JP2019060831A - Laser induced analyzer and laser induced analytical method - Google Patents

Abstract

To provide a technology capable of obtaining high analysis accuracy even when any shape of sample exists.SOLUTION: A laser induced analyzer includes: a stage 1 on which a sample 9 is mounted; a drive mechanism 2 for moving the stage 1 to a predetermined moving direction intersecting with the upper face thereof; a surface sensor 5 for measuring a position Po of the surface located on a line parallel to the moving direction passing through a converging point P of laser beams; and a focusing part for controlling the drive mechanism so that the position Po measured by the surface sensor 5 matches with the position of the converging point P.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a technique for analyzing an analyte by laser-induced plasma spectroscopy (LIPS).

  Patent Document 1 describes an apparatus for analyzing a substance solidified from liquid state by evaporation to dryness using laser induced plasma spectroscopy. Here, first, a small amount of substance in a liquid state is dropped on a fixed plate, and this is heated to evaporate the solvent. Then, the substance (dried substance) left on the plate is analyzed by laser induced plasma spectroscopy to identify the type and amount (concentration) of elements contained in the substance.

Here, laser induced plasma spectroscopy will be described. In this analysis method, a short pulse laser beam is emitted from a laser device, condensed (focused) by a lens, and irradiated onto a sample surface. At this time, a high-temperature high-density plasma (breakdown plasma) is generated at a spot (focusing point) at which the laser light is focused, and atoms on the sample surface are excited at the spot. The excited atoms emit light of a specific wavelength and undergo state transition. Therefore, by acquiring the emission spectrum of the light generated at this time with a spectrometer and specifying the position (wavelength) and the intensity of the peak appearing in the emission spectrum, the type and amount (concentration) of the element contained in the sample can be obtained. It can be identified.
In addition, when the substance contained in gas is pinpointed by this method, it may be called laser-induced breakdown spectroscopy (LIBS).

JP, 2016-95139, A

  As described above, conventionally, as a method for obtaining a sample, generally, a small amount of liquid to be analyzed is dropped on a predetermined shaped plate (typically, a rectangular flat silicon chip) and evaporated to dryness. It was

  In recent years, it has been considered to obtain samples by a method different from such a method. For example, a tube for capturing a sample (for example, a resin tube) is connected in advance to an end of a pipe through which a liquid to be analyzed flows. When there is a time zone in which the liquid does not flow in the pipe, a substance (dried substance) obtained by evaporation of the liquid adheres to the inner wall of the tube. Therefore, by cutting off a part of the tube, it is possible to obtain a sample in which the dried solid matter adheres to the inner surface of the tube piece.

  The sample carried into the analyzer is placed on a predetermined stage to be irradiated with laser light. In the conventional analyzer, it is assumed that the dried material adhered on the fixed plate is carried as a sample, and when such a sample is placed on the stage, collection of the laser light is performed. Optical adjustment of the laser device, the lens, etc. was made such that the light spot coincides with the surface of the sample.

  Therefore, for example, a sample having a non-flat surface, such as a sample having a dry solid attached to the inner surface of a tube piece, a sample having a flat surface even if the surface is flat, and the like, and which has a different thickness than the shaped plate, etc. When placed, it is not guaranteed that the surface of the sample coincides with the focal point of the laser light. When the surface of the sample comes to a position deviated from the focusing point of the laser beam, the laser beam is not sufficiently focused on the surface of the sample, and a sufficient energy density can not be obtained. As a result, atoms on the surface of the sample are not sufficiently excited, and sufficient emission intensity can not be obtained. This lowers the analysis accuracy.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a technique capable of obtaining high analysis accuracy regardless of the shape of a sample.

The present invention made to solve the above problems is
A laser induced analyzer which collects laser light and irradiates the surface of a sample, and analyzes the sample based on an emission spectrum of light generated by the irradiation,
A stage on which the sample is placed;
A drive mechanism for moving the stage in a predetermined movement direction intersecting the upper surface thereof;
A surface sensor that measures the position of the surface on a line parallel to the moving direction through the focusing point of the laser light;
A focusing unit that controls the drive mechanism such that the position measured by the surface sensor coincides with the position of the focusing point;
Equipped with

  According to this configuration, with the sample mounted on the stage, the surface sensor measures the position of the surface of the sample on a line parallel to the moving direction of the stage through the focusing point of the laser light. The stage is moved such that the position coincides with the position of the focusing point. That is, the stage is moved so that the focal position of the laser light is included in the surface of the sample mounted thereon. Therefore, regardless of the shape of the sample, the laser light can be sufficiently focused on the surface. As a result, high analysis accuracy can be obtained.

