JP2007272110A - Microscope apparatus, focus detection apparatus, and focus detection control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To determine a parameter for easily and surely controlling the operation of a microscope even when a microscope unit to be used for observing samples having respectively different reflection factors has optical dispersion. <P>SOLUTION: A control part 121 has a storage part for storing parameters for at least two or more samples 102, where each parameter controls the operation of a microscope apparatus and is allowed to correspond to each sample 102 to be observed. The control part 121 controls the operation of the microscope on the basis of the parameter corresponding to a selected sample 102 in accordance with a sample selection instruction sent from a PC 123. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a microscope technology, and in particular, a microscope apparatus having an autofocus (hereinafter referred to as “AF”) function, or an IC (semiconductor integrated circuit), LCD incorporating a microscope having an autofocus function The present invention relates to a technique suitable for implementation in an automatic inspection apparatus such as (liquid crystal display), medical care, and living organisms.

  Microscopes are used not only in the fields of medicine and biology but also in the industrial field for purposes such as inspection of IC wafers and magnetic heads, quality control of metal structures, and research and development of new materials.

  Recent microscopes equipped with an AF sensor and widely equipped with an AF function that automatically performs focusing by electrically driving the Z stage based on the AF signal detected by the AF sensor Has been.

  The AF method is roughly divided into an active AF method that performs an AF operation by detecting reflected light when a sample is irradiated with light such as an infrared laser that is different from illumination light for sample observation, and obtained from a microscope. A passive AF method is known in which the contrast of an image is calculated to perform an AF operation.

  The passive AF method has a problem that focusing cannot be performed with a sample with poor contrast such as a bare wafer, and the focusing speed is low even with a sample such as a wafer on which a pattern is drawn. For this reason, the active AF method is generally used in industrial applications where inspection throughput is important.

  In recent years, as disclosed in, for example, Patent Document 1, for the purpose of automating the inspection process of a semiconductor wafer or LCD, an inspection apparatus manufacturer purchases a microscope with an AF function as a unit, and the semiconductor wafer. Increasingly, the microscope is used by remotely operating the microscope with a command transmitted from a control device such as a PC after being incorporated in an automatic inspection device or the like.

A microscope that employs the active AF method is disclosed in, for example, Patent Document 2. A configuration example of an optical system of a microscope adopting the active AF method is shown in FIG.
AF light emitted from a laser diode 1801 (hereinafter referred to as “LD”) that emits infrared light that is invisible light as measurement light passes through a collimator lens 1802 and becomes a parallel light flux. Only the P-polarized light component is reflected by a PBS (Polarized Beam Splitter) 1804 through a light projection side stopper 1803 that cuts half of the light, and is guided to a condenser lens 1805.

  The chromatic aberration correction lens 1806 is for correcting a deviation (chromatic aberration) between the focal position of the observation light and the AF light generated due to chromatic aberration of the objective lens, and is not movable in the optical axis direction according to the objective lens. The illustrated zoom machine groove is provided. The light beam once condensed by the condenser lens 1805 passes through the chromatic aberration correction lens 1806, passes through the λ / 4 plate 1807, is polarized by 45 °, and then is reflected by the dichroic mirror 1808. Thereafter, the light beam is irradiated onto the sample 102 through the objective lens 105.

  The luminous flux of the AF light reflected by the sample 102 passes through the objective lens 105, is again reflected by the dichroic mirror 1808, passes through the λ / 4 plate 1807, is further polarized by 45 °, and is switched to the S polarization component. Thereafter, this light beam passes through the chromatic aberration correction lens 1806 and the condenser lens 1805 and enters the PBS 1804. Since this light beam is an S-polarized light component at this time, it passes through the PBS 1804 as it is, passes through the light receiving side stopper 1809 and the light receiving side condensing lens 1810, and then is divided into two-division photodiodes (hereinafter abbreviated as “two-division PD”). The image is formed at 1811.

  Although not shown, the two-divided PD 1811 is a photodetector in which two photodiodes (referred to as sensor A and sensor B) are arranged around the optical axis. The current signal corresponding to the light intensity of the spot imaged by the two-divided PD 1811 is subjected to current / voltage conversion and amplification by the IV conversion amplifier 1812 and then converted to a digital value by the A / D converter 1813. Are processed.

Here, the principle of the AF operation in the optical system shown in FIG. 18 will be described.
FIG. 19 shows a state of image formation of AF light with the two-divided PD 1811 of the medium magnification objective lens.

  First, it is assumed that the sample 102 is positioned above the in-focus position, that is, on the side closer to the objective lens 105. In this case, the spot image formed by the two-divided PD 1811 is positioned closer to the sensor B than the center position (see 1900 (a)).

  Next, it is assumed that the sample 102 is located below the in-focus position, that is, on the side far from the objective lens 105. In this case, the spot image formed by the two-divided PD 1811 is positioned closer to the sensor A than the center position (see 1900 (b)).

  Here, it is assumed that the sample 102 is accurately at the in-focus position. In this case, the spot image formed is positioned in a range equivalent to the sensor A and the sensor B at the center of the two-part PD 1811 (see 1900 (c)).

The relationship between the Z stage position in the optical system shown in FIG. 18 and the output signal of the two-part PD 1811 is shown in graphs in FIGS. 20A and 20B.
20A and 20B show curves when the objective lens 105 is a low magnification lens (dotted curve), a medium magnification lens (dashed curve), and a high magnification lens (solid curve). Has been. Here, FIG. 20A shows the relationship between the position of the Z stage (that is, the position of the sample 102) not shown in FIG. 18 and the output signal levels of the sensors A and B. 20B shows a signal (A−B) / (A + B) calculated based on the Z stage position and the output signal levels of the sensors A and B (hereinafter, this signal is referred to as an “AF signal”). The signal level). 20A and 20B, the horizontal axis indicates the Z stage position, and the vertical axis indicates the signal level.

  Here, as can be seen from FIG. 20B, the inclination of the AF signal is increased when the objective lens 105 is used at a high magnification, and the inclination of the AF signal is reduced when the objective lens 105 is used at a low magnification. This is because a high-magnification objective lens has a shallow focal depth, and a low-magnification objective lens has a deep focal depth.

Next, an algorithm of AF operation in the optical system shown in FIG. 18 will be described.
When the execution of the AF operation is started, first, it is calculated based on the output signal levels of the sensor A and the sensor B (A + B) in order to confirm whether or not the calculation unit can capture the sample 102. A magnitude comparison is performed between a signal (hereinafter, this signal is referred to as a “SUM signal”) and the sample acquisition threshold (NTH) shown in FIG. 20A. This sample capture threshold is a threshold for determining the range of the Z stage position where the AF operation is executed.

  Here, when the SUM signal is small, first, the gain of the IV conversion amplifier 1812 is increased so that the SUM signal becomes larger than the sample acquisition threshold. In this way, when the SUM signal is still smaller than the sample acquisition threshold, it is determined that the sample 102 has not been acquired, the Z stage is driven at a high speed, and the position where the SUM signal becomes larger than the sample acquisition threshold. Move the sample 102 to.

  On the other hand, when the SUM signal is larger than the sample capture threshold, the Z stage is driven at a low speed so that the AF signal falls within the focus determination threshold (± FTH) shown in FIG. 20B (focus range). Move the sample 102 to. The focus determination threshold is a threshold for determining whether or not the sample 102 is at the focus position of the objective lens 105, and the Z stage position is included in the range of the focal depth of all the objective lenses 105 used. Is set in advance.

  In Patent Document 2 described above, the sample capture threshold value and the focus determination threshold value (hereinafter, these threshold values are collectively referred to as “AF parameters”) can be set for each magnification of the objective lens. A technique for enabling the observer to set the above is disclosed.

  By the way, when the microscope employing the above-described AF system is used in a semiconductor inspection apparatus, an antireflection film having a reflectance of 1% or less from a metal film having a reflectance of 90% or more according to a semiconductor wafer manufacturing process. It is necessary to provide a high-speed and accurate AF operation for various samples up to an attached pattern wafer. FIG. 21A and FIG. 21B show setting examples of the noise determination threshold when the AF system is used for such purposes.

