JP3613402B2 - Method and apparatus for imaging fine line width structure using optical microscope - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a deflection optical microscope and, more particularly, to a method of imaging such a microscope by operating such a microscope below a dense array of strips and between them. In an embodiment, the present invention relates to a confocal scanning deflection optical microscope, and further to a method of operating such a microscope to image a semiconductor substrate below and between dense strips.
[0002]
[Prior art]
In various commercially important operations, an optical microscope can be used to image a semiconductor substrate beneath and between arrays of dense strips (such as areas having a width of 0.7 microns or less). It was desired. For example, it may be desirable to measure the width of one or more photoresist lines in an array of photoresist lines deposited on a substrate during a fine lithography step in manufacturing a semiconductor product. Typically, such structures are “one-to-one dense array lines” on the substrate (ie, structures in which the space between adjacent deposited lines on the substrate is approximately equal to the width of each line). is there. Measurements made on a dense array of photoresist lines are made by examining the fine lithography process more accurately than measuring isolated line widths.
[0003]
If a dense array (such as a one-to-one dense array) has a width of about 0.7 microns or less, can a conventional optical microscope receive almost no light reflected from the substrate between the lines? Or it was not possible at all. Measuring the exact line width is very difficult once the optical signal from the groove between the lines is lost. For this reason, until the present invention, in the manufacture of semiconductors, scanning of an electron microscope had to be used in order to measure the line width of a dense array of 0.7 microns or less in practice.
[0004]
The advantage of the present invention is that the optical microscope is improved, and the present invention provides convenience and economy that the microscope can visualize the characteristics of the line width. One type of optical microscope that can be improved by the present invention is a confocal scanning optical microscope (CSOM). The first advantage of CSOM that images a plurality of samples at a time through a pinhole array is that the depth of field is shallower than many other optical microscopes. Thus, CSOM can resolve both height and width information, and can also image (individual) regions of samples of different heights at wavelengths with reduced interference.
[0005]
Examples of CMOS are U.S. Pat. No. 4,927,254 issued May 22, 1990 to Kino et al., U.S. Pat. No. 4,927,254 issued to Kino et al. 5,022,743 and the article “Confocal Scanning Optical Microscopy” by GS Kino and T. R. Corle, Physics Today, 42, 55-62 (September 1989).
[0006]
The latter paper describes a CSOM in which light from an arc lamp travels through a rotating scanning nippo disc (a perforated disc in which a number of holes are spirally drilled or etched). Will be explained. Each irradiated hole in the Nipo disk represents a spot that is imaged on the sample. The light reflected from the sample passes back through the disk and reaches the eyepiece or camera. Multiple points on the sample are illuminated by light passing through the Nipo disk at the same time, thereby effectively operating the system in parallel as a very large number of confocal microscopes. The sample is scanned as the disk rotates, and a rotating helical hole pattern sweeps the point pattern illuminated across the sample. While the disk rotates, the system presents a real-time confocal scan image of the sample.
[0007]
[Problems to be solved by the invention]
The present invention is a method and apparatus for imaging a semiconductor substrate below (and between) an array of dense strips using a polarizing optical microscope. The strip is made of an insulator or other material (eg, polycrystalline silicon). The present invention visualizes dense strips of photoresist lines on common substrates (such as silicon, polycrystalline silicon, silicon nitride, BPSG, silicon oxide and aluminum) used in the semiconductor industry, Other fine strips on other types of substrates are also imaged.
[0008]
In an optimal embodiment of the present invention, the optical microscope of the present invention is a polarizing device (for polarizing optical radiation), an analyzer (polarized light reflected from the sample is transmitted through this device), And a delay plate (eg, a quarter-wave plate) that is rotatably mounted, the delay plate being rotated in an optimal direction, and within the sample inspection area (where the sample is a dense strip on the substrate) The optical signal transmitted through the analyzer from the substrate (having the same) is enhanced (or maximized).