Preferably, the laser induced analyzer comprises
An in-plane drive mechanism for moving the stage in a plane parallel to the upper surface thereof;
Further comprising

  According to this configuration, by moving the stage in a plane parallel to the top surface, it is possible to irradiate the laser light to an appropriate position in the surface of the sample on the stage.

  The in-plane drive mechanism described above may include a pivot mechanism that rotates the stage about a rotation axis orthogonal to the top surface thereof. Alternatively, the in-plane drive mechanism may include a translation mechanism that moves the stage along each of two linear axes parallel to the top surface and nonparallel to each other. Alternatively, the in-plane drive mechanism may include both the pivot mechanism and the linear motion mechanism.

Preferably, the laser induced analyzer comprises
An irradiation control unit that emits a laser beam a plurality of times while moving the stage by controlling the in-plane drive mechanism;
Further comprising

  According to this configuration, a plurality of emission spectra can be obtained by irradiating each of a plurality of different positions on the sample surface with a laser beam. By integrating or averaging these plural emission spectra, for example, the influence of noise can be reduced and the S / N ratio can be increased.

Moreover, the present invention according to another aspect is
A laser induced analysis method of collecting laser light and irradiating the surface of a sample, and analyzing the sample based on an emission spectrum of light generated by the irradiation,
Placing the sample on a stage;
Measuring a position of a surface on a line parallel to a predetermined direction crossing the top surface of the stage, passing through the focusing point of the laser light;
A focusing step of moving the stage in the predetermined direction to align the position measured in the surface measurement step with the position of the focusing point;
Equipped with

Preferably, the laser induced analysis method comprises
Repeatedly irradiating the laser beam a plurality of times while moving the stage along a predetermined trajectory defined in a plane parallel to the upper surface of the stage;
Further comprising

In the laser induced analysis method,
It is preferable to perform the surface measurement step repeatedly alternately with the emission of the laser beam while the repeated irradiation step is performed.

  According to this configuration, the stage can be moved along the predetermined trajectory in a plane parallel to the upper surface only once, so if the number of laser beam irradiations is relatively small, it is necessary to repeat the irradiation process and the surface measurement process. The total time required can be kept short.

Alternatively, in the laser induced analysis method,
It is also preferable to repeat the surface measurement process a plurality of times while moving the stage along the predetermined trajectory before the repetitive irradiation process.

  According to this configuration, since the time required for the repeated irradiation process can be kept short, the total time required for the repeated irradiation process and the surface measurement process can be kept short when the number of times of laser beam irradiation is relatively large.

  According to the present invention, regardless of the shape of the sample, the laser light can be sufficiently focused on the surface. As a result, high analysis accuracy can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS The figure which shows typically the structure of the laser induction analyzer which concerns on 1st Embodiment. The figure for demonstrating the focusing operation | movement performed by this laser induced analyzer. FIG. 2 is a diagram showing the flow of processing performed by the laser induced analyzer. The figure which shows typically the structure of the laser induction analyzer which concerns on 2nd Embodiment. The figure for demonstrating the focusing operation | movement performed by this laser induced analyzer. The figure which shows the structural example of a positional infomation table. FIG. 2 is a diagram showing the flow of processing performed by the laser induced analyzer. The figure which shows typically the structure of the laser induction analyzer which concerns on 3rd Embodiment. FIG. 2 is a diagram showing the flow of processing performed by the laser induced analyzer. The figure which shows typically the structure of the laser induction analyzer which concerns on 4th Embodiment. The figure for demonstrating the focusing operation | movement performed by this laser induced analyzer. FIG. 2 is a diagram showing the flow of processing performed by the laser induced analyzer.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments described below, and it goes without saying that various aspects are included without departing from the scope of the present invention.

<0. Sample>
Before specifically describing the laser induced analyzer according to the embodiment, a sample to be analyzed by the laser induced analyzer will be described with reference to FIG.