  21A and 21B show the relationship between the Z stage position and the SUM signal, respectively. Here, FIG. 21A shows a case where the reflectance of the sample to be observed is 1%, and FIG. 21B shows a case where the reflectance of the sample to be observed is 90%. In FIGS. 21A and 21B, the magnification of the objective lens is the same.

  21A and 21B, the horizontal axis indicates the Z stage position, and the vertical axis indicates the signal level of the SUM signal. Further, the noise determination threshold and the Z stage low speed range shown in both FIG. 21A and FIG. 21B correspond to the sample capture threshold and capture range in FIG. 20A, respectively.

  When an AF system is used in a semiconductor inspection apparatus, the noise determination threshold is set according to the magnification of the objective lens. Here, the noise determination threshold value is set to be low in order to enable even a sample with low reflectance to be captured (see FIG. 21A). For this reason, the Z stage low speed range becomes wide in the sample having a high reflectance (see FIG. 21B), and as a result, the AF operation becomes low speed.

  With regard to this problem, for example, Patent Document 3 discloses a technique of measuring the reflectance of a sample and setting a sample capture threshold based on the reflectance. However, in this technique, it is necessary to provide a measurement unit that measures the reflectance of the sample.

Further, for example, in Patent Document 4, an amplifier that amplifies the output signal of a sensor is of a time integration type, and the longest integration time is changed for each observation condition (objective magnification, reflectance), so that it is more than necessary. A technique for preventing the integration time from becoming long is disclosed.
JP 2003-167183 A JP 2005-10665 A JP-A-8-220418 JP 2001-91856 A

  When an AF system is used in a semiconductor inspection apparatus, if an objective lens with a magnification exceeding 100 times is used, the optical depth of the AF unit will vary as the variation in the tilt of the AF signal due to the shallow depth of focus. . This problem will be described with reference to FIGS. 22A and 22B.

  22A and 22B show the relationship between the Z stage position and the AF signal. 22A and 22B, the horizontal axis indicates the Z stage position, and the vertical axis indicates the signal level of the AF signal.

  FIG. 22A shows a case where there is little variation in the optical adjustment of the microscope unit, and FIG. 22B shows a case where this variation is large. As can be seen by comparing FIG. 22A and FIG. 22B, when the variation in the optical adjustment of the microscope unit is large, the focusing range may go out of the focal depth of the objective lens. An accurate AF operation cannot be provided. This problem cannot be dealt with by the techniques disclosed in Patent Document 3 and Patent Document 4 described above.

  Regarding this problem, if the focus determination threshold value is narrowed to cope with this variation, the AF signal will not always fall within the focus determination threshold value, and as a result, the Z stage will cause hunting (repeated vertical movement). turn into.

  As another problem, the user of the microscope unit may prioritize the focusing accuracy over the AF speed (for example, use in an automatic defect review apparatus), or may prioritize the AF speed over the focusing accuracy. There are also (for example, alignment applications). In a microscope unit, AF parameter tuning is currently determined by trial and error based on repeated experiments by the user, and it takes a considerable amount of time to determine AF parameters.

  With respect to this problem, the technique disclosed in the above-mentioned Patent Document 3 automatically determines the sample capture threshold, and therefore cannot tune the AF parameter according to the application. Also in the technique disclosed in the above-mentioned Patent Document 4, the longest integration time is determined by experiments after all.

  The present invention has been made in view of the above-described problems, and the problem to be solved is easy and reliable even if the microscope unit used for observing samples having different reflectivities has optical variations. In addition, it is possible to determine parameters for controlling the operation of the microscope.

  A microscope apparatus according to one aspect of the present invention is a parameter that controls the operation of the microscope apparatus and stores the parameter associated with each sample to be observed for at least two samples. And a control unit that controls the operation of the microscope apparatus based on the parameter associated with the selected sample in response to an instruction to select the sample. Yes, this feature solves the aforementioned problems.

  In the above-described microscope apparatus according to the present invention, an illumination optical system that irradiates the sample with illumination light emitted from the light source via the objective lens, and an image of the sample irradiated with illumination light from the light source are formed. An observation optical system for adjusting the distance between the objective lens and the sample, and the parameters include a driving range of the focusing unit, a position of the focusing unit, and the microscope apparatus. It is also possible to configure such that at least one of the position of the optical aperture provided in the light source and the voltage applied to the light source.

  According to another aspect of the present invention, a focus detection apparatus adjusts the distance between the objective lens and the sample to perform a focusing operation on the sample, and controls the operation of the autofocus unit. A storage unit that stores parameters associated with each sample for at least two or more samples, and is associated with the selected sample according to an instruction to select the sample. And a control unit that controls the operation of the autofocus unit based on the parameter. The feature described above is solved by this feature.

  In the above-described focus detection apparatus according to the present invention, the parameter includes a threshold value for determining the interval range for operating the autofocus unit, and for determining whether or not the sample is at the in-focus position. It may be configured to be at least one of a threshold value, a change speed of the interval when the autofocus unit is operated, and a maximum operation time of the autofocus unit.

  In the focus detection apparatus according to the present invention described above, the autofocus unit includes a light receiving unit that outputs an electrical signal having a magnitude corresponding to the intensity of reflected light reflected from the sample, and the parameter is The integration time when performing the time integration of the electric signal can also be configured.

  In the above-described focus detection apparatus according to the present invention, a light source for irradiating the sample with measurement light for focus detection via the objective lens, the measurement light from the objective lens, and illumination light for observing the sample And a chromatic aberration correction unit that corrects the chromatic aberration, and the autofocus unit can be configured to operate based on the reflected light of the measurement light applied to the sample.

At this time, the parameter may be configured to be a value that determines a correction amount of chromatic aberration in the chromatic aberration correction unit.
Further, in the above-described focus detection device according to the present invention, the control unit controls the operation of the autofocus unit according to the instruction of the adjustment range of the interval, and under the limitation of the adjustment range of the instruction. It can also comprise so that the said focusing part may be controlled.

  In the focus detection apparatus according to the present invention described above, when the control unit obtains an instruction to register the parameter in the storage unit, the control unit controls the focusing unit to repeatedly change the interval at a constant interval. In addition, the information output from the autofocus unit at each change may be stored.

The focus detection apparatus according to the present invention described above may further include an instruction unit that gives an instruction to the control unit.
In addition, a focus detection control method, which is another aspect of the present invention, is a parameter for controlling an autofocus operation in which a focusing operation is performed on a sample by adjusting the distance between the objective lens and the sample. The parameter associated with each sample is stored in advance in the storage unit for at least two or more samples, and the parameter associated with the selected sample is in response to an instruction to select the sample. The autofocus operation is controlled based on the above, and the above-described problems are solved by this feature.

  According to the present invention, the parameters for controlling the operation of the microscope can be easily and reliably performed even when the microscope unit used for observing the samples having different reflectivities has optical variations. There is an effect that is determined.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a schematic configuration of a microscope apparatus including a focus detection apparatus according to the present embodiment. In the figure, the description of the same parts as those of the optical system shown in FIG. 18 is omitted.
In FIG. 1, a revolver unit 104 is disposed in the microscope body 1 at a position facing an XY stage 103 on which a sample 102 can be mounted. The revolver unit 104 can mount up to six objective lenses 105, and numbers # 1 to # 6 are assigned to revolver holes (not shown).

  The revolver unit 104 includes a mounter 106 to which the objective lens 105 is attached, a revolver motor 107 that electrically drives the mounter 106 to insert the objective lens 105 into the optical axis, and a revolver sensor group 108. The revolver sensor group 108 includes a revolver connection sensor that detects that the revolver unit 104 is connected, a hole number sensor that detects the current hole number, and a movement that detects that the objective lens 105 has been inserted into the optical axis. Although it is composed of a completion sensor, it is not shown here.

  The illumination unit 109 includes a microscope light source 110 that emits visible light as illumination light, for example. Light from the microscope light source 110 passes through the illumination system lens 111 and the optical aperture 112 and is guided to the half mirror 113. The light deflected 90 ° by the half mirror 113 is irradiated to the sample 102 through the objective lens 105.