[0009]
In the most preferred embodiment of the present invention, the delay device is a quarter wave plate placed close to the sample (between the polarizing device and the sample), and the linearly polarized radiation from the polarizing device. Projection of the polarization axis onto the sample forms an angle of about 45 degrees with respect to the main linear shape of the sample. The optical (slow) axis of the quarter wave plate is oriented in the direction of the optimum angle (typically about 25 degrees) with respect to the main linear shape of the sample, in which direction the quarter wavelength The plate converts linearly polarized illumination into elliptically polarized illumination, and this elliptically polarized illumination undergoes polarization rotation when reflected from the sample, and the quarter-wave plate then receives the elliptically polarized illumination reflected from the sample by the analyzer. Converts radiation into an orientation that can be transmitted.
[0010]
If the microscope retardation plate according to the present invention is oriented in an optimal direction and the microscope uses an optical lens with sufficiently short wavelength radiation and a properly selected focal length, the microscope is dense and very The substrate below and between the narrow strips (each strip having a width of 0.7 microns or less) can be imaged.
[0011]
[Means for Solving the Problems]
The apparatus according to the present invention can also be used to image a sample consisting of one (or more) strips deposited on a substrate. In order to image a sample with only one strip deposited on the substrate, the delay characteristics of the variable delay device of the device are controlled so that it is reflected from the area of the substrate immediately adjacent to the strip, and the radiation The transmission that has passed through the delay device must be emphasized.
[0012]
The method of the present invention images a substrate below or between dense insulator strips (eg, photoresist strips) that is reflected from or passes through a sample in an analyzer. Receiving the polarized and transmitted radiation, and rotating a delay plate (e.g., a quarter wave plate) provided in the irradiation path in an optimal direction to enhance the signal from the substrate (i.e., A direction in which the optical signal transmitted through the analyzer from the region to be inspected on the sample substrate is maximized).
[0013]
【Example】
FIG. 1 shows a real-time confocal scanning microscope with a delay plate mounted rotatably according to the present invention. The optical microscope of FIG. 1 includes a motor 13 that rotates a Nipkow disc 1 about an axis 2. The light from the light source 3 (arc lamp or other strong light source) is focused by the condenser lens 5, transmitted through the aperture 9 and the collimating lens 8, then polarized by the polarizer 7, and beam split by the lens 10. The light is focused on the cube 11 and further reflected toward the disk 1 by the beam splitting cube 11. A part of the light colliding with the disk 1 is transmitted through the hole of the disk 1, and then passes through the field lens 26, the tube lens 15, the delay plate 17 (which is a quarter wavelength plate) and the objective lens 19. Sample 21 is reached.
[0014]
The outer edge of the delay plate 17 (or the member to which the plate 17 is attached) meshes with the gear 14. The step motor 12 rotates the gear 14 to rotate the delay plate 17 with respect to the axis. The axis 22 is substantially orthogonal to the surface of the sample 21 and serves as a common optical axis for the lens 15, the lens 19, and the plate 17. As a variation of the embodiment of FIG. 1 (as detailed below), the plate 17 is mounted so that the optical axis is in a direction inclined at a non-zero inclination angle relative to the orthogonal axis 22 of the sample.
[0015]
A part of the irradiation light is reflected from the sample 21 and then returns through the same position of the lens 19, the plate 17, the lens 15, the lens 26, and the hole of the disk, and passes through the lens 25. Part of the reflected light that has passed through the lens 25 is then transmitted to the beam splitting cube 11, the analyzer 27, and the lens 31. The polarized light transmitted through the analyzer 27 and the lens 31 becomes incident light to the video recording device 33 (which may be a camera such as a CCD camera). Alternatively, the eyepiece may be replaced with the video recording device.
[0016]
Polarizer 7, quarter wave plate 17 and analyzer 27 all function to reduce interference from unwanted reflections from disk 1. The analyzer 27 is directed to an angle that blocks light reflected from the upper surface of the disk 1 and that has not been transmitted twice through the quarter-wave plate 17.
