the hologram surface 21a and the photodetector surface 22a is fixed. Can be the same. For this reason, in the image sensor 8 located on the image plane, the size of the alignment mark on the photodetector surface 22a and the size of the alignment mark on the hologram surface 21a can be made the same. As a result, it is possible to accurately check the amount of positional deviation between the hologram surface 21a and the photodetector surface 22a.

  Next, a method for aligning the hologram surface 21a and the photodetector surface 22a using the observation apparatus 1A will be described. As described above, the image of the alignment mark on the photodetector surface 22 a and the alignment mark on the hologram surface 21 a are captured by the image sensor 8. The acquired image is subjected to image processing and analysis by an image processing apparatus (not shown). As a result, the relative positional relationship between the alignment marks, that is, the shift amount is detected.

  Control data corresponding to the detected deviation amount is output from the image processing apparatus to the stage control apparatus. The stage control device drives a stage (not shown) described above according to the control data. The position of the hologram element 21 can be adjusted by driving the stage.

  FIG. 2 is a cross-sectional view showing a schematic configuration of the three-wavelength optical pickup device 30 adjusted and fixed by the observation device 1A of FIG.

  Referring to FIG. 2, a three-wavelength optical pickup device 30 includes a main housing 50 and a laser unit 51, and records on a BD (Blu-ray Disc), DVD (Digital Versatile Disc), and CD (Compact Disc) system. Perform playback. The laser unit 51 includes a two-wavelength semiconductor laser 31, a blue semiconductor laser 32, a dichroic beam splitter 33, a diffraction element 34, and a laser unit housing 36.

  The two-wavelength semiconductor laser 31 emits laser light with wavelengths of 650 nm and 780 nm. Of these laser beams, CD-based recording / reproduction is performed using a 780 nm band laser beam, and DVD-based recording / reproduction is performed using a 650 nm band laser beam. The blue semiconductor laser 32 emits laser light having a wavelength of 405 nm. BD recording / reproduction is performed using the 405 nm band laser light.

  The diffractive element 34 divides the laser light emitted from the two-wavelength semiconductor laser 31 into three light spots of zero-order light and ± first-order light. Since the diffractive element 34 is provided, the three-wavelength optical pickup device 30 can detect a tracking error signal using a three-beam method, a DPP (Differential Push-Pull) method, or the like.

  The dichroic beam splitter 33 reflects laser light having a wavelength near 405 nm and transmits laser light having wavelengths near 650 nm and 780 nm. The dichroic beam splitter 33 guides the laser beam DL emitted from the two-wavelength semiconductor laser 31 and the laser beam BL emitted from the blue semiconductor laser 32 to substantially the same optical path. That is, the dichroic beam splitter 33 plays a role of combining and emitting light beams emitted from a plurality of semiconductor lasers.

  The two-wavelength semiconductor laser 31, the blue semiconductor laser 32, the dichroic beam splitter 33, and the diffraction element 34 described above are housed in a laser unit housing 36 and form a laser unit 51 as a whole. The laser unit 51 is attached to the main housing 50.

  The main housing 50 includes a hologram element 21, a photodetector (Optical Integrated Circuit: OPIC) 22, a hologram holder 23, a polarization beam splitter 41, a collimator lens 42, a broadband quarter wavelength plate 43, and two wavelengths. A rising mirror 44, a blue rising mirror 45, a two-wavelength objective lens 46, a blue objective lens 47, a sensor lens 48, and a collimating lens driving unit 49 are included. The hologram element 21, the photodetector 22, and the hologram holder 23 constitute a photodetector unit 29.

  The two-wavelength objective lens 46 and the blue objective lens 47 are mounted on an actuator (not shown). The actuator can drive the two-wavelength objective lens 46 and the blue objective lens 47 in the optical axis direction and the direction orthogonal to the optical axis. The polarization beam splitter 41 changes the direction of the laser light DBL by reflecting the laser light DBL emitted from the laser unit 51.

  Here, the laser beams DL and BL constituting the laser beam DBL are both linearly polarized light. The polarization beam splitter 41 is designed to reflect the laser beam DBL emitted from the laser unit 51 and transmit linearly polarized light orthogonal to the polarization direction. As will be described later, in general, the laser light emitted from the light source and the reflected light from the optical disc are different from each other in polarization direction by about 90 degrees. The polarization beam splitter 41 is designed to reflect forward light and transmit backward light.