  The light reflected by the sample 102 passes through the objective lens 105, passes through the half mirror 113, and is guided to the lens barrel 114. The observer can observe the image of the imaged sample 102 through the eyepiece lens 115 or by displaying an image obtained by the CCDD force mellar 116 on a monitor (not shown).

  A sample 102 is placed on the XY stage 103. The XY stage 103 is movable in the XY direction that is perpendicular to the optical axis, and is mounted on a Z stage 117 that is movable in the Z direction that is the direction of the optical axis. When the observer moves the Z stage 117 that is the focusing unit, the distance between the sample 102 and the objective lens 105 is adjusted, and the sample 102 can be placed at the focus position of the objective lens 105.

  An AF unit 118 is installed above the illumination unit 109. The AF unit 118 includes a light source driving unit 119, a chromatic aberration lens motor 120, a light receiving circuit 122, and an optical system 124. The light receiving circuit 122 and the optical system 124 have the same configuration as that shown in FIG.

  A PC 123 is connected to the control unit 121. A predetermined control program is executed in the PC 123, and various instructions are given to the control unit 121 in accordance with operations performed by the observer.

The control unit 121 has the internal configuration shown in FIG.
As shown in FIG. 2, the control unit 123 includes a CPU (Central Processing Unit) 201, a RAM 202 that temporarily stores various data such as calculation data, a ROM 203 that stores control programs and various data in advance, I / O 205a, 205b that exchanges various data with each of the nonvolatile memory 204, the revolver unit 104, the AF unit 118, the Z stage 117, and the PC 123 in which AF parameters, chromatic aberration correction lens positions, and the like are stored. , 205c and 205d, and drivers 206a, 206b and 206c for driving the motors of the respective units.

  The CPU 201 controls the AF operation. That is, the signal from the light receiving circuit 122 in the AF unit 118 is acquired via the AFI / O 205a to calculate the SUM signal and the AF signal, and the sample acquisition determination and the focus determination are performed using these signals. . Further, when the determination result of the sample capture determination or the focus determination is NG, the CPU 201 instructs the drive amount and drive speed to the Z stage driver 206b via the Z stage I / O 205b.

In the RAM 202, a value indicating the current sample number information is stored in a storage area of a SAMPLE address (not shown). In order to rewrite the stored data at the SAMPLE address, the PC 123 sends the following sample selection command to the control unit 121.
SAMPLE “Sample Number”
Send. Upon receiving the above command, the control unit 121 stores data of “sample number” in the storage area of the SAMPLE address in the RAM 202.

The nonvolatile memory 204 stores various data written by the CPU 201. Hereinafter, a memory map of the nonvolatile memory 204 shown in FIG. 3 will be described.
First, in each storage area from address OB [1] to address OB [6], a value indicating the type of objective lens 105 attached to each of revolver holes # 1 to # 6 of revolver unit 104 is stored. .

In each storage area from the address AFPRM [0] [1] [0] to the address AFPRM [2] [6] [3], a sample capture threshold (AF parameter 0) and a focus determination threshold (AF parameter 1) are stored. Each parameter for controlling the AF operation in the microscope apparatus of FIG. 1 such as the longest integration time (AF parameter 2) and the chromatic aberration lens position (AF parameter 3) is associated with each sample 102 and each objective lens 105 type. Is remembered. The AFPRM address, which is a three-dimensional array, is
AFPRM [sample number] [revolver hole position] [AF parameter number]
It has the structure of the arrangement.

PC 123 sends command to control unit 121
OBTYPE “Revolver hole number”, “Revolver type number”
, The type of the objective lens 105 attached to the revolver holes # 1 to # 6 can be registered in the control unit 123. It should be noted that the objective lens number is associated with the objective lens 105 as illustrated in FIG. 4 according to its type. The objective lens type number is used as the “revolver type number” in the above command. For example, when a “universal 10X” objective lens is mounted in the revolver hole # 2, the PC 123
OBTYPE 2, 7
Is transmitted to the control unit 121. Upon receiving this command, the control unit 121 stores the value “7” in the OB [2] address of the nonvolatile memory 204.

Similarly, in order to register the AF parameter in the control unit 121, the PC 123 uses a command
AFPRM “AF parameter number”, “value to write”
Is transmitted to the control unit 121. When the control unit 121 receives this command, the control unit 121 reads out the sample number information indicating the current sample 102 from the SAMPLE address in the RAM 202, and revolves the revolver hole number currently located on the optical axis. Obtained from the unit I / O 205c. Then, the “write value” indicated in the command is stored in the AFPRM address of the nonvolatile memory 204 corresponding to the current sample number and the revolver hole number and the AF parameter number indicated in the received command. .

For example, when registering “3000” as the sample capture threshold of sample 0 when using the objective lens 105 mounted in the revolver hole # 1, the PC 123
AFPRM 1,3000
Is transmitted to the control unit 121. Upon receiving this command, the control unit 121 stores the value “3000” in the AFPRM [0] [1] [0] address of the nonvolatile memory 204.

In this way, each AF parameter is stored in the nonvolatile memory 204 in association with each sample 102 and each type of the objective lens 105.
As shown in the memory map of FIG. 5, the ROM 203 stores in advance the default values of the AF parameters for each type of the objective lens 105 in each storage area from address L5X [0] to address U100X [2]. .

In the PC 123, an operation instruction and various setting instructions for the microscope main body 1 are performed by commands.
Here, FIG. 6 will be described. This figure shows a screen of a graphical user interface (hereinafter abbreviated as “GUI”) displayed on a display unit (not shown) of the PC 123 when the microscope operation software is executed on the PC 123. An example is shown.

  The microscope operation GUI shown in FIG. 6 is used to issue a microscopic communication button 301 for starting communication with the microscope main body 1, a sample selection button group 302 for instructing selection of the sample 102, and a switching instruction for the objective lens 105. Objective lens switching button group 303, Z stage operation button group 304 for instructing to move the Z stage 117, Z stage display unit 305 for displaying the current position of the Z stage 117, and current upper and lower limits of the Z stage 117 A limit position display unit 306 for displaying a limit position on the software and a range in which AF is operated (hereinafter referred to as “AF zone”), a limit position setting unit 307 for setting the limit position, and AF zone input unit 307a, AF execution button 308 for starting execution of AF operation, current AF A status display unit 309 for displaying the operation state (status) of the operation, an AF parameter setting button 310 for transitioning the display screen on the PC 123 to the AF parameter setting screen, and a drive instruction for driving the chromatic aberration lens motor 120 A chromatic aberration lens drive button group 311, a chromatic aberration lens display unit 312 for displaying the current position of the chromatic aberration lens, a chromatic aberration lens registration button 313 for registering the current position of the chromatic aberration lens motor 120, and the upper and lower sides of the Z stage 117 (sample 102). A center position setting button 314 for storing the center position of the movement in the nonvolatile memory 404 is provided.

  Next, FIG. 7 will be described. This figure shows an example of a parameter setting GUI screen that is displayed on a display unit (not shown) of the PC 123 when the microscope operation software is executed by the PC 123.

  The parameter setting GUI shown in FIG. 7 includes a measurement start button 401 for instructing start of measurement of the SUM signal and AF signal for parameter determination, a data display unit 402 for displaying the value of the data after measurement, SUM signal display unit 403 and AF signal display unit 404 for displaying a SUM signal and an AF signal in graphs, sample acquisition for setting and displaying a sample acquisition threshold value, a focus determination threshold value, and an integration time on the graph. A range setting unit 405, a focusing threshold setting unit 408, an integration time setting unit 407, and an AF parameter registration button 408 for registering AF parameters are provided.

Hereinafter, an operation of the microscope apparatus of FIG. 1 configured as described above will be described.
First, the initial setting operation will be described. Before the use of the microscope is started, the assignment (assignment) of the type of the objective lens 105 attached to the revolver unit 104 is performed as an initial setting.

  When the microscope operation software is executed by the PC 123, first, the microscope operation GUI shown in FIG. 6 is displayed. Here, when the observer operates a pointing device or the like provided in the PC 123, the microscope communication button 301 is pressed. Then, the microscope main body 1 becomes communicable with the PC 123.