[0017]
FIG. 2 is an enlarged side sectional view of a part of the sample shown in FIG. As shown in FIG. 2, the sample includes a dense one-to-one strip 102 deposited on a substrate 100. Each strip 102 has a width approximately equal to L, and the width of each groove between adjacent strips 102 is also equal to the distance L. The strip 102 can be composed of an insulating material or some other material (eg, polycrystalline silicon). Oite in the Examples, strips 102 is a photoresist line which is deposited on the substrate 100. Substrate 100 is typically a thin film of polycrystalline silicon, silicon nitride, BPSG, silicon oxide or other substrate material deposited on silicon, gallium arsenide or other substrate material.
[0018]
FIG. 3 is a plan view of a part of the sample of FIG. According to the present invention, as shown in FIG. 3, the retardation plate 17 is rotated until the projection “A” of the optical axis on the sample is oriented at a non-zero angle with respect to the longitudinal axis of the strip 102. The optical axis “A” of the delay plate 17 may be either the fast axis or the slow axis .
[0019]
Referring to FIG. 1 again, in the embodiment, the polarizer 7 irradiates the sample 21 with linearly polarized light irradiation (excluding the plate 17 from the system) from the polarizer 7 and its polarization axis is the main of the sample. The quarter-wave plate 17 is tilted so that it is oriented at an angle approximately equal to 45 degrees with respect to the straight structure (strip 102), and the quarter-wave plate 17 projects its optical axis onto the sample (as shown in FIG. 3) Is directed to the optimum experimentally determined angle “a” (as shown in FIG. 3) with respect to the main linear structure (strip 102) of the sample. The optimum angle “a” (in the range of 0 to 90 degrees) is an angle that maximizes the optical signal transmitted from the substrate 100 in the inspection region of the sample 21 via the analyzer 27. The optimum angle “a” depends on the width L of the sample strip 102, but is typically about 25 degrees for the type of material comprising the strip 102 and the substrate 100.
[0020]
In the optimum direction, the quarter wavelength plate 17 converts the linearly polarized light irradiation from the polarizer 7 into elliptically polarized light, and when the elliptically polarized light is reflected from the sample 21, it undergoes polarization rotation and becomes a quarter wavelength. The plate 17 converts the elliptically polarized light reflected from the sample into polarized light that can be transmitted by the analyzer 27.
[0021]
Assuming that the optical axis of the quarter-wave plate 17 is oriented at approximately 45 degrees with respect to the incident linearly polarized light, then the quarter-wave plate converts the linearly polarized light into circularly polarized light. You should know that it will convert. In a conventional polarizing optical microscope, it is speculated that the sample will reflect circularly polarized incident light back into the circularly polarized quarter wave plate, and such reflected circularly polarized illumination is 1 It was speculated that after being transmitted through a quarter wave plate, it would be converted back to purely linearly polarized radiation. At present, however, a sample with a fine strip of linear structure deposited on a substrate will substantially polarize the polarization of the circularly polarized incident light along with the reflection so that the reflected illumination is not a circle. It is recognized to be elliptically polarized. For this reason, the optical axis of the quarter wavelength plate 17 of the present invention is 45 with respect to the polarization direction of the linearly polarized incident light when imaging the linear structure of the dense strips deposited on the substrate. It is aimed at an optimal angle different from the degree.
[0022]
In FIG. 4, the microscope according to the present invention includes a motor 63 that rotates the Nipo disk 51 around the disk axis 62. The light source 53 (including the light from the light source 53 reflected from the mirror 53A) is transmitted through the filter 58D, and passes through the plate 56 which is focused on the pinhole aperture by the condenser lens 55 and perforated. Thereafter, the light is transmitted to the polarizing beam splitting cube 57 via the lens 52, the iris diaphragm 54, the preliminary polarizing cube 58A, the neutral filter 58B, and the color filter 58C. The light source 53 may be an arc lamp or other intensity light source.
[0023]
In the embodiment of FIG. 4, the cube 57 includes triangular prisms 57A and 57B, an insulating film interface 60 and an absorption layer 59 sandwiched between the triangular prisms 57A and 57B. Layer 59 is preferably a sheet of black glass optically bonded to the rear surface of component 57B.