  The collimating lens 42 makes the light beam reflected by the polarization beam splitter 41 substantially parallel light. Note that substantially parallel light includes completely parallel light. The collimating lens 42 is mounted on a collimating lens driving unit 49. The collimating lens driving unit 49 drives the collimating lens 42 in the optical axis direction. The three-wavelength optical pickup device 30 uses a blue objective lens 47 having a large numerical aperture in BD recording and reproduction. For this reason, the influence of spherical aberration due to the thickness error of the protective layer of the optical disk becomes large. This spherical aberration is corrected by driving the collimating lens 42.

  The broadband quarter wavelength plate 43 converts linearly polarized light having a wavelength of 405 nm to 780 nm into circularly polarized light, and conversely converts circularly polarized light into linearly polarized light. As the linearly polarized light beam reciprocates through the broadband quarter-wave plate 43, the polarization direction of the light beam rotates 90 degrees. The two-wavelength raising mirror 44 reflects the laser light having a wavelength of 650 nm and 780 nm and transmits the laser light having a wavelength of 405 nm. The reflected laser light is incident on the two-wavelength objective lens 46. On the other hand, the blue rising mirror 45 reflects laser light having a wavelength of 405 nm. The reflected laser light is incident on the blue objective lens 47.

  The two-wavelength objective lens 46 condenses laser light on the CD system and DVD system, and forms a light spot on the optical information recording layer. The blue objective lens 47 condenses laser light on the BD system and forms a light spot on the optical information recording layer. The hologram element 21 has a function of diffracting the return light from the optical disk and dividing it into a plurality of diffracted light beams. For example, the hologram element 21 transmits 80% of the incident laser light as it is as 0th-order light, and divides the remaining 20% into ± 1st-order light and emits it in two.

  The sensor lens 48 is a lens having a cylindrical surface. The sensor lens 48 gives astigmatism to the reflected light from the optical disk. By inserting the sensor lens 48, the focus error signal can be detected by the astigmatism method. The photodetector 22 receives the light beam given astigmatism and converts it into various servo signals.

Next, the operation of the three-wavelength optical pickup device 30 will be described with reference to FIG.
The laser beam DL having a wavelength of 650 nm emitted from the two-wavelength semiconductor laser 31 passes through the dichroic beam splitter 33. The transmitted light is reflected by the polarization beam splitter 41 and its direction is changed by 90 degrees. The reflected light is converted into parallel light by the collimating lens 42.

  The collimated laser beam DL passes through the broadband quarter-wave plate 43 and becomes circularly polarized light. The circularly polarized light beam is reflected by the two-wavelength raising mirror 44 to be changed in the direction of the optical disk. Such a change in the direction of the optical disk is also referred to as startup in the direction of the optical disk. The raised light beam is condensed on the recording / reproducing surface of the optical disk by the two-wavelength objective lens 46.

  The light beam reflected by the recording / reproducing surface of the optical disc follows a path opposite to the forward path. That is, the reflected light passes through the two-wavelength objective lens 46, the two-wavelength raising mirror 44, and the broadband quarter-wave plate 43 and becomes linearly polarized light that is orthogonal to the forward light beam. The linearly polarized light beam passes through the collimating lens 42 and passes through the polarization beam splitter 41. The transmitted light is guided to the signal detection optical system through a path of the sensor lens 48, the hologram element 21, and the photodetector 22.

  On the other hand, the laser beam BL having a wavelength of 405 nm emitted from the blue semiconductor laser 32 is reflected by the dichroic beam splitter 33. The reflected light is further reflected by the polarization beam splitter 41, and its direction is changed by 90 degrees. The reflected light is converted into parallel light by the collimating lens 42.

  The collimated laser beam BL passes through the broadband quarter-wave plate 43 and becomes circularly polarized light. The circularly polarized light beam passes through the two-wavelength raising mirror 44. The transmitted light is reflected by the blue rising mirror 45 and is raised in the direction of the optical disk. The raised light beam is condensed on the recording / reproducing surface of the optical disk by the blue objective lens 47.