  Thereafter, when one of the objective lens switching buttons 303 is selected and pressed, and subsequently a revolver assign button (not shown) is pressed, the type and magnification of the objective lens 105 attached to each revolver hole are assigned. The In the screen example of FIG. 6, U5X (universal 5X) is assigned to the revolver hole # 1, similarly U10X (universal 10X) is applied to the revolver hole # 2, U20X (universal 20X) is applied to the revolver hole # 3, and the revolver hole. # 4 is assigned U50X (universal 50X), revolver hole # 5 is assigned U100X (universal 100X), and revolver hole 6 is assigned L150X (long operation 150X). Here, the “universal” type is an ordinary objective lens, and the “long operation” type is an objective lens having a long WD (Work Distance).

When the revolve assign button is pressed, the objective lens assign command
OBTYPE "Revolver hole number", "Objective lens type number"
Are transmitted from the PC 123 to the control unit 121 by the number of revolver holes. When the control unit 121 receives this command, it writes the objective lens type number in the storage area of the OB [revolver hole number] address in the nonvolatile memory 204.

  When the assignment of the type information of the objective lens 105 is completed, the CPU 201 refers to the objective lens type number stored in each storage area from the address OB [1] to the address OB [6] of the nonvolatile memory 204. At the same time, among the default values of the AF parameters stored in the ROM 203, those corresponding to the objective lens type number are read, and the read default values are written in the storage area for the AF parameters in the nonvolatile memory 204.

For example, the command
OBTYPE 1, 6
In this case, since the type of the objective lens 105 having the objective lens type number “6” is universal 5X (U5X), the CPU 201 moves from the U5X [0] address to the U5X [2] address in the ROM 203. The value stored in each storage area is read out, and the same data is read from address AFPRM [0] [1] [0] to address AFPRM [0] [1] [2], address AFPRM [1] [1] [0]. To AFPRM [1] [1] [2] addresses, and AFPRM [2] [1] [0] addresses to AFPRM [2] [1] [2] addresses.

Next, the vertical drive operation of the Z stage 117 will be described.
For this operation, the observer operates a pointing device or the like provided in the PC 123 to press the Z stage operation button group 404 on the screen of FIG. When the PC 123 detects this pressing operation, the PC 123 transmits a Z stage drive command to the control unit 121. When the control unit 121 receives this command, it sends a drive instruction to the Z stage I / O 205b.

The upper limit position and the lower limit position that determine the driving range of the Z stage 117 and the AF zone described above are set by a pressing operation on the limit position setting unit 307.
When the button on the limit position setting unit 307 is pressed, the following setting command: Upper limit setting command: UPLMT “Z stage value to be set”
Lower limit setting command: DOWNLMMT “Z stage value to be set”
AF zone setting command:
AFZONE “current position ± input value to AF zone input unit 307a”
PC123 transmits. When the control unit 121 receives these misalignment commands, the storage areas of the UPLMT address, the DOWNLMT address, the CENTER address, and the AFZONE address of the nonvolatile memory 204 shown in the memory map of FIG. Write a value to The “current position” in the AF zone setting command is written in the storage area of the CENTER address, and “the input value to the AF zone input unit 307a” in the AF zone setting command is written in the storage area of the AFZONE address. It is.

Here, an example of setting each limit position will be described.
The observer presses the Z stage operation button group 304 to prevent contact between the objective lens 105 and the sample 102, and the objective lens 105 and the sample 102 having the shortest working distance among those attached to the revolver unit 104 are displayed. The Z stage 117 is moved to a position where no contact is made. Then, the upper limit button is pressed to set this position as the upper limit position.

The setting of the lower limit position and the AF zone is the same, and the setting is performed by moving the Z stage 117 and pressing the limit position setting unit 307.
Next, setting of each limit position when the sample 102 is replaced will be described.

In this case, the observer sets the sample 102 on the XY stage 103 and then presses the sample selection button group 302, for example, No. 2. Then, the Z stage operation button group 301 is pressed to focus on the exchanged sample 102. Here, when the center position setting button 314 is pressed, the PC 123 displays the center position change command.
CHANGECENTER “Current Z stage position”
Send. Upon receiving this command, the control unit 121 first stores “current Z stage position” in the storage area of the NEWCENTER address in the RAM 202. Subsequently, the value stored in the CENTER address of the nonvolatile memory 204 is read out and stored in the storage area of the CURCENTER address in the RAM 202. Then, the following expression is calculated, and the obtained value is stored in the storage area of the DIF address in the RAM 202.

(Value of DIF address) =
(Value of NEWCENTER address)-(value of CURCENTER address)
Thereafter, the control unit 121 performs an operation of the following formula, and writes the obtained value in the storage area of each address of the nonvolatile memory 204.

(UPLMT address value) = (Current UPLMT address value) + (DIF address value)
(Value of DOWNLMT address) =
(Current DOWNLMT address value)-(DIF address value)
(Value of CENTER address) = (Value of NEWCENTER address)
When the CPU 201 of the control unit 121 performs the above processing, the limit position and the AF zone are appropriately set for the sample 102 after replacement.

Next, the AF operation will be described.
When the observer presses the AF execution button 308 on the screen of FIG. 6, the PC 123 transmits an AF execution command to the control unit 121. When the control unit 121 receives this command, it acquires the value stored in the SAMPLE address in the RAM 202 and also acquires the current objective lens hole position from the revolver unit I / O 205c. AFPRM [value of SAMPLE address] [current objective lens hole position] [0] address in the non-volatile memory 204
AFPRM [value of SAMPLE address] [current objective lens hole position] [3] Using the AF parameter stored in each storage area of address, the selected sample 102 and the objective positioned on the current optical axis An AF operation based on the AF parameter associated with the lens 105 is executed. However, at this time, the AF operation is executed within the range of the AF zone.

  Here, when the AF is successful, the AF operation shifts to the follow-up mode. Then, the character “follow” is displayed on the status display section 309 of the screen of FIG. 6 and the AF light source (LD 1801 in FIG. 18) of the AF unit 118 maintains the light emission state. In this mode, even if the XY stage 103 is moved, the position of the Z stage 117 (that is, the position of the sample 102) is always the focus position of the AF unit 118 (that is, the focus position of the objective lens 105). Control to follow is performed by the control unit 121.

  Incidentally, in order to correct the chromatic aberration between the AF unit 118 and the illumination unit 109, that is, the difference between the focus position of the AF unit 118 and the focus position of the illumination unit 109, a chromatic aberration correction lens (1806 in FIG. 18) in the AF unit 118 is used. ) Must be adjusted. Next, this adjustment operation will be described.

  When the chromatic aberration lens driving button group 311 is pressed while the AF operation is operating in the follow-up mode, the operation is transmitted from the PC 123 to the control unit 121 to drive the chromatic aberration lens motor 120. At this time, the value of the chromatic aberration lens display unit 312 is updated according to the driving amount of the chromatic aberration lens motor 120. At this time, since the focus position of the AF unit 118 changes, the Z stage 117 moves and follows. In this way, by moving the chromatic aberration correction lens, when the focus position of the AF unit 118 and the focus position of the illumination unit 109 coincide with each other, the chromatic aberration lens registration button 313 on the screen of FIG. 6 is pressed. Then, the PC 123 transmits the following AF parameter setting command to the control unit 121.

AFPRM 3, “Current position of chromatic aberration lens motor 120”
When this command is received by the control unit 121, the value stored in the SAMPLE address in the RAM 202 is acquired, and the current objective lens hole position is acquired from the revolver unit I / O 205c. Then, the “current position of the chromatic aberration lens motor 120” is stored in the storage area of the AFPRM [value of SAMPLE address] [current objective lens hole position] [3] address in the nonvolatile memory 204.

The position of the chromatic aberration lens motor 120 needs to be adjusted for each objective lens 105 mounted on the revolver unit 104.
Next, new setting of AF parameters will be described.

  In order for the observer to set AF parameters, the AF parameter setting button 310 on the screen shown in FIG. When the AF parameter setting button 310 is pressed, the PC 123 switches the display screen and displays the parameter setting GUI shown in FIG.