[0024]
Part of the light emitted from the cube 57 reaches the disk 51 via the second objective lens 61 and is transmitted through the hole of the disk 51, and then the field lens 65, the tube lens 67, and the delay plate 69. The sample 21 passes through the compensation plate 70 and the objective lens 71. Desirably, the delay plate 69 is a quarter wave plate, although an eighth wave plate or other delay plate can be used in other embodiments of the present invention. After being reflected from the sample 21, the light is transmitted through the lens 71, the components 69 and 70, the lens 67, the lens 65, the same position of the hole in the disk 51 and the lens 61. After being rotated and polarized by passing through the component 69 twice, this light becomes the incident light of the cube 57, and part of the incident light passes through the film 60 and passes through the surface of the component 57B to the cube 57. Exit. After exiting the cube 57, the polarized light irradiation from the sample 21 reaches the video camera 83 via the analysis cube 75, the lens 77, the magnification controller 79 and the camera relay lens 80. In another embodiment of the present invention, the eyepiece may be used as a device for receiving an image (in place of the camera 83 or in addition to the camera 83).
[0025]
U.S. Pat. No. 5,067,985, issued on Nov. 26, 1991, describes an embodiment of the device similar to FIG. 4 (however, it is a rotatably mounted delay plate 69, motor 75 and gear 74), the embodiment includes a desired arrangement of cubes 57.
[0026]
The pre-polarization cube 58A, cube 57, analyzer 75, and retardation plate 69 all function to reduce interference due to unwanted reflections from the disk 51 in the following manner. The cube 57 is directed to block the illumination light that exits the side of the component 57A and returns to the side of the disk. Accordingly, the cube 57 functions to polarize the irradiation light preliminarily polarized by the component 58A to irradiate the sample 21, and further functions as an analyzer that selectively transmits the reflected light from the sample 21. .
[0027]
The analysis cube 75 receives the light transmitted through the cube 57 and selectively transmits the light reflected from the sample 21. Both the beam splitting cube 57 and the analysis cube 75 are provided in the collimated beam path between the second objective lens 61 and the tube lens 77.
[0028]
The beam splitting cube 57 provided in the collimated beam path between the second objective lens 61 and the tube lens 77 has a beam splitting cube between the Nipo disk and both the second objective lens and the second tube lens. The chromatic aberration appearing in the embodiment arranged in is substantially reduced.
[0029]
The outer edge of the delay plate 69 meshes with the gear 94. The step motor 75 rotates the gear 74 to rotate the delay plate 69 about the optical axis of the lens 71 and the lens 67.
[0030]
In the embodiment of FIG. 4, the components 58A and 57 preferably have linearly polarized illumination light projected from the cube 57 onto the sample 21 (assuming that the plate 69 is excluded from the system), whose polarization axis is the main axis of the sample. Oriented to face an angle of approximately 45 degrees with respect to the linear structure. Further, the plate 69 is a quarter wavelength plate, and the projection of its optical axis onto the sample is experimentally obtained (as also shown in FIG. 3) with respect to the main linear structure (strip 102) of the sample. The optimum angle “a” is desirable. Such an optimum angle “a” is an angle (in the range of 0 to 90 degrees) that maximizes an optical signal transmitted from the inspection region of the substrate 100 of the sample 21 through the cube 57. Just as in the embodiment of FIG. 1, the optimum angle “a” depends on the width L of the sample strip 102, but the substrate material is typically about 25 degrees.
[0031]
In the optimal direction, the quarter-wave plate 69 of the above embodiment converts the linearly polarized light from the cube 57 into elliptically polarized light, and the elliptically polarized light undergoes polarization rotation when reflected from the sample 21, The quarter wave plate 69 is able to transmit the reflected elliptically polarized illumination light from the plate 69 through both cubes 57 and 75 with the polarization most closely matched to the polarization of the linearly polarized illumination light. Converts to irradiating light.
[0032]
When the microscope retardation plate according to the present invention is tilted optimally and the microscope uses sufficiently short wavelength illumination light and an optical instrument with an appropriately selected focal length, the microscope is very narrow and dense. The substrate below or between the strips (each strip having a width of 0.7 microns or less) can be imaged.
