This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2004-285340, filed Sep. 29, 2004, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a compound microscope comprising an optical microscope and a scanning probe microscope (SPM). The optical microscope is, for example, a laser scanning microscope (LSM) that acquires data representing a two-dimensional image of a sample at resolution of sub-micron order. The scanning probe microscope is configured to acquire data representing the physical properties of the sample, including the shape of the sample, at higher resolution of the two-dimensional shape acquired by the optical microscope.
2. Description of the Related Art
Jpn. Pat. Appln. KOKAI Publication No. 10-142238 discloses a compound microscope that comprises, for example, a scanning probe microscope and an optical microscope attached to the scanning probe microscope. The two microscopes can therefore be used as a single unit. The compound microscope has a monitor, an instructing unit, and a controller. The monitor is provided common to the scanning probe microscope and the optical microscope. The instructing unit sets a magnification at which the monitor should display images for observation. The controller selects the scanning probe microscope or the optical microscope in accordance with the magnification set by the instructing unit. The microscope thus selected is used to acquire image data of a sample at the magnification, and the monitor displays an image represented by the image data.
When the magnification is set, either the scanning microscope or the optical microscope is automatically selected in accordance with the magnification. (Namely, the SPM mode or the optical-microscope mode is automatically selected.) If the magnification set is high, the scanning probe microscope is selected and starts operating. The probe of the scanning probe microscope is moved in the X, Y and Z directions. The microscope generates signals Vx, Vy and Vz that represent the distances the probe has been moved in the X, Y and Z directions, respectively. The signals Vx, Vy and Vz are stored in a storage means. The signals Vx, Vy and Vz are combined into a video signal that represents an image of the sample. The video signal is supplied to the monitor. The monitor displays the image of the sample, which shows the surface condition of the sample.
The magnification set may be low. In this case, the optical microscope is selected and starts operating. The observation camera of the optical microscope photographs a sample and generates a video signal that represents an image of the sample. The video signal is supplied to the monitor through an image-switching unit. The monitor displays the image of the sample, which shows the surface condition of the sample.
According to a main aspect of this invention, there is provided a compound microscope that comprises: an optical microscope which acquires image data representing an image of an sample; a scanning probe microscope which acquires physical-property data representing physical properties of the sample; a storage unit which stores the image data and physical-property data acquired by the optical microscope and scanning probe microscope, respectively; an data-analyzing unit which analyzes the physical-property data stored in the storage unit, while the optical microscope is acquiring the image data, and which analyzes the image data stored in the storage unit, while the scanning probe microscope is acquiring the physical-property data; and a display unit which displays results of analysis that the data-analyzing unit performs on the physical-property data stored in the storage unit, while the optical microscope is acquiring the image data, and which displays results of analysis that the data-analyzing unit performs on the image data stored in the storage unit, while the scanning probe microscope is acquiring the physical-property data.
The first embodiment of this invention will be described, with reference to the accompanying drawings.
The optical microscope unit 5 can acquire data representing images of at least two dimensions, including an optical image of the sample 3 (i.e., optical-microscope image). The Z-drive mechanism 6 is coupled to the lower surface of the optical microscope unit 5, which faces the YX stage 2. The revolver 7 is secured to the lower surface of the Z-drive mechanism 6. The Z-drive mechanism 6 can move the revolver 7 up and down. The revolver 7 can rotate with respect to the Z-drive mechanism 6. The revolver 7 holds the objective lens 8 and the SPM unit 9. The objective lens 8 has different magnifications. Thus, when the revolver 7 is rotated, one of the objective lens 8, which has the desired magnification, or the SPM unit 9 comes to face the sample 3 placed on the XY stage 2.
The optical microscope unit 5 has an optical system that can acquire data representing images of at least two dimensions. It is more desired that the optical microscope unit 5 have an optical system that can acquire data that represents a three-dimensional image of the sample 3. The optical microscope unit 5 may be a scanning laser microscope unit that can acquire data representing a three-dimensional image of the sample 3 (hereinafter referred to as “shape data”). Nonetheless, the optical microscope unit 5 is not limited to a scanning laser microscope unit. It may be an optical system of any other type that can acquire data that represents images of at least two dimensions.