In parallel with this screen switching, the PC 123 transmits a sample selection command to the control unit 121. For example, if the first sample selection button group 301 is pressed on the screen shown in FIG.
SAMPLE 1
Is sent. Upon receiving this command, the control unit 121 stores “1” in the storage area of the SAMPLE address in the RAM 202.

  When the parameter setting GUI is displayed, an AF signal for the sample 102 currently set on the XY stage 103 with the objective lens 105 currently in use under the current position of the chromatic aberration lens motor 120 is acquired. First, the pressing operation of the measurement start button 401 on the screen of FIG. 7 is performed.

  Hereinafter, the contents of the process performed when the PC 123 executing the microscope operation software detects the pressing operation of the measurement start button 401 will be described with reference to the flowchart of FIG. 8 showing the process contents.

  First, in S101, processing for transmitting an AF execution command to the control unit 121 is performed. Upon receiving this command, the control unit 121 starts control processing for the AF operation. At this time, since the AF operation with the default value of the AF parameter is performed, the speed of the AF operation until focusing is slow, and the focusing accuracy may be low.

  Next, in S102, processing for determining whether AF has succeeded is performed. Here, when it is determined that the AF has failed (when the determination result of S102 is No), an error is displayed in S111, and thereafter the processing of FIG. 8 is terminated.

  On the other hand, when it is determined that the AF is successful (when the determination result in S102 is Yes), data for creating a graph indicating the relationship between the position of the Z stage 117, the SUM signal, and the AF signal is obtained. In addition, a process for acquiring the SUM signal and the AF signal is started while moving the Z stage 117.

  That is, first, in S103, processing for transmitting a command to move the Z stage 117 upward by the measurement range to the control unit 121 is performed. The control unit 121 that has received this command moves the Z stage 117 in accordance with the instruction of the command.

Next, in S104, processing for substituting the initial value 0 for the variable i is performed. The variable i is a measurement number counter.
In S105, processing for transmitting an AF signal acquisition command to the control unit 121 is performed. When receiving this command, the control unit 121 returns the current A sensor output signal, B sensor output signal, SUM signal, and AF signal to the PC 123.

  When the acquisition of these signals is completed, the PC 123 performs a process of moving the Z stage 117 downward by a predetermined value (for example, one pitch) in S106, and in the subsequent S107, the variable i is incremented (increased by 1). Process).

  In S108, processing for determining whether or not the number of times of measurement of the signal (that is, the value of the variable i) has reached a predetermined number is performed. Here, when it is determined that the number of measurements has not reached the specified number (when the determination result is No), the process returns to S105, and the acquisition of the signal is repeated.

  On the other hand, when it is determined that the number of measurements has reached the specified number (when the determination result is Yes), the relationship between the Z stage position and the SUM signal is displayed on the SUM signal display unit 403 of the screen of FIG. In the subsequent S110, a process for displaying a graph representing the relationship between the Z stage position and the AF signal is performed, and then the process of FIG. 8 ends.

  FIG. 9 shows an example of a parameter setting GUI screen on which two graphs are displayed by the processing of S109 and S110. In this figure, the Y axes 902a and 902b of each graph pass through the focal point, that is, the intersection of the graph of the AF signal displayed on the AF signal display unit 404 and the X axis (that is, the so-called zero cross point). Display in position. Therefore, the X coordinate of this focal point is “0”.

  When these graphs are displayed on the parameter setting GUI, the observer operates a pointing device or the like provided in the PC 123 to position either the SUM signal display unit 403 or the AF signal display unit 404. As shown in FIG. 9, click position display lines 901a and 901b are displayed on the graph. In addition to this, each of the A sensor output signal, the B sensor output signal, the SUM signal, and the AF signal when the Z stage is located at the position indicated by the click position display lines 901a and 901b is displayed on the data display unit 402. The signal level is displayed.

  Further, when the above-described display is made on the parameter setting GUI, the observer inputs a desired value for setting the sample capture range to the sample capture range input unit 1002 and sets the sample capture range as shown in FIG. When the button 1001 is pressed, a sample capture range display line 1003 is displayed, and a sample capture range corresponding to the input value is displayed on the SUM signal display unit 403. In the example of FIG. 10, since the value “5.1” is input to the sample capturing range input unit 1002, the sample capturing range display line 1003 is displayed at the positions of X = −5.1 and X = + 5.1. Has been.

  Similarly, as shown in FIG. 10, when the observer inputs a desired value for setting the focus threshold value to the focus threshold value input unit 1005 and presses the focus threshold value setting button 1004, the focus range display line is displayed. 1006 is displayed, and an in-focus range corresponding to the input value is displayed on the AF signal display unit 404. In the example of FIG. 10, since the value “0.3” is input to the focus threshold value input unit 1005, the focus range display line 1006 is displayed at the positions of X = −0.3 and X = + 0.3. Has been.

  By the way, as a result of the PC 123 performing the process shown in FIG. 8, when the graph of the SUM signal having a low signal level as shown in FIG. 11A is displayed on the parameter setting GUI, the observer clicks the integration time increase button. A pressing operation 1101 is performed. Then, the graph of the SUM signal is enlarged in the vertical axis direction, and a graph similar to that obtained by actually increasing the integration time and measuring the SUM signal as shown in FIG. 11B is obtained.

In order to deform the graph in this way, the PC 123 performs the following calculation on the signal level of each SUM signal for each Z stage position, and draws the graph using the calculated signal level.
(Signal level after calculation) =
{(Integration time after change) / (Integration time before change)} × (Signal level before calculation)
In this way, the observer first presses down the integration time increase button 1101 or the integration time decrease button 1102 before saturating the signal level of the SUM signal before inputting the desired values for setting the sample capture range and the focusing threshold. Make adjustments so that they are as large as possible.

As described above, when the setting of the AF parameter is completed, the observer performs the pressing operation of the AF parameter registration button 408. The PC 123 that has detected this pressing operation determines the Y-coordinate of each of the two points where the sample capture range display line 1003 and the graph of the SUM signal intersect each other as the sample capture threshold, and sets the focus range. The Y coordinate of each of the two points where the display line 1006 and the AF signal graph intersect each other is determined as the focus determination threshold value. Further, at this time, the integration time displayed in the integration time setting unit 407 is determined as the longest integration time. And the following AF parameter setting command
AFPRM 0, “determined sample capture threshold”
AFPRM 1, “determined focus determination threshold”
AFPRM 2, “determined maximum integration time”
Are continuously transmitted to the control unit 121.

Upon receiving these commands, the control unit 121 acquires a value (for example, “1”) stored in the SAMPLE address in the RAM 202 and also sets the current objective lens hole position (for example, “# 2”) to the revolver unit I. Obtained from / O205c. AFPRM [value of SAMPLE address] [current objective lens hole position] [0] address in the non-volatile memory 204
These AF parameters determined in the respective storage areas of AFPRM [value of SAMPLE address] [current objective lens hole position] [2] are stored in order.

  Thereafter, when the observer performs an operation of returning the display of the PC 123 from the parameter setting GUI to the microscope operation GUI, and subsequently performs an operation of pressing the AF execution button 308, the PC 123 transmits an AF execution command to the control unit 121. . Upon receiving this command, the control unit 121 reads the AF parameter from the above-described storage area of the nonvolatile memory 204, and executes the AF operation using this appropriate AF parameter.

  As described above, according to the present embodiment, appropriate AF parameters can be set easily and reliably for each sample to be observed, and the AF operation using the AF parameters thus set is performed. be able to.

FIG. 12 shows a schematic configuration of the microscopic device including the focus detection device according to the present embodiment. Here, different parts of the configuration shown in FIG. 1 will be described.
In the microscope apparatus shown in FIG. 12, an operation unit 1201 is connected to the microscope main body 1. The operation unit 1201 is of a desktop type, and its configuration is shown in FIG.