  The light beam reflected by the recording / reproducing surface of the optical disc follows a path opposite to the forward path. That is, the reflected light passes through the blue objective lens 47, the blue rising mirror 45, the two-wavelength rising mirror 44, and the broadband quarter-wave plate 43, and becomes linearly polarized light that is orthogonal to the forward light beam. The linearly polarized light beam passes through the collimating lens 42 and passes through the polarization beam splitter 41. The transmitted light is guided to the signal detection optical system through a path of the sensor lens 48, the hologram element 21, and the photodetector 22.

  As described above, in the three-wavelength optical pickup device 30 of FIG. 2, the optical system from the broadband quarter-wave plate 43 to the photodetector 22 is common to the BD, DVD, and CD in the return optical system. . A common photodetector 22 detects the track error signal, the focus error signal, and the reproduction signal for BD, DVD, and CD. In addition, in order to simplify the adjustment, the light receiving portions for detecting the reproduction signals of BD and DVD are made the same.

  As described above, in the three-wavelength optical pickup device 30 of the first embodiment, a plurality of light sources are provided, but the signal detection optical system is integrated into one system. As a result, the number of components of the three-wavelength optical pickup device 30 can be reduced, and the structure is advantageous for downsizing and cost reduction of the device.

  The photodetector unit 29 mounted on the three-wavelength optical pickup device 30 will be described in more detail below.

  FIG. 3 is a cross-sectional view showing the configuration of the photodetector unit 29. With reference to FIG. 3, the photodetector unit 29 includes a hologram element 21, a photodetector 22, a hologram holder 23, and an adhesive layer 24.

FIG. 4 is a front view showing the configuration of the hologram element 21.
Referring to FIG. 4, hologram element 21 includes a hologram 210 patterned into six parts. The light beams that pass through the respective areas of the hologram 210 are diffracted at different diffraction angles and are incident on the photodetector 22.

FIG. 5 is a front view showing the configuration of the photodetector 22.
With reference to FIG. 5, the photodetector 22 includes a plurality of photodetectors 221 to 227. The light beams diffracted by the hologram 210 of the hologram element 21 enter the corresponding light detection units 221 to 227, respectively. A tracking error signal is generated based on the incident light. If the hologram element 21 and the photodetector 22 are misaligned, diffracted light does not enter the corresponding portions of the light detection units 221 to 227. In this case, the photodetector unit 29 cannot detect the tracking error signal.

  Returning to FIG. 1, the distance between the hologram element 21 and the photodetector 22 is several mm or more. The positional deviation between the hologram element 21 and the photodetector 22 needs to be adjusted and fixed with an accuracy of several tens of μm in the XY plane and about one hundred μm in the Z direction. The observation apparatus 1A is used for observing the alignment mark for this alignment. The hologram element 21 is attached to a stage (not shown) via a hologram holder 23. The stage enables the hologram element 21 to be adjusted in the XYZ directions and the optical axis rotation direction.

  The hologram element 21 can be adjusted in the Z direction by sandwiching an adhesive layer 24 between the hologram element 21 and the hologram holder 23 in addition to the stage (not shown). The height of the hologram element 21 is adjusted by controlling the thickness of the adhesive layer 24 by the pressing force of the hologram element 21. At this time, confirmation is made using the autocollimator 6 so that the hologram element 21 does not extremely tilt with respect to the partial reflection mirror surface 3a.

  As described above, the observation apparatus 1A according to the first embodiment is used for assembling and adjusting the photodetector unit 29, for example. Thereby, the hologram surface 21a and the photodetector surface 22a can be observed simultaneously. As a result, it is possible to perform alignment by simultaneously forming the alignment marks formed on the respective surfaces on the same image plane. Furthermore, since the distance between the objective lens 5 and the imaging element 8 is fixed in the optical microscope 19, the observation magnifications of the hologram surface 21a and the photodetector surface 22a can be made the same.

[Embodiment 2]
FIG. 6 is a schematic diagram for explaining the structure of an observation apparatus 1B according to Embodiment 2 of the present invention.