The light source 11 emits a laser beam. The beam expander 12 increases the diameter of the laser beam emitted from the light source 11. The half-mirror 13 is located in the optical path of the laser beam that has passed through the beam expander 12. The first galvano-mirror 14 reflects the laser beam coming from the half-mirror 13, in the Y-axis direction. The second galvano-mirror 15 reflects the laser beam coming from the first galvano-mirror 14, in the X-axis direction. The objective lens 8 focuses the laser beam coming from the second galvano-mirror 15.
As indicated above, the beam expander 12 increases the diameter of the laser beam emitted from the light source 11. The laser bean passes through the half-mirror 13 and reaches the first galvano-mirror 14. The first galvano-mirror 14 reflects the laser beam in, for example, the Y-axis direction. The second galvano-mirror 15 reflects this laser beam in, for example, the X-axis direction. As a result, the beam spot that the laser beam focused by the objective lens 8 forms on the sample 3 moves in the X-axis and Y-axis directions.
The scanning laser microscope unit 10 has an image-forming lens 16, a pinhole plate 17, and a light-receiving element 18. The image-forming lens 16 focuses the light beam reflected by the half-mirror 13 at the pinhole made in the pinhole plate 17. The pinhole is located at a point where the laser beam is focused by the objective lens 8. The light-receiving element 18 detects the intensity of the light beam coming through the pinhole made in the pinhole plate 17.
The half-mirror 13 reflects the light beam reflected from the surface of the sample 3 and applies it to the image-forming lens 16. The image-forming lens 16 focuses the light beam. The light beam thus focused passes through the pinhole made in the plate 17, reaching the light-receiving element 18. The light-receiving element 18 detects the intensity of the light beam and generates a light-intensity signal.
The SPM unit 9 provides a scanning-probe microscope image (hereinafter referred to as SPM image), i.e., physical-property data that contains the data representing the shape of the sample 3. The SPM unit 9 has a cantilever 19. A probe stylus 20 is attached to the free end of the cantilever 19. The SPM unit 9 incorporates a scanner and a displacement sensor. The scanner scans the cantilever in the X-axis and Y-axis directions and performs Z-axis servo control. The displacement sensor detects the displacement of the cantilever 19.
The displacement sensor is of so-called optical-lever type and detects the displacement of the cantilever 19. It has a light source and a light-receiving element. The light source applies a light beam to the cantilever 19. The light-receiving element detects the position of the light beam reflected by the cantilever 19.
The SPM unit 9 incorporates a Z-axis drive mechanism (not shown) that moves the probe stylus 20 toward the sample 3.
The control system of the compound microscope will be described. As
The control unit 22 controls the SPM unit 9 and the scanning laser microscope unit 10, making them acquire data about the sample 3.
The RAM 23a has an optical-microscope image memory 23a-1 and an SPM image memory 23a-2. The optical-microscope image memory 23a-2 stores the shape data acquired by the scanning laser microscope unit 10 and representing the shape of the sample 3. The SPM image memory 23a-2 stores the image data acquired by the SPM unit 9 and representing the SPM image of the sample 3.
The ROM 23b stores various programs. Among these programs are an optical-microscope operating program, an SPM operating program, a shape-data analyzing program, and a physical-property analyzing program. The optical-microscope operating program is used to control the scanning laser microscope unit 10. The SPM operating program is used to control the SPM unit 9. The shape-data analyzing program is use to analyze the shape data acquired by the scanning laser microscope unit 10. The physical-property analyzing program is used to analyze the physical-property data acquired by the SPM unit 9.
When operated, the instruction input unit 24 generates an instruction for changing the operating conditions of the scanning laser microscope unit 10, an instruction for changing the operating conditions of the SPM unit 9, and an instruction for changing the conditions of analyzing the shape data about the sample 3. The unit 24 further generates an instruction for analyzing the SPM image of the sample 3 and an instruction for switching the image on the display unit 25.