  As illustrated in FIG. 13, the operation unit 1201 issues a sample selection button group 1301 for instructing selection of the sample 102, an objective lens selection button group 1302 for instructing switching of the objective lens 105, and a movement instruction for the Z stage 117. A Z stage operation unit 1303 configured by a rotary encoder, a limit position setting button 1303a for setting the drive range of the Z stage 117, and a center position for setting the center position of the vertical movement of the Z stage 117 An AF status display unit 1306 including a setting button 1304, an AF execution button 1305 for starting execution of the AF operation, and an LED (light emitting diode) lamp for displaying whether the AF operation is operating in the follow-up mode. , Color for instructing driving of the chromatic aberration lens motor 120 Difference lens drive button group 1307, chromatic aberration lens registration button 1308 for registering the position of the chromatic aberration lens motor 120, AF parameter setting button 1309 for shifting the operation mode of the microscope apparatus to the AF parameter setting mode, microscope apparatus The housing includes a display unit 1310 for displaying a menu when various settings are made, and a setting unit 1311 for performing selection instructions and setting instructions for the menu.

  The operation unit 1201 described above is connected to the control unit 121. FIG. 14 shows an internal configuration of the control unit 121 in FIG. In the configuration of the control unit 121 shown in the figure, in place of the PCI / O 205d in the configuration shown in FIG. 2, reception of signals from various button groups provided in the operation unit 1201, display instructions from the CPU 201, and the like Is provided to the operation unit 1201.

Hereinafter, the operation of the microscope apparatus of FIG. 12 configured as described above will be described.
First, as an initial setting operation, an operation of assigning (assigning) the type of the objective lens 105 attached to the revolver unit 104 will be described.

  When the observer selects and presses one of the objective lens selection button group 1302 of the operation unit 1201 and then presses either the selection button 1311a or 1311b of the setting unit 1311, the display unit 1310 displays an objective lens. 105 types are displayed. Here, when the selection button 1311a or 1311b is repeatedly pressed, the type display of the objective lens 105 displayed on the display unit 1310 is switched each time the selection button 1311a or 1311b is pressed. Here, when the type of the desired objective lens 105 is displayed, the observer presses the registration button 1311c.

  When the CPU 201 detects that the registration button 1311c is pressed, the CPU 201 acquires information on the revolver hole currently located on the optical axis and corresponds to the type of the objective lens 105 currently displayed on the display unit 1310. The objective lens type number is acquired, and the objective lens type number is written in the storage area of the OB [revolver hole number] address in the nonvolatile memory 204.

By repeating the above processing, the types of all objective lenses 105 attached to the revolver unit 104 are assigned.
When the assignment of the type information of the objective lens 105 is completed, the CPU 201 refers to the objective lens type number stored in each storage area from the address OB [1] to the address OB [6] of the nonvolatile memory 204. At the same time, among the default values of the AF parameters stored in the ROM 203, those corresponding to the objective lens type number are read, and the read default values are written in the storage area for the AF parameters in the nonvolatile memory 204.

Next, the vertical drive operation of the Z stage 117 will be described.
When the observer rotates the Z stage operation unit 1303, a pulse signal of the rotary encoder is sent to the Z stage I / O 205b. The Z stage I / O 205b converts this pulse signal into the drive amount of the Z stage 117, and drives the Z stage 117.

A method for setting the upper limit position and the lower limit position for determining the drive range of the Z stage 117 and the AF zone described above will be described.
When the observer presses the limit position setting button 1303a, the characters “UPLMT” are displayed on the display unit 1310. At this time, when the observer presses the registration button 1311c, the CPU 201 stores the current position of the Z stage 117 in the storage area of the UPLMT address of the nonvolatile memory 204.

  Thereafter, when the observer presses the selection button 1311a, the characters “DOWNLMT” are displayed on the display unit 1310. When the observer presses the registration button 1311c at this time, the CPU 201 stores the current position of the Z stage 117 in the storage area of the DOWNLMMT address of the nonvolatile memory 204.

  The AF zone setting will be described. When the observer presses the selection button 1311a or 1311b to display the characters “AFZONE” on the display unit 1310 and presses the registration button 1311c, a numerical value is displayed on the display unit 1310. At this time, when the observer presses the selection button 1311a or 1311b, the displayed numerical value is increased or decreased. Here, when a desired numerical value is displayed as the AF zone setting value, the registration button 1311c is pressed again. Then, the CPU 201 stores the numerical value being displayed in the storage area of the AFZONE address of the nonvolatile memory 204.

Next, setting of each limit position when the sample 102 is replaced will be described.
In this case, the observer sets the sample 102 on the XY stage 103 and then presses, for example, No. 2 of the sample selection button group 1301. Then, the Z stage operation unit 1303 is rotated to focus on the replaced sample 102. When the center position setting button 1304 is pressed, the CPU 201 stores the current position of the Z stage 117 in the storage area of the NEWCENTER address in the RAM 202. Subsequently, the value stored in the CENTER address of the nonvolatile memory 204 is read out and stored in the storage area of the CURCENTER address in the RAM 202. Then, the following expression is calculated, and the obtained value is stored in the storage area of the DIF address in the RAM 202.

(Value of DIF address) =
(Value of NEWCENTER address)-(value of CURCENTER address)
Thereafter, the CPU 201 performs an operation of the following formula, and writes the obtained value in the storage area of each address of the nonvolatile memory 204.

(UPLMT address value) = (Current UPLMT address value) + (DIF address value)
(Value of DOWNLMT address) =
(Current DOWNLMT address value)-(DIF address value)
(Value of CENTER address) = (Value of NEWCENTER address)
When the CPU 201 of the control unit 121 performs the above processing, the limit position and the AF zone are appropriately set for the sample 102 after replacement.

Next, the AF operation will be described.
When the observer depresses the AF execution button 1305 of the operation unit 1201, the CPU 201 that detects the depressing operation acquires a value stored at the SAMPLE address in the RAM 202 and revolves the current objective lens hole position. Obtained from the unit I / O 205c. AFPRM [value of SAMPLE address] [current objective lens hole position] [0] address in the non-volatile memory 204
AFPRM [value of SAMPLE address] [current objective lens hole position] [3] Using AF parameters stored in each storage area, the sample 102 and the objective positioned on the current optical axis are used. An AF operation based on the AF parameter associated with the lens 105 is executed. However, at this time, the AF operation is executed within the range of the AF zone.

Here, when the AF is successful, the AF operation shifts to the follow-up mode. At this time, the AF status display portion 1306 is turned on.
Next, the adjustment operation of chromatic aberration between the AF unit 118 and the illumination unit 109 will be described.

When the chromatic aberration lens driving button group 1307 is pressed while the AF operation is operating in the follow-up mode, the CPU 201 that detects the pressing operation drives the chromatic aberration lens motor 120 to detect the chromatic aberration correction lens. Move. When the focus position of the AF unit 118 matches the focus position of the illumination unit 109, the observer presses the chromatic aberration lens registration button 1308. Then, the CPU 201 that has detected this pressing operation acquires the value stored at the SAMPLE address in the RAM 202 and also acquires the current objective lens hole position from the revolver unit I / O 205c. Then, the “current position of the chromatic aberration lens motor 120” is stored in the storage area of the AFPRM [value of SAMPLE address] [current objective lens hole position] [3] address in the nonvolatile memory 204.

Next, new setting of AF parameters will be described.
First, the observer selects and presses the sample selection button group 1301 to which the number of the sample 102 for which AF parameter is set is assigned, and then presses the AF parameter setting button 1309.

  Hereinafter, the contents of the process performed when the CPU 201 of the control unit 121 detects the pressing operation of the AF parameter setting button 1309 will be described with reference to the flowchart of FIG. 15 showing the process contents.

  First, in S201, the CPU 201 starts control processing for the AF operation. At this time, since the AF operation with the default value of the AF parameter is performed, the speed of the AF operation until focusing is slow, and the focusing accuracy may be low.

  Next, in S202, processing for determining whether AF has succeeded is performed. Here, when it is determined that the AF has failed (when the determination result in S202 is No), in S210, the AF status display unit 1306 blinks to display an error, and thereafter the processing of FIG. 15 is performed. finish.

  On the other hand, when it is determined that the AF is successful (when the determination result in S202 is Yes), data for creating a graph indicating the relationship between the position of the Z stage 117, the SUM signal, and the AF signal is obtained. In addition, a process for acquiring the SUM signal and the AF signal is started while moving the Z stage 117.