[0033]
FIG. 5 is an enlarged cross-sectional view of a rotatably mounted delay plate employed in a preferred embodiment of the present invention. FIG. 5 shows a delay plate 117 and a device for holding the delay plate 117 rotatably. The delay plate 117 is mounted such that its orthogonal axis N is inclined with respect to the axis 122 at an angle F. For this reason, stray light reflection from the top and bottom surfaces of the delay plate 117 passes through the delay plate 117 and the sample It is possible to prevent interference with the irradiation light reflected from and transmitted again through the delay plate 117. The angle F is equal to about 3 degrees in the embodiment of the present invention.
[0034]
When the delay plate 117 is tilted and mounted (that is, when the delay plate 117 is mounted with a non-zero tilt of angle F as shown in FIG. 5), the beam transmitted through the delay plate 117 is transmitted through the gear 115 and the delay. The plate 117 precesses about the axis 122 as a unit. The effect of this precession can be eliminated by providing a second transmission plate 128 attached to the compensating tilt angle .
[0035]
In FIG. 5, the plate 128 has the same size as the inclination angle of the delay plate 117, but is attached so that the sign is reversed. The plates 117 and 128 are fixed to the base 124. The pedestal 124 is then attached to the central orifice of the ring gear 115 so that the central longitudinal axis of the pedestal 124 is aligned with the central longitudinal axis of the gear 115. The plate 128 can be made of a material equal to the refractive index and thickness of the quarter wave plate 117 (although not necessary). If the plate 128 has a different thickness or refractive index than the plate 117, then the thickness, refractive index, and position of the plate 128 will change as a result of the beam being transmitted through the other of the plates 117 and 128. After having deviated from axis , each of plates 117 and 128 must be selected to pass the beam through the assembly of FIG. 5 back to the optical axis of the assembly (vertical axis 122 in FIG. 5). Don't be.
[0036]
In the assembly of FIG. 5, the metal cover plate 120 is fixedly attached to the upper surface of the support member 130, whereby the assembled plate 120 and the components 115, 124, 117 in which the member 130 is assembled. , 128 and 116 are enclosed.
[0037]
A base 118 is attached to the upper surface of the plate 120. A lens housing can be mounted in the pedestal 118 and a lens (such as lens 15 in FIG. 1 or lens 67 in FIG. 4) can be mounted in the lens housing.
[0038]
The outer edge of the gear 115 (preferably made of nylon) constitutes a set of teeth that mesh with the teeth of the gear 114. When the step motor 112 drives the gear 114, the rotation of the gear 114 then causes the assembly of components 115, 119, and 124, plates 117 and 128, and the bearing 116 to move relative to the support member 130 (vertical in FIG. 5). Rotate as a unit (around the axis 122). The outer race of the ball bearing member 116 rests on the member 130, and the inner race of the member 116 is free to rotate with little friction against the support member 130, so that the members 115, 116, 117, 119, 124 and The entire assembly of 128 can rotate with the member 130 with low friction.
[0039]
The Hall detector unit 126 is fixedly attached to a position of the member 130 that detects the periphery of the magnet 119 (fixedly attached to the rotating member) when the assembly rotates the unit 126. Yes. The output of the Hall detector 126 is processed by a microprocessor (not shown), which can clarify the initial rotational position of the gear 115 (and hence the delay plate 117). When the system is initialized, the stepper motor 112 can operate to rotate the gear 115 until the output of the Hall detector unit 126 indicates that the gear 115 is in the initial position. In a variation of the apparatus of FIG. 5, other types of detectors can be used to clarify the initial rotational position of the gear 115 (and thus the delay plate 117).
[0040]
Following system initialization , the stepper motor drive generates an output signal indicating the number of steps that motor 112 has rotated gear 115 (from the initial position of gear 115). This output signal is converted into a digital data stream in an interface circuit (not shown), which is then processed in a microprocessor (not shown) to provide the current rotational position of the gear 115 (and hence the delay plate 117). Ask for.