  The laser induced analyzer 10 is used to analyze the cleaning liquid used for cleaning in the cleaning apparatus 20 that cleans a semiconductor substrate or the like using various cleaning liquids such as deionized water or a chemical solution, for example.

  In this case, the sample 9 is obtained, for example, as follows. That is, for example, a predetermined amount of cleaning liquid is periodically collected from the cleaning apparatus 20, and the collected cleaning liquid is used as the holding member 90 (typically, a rectangular silicon chip obtained by cutting a silicon wafer, or the silicon chip Drops on the surface of the concave part on the surface of the concave part for holding the liquid drop). Then, the holding member 90 holding the droplets of the cleaning liquid is heated by the heat processing unit 30 configured of, for example, a heater, a hot plate or the like, and the droplets on the holding member 90 are evaporated to dryness. As a result, the upper surface of the holding member 90 is obtained by attaching the solidified substance (dried substance) to which the cleaning liquid is evaporated to dryness and solidified, which is referred to as a sample 9.

  Alternatively, the sample 9 can be obtained as follows. That is, a tube for capturing a sample (for example, a resin tube) is connected in advance to an end of a pipe (for example, a waste liquid pipe) of the cleaning device 20. Then, a part of the tube is cut out in a time zone in which the liquid does not flow in the pipe (for example, at the time of regular maintenance of the device). As a result, a substance in which the liquid flowing through the waste liquid pipe is evaporated to dryness (dried substance) adheres to the inner surface of the tube piece is obtained, which is referred to as a sample 9.

  The series of processes for obtaining the sample 9 may be performed automatically by a mechanical mechanism or may be performed manually by an analyst. Further, in the example of the figure, the laser induced analysis device 10 is provided with the heat processing unit 30, but the heat processing unit 30 is not an essential element in the laser induced analysis device 10.

<1. First embodiment>
<1-1. Device configuration>
The laser induced analyzer according to the first embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a view schematically showing a configuration example of a laser induced analyzer 10. As shown in FIG. FIG. 2 is a diagram for explaining the focusing operation performed by the laser induced analyzer 10. As shown in FIG.

  The laser induced analyzer 10 is an apparatus for analyzing the sample 9 by laser induced plasma spectroscopy, condenses the laser light and irradiates the surface of the sample 9, and based on the emission spectrum of the light generated by the irradiation. Analyze sample 9

  The laser induced analyzer 10 includes a stage 1 on which the sample 9 is placed, an elevating mechanism 2 for moving the stage 1 up and down, a light source unit 3 for irradiating the sample 9 on the stage 1 with laser light, and a sample 9 for irradiating the laser light. To receive light generated by the light source and acquire its emission spectrum, a surface sensor 5 disposed above the stage 1, and a control unit that controls each of these elements to execute a series of operations 6 mainly.

  The stage 1 is a member having a flat and horizontal mounting surface formed on the upper surface, and the sample 9 is mounted on the mounting surface.

  The elevating mechanism 2 is a mechanism for moving the stage 1 in a predetermined direction (here, the vertical direction) intersecting the surface thereof. Specifically, the elevating mechanism 2 can be configured to include, for example, a screw shaft extending in the vertical direction, a drive motor for rotating the same, a guide shaft extending parallel to the screw shaft, and the like. The drive motor is composed of a numerically controllable motor (specifically, for example, a pulse motor, a stepping motor, a servomotor, an ultrasonic motor, etc.), and the drive motor has a rotation angle only instructed by the control unit 6 By rotating (ie numerically controlled), the stage 1 moves vertically by the indicated distance.

  The light source unit 3 includes a light source (laser device) 31 that emits a laser beam. For example, a YAG laser can be used as the light source 31. The light source unit 3 further includes an irradiation optical system 32 for guiding the laser light emitted from the light source 31 and a lens 33 for condensing the laser light led out from the irradiation optical system 32. The lower the height of the laser induced analyzer 10 is, the more the sense of stability increases. Therefore, as illustrated, the light axis of the laser beam emitted from the light source unit 3 is oblique to the mounting surface of the stage 1 as illustrated. It is preferable to arrange | position in the position and attitude | position which cross | intersect.