That is, first, in S203, processing for moving the Z stage 117 is performed.
Next, in S204, processing for substituting the initial value 0 for the variable i is performed. The variable i is a measurement number counter.

  In S205, the current A sensor output signal and B sensor output signal are acquired via the AFI / O 205a, the SUM signal and AF signal are acquired from these output signals, and the SUM address and AF address in the RAM 202 are stored. Processing to store in the area is performed. Each storage area of the SUM address and the AF address in the RAM 202 has an array structure, and the SUM signal and the AF signal are stored in association with the position of the Z stage 117, respectively.

  When the acquisition of these signals is completed, a process for moving the Z stage 117 downward by a predetermined value (for example, one pitch) is performed in S206, and a variable i is incremented (increased by 1) in the subsequent S207. Is done.

  In S208, processing for determining whether or not the number of signal measurements (that is, the value of the variable i) has reached a predetermined number is performed. Here, when it is determined that the number of measurements has not reached the specified number (when the determination result is No), the process returns to S205, and the acquisition of the signal is repeated.

  On the other hand, when it is determined that the number of measurements has reached the specified number (when the determination result is Yes), in step S209, a buzzer (not shown) built in the operation unit 1201 is pronounced to observe the end of the measurement. The process of notifying the person is performed, and then the process of FIG. 15 is terminated.

  After the CPU 201 performs the above processing and notifies the end of the measurement, when the observer presses the registration button 1311c of the operation unit 1201, the characters “SAMPLETH” are displayed on the display unit 1310. Here, when the observer presses the selection button 1311a or 1311b, a numerical value is displayed on the display unit 1310. At this time, when the observer further presses the selection button 1311a or 1311b, the displayed numerical value is increased or decreased.

  Here, when a desired numerical value is displayed as the sample capture threshold, the registration button 1311c is pressed again. Then, the CPU 201 that has detected the pressing of the registration button 1311 c stores the numerical value being displayed in the storage area of the SAMPLETH address in the RAM 202. Further, the processing shown in the flowchart of FIG. 16 is performed based on the numerical value being displayed on the display unit 1310 and the signal level data of the SUM signal stored in the storage area of the SUM address in the RAM 202.

Hereinafter, the processing shown in FIG. 16 will be described.
First, in S301, a process of substituting an initial value 0 for a variable i is performed.
In the subsequent S302, the size comparison between the value (sample capture threshold) stored in the storage area of the SAMPLETH address of the RAM 202 and the value (signal level of the SUM signal) stored in the SUM [i] address is performed. .

  Here, when the value stored at the address SUM [i] is equal to or less than the sample capture threshold (when the result of the determination process in S302 is No), the current value of the variable i is stored in the RAM 202 in S303. Processing for determining whether or not the number of data of the SUM signal being performed has been reached is performed. Here, when it is determined that the value of the variable i has not reached the number of data (when the determination result is No), a process of incrementing the variable i (increasing by 1) is performed in S304. Thereafter, the process returns to S302, and the above-described size comparison is performed again.

  On the other hand, when it is determined in S303 that the value of the variable i has reached the number of data (when the determination result is Yes), the signal levels of the SUM signals stored in the RAM 202 are all from the sample capture threshold. Is also small. This means that the integration time setting is inappropriate. Therefore, in S305, the longest integration time is increased by “1”, and {(integration time after change) / (integration time before change)} for each signal level data of the SUM signal stored in the RAM 202. A process for storing again the value obtained by multiplying by is performed. Thereafter, the process returns to S101 and the above-described process is performed again.

By the way, in S302, when the value stored in the SUM [i] address is larger than the sample capture threshold (when the result of the determination process in S302 is Yes), in S306, the CPU 201 determines the current SUM [i]. The value stored at the address is stored in the storage area of the AFPRM [SAMPLE address value] [current objective lens hole position] [0] address in the non-volatile memory 204. In the subsequent S307, the CPU 201 stores the current longest integration time value in the storage area of the AFPRM [SAMPLE address value] [current objective lens hole position] [2] address in the nonvolatile memory 204. Done. Thereafter, the processing in FIG. 16 is terminated.

  After the sample capture threshold and the longest integration time are set as described above, when the observer presses the selection button 1311a, the characters “AFTH” are displayed on the display unit 1310. Here, when the observer further presses the selection button 1311a or 1311b, a numerical value is displayed on the display unit 1310. At this time, when the observer further presses the selection button 1311a or 1311b, the displayed numerical value is increased or decreased.

  Here, when a desired numerical value is displayed as the focus determination threshold, the observer presses the registration button 1311c again. Then, the CPU 201 that detects the pressing of the registration button 1311 c stores the numerical value being displayed in the storage area of the RAM 202 at the AFTH address. Further, based on the numerical value being displayed on the display unit 1310 and the signal level data of the AF signal stored in the storage area of the AF address in the RAM 202, the processing shown in the flowchart of FIG. 17 is performed.

Hereinafter, the processing shown in FIG. 17 will be described.
First, in S401, a process for substituting an initial value 0 for a variable i is performed.
In the subsequent S402, the size comparison between the value stored in the storage area of the AFTH address in the RAM 202 (focus determination threshold) and the value stored in the AF [i] address (the signal level of the AF signal) is performed. Is called.

  Here, when the value stored in the AF [i] address is equal to or smaller than the focus determination threshold value (when the result of the determination process in S402 is No), the variable i is incremented (increased by 1) in S403. ) Is performed, and then the process returns to S402, and the above-described size comparison is performed again.

On the other hand, when the value stored in the AF [i] address is larger than the sample capture threshold in S402 (when the result of the determination process in S402 is Yes), in S404, the CPU 201 determines the current AF [i]. The value stored at the address is stored in the storage area of the AFPRM [SAMPLE address value] [current objective lens hole position] [1] address in the non-volatile memory 204. Thereafter, the processing of FIG.

  When the observer presses the AF execution button 1305 after setting the AF parameters as described above, the CPU 201 reads the AF parameters from the above-described storage area of the non-volatile memory 204, and executes this appropriate AF. An AF operation using parameters is executed.

  As described above, according to the present embodiment, it is possible to easily and surely set appropriate AF parameters for each sample to be observed without using an expensive PC with a large installation space. Thus, the AF operation using the AF parameter set in this manner can be performed.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment.
For example, in the first embodiment, an example of a GUI of a microscope with an AF function has been described. Instead of this, it is possible to implement the present invention with a GUI for operating a microscope unit or an AF unit incorporated in a semiconductor inspection apparatus or the like.

  In the first and second embodiments, a microscope that employs active AF has been described. As the AF method, passive AF such as a contrast detection method can be adopted to implement the present invention.

  In the first and second embodiments, the initial setting of AF parameters after the observer purchases the microscope has been described. Alternatively, this initial setting can be performed by a service person or a factory staff in the adjustment at the time of shipment adjustment or repair of the microscope.

  In the first embodiment and the second embodiment, the setting example of the sample capture range, the focus determination threshold value, and the maximum integration time has been described as the AF parameter setting example. In addition, it is also possible to set the Z stage speed during AF, the timeout time, etc. as AF parameters.

In the first embodiment, the AFPRM [value of SAMPLE address] [current objective lens hole position] [0] address in the non-volatile memory 204.
The AF parameters stored in the respective storage areas of AFPRM [value of SAMPLE address] [current objective lens hole position] [2] are collectively rewritten. In addition to this, it is possible to perform rewriting separately.

  In the first and second embodiments, the values stored in the control unit 121 for each sample 102 are AF parameters and chromatic aberration lens position information. In addition to this, the upper limit and lower limit limit positions (movement range of the focusing unit) of the Z stage 117, the AF zone, the position of the optical aperture 112, the focusing position, the applied voltage value to the lamp that is the microscope light source 110, Various microscope parameters may be stored for each sample 102. In this case, it is necessary to secure a storage area for storing each parameter in the nonvolatile memory 204 and prepare a command for writing each parameter in a predetermined storage area of the nonvolatile memory 204. Needless to say.