[0041]
Another embodiment of the present invention provides a variable delay plate that is fixedly mounted rather than a rotatably mounted delay plate that can change the orientation of the optical axis by mechanical rotation. To change in response to an externally generated control signal. FIG. 6 shows a real-time confocal scanning microscope, which includes a variable delay plate 17 'fixedly mounted. The apparatus of FIG. 6 is the same as the apparatus of FIG. 1, except that the rotatably mounted delay plate 17, motor 12 and gear 14 of FIG. 1 are fixedly mounted (in FIG. 6). Except for the delay plate 17 'and the voltage source 18 that supplies the drive voltage signal to the plate 17'.
[0042]
In the description and claims that follow, the expression “variable delay device” refers to a fixedly mounted delay device whose dual refractive index changes in response to an externally generated control signal, and to be rotatable. It means both a mounted retardation plate with a fixed double refractive index (the direction of its optical axis can be changed mechanically). In the description and claims that follow, the expression “deflection characteristics” refers to the characteristics of the delay that determines the deflection of the beam transmitted through the delay (such as the direction of the fast or slow axis , or the double index of refraction). Stuff). The deflection of the transmitted beam can be changed by changing either the double index of the delay (if the delay is like a Pockels cell or a liquid crystal delay) or the optical axis of the delay Can do.
[0043]
6, the variable delay 17 'is a liquid crystal variable delay (such as a Part No. LVR-0.7-STD available from Meadowlark Optics, Longmont, Colorado), a Pockels cell, or commercially Other electro-optic wave plates selected from those available can be used. In an embodiment in which the variable delay 17 'is an electro-optic wave plate, a voltage applied across the variable delay 17' from the voltage source 18 to the desired deflection of the illumination light transmitted through the delay 17 '. Can be achieved by adjusting.
[0044]
Various modifications and alterations in the structure and method of the invention will be apparent to those skilled in the art and do not depart from the scope and spirit of the invention. Although the present invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to the specific embodiments.
[Brief description of the drawings]
FIG. 1 is a simplified side view of a first embodiment of a real-time confocal scanning microscope according to the present invention.
FIG. 2 is a side cross-sectional view of a sample having a dense one-to-one line structure deposited on a substrate of the type that can be imaged by the present invention.
3 is a plan view of a part of the sample in FIG. 2, and is a view showing an optimum direction of an optical axis of a delay plate of an optimum embodiment according to the present invention.
FIG. 4 is a simplified side view of a second embodiment of a real-time confocal scanning microscope according to the present invention.
FIG. 5 is an exploded cross-sectional view of a rotatably mounted delay plate used in an optimal embodiment of the present invention.
FIG. 6 is a simplified side view of a third embodiment of a real-time confocal scanning microscope according to the present invention.
[Explanation of symbols]
7 Polarizers 17 and 69 Delay plate 21 Sample 27 Analyzer

Claims (26)

A polarizing optical microscope for imaging a sample including an array of dense strips on a substrate,
A variable delay device placed near the sample and having a delay characteristic ;
An apparatus for directing polarized light irradiation to the variable delay device, wherein the variable delay device is arranged to transmit a part of an irradiation beam to a sample and further transmit a reflected beam from the sample, and the reflected beam is A directing device including illumination light from an illumination beam reflected from the sample;
An analyzer arranged to receive the reflected beam and transmit a portion of the reflected beam;
The variable delay device is elliptically polarized to transmit a part of the irradiation beam, and the reflected beam is caused to generate a second polarization, and the reflected beam component consisting of light reflected from the substrate is transmitted. Means for controlling the delay characteristic in order to intensify via the analyzer ;
A polarizing optical microscope. 2. The polarizing optical microscope according to claim 1, wherein the polarized irradiation beam is linearly polarized when entering the variable delay device. 3. The polarization optical microscope according to claim 2 , wherein the variable delay device includes the directing device that guides the polarized irradiation beam to the variable delay device and the analyzer, and the variable delay device is rotatably attached to the sample. A polarizing optical microscope that is a four-wavelength plate. 2. The polarizing optical microscope according to claim 1, wherein the variable delay unit is fixedly attached to a delay unit having a double refractive index that is variable in response to a change in an externally generated control signal. . 5. The polarizing optical microscope according to claim 4 , further comprising a device for supplying the control signal to the variable delay device. The polarizing optical microscope according to claim 1, wherein the variable delay device is a delay plate,