  The light source unit 3 is previously adjusted so that the focal point of the lens 33, that is, the position (focusing point) P (see FIG. 2) at which the laser light is condensed by the lens 33 is at a predetermined position. The position information (focus point location information 601) of the focusing point P is stored in advance in the storage device 60 provided in the control unit 6. However, the position of the condensing point P is a predetermined position (for example, the central position of the mounting surface) in the mounting surface of the stage 1 when viewed from the moving direction (here, the vertical direction) of the stage 1 by the lift mechanism 2 It is defined in the overlapping position.

  The analyzer 4 receives the light generated by irradiating the sample 9 on the stage 1 with the laser light, and acquires its emission spectrum. The analyzer 4 includes, for example, a diffraction grating (spectroscopic means) 41 that splits (spectrizes) light introduced through the fiber 40 or the like for each wavelength, and an imaging device that receives the spectrally separated light and acquires a light emission spectrum And 42. The tip position and angle of the fiber 40 are strictly adjusted with respect to the optical axis direction of the laser beam emitted from the light source unit 3 and the position of the focusing point P, and the light emission caused by the laser beam irradiation is sufficiently It can receive light.

  The surface sensor 5 is, for example, an optical displacement sensor (optical distance sensor), and measures the position of the surface on the optical axis. Here, the surface sensor 5 has an optical axis parallel to the moving direction (here, the vertical direction) of the stage 1 by the elevating mechanism 2 and a virtual line (focusing point passing line) PL passing through the focusing point P (See FIG. 2). Therefore, in a state where the sample 9 is mounted on the stage 1, the surface sensor 5 detects the position of the surface of the sample 9 on the focusing point passing line PL (that is, the focusing point passing line PL intersects the surface of the sample 9 Measure the position of the point (point on the line) Po (see FIG. 2).

  The control unit 6 is electrically connected to each unit included in the laser induced analyzer 10 to control the operation of each unit. The control unit 6 includes a storage device 60. In the storage device 60, the above-described focusing point position information 601 and the like are stored. In addition, in the control unit 6, as a functional block, a surface measurement unit 61, a focusing unit 62, an irradiation control unit 63, and the like are realized. The entity of the control unit 6 is a personal computer on which required operating software (OS) and the like are installed, and an input unit and a display unit are connected (all are not shown).

  The surface measuring unit 61 causes the surface sensor 5 to measure the position of the surface of the sample 9 (that is, the position of the point Po on the line) on the focusing point passing line PL in a state where the sample 9 is mounted on the stage 1 And notifies the focusing unit 62 of positional information of the line point Po obtained by the measurement.

  The focusing unit 62 controls the elevation mechanism 2 based on the positional information of the point Po on the line notified from the surface measurement unit 61 so that the position of the point Po on the line coincides with the position of the condensing point P. Specifically, the focusing unit 62 first calculates the difference between the position information of the point Po on the line and the position information of the condensing point P (the condensing point positional information 601 stored in the storage device 60). . The point Po on the line and the condensing point P are both on the condensing point passing line PL, and the difference is the distance between the two points Po and P on the condensing point passing line PL (FIG. 2A). Then, the focusing unit 62 instructs the lifting and lowering mechanism 2 to lift and lower the stage 1 by the difference. By moving the stage 1 by the difference along the focusing point passing line PL, the position of the point Po on the line three-dimensionally coincides with the position of the focusing point P (FIG. 2 (b)) ). Needless to say, the moving direction of the stage 1 is defined from the positive and negative of the difference.

  The irradiation control unit 63 causes the light source unit 3 to emit a laser beam in a state where the point Po on the line coincides with the condensing point P. When the focusing point P coincides with a point Po on the line on the surface of the sample 9, the emitted laser light is sufficiently focused on the surface of the sample 9, whereby the laser light is focused on the surface of the sample 9. An atom is sufficiently excited. As a result, light emission with sufficient intensity occurs. The emission is introduced into the analyzer 4 via the fiber 40, where the emission spectrum is acquired.

<1-2. Flow of processing>
The flow of processing performed in the laser induced analyzer 10 will be described with reference to FIG. 3 in addition to FIG. 1 and FIG. FIG. 3 is a diagram showing the series of flows.

  First, the sample 9 is prepared by an appropriate method and placed on the stage 1 (step S11).

  Next, the surface measuring unit 61 causes the surface sensor 5 to measure the position of a point Po on the surface of the sample 9 on the stage 1 (FIG. 2A) (step S12). When the position information of the point Po on the line is obtained by the measurement, the surface measuring unit 61 notifies the focusing unit 62 of the position information.