The CPU 21 has a multi-task function, performing several processes at the same time. The CPU 21 analyzes the SPM image provided by the SPM unit 9, while the scanning laser microscope unit 10 is acquiring the image data. That is, the CPU 21 simultaneously executes the physical-property analyzing program and the optical-microscope operating program stored in the ROM 23b.
The CPU 21 analyzes the shape data about the sample 3, acquired by the scanning laser microscope unit 10, while the SPM unit 9 is acquiring the image data. In other words, the CPU 21 simultaneously executes the shape-data analyzing program and the SPM operating program.
The CPU 21 functions as analysis unit. More specifically, the CPU 21 analyzes the shape data about the sample 3, acquired by the scanning laser microscope unit 10, or the SPM image provided by the SPM unit 9. Thus, the CPU 21 generates at least one of data items. representing a section of the sample 3, the roughness thereof, the length thereof, the results of a filtering process and the results of an inclination-adjusting process.
The CPU 21 makes the display unit 25 display the results of the analysis of the SPM image provided by the SPM unit 9, while the scanning laser microscope unit 10 is acquiring the shape data about the sample 3. The CPU 21 makes the display unit 25 display the results of the analysis of the shape data about the sample 3, provided by the scanning laser microscope unit 10, while the SPM unit 9 is acquiring the SPM image of the sample 3.
Controlled by the CPU 21, the display unit 25 displays one or more of the data items on the same screen. The data items are: the conditions of operating the SPM unit 9 and scanning laser microscope unit 10; the shape data acquired by the scanning laser microscope unit 10; the physical-property data acquired by the SPM unit 9; and the results of analysis performed by the CPU 21 (i.e., results of analysis performed on the shape data and SPM image of the sample 3).
When the scanning laser microscope unit 10 finishes acquiring the shape data about the sample 3, while the CPU 10 is analyzing the physical-property data acquired by the SPM unit 9, the display unit 25 displays the shape data about the sample 3 that the unit 10 has just acquired.
When the SPM unit 9 finishes acquiring the physical-property data about the sample 3 while the CPU 10 is analyzing the shape data about the sample 3 acquired by the scanning laser microscope unit 10, the display unit 25 displays the physical-property data that the SPM unit 9 has just acquired.
As
As
The analysis-result screen A has an analysis-condition display frame (first analysis-condition -display region) G1, an X-section analysis display frame (second first analysis-condition display region) H1, a Y-section analysis display frame H2, and a top-view display frame H3.
Data for changing the conditions in which the CPU 21 analyzes data and images are displayed in the analysis-condition display frame G1. The results of the analysis performed by the CPU 21, e.g., the analysis of the X-axis cross section of the sample 3, are displayed in the X-section analysis display frame H1. The results of analysis of the Y-axis cross section of the sample 3 are displayed in the Y-section analysis display frame H2. The image of the sample 3, as viewed from above, is displayed in the top-view display frame H3.
How the compound microscope operates will be described.
First, the operator operates the instruction input unit 24, inputting the instruction that the display unit 25 should display the control-menu screen D. On receiving this instruction, the CPU 21 causes the display unit 21 to display the control-menu screen D (
The operator further operates the instruction input unit 24, inputting desirable conditions of acquiring data about the sample 3. In accordance with the data-acquisition conditions thus input, the CPU 21 generates an acquisition-start instruction to the scanning laser microscope unit 10.
In the scanning laser microscope unit 10 that as received the acquisition-start instruction, the light source 11 emits a laser beam. The laser beam travels through the beam expander 12, half-mirror 13, first galvano-mirror 14 and second galvano-mirror 15. The laser beam is applied to the objective lens 8. The objective lens 8 focuses the laser beam on the sample 3. As the first and second galvano-mirrors 14 and 15 are moved, the beam spot moves on the sample 3 in the X- and Y-axis directions. Raster scanning is thereby accomplished.
The sample 3 reflects the laser beam, which travels back to the half-mirror 13. The half-mirror 13 reflects the beam, guiding it to the image-forming lens 16. The lens 16 focuses the beam at the pinhole made in the pinhole plate 17.