  In the first embodiment, the storage type of the objective lens type, the chromatic aberration lens position, and the AF parameter is the nonvolatile memory 204 in the control unit 121. Instead, these are stored in the memory of the PC 123 so that the microscope operation software manages these information. When the AF parameter switching such as switching of the objective lens 105 is necessary, the AF It is also possible to configure so that the parameter is transmitted to the control unit 121 by a command.

  In the first embodiment, the limit position of the Z stage 117 and the storage location of the AF zone are stored in the nonvolatile memory 204 in the control unit 121. Instead, these are stored in the memory of the PC 123 so that the microscope operation software manages these information. When the Z stage 117 exceeds the limit position, transmission of the stage drive command is stopped. Then, it can be configured to stop.

  As a means for instructing selection of the sample 102, instead of using a button, the read value of the lot ID of the IC wafer is notified to the PC 123, and the PC 123 sets an AF parameter corresponding to the ID and performs an AF operation. It is also possible to configure to execute.

  In the first and second embodiments, the argument of the AF parameter setting command “AFPRM” is “parameter number” and “value to be written”. However, the argument is not limited to this, and “sample number” ”,“ Hole number of objective lens ”,“ character string for determining parameter ”, and“ parameter value to be set ”may be specified.

In addition, the operation unit 1201 in the second embodiment is of a desktop type. Alternatively, the operation unit 1201 can be formed by a group of buttons installed on the microscope body 1.
In the first and second embodiments, the AF zone is set by a plus or minus deviation amount from the center position. Instead of this, it is also possible to configure the AF zone boundaries to be set independently. In this case, needless to say, a storage area for storing the upper limit value and the lower limit value of the AF zone is required.

  In the first embodiment, the larger of the two points where the SUM signal graph and the sample capture threshold intersect, and the two points where the AF signal graph and the focus determination threshold intersect. The one with the larger absolute value is selected and used as the AF parameter. Alternatively, the smaller one may be selected and used as the AF parameter, or one intersecting point may be used as the AF parameter. .

1 is a diagram illustrating a schematic configuration of a microscopic device including a focus detection device according to Embodiment 1. FIG. It is a figure which shows the internal structure of the control part in FIG. It is a memory map of a non-volatile memory. It is a figure which shows the example of matching with an objective lens and an objective lens number. It is a memory map of the storage area of AF parameter default value for every kind of objective lens in ROM. It is a figure which shows the example of a screen of GUI for microscope operation. It is a figure which shows the example of a screen of parameter setting GUI. It is a flowchart which shows the content of the process which PC performs. It is a figure which shows the graph display example (the 1) in parameter setting GUI. It is a figure which shows the graph display example (the 2) in parameter setting GUI. It is a figure which shows the example of a graph display in the parameter setting GUI (the 3). It is a figure which shows the graph display example (the 4) in parameter setting GUI. FIG. 10 is a diagram illustrating a schematic configuration of a microscopic device including a focus detection device according to a second embodiment. It is a figure which shows the structure of the operation part in FIG. It is a figure which shows the internal structure of the control part in FIG. It is a flowchart (the 1) which shows the content of the process which CPU of a control part performs. It is a flowchart (the 2) which shows the content of the process which CPU of a control part performs. It is a flowchart (the 3) which shows the content of the process which CPU of a control part performs. It is a figure which shows the structural example of the optical system of the microscope which employ | adopts the active AF system. It is a figure which shows the mode of the imaging of AF light in 2 division PD of a medium magnification objective lens. FIG. 19 is a diagram (part 1) illustrating the relationship between the Z stage position and the output signal of the two-part PD in the optical system illustrated in FIG. 18; FIG. 19 is a diagram (part 2) illustrating the relationship between the Z stage position and the output signal of the two-part PD in the optical system illustrated in FIG. It is a figure which shows the setting example (the 1) of a noise determination threshold value. It is a figure which shows the example of a setting of the noise determination threshold value (the 2). FIG. 6 is a diagram (part 1) for explaining the influence of variation in optical adjustment of an AF unit on an AF operation. FIG. 6 is a diagram (part 1) for explaining the influence of variation in optical adjustment of an AF unit on an AF operation.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Microscope main body 102 Sample 103 XY stage 104 Revolver unit 105 Objective lens 106 Mounter 107 Revolver motor 108 Revolver sensor group 109 Illumination unit 110 Microscope light source 111 Illumination system lens 112 Optical aperture 113 Half mirror 114 Lens barrel 115 Eyepiece lens 116 CCD camera 117 Z stage 118 AF unit 119 Light source driving unit 120 Chromatic aberration lens motor 121 Control unit 122 Light receiving circuit 123 PC
201 CPU
202 RAM
203 ROM
204 Non-volatile memory 205a AFI / O
205b Z stage I / O
205c Revolver unit I / O
205d PCI / O
206a Chromatic aberration lens driver 206b Z stage driver 206c Revolver driver 1201 Operation unit 1801 Laser diode 1802 Collimating lens 1803 Light emitting side stopper 1804 Polarizing beam splitter 1805 Condensing lens 1806 Chromatic aberration correction lens 1807 λ / 4 plate 1808 Dyclock mirror 1809 Light receiving side stopper 1810 Light Condensing Lens 1811 Two-Division Photodiode 1812 IV Converter Amplifier 1813 A / D Converter

Claims (11)

A storage unit that stores the parameters for controlling the operation of the microscope apparatus and associated with each sample to be observed for at least two samples;
In accordance with an instruction for selecting the sample, a control unit that controls the operation of the microscope apparatus based on the parameter associated with the selected sample;
A microscope apparatus characterized by comprising: An illumination optical system for irradiating the sample with illumination light emitted from a light source via an objective lens;
An observation optical system that forms an image of a sample irradiated with illumination light from the light source;
A focusing unit for adjusting the distance between the objective lens and the sample;
Further comprising
The parameter is at least one or more of a driving range of the focusing unit, a position of the focusing unit, a position of an optical diaphragm provided in the microscope apparatus, and a voltage applied to the light source.
The microscope apparatus according to claim 1. An autofocus unit that adjusts the distance between the objective lens and the sample and performs a focusing operation on the sample;
A storage unit for controlling the operation of the autofocus unit and storing the parameter associated with each sample for at least two samples;
A control unit that controls the operation of the autofocus unit based on the parameter associated with the selected sample in response to an instruction to select the sample;
A focus detection apparatus comprising: The parameter includes a threshold value for determining the range of the interval for operating the autofocus unit, a threshold value for determining whether the sample is in the in-focus position, and the parameter value when the autofocus unit is operated. It is at least one of the change speed of the interval and the maximum operation time of the autofocus unit,
The focus detection apparatus according to claim 3. The autofocus unit includes a light receiving unit that outputs an electrical signal having a magnitude corresponding to the intensity of reflected light reflected from the sample.
The parameter is an integration time when performing time integration of the electrical signal.
The focus detection apparatus according to claim 3. A light source that irradiates the sample with measurement light for focus detection via the objective lens;
A chromatic aberration corrector for correcting chromatic aberration between the measurement light at the objective lens and illumination light for observing the sample;
In addition,
The autofocus unit operates based on reflected light of the measurement light irradiated on the sample.
The focus detection apparatus according to claim 3.   The focus detection apparatus according to claim 6, wherein the parameter is a value that determines a correction amount of chromatic aberration in the chromatic aberration correction unit.   The control unit controls the operation of the autofocus unit according to an instruction of the adjustment range of the interval, and controls the focusing unit under the limitation of the adjustment range according to the instruction. The focus detection apparatus according to claim 3.   When the control unit acquires an instruction to register the parameter in the storage unit, the control unit controls the focusing unit to repeatedly change the interval at a constant interval, and from the autofocus unit every time the change is made The focus detection apparatus according to claim 3, wherein the output information is stored.   The focus detection apparatus according to claim 3, further comprising an instruction unit that gives an instruction to the control unit. A parameter for controlling an autofocus operation that adjusts the distance between the objective lens and the sample to perform a focusing operation on the sample, and is stored for at least two samples. Store in advance,
In response to an instruction to select the sample, the autofocus operation is controlled based on the parameter associated with the selected sample.
A focus detection control method characterized by the above.