A polarization optical microscope including a rotatable attachment device for attaching the delay plate so as to be rotatable with respect to the sample around a rotation axis. The polarizing optical microscope according to claim 6 , further comprising:
A polarizing optical microscope comprising a device for rotating the delay plate attached in a freely rotatable manner, whereby the optical axis of the delay plate is directed in a desired direction within a plane orthogonal to the rotation axis. The polarizing optical microscope according to claim 7, wherein the rotating device that rotates the rotatable delay plate includes:
A motor,
A polarizing optical microscope comprising: a gear device connected between the motor and the rotatable mounting device. A polarizing optical microscope for imaging a sample comprising at least one strip on a substrate ,
A variable delay device placed near the sample and being a delay plate ;
An apparatus for directing polarized light irradiation to the variable delay device, wherein the variable delay device is arranged to transmit a part of an irradiation beam to a sample and further transmit a reflected beam from the sample, and the reflected beam is A directing device including illumination light from an illumination beam reflected from the sample ;
An analyzer arranged to receive the reflected beam and transmit a portion of the reflected beam ;
A rotatable mounting device for mounting a delay plate rotatably about a rotation axis, wherein the sample has an orthogonal axis, and the rotation axis is substantially parallel to the orthogonal axis. Have
The rotatable mounting device comprises :
A delay plate mounting device for mounting the delay plate having the rotation axis with a non-zero inclination angle with respect to the orthogonal axis ;
A transmission plate ;
A transmission plate mounting device , wherein the transmission plate is mounted at a compensation tilt angle, and the non-zero tilt angle and the compensation tilt angle have opposite signs ;
A polarizing optical microscope . The polarizing optical microscope according to claim 9 , further comprising a device for rotatably mounting the delay plate.
A polarization optical microscope including a detector that generates a signal indicating a rotation position of the delay plate around the rotation axis. A real-time confocal scanning microscope for imaging a sample comprising at least one strip on a substrate,
A disk mounted rotatably and formed with an array of holes;
A variable delay device disposed between the sample and the sample that is rotatably mounted, and having a delay characteristic;
A beam splitting device for directing a polarized irradiation beam toward the variable delay device, wherein the variable delay device is arranged to transmit a part of the irradiation beam to the sample and to receive a reflected beam from the sample. A beam splitting device in which the reflected beam includes illumination from an illumination beam reflected from the sample, the beam splitting device transmitting an image portion of the reflected beam;
A video receiver arranged to receive the video portion of the reflected beam from the beam splitter;
An analyzer disposed between the beam splitting device and the image receiving device for receiving the reflected beam and transmitting an image portion of the reflected beam to the image receiving device ;
The variable delay device is elliptically polarized to transmit a part of the irradiation beam, and the reflected beam is caused to generate a second polarization, and the reflected beam component consisting of light reflected from the substrate is transmitted. Means for controlling the delay characteristic of the variable delay device to enhance the power via the analyzer ;
Real-time confocal scanning microscope. 12. The real-time confocal scanning microscope of claim 11 , wherein the sample includes an array of dense strips on a substrate, and the reflected beam component is reflected from below the substrate and between the array of strips. Real-time confocal scanning microscope. 12. The real time confocal scanning microscope according to claim 11 , wherein the variable delay is fixedly attached to a delay having a double refractive index that is variable in response to an externally generated control signal. Confocal scanning microscope. The real-time confocal scanning microscope according to claim 13 , further comprising a device for supplying the control signal to the variable delay device. The real-time confocal scanning microscope according to claim 11 , wherein the variable delay device is a delay plate;
A real-time confocal scanning microscope including a rotatable attachment device for attaching the delay plate to the sample so as to be rotatable about a rotation axis. The real-time confocal scanning microscope of claim 15 , further comprising:
A real-time confocal scanning microscope including an apparatus for rotating the delay plate attached in a freely rotatable manner, thereby directing an optical axis of the delay plate in a desired direction in a plane orthogonal to the rotation axis. 17. The real-time confocal scanning microscope according to claim 16, wherein the rotating device that rotates the rotatably mounted delay plate is a motor and a gear connected between the motor and the rotatable mounting device. A real-time confocal scanning microscope. The real-time confocal scanning microscope according to claim 11 , wherein the variable delay device is a quarter-wave plate rotatably attached to the sample and the beam splitting device. A real-time confocal scanning microscope for imaging a sample comprising at least one strip on a substrate ,
A disk that is rotatably mounted and formed with aligned holes ;
A variable delay device having a delay characteristic, which is arranged between the disk and the sample which are rotatably mounted ;
A beam splitting device for directing a polarized irradiation beam toward the variable delay device, wherein the variable delay device is arranged to transmit a part of the irradiation beam to the sample and to receive a reflected beam from the sample. A beam splitting device, wherein the reflected beam includes illumination from an illumination beam reflected from the sample, the beam splitting device transmitting an image portion of the reflected beam ;
A rotatable mounting device for mounting a delay plate rotatably about a rotation axis, wherein the sample has an orthogonal axis, and the rotation axis is substantially parallel to the orthogonal axis. Have
The rotatable mounting device is
A delay plate mounting device for mounting the delay plate having the rotation axis with a non-zero inclination angle with respect to the orthogonal axis ;
A transmission plate ;
A transmission plate mounting device , wherein the transmission plate is mounted at a compensation tilt angle, and the non-zero tilt angle and the compensation tilt angle have opposite signs ;
Real-time confocal scanning microscope . A method of imaging a sample having a dense array of strips on a substrate,
(a) imaging a sample using a polarizing optical microscope, wherein the polarizing optical microscope comprises a variable delay; and
(b) changing the delay characteristics of the variable delay device while directing the step (a) and directing an elliptical polarized illumination beam from the variable delay device to the sample;
An imaging method comprising: The imaging method according to claim 20 , wherein
Said step (a) outputting a linearly polarized illumination beam;
A directing stage in which the linearly polarized illumination beam is directed to the variable delay, and the linearly polarized illumination beam is transmitted through the variable delay to be converted into the elliptically polarized illumination beam;
An imaging method comprising: The imaging method according to claim 21 , wherein the variable delay device is a quarter-wave plate. 21. The imaging method according to claim 20 , wherein the variable delay is fixedly attached to a delay having a variable double refractive index, and the step (b) includes the fixedly attached delay. Providing a control signal to the detector to change the double refractive index of the fixedly attached delay device. 21. The imaging method according to claim 20 , wherein said variable delay device is rotatably attached to a delay plate, and said step (b) comprises the step of rotating said delay plate relative to said sample about a rotation axis. Including imaging methods. 25. The imaging method according to claim 24 , wherein said step (b) includes the step of rotating said delay plate and directing the optical axis of said delay plate in a desired direction within a plane perpendicular to said rotation axis. . A method of imaging a sample having a dense array of strips on a substrate ,
(a) imaging a sample using a polarizing optical microscope, wherein the polarizing optical microscope comprises a variable delay ; and
(b) during the step (a) , changing the delay characteristics of the variable delay device to direct an elliptical polarized illumination beam from the variable delay device to the sample, wherein the polarization The optical microscope has an analyzer ,
Said step (a) comprises :
Transmitting irradiation light from the sample through the analyzer, wherein the irradiation light is transmitted once through the variable delay device, reflected from the sample, and further reaches the analyzer A transmission step of performing a second transmission of the variable delay before
Said step (b) comprises :
An irradiation beam that has been optimally changed to an ellipse by changing the delay characteristics of the variable delay device is directed to the sample, and the irradiation beam that has been optimally changed to an ellipse is reflected from the substrate in the detection region of the sample and reflected by the irradiation light. Including a step of changing the delay characteristic, which results in enhanced transmission via the analyzer ,
Visualization method .

Images