The laser beam reflected by the sample 3 passes the pinhole only if the sample 3 has its surface located at or near the focal point of the objective lens 8. If the surface of the sample 3 is far from the focal point of the objective lens 8, the laser beam cannot pass through the pinhole. It can pass through the pinhole when the laser beam is focused at the very surface of the sample 3.
The light beam reflected passes through the pinhole and reaches the light-receiving element 18. The element 8 detects the intensity of the light beam and generates a signal representing the intensity of the beam.
The CPU 21 receives the signal output from the light-receiving element 18 and representing the intensity of the light beam. The CPU 21 processes this signal and the data representing the XY position where the laser beam is focused in the raster scanning performed by the first and second galvano-mirrors 14 and 15. As a result, the CPU 21 determines the Z position where the laser beam is focused, thus acquiring an image of that part of the sample 3 which lies in the plane containing the point where the laser beam is focused.
Every time the raster scanning is carried out, obtaining an image of the sample 3, the CPU 21 makes the Z-drive mechanism 6 move the objective lens 8 in the Z-axis direction by a predetermined distance. Thus, as the raster scanning is repeated, the CPU 21 acquires height data and processes this data, acquiring a two-dimensional or three-dimensional shape data about the sample 3. The a two-dimensional or three-dimensional shape data is stored in the optical-microscope image memory 23a-1.
The CPU 21 generates data representing such a three-dimensional image as shown in
The extended focus image of
Next, the SPM unit 9 acquires the image data representing that part of the sample 3 that is almost identical to the part of which data has been acquired by the scanning laser microscope unit 10.
In the control-menu screen D (
The CPU 21 gives an instruction to the display unit 25, instructing that the unit 25 should display the condition display region F1. Thus, the display unit 25 displays the control-menu screen D (
The operator operates the instruction input unit 24, setting SPM-analysis conditions and instructing that the SPM unit 9 should start performing SPM analysis on the sample 3. On receiving this instruction, the CPU 21 sets data-acquisition parameters in the control-menu screen D. Thereafter, the CPU 21 instructs the SPM unit 9 to acquire the image data of the sample 3.
The SPM unit 9 moves the cantilever 19 having the probe stylus 20, in the X- and Y-axis directions. At the same time, the SPM unit 9 undergoes a servo control, moving in the Z-axis direction. The displacement sensor of the SPM unit 9 detects the displacement of the cantilever 19. The light source of the displacement sensor applies a light beam to the cantilever 19. The light-receiving element of the displacement sensor detects the position of the light beam reflected by the cantilever 19 and generates a signal representing this position.
The CPU 21 receives the signal from the displacement sensor, acquiring an SPM image of the sample 3. The CPU 21 generates data representing the SPM. This data is stored in the SPM image memory 23a-2.
During the SPM unit 9 is acquiring the image data, the operator may operate the instruction input unit 24, instructing that the two-dimensional or three-dimensional shape data about the sample 3, acquired by the scanning laser microscope unit 10, be analyzed. Then, the CPU 21 causes the display unit 25 to display an analysis-result screen A, as is illustrated in
Buttons for selecting a two-dimensional shape data and a three-dimensional shape data, respectively, and various conditions of analyzing the shape data selected are displayed in the of analysis-condition display frame G1 in the analysis-result screen A. Note that either shape data has been acquired by the scanning laser microscope unit 10 and represents the two- or three-dimensional image of the sample 3.
The CPU 21 reads the two- or three-dimensional shape data about the sample 3 from the optical-microscope image memory 23a-1, in accordance with the shape-data selection button and the conditions of analyzing, all set and displayed in the analysis-condition display frame G1. The CPU 21 then analyzes the two- or three-dimensional shape data read from the memory 23a-1.
For example, the CPU 21 analyzes the two- or three-dimensional shape data in terms of the surface roughness of the sample 3 or the length of each part of the sample 3. In addition, the CPU 21 performs a filtering process to reduce the image noise, and an inclination-adjusting process to adjust the inclination of the image.
As
How the scanning laser microscope unit 10 acquires data about the sample 3 will be explained again.