  With reference to FIG. 6, the observation apparatus 1 </ b> B of the second embodiment includes an objective lens 5, a partial reflection mirror 11, a mirror holding holder 12, and an optical microscope 19. The objective lens 5 is integrated with the partial reflection mirror 11 by a mirror holding holder 12. The optical microscope 19 includes a beam splitter 7, an image sensor 8, and an illumination light source 9. The optical microscope 19 does not have to be unique to the observation apparatus 1B, and may be a commercially available one, for example.

  The partially reflecting mirror 11 is provided with a mirror surface 11a having a circular outer shape on one surface of the transparent flat plate, and a dichroic beam splitter surface 11b having an annular pattern shape on the opposite surface of the transparent flat plate. ing. In the second embodiment, the distance between the mirror surface 11a and the dichroic beam splitter surface 11b is fixed.

  The observation apparatus 1B is used for assembly adjustment of the photodetector unit 29, for example. The photodetector unit 29 includes a hologram element 21, a photodetector 22, a hologram holder 23, and an adhesive layer 24. The photodetector unit 29 is mounted on an optical pickup device. The hologram element 21 is provided with a hologram surface 21a on one surface. The light detector 22 is provided with a light detector surface 22a on one surface.

  By using the observation device 1B for assembly adjustment of the photodetector unit 29, the hologram surface 21a and the photodetector surface 22a can be observed simultaneously. Thus, as in the first embodiment, it is possible to perform alignment by simultaneously forming the alignment marks formed on the respective surfaces on the same image plane.

  Next, a mechanism for enabling observation of the hologram surface 21a and the photodetector surface 22a simultaneously will be described. For example, the light beam from the illumination light source 9 is reflected by the beam splitter 7, passes through the objective lens 5 and the partial reflection mirror 11, and is condensed on the hologram surface 21 a and the photodetector surface 22 a. This condensing point is referred to as an “object point” as in the first embodiment. The light beam emitted from the object point corresponds to the reflected light from the condensing point. Here, the photodetector surface 22a corresponds to the first object surface, and the hologram surface 21a corresponds to the second object surface.

  A light ray (solid line) emitted from an object point on the photodetector surface 22a passes through the dichroic beam splitter surface 11b. Thereafter, the light beam passes through the objective lens 5 and the beam splitter 7 and is condensed on the image sensor 8 located on the image plane. The distance between the photodetector surface 22a and the objective lens 5 is adjusted by moving the objective lens 5 through the mirror holding holder 12, for example. Thereby, control is performed so that an image of the photodetector surface 22a (first object surface) is formed on the image sensor 8 (image surface).

  A light ray (broken line) emitted from an object point on the hologram surface 21a is first reflected by the mirror surface 11a. Next, the reflected light is reflected by the dichroic beam splitter surface 11b. After that, the light ray follows a path similar to the object point on the photodetector surface 22a and is condensed on the image sensor 8 located on the image plane.

  Here, fixing with the mirror holding holder 12 is performed so that the optical path length of the light beam emitted from the object point on the photodetector surface 22a is the same as the optical path length of the light beam emitted from the object point on the hologram surface 21a. Prior to this, the distance between the mirror surface 11a and the dichroic beam splitter surface 11b is adjusted in advance. Thereby, in the image sensor 8 located on the image plane, the image of the photodetector surface 22a (first object surface) and the image of the hologram surface 21a (second object surface) are simultaneously formed. As a result, the alignment mark on the photodetector surface 22a and the alignment mark on the hologram surface 21a can be aligned.

  Furthermore, in the second embodiment, for example, the observation light wavelength of the hologram surface 21a (second object surface) can be set to red, and the observation light wavelength of the photodetector surface 22a (first object surface) can be set to blue. At this time, the dichroic beam splitter surface 11b is selected so as to transmit blue observation light and reflect red observation light. Thereby, since the loss of the light beam does not occur on the mirror surface 11a and the dichroic beam splitter surface 11b, the brightness of the observation image on the image sensor 8 can be made the same.

  As described above, in the second embodiment, the distance between the mirror surface 11a and the dichroic beam splitter surface 11b is fixed. Therefore, the observation apparatus 1B is used when the distance between the photodetector surface 22a (first object surface) and the hologram surface 21a (second object surface) is substantially fixed.