In the same way as described above, the scanning laser microscope unit 10 carries out raster scanning on the sample 3 by applying a laser beam to the sample 3. The light beam reflected from the sample 3 passes through the pinhole of the pinhole plate 17, reaching the light-receiving element 18. The element 18 generates a signal representing the intensity of the light beam. The CPU 21 receives this signal and generates data that represents an optical-microscope image of a part of the sample 3. Every time the raster scanning is carried out, obtaining an image of the sample 3, the CPU 21 makes the Z-drive mechanism 6 move the objective lens 8 in the Z-axis direction by a predetermined distance. As the raster scanning is so repeated, the CPU 21 acquires three-dimensional shape data about the sample 3.
While the laser microscope unit 10 is acquiring the two- or three-dimensional shape data about the sample 3, the operator may operate the instruction input unit 24, instructing that the SPM image of the sample 3, acquired by the SPM unit 9, be analyzed. In this case, the CPU 21 causes the display unit 25 to display an analysis-result screen A, as is illustrated in
The CPU 21 reads the data representing an SPM image from the SPM image memory 23a-2, in accordance with the SPM-image selection button and the SPM-image analyzing conditions, all set and displayed in the analysis-condition display frame G1. For example, the CPU 21 analyzes the SPM image of the sample 3 in terms of the surface roughness of the sample 3 or the length of each part of the sample 3. Further, the CPU 21 performs a filtering process to reduce the image noise, and an inclination-adjusting process to adjust the inclination of the image.
In the first embodiment described above, the CPU 21 analyzes the two- or three-dimensional shape data about the sample 3, acquired by the scanning laser microscope unit 10, while the SPM unit 9 is acquiring an SPM image of the sample 3. The CPU 21 makes the display unit 25 display the results of the analysis of the two- or three-dimensional shape data about the sample 3. While the scanning laser microscope unit 10 is acquiring a two- or three-dimensional shape data about the sample 3, the CPU 21 analyzes the SPM image of the sample 3, which the SPM unit 9 has provided, and causes the display unit 25 to display the results of the analysis.
Thus, the results of the analysis of the two- or three-dimensional shape data about the sample 3, acquired by the scanning laser microscope unit 10, can be displayed while the SPM unit 9 is acquiring the image data of the sample 3. This has been impossible hitherto. The analysis of two- or three-dimensional shape data about the sample 3 results in images of, for example, the X-axis cross section, Y-axis cross section and top of the sample 3. On the basis of the results of the analysis of the two- or three-dimensional shape data about the sample 3, the surface roughness of the sample 3 is analyzed, the length of each part of the sample 3 is determined. Further, various image-processing methods, such as a filtering process of reducing the image noise and an inclination-adjusting process of adjusting the inclination of the image, are carried out.
The SPM image of the sample 3, provided by the SPM unit 9, can be analyzed and the results of this analysis can be displayed, while the scanning laser microscope unit 10 is acquiring data about the sample 3. The analysis of the SPM image results in images of, for example, the X-axis cross-section, Y-axis cross-section and top of the sample 3. On the basis of the results of the analysis of the SPM image, the surface roughness of the sample 3 is analyzed, the length of each part of the sample 3 is determined. Further, various image-processing methods, such as a filtering process of reducing the image noise and an inclination-adjusting process of adjusting the inclination of the image, are carried out.
Thus, the scanning laser microscope unit 10 can use the time during which the SPM unit 9 remains in standby state, and the SPM unit 9 can operate while the scanning laser microscope unit 10 is acquiring data about the sample 3.
A second embodiment of this invention will be described, with reference to
The scanner 31 scans the cantilever 19 in the X-axis and Y-axis directions and performs Z-axis servo control. The displacement sensor 32 is of so-called optical-lever type and detects the displacement of the cantilever 19. The sensor 32 has a light source and a light-receiving element. The light source applies a light beam to the cantilever 19. The light-receiving element detects the position of the Light beam reflected by the cantilever 19.
In the hollow cylindrical body 30, a Z-axis drive mechanism 33 is provided. The mechanism 33 moves the probe stylus 20 toward the sample 3.
An objective lens 34 is provided in the hollow cylindrical body 30. The objective lens 34 is used in place of the objective lens 8 of the scanning laser microscope unit 10 (
Hence, the scanning laser microscope unit 10 can acquire a two- or three-dimensional shape data about the sample 3, using the objective lens 34, while the SPM unit 9 remains selected and operating.
The operator may operate the instruction input unit 24, switching the SPM mode to the optical-microscope mode. Then, the CPU 21 causes the display unit 25 to stop displaying the control-menu screen D for the SPM unit 9 and start displaying the control-menu screen D for the scanning laser microscope unit 10. At the same time, the CPU 21 instructs the scanning laser microscope unit 10 to start operating.
The operator may operate the instruction input unit 24, conversely switching the optical-microscope mode to the SPM mode. In this case, the CPU 21 causes the display unit 25 to stop displaying the control-menu screen D for the scanning laser microscope unit 10 and start displaying the control-menu screen D for the SPM 9. At the same time, the CPU 21 instructs the SPM unit 9 to start operating.
How the compound microscope operates will be described in detail.
As long as the SPM unit 9 remains selected and facing the sample 3, the display unit 25 displays the control-menu screen D for the SPM unit 9, as illustrated in
Before or after the data acquisition by the SPM 9, the operator may want to determine whether the probe stylus 20 takes a desired position with respect to the sample 3. In this case, the operator operates the instruction input unit 24, switching the SPM mode to the optical-microscope mode. The CPU 21 therefore causes the display unit 25 to stop displaying the control-menu screen D for the SPM unit 9 and starts displaying the control-menu screen D for the scanning laser microscope unit 10, and instructs the scanning laser microscope unit 10 to start operating.
Thus, the scanning laser microscope unit 10 uses the objective lens 34, acquiring a two- or three-dimensional shape data about the sample 3, though the SPM unit 9 faces the sample 3.
The CPU 21 analyzes the two- or three-dimensional shape data about the sample 3 acquired by the use of the objective lens 34. The positional relation between the sample 3 and the probe stylus 20 can therefore be determined.
Conversely, the operator may switch the optical-microscope mode to the SPM mode. In this case, the objective lens 8 is moved to the position where it faces the sample 3. The CPU 21 causes the display unit 25 to stop displaying the control-menu screen D for the scanning laser microscope unit 10 and start displaying the control-menu screen D for the SPM unit 9. At the same time, the CPU 21 instructs the SPM unit 9 to start operating.
The CPU 21 does not immediately start acquiring data about the sample 3. It switches the control-menu screen, from the one for the scanning laser microscope unit 10 to the one for the SPM unit 9, after completing the data acquisition by using the objective lens 34 incorporated in the SPM unit 9. Thereafter, the CPU 21 causes the SPM unit 9 to acquire data.
In the second embodiment, the SPM unit 9 incorporates an objective lens 34. The objective lens 34 enables the scanning laser microscope unit 10 to acquire a two- or three-dimensional shape data about the sample 3 even if the SPM unit 9 faces the sample 3.
The present invention is not limited to the first and second embodiments. Various modifications can be made.
For example, the optical microscope may be an optical microscope unit such as a bright-field microscope, a dark-field microscope, an incident-light microscope, a transmission microscope, a polarizing microscope, an interference microscope, or a confocal laser microscope. If the optical microscope is such an optical microscope unit, the data representing a two-dimensional image the light-receiving element (e.g., CCD sensor) has received from the optical microscope unit is stored in the storage unit 23. This brings forth the same advantage as in the second embodiment.
The mechanism for switching between the objective lens 8 and the SPM unit 9 may be attained if the SPM unit 9, for example, is removed from the optical microscope unit 5 and secured to the gantry frame 4. If this is the case, the XY stage 2 is an electrically driven stage that helps to detect XY coordinates, and the sample 3 is placed below the objective lens 8 or the SPM unit 9.
Number | Date | Country | Kind |
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2004-285340 | Sep 2004 | JP | national |