  As described above, in the observation apparatus 1B according to Embodiment 2, the objective lens 5 and the partial reflection mirror 11 are integrated. Further, the partial reflection mirror 11 is provided with a mirror surface 11a having a circular outer shape on one surface of the transparent flat plate, and an dichroic beam splitter surface 11b having an annular pattern shape on the opposite surface of the transparent flat plate. Is provided. Thereby, in addition to the effect in the observation apparatus 1A of Embodiment 1, the brightness of the observation image in the image pick-up element 8 can be made the same.

  The present invention can be used as an observation apparatus and an observation method for optically observing simultaneously because the alignment marks of two objects having different heights are relatively aligned.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include meanings equivalent to the scope of claims for patent and all modifications within the scope.

  1A, 1B observation device, 2, 3, 11 partial reflection mirror, 2a, 3a partial reflection mirror surface, 4 mirror holding holder, 5, 61, 63, 65 objective lens, 6 autocollimator, 7 beam splitter, 8 imaging device, 9 Illumination light source 10, 33 Dichroic beam splitter, 11a Mirror surface, 11b Dichroic beam splitter surface, 12 Mirror holding holder, 19 Optical microscope, 21 Hologram element, 21a Hologram surface, 22 Photo detector, 22a Photo detector surface, 23 Hologram holder, 24 adhesive layer, 29 photodetector unit, 30 3 wavelength optical pickup device, 31 2 wavelength semiconductor laser, 32 blue semiconductor laser, 34 diffraction element, 36 laser unit housing, 41 polarization beam splitter, 42 collimating lens, 43 broadband 1/4 wavelength plate, 44 wavelength rising mirror, 45 blue rising mirror, 46 2 wavelength objective lens, 47 blue objective lens, 48 sensor lens, 49 collimating lens drive unit, 50 main housing, 51 laser unit, 60 light source, 62, 67 Half mirror, 64, 66 Prism, 68 First object surface, 69 Second object surface, 70 Image surface, 100 Observation device, 210 Hologram, 221 to 227 Light detection unit.

Claims (10)

An observation apparatus for optically observing first and second objects having different heights arranged on the same axis,
First and second partially reflecting mirrors disposed on the same axis;
An optical observation system for detecting light from the first and second objects via the first and second partial reflection mirrors;
The optical observation system observes the first object by the transmitted light of the first and second partial reflection mirrors, and the first object and the first partial reflection mirror and the first object. An observation apparatus for observing with two transmitted light after reciprocation between two partial reflection mirrors.   The optical distance between the first partial reflection mirror and the second partial reflection mirror is half of the optical distance between the first object and the second object. Item 2. The observation device according to Item 1.   The observation apparatus according to claim 1, wherein a ratio between the reflectance and the transmittance of each of the first and second partial reflection mirrors is 1: 1.   The observation apparatus according to claim 1, wherein the first partial reflection mirror has a circular outer shape, and the second partial reflection mirror has an annular shape.   The observation apparatus according to claim 1, wherein the first partial reflection mirror has a circular mirror surface, and the second partial reflection mirror has an annular dichroic beam splitter surface.   The first object is observed by blue observation light transmitted through the dichroic beam splitter surface, and the second object is observed by red observation light reflected from the dichroic beam splitter surface. Item 6. The observation device according to Item 5. The optical observation system is
An objective lens for condensing light from the first and second objects;
An image sensor that receives the collected light, and
The observation apparatus according to claim 1, wherein a distance between the objective lens and the imaging element is fixed. The optical observation system is
An objective lens for condensing light from the first and second objects;
The observation apparatus according to claim 1, wherein a distance between the objective lens and the first and second partial reflection mirrors is fixed.   The observation apparatus according to claim 1, wherein the first object is a photodetector of a photodetector unit, and the second object is a hologram element of the photodetector unit. . An observation method for optically simultaneously observing first and second objects having different heights arranged on the same axis,
Observing the first object with the transmitted light of the first and second partially reflecting mirrors arranged on the same axis;
An observation method comprising: observing the second object with transmitted light after reciprocating between the first partial reflection mirror and the second partial reflection mirror.