  Next, the focusing unit 62 reads the focusing point position information 601 stored in the storage device 60, and calculates the difference between this and the position information of the line point Po obtained by the measurement in step S12, An instruction is given to the lift mechanism 2 to lift and lower the stage 1 by the difference. As the lifting mechanism 2 lifts and lowers the stage 1 according to the instruction, the position of the point Po on the line coincides with the position of the focusing point P (FIG. 2 (b)) (step S13).

  Thereafter, the irradiation control unit 63 causes the light source unit 3 to emit a laser beam (step S14). Since the position of the stage 1 is adjusted so that the point Po on the line on the surface of the sample 9 on the stage 1 and the condensing point P coincide with each other in step S13, the emitted laser light is the sample 9 Is fully focused on the surface of the As a result, a high-temperature, high-density plasma is generated to sufficiently excite atoms present on the surface of the sample 9 in the spot where the laser light is collected. Each excited atom undergoes state transition while emitting light of a specific wavelength. The light generated at this time is introduced into the analyzer 4 through the fiber 40. In the analyzer 4, the introduced light is dispersed by the diffraction grating 41 and detected by the imaging device 42, whereby an emission spectrum is acquired.

  The emission spectrum acquired by the analyzer 4 is sent to the control unit 6, where it is subjected to predetermined arithmetic processing as necessary, and then stored in the storage device 60. Also, it is displayed on the display unit as necessary. An analyst can specify the type and amount of elements contained in the sample 9 by, for example, specifying the position (wavelength) and the intensity of the peak appearing in the emission spectrum.

<2. Second embodiment>
<2-1. Device configuration>
The laser induced analyzer according to the second embodiment will be described with reference to FIGS. 4 and 5. FIG. 4 is a view schematically showing a configuration example of the laser induced analysis device 10a. FIG. 5 is a diagram for explaining the focusing operation performed by the laser induced analyzer 10a. In the following, only the differences from the first embodiment will be described. The same elements as those of the laser induced analyzer 10 according to the first embodiment are indicated by the same reference numerals and the explanation thereof is omitted.

  The laser induced analyzer 10a is added to the same elements as the laser induced analyzer 10 according to the first embodiment (stage 1, elevating mechanism 2, light source unit 3, analyzer 4, surface sensor 5, and control unit 6a). And the rotation mechanism 7 is provided.

  The pivoting mechanism 7 is a mechanism for rotating the stage 1 around a rotation axis 70 orthogonal (ie, vertical) to the upper surface thereof. However, the rotation axis 70 is defined at a position separated from the focusing point passing line PL (see FIG. 5A). Specifically, the rotating mechanism 7 can be configured to include, for example, a rotating shaft portion whose upper end is fixed to the lower surface of the stage 1 and extends in the vertical direction, a drive motor for rotating the same, and the like. Also here, the drive motor is constituted by a numerically controllable motor, and the stage 1 is instructed by rotating the drive motor by the rotation angle instructed by the control unit 6a (ie numerically controlled). Rotate by an angle.

  The irradiation control unit 63a rotates the stage 1 by controlling the rotation mechanism 7 and emitting laser light from the light source unit 3 intermittently (typically at a constant cycle) a plurality of times, thereby rotating the stage 1 A laser beam is irradiated to each of a plurality of points (irradiated points K1, K2,...) Aligned on a circumference centered on the axis 70. For example, when the irradiation control unit 63a causes the laser light to be emitted 20 times at an interval of 1 second while rotating the stage 1 once at an equal angular velocity for 20 seconds, 18 ° on the circumference around the rotation axis 70 A laser beam is irradiated to each of 20 points (irradiation point K1, K2, ..., K20) located in a line by an angle interval.

  The surface measuring unit 61a causes the surface sensor 5 to measure the positions of the plurality of irradiation points K1, K2,... On the surface of the sample 9. Specifically, the surface measuring unit 61a causes the surface sensor 5 to intermittently measure the position of the point Po on the line while controlling the rotation mechanism 7 to rotate the stage 1, thereby centering around the rotation axis 70. The position information of each of the plurality of irradiation points K1, K2,. The surface measurement unit 61a stores the acquired plurality of pieces of position information in the form of, for example, a table (position information table) 602 in the storage device 60a. A configuration example of the position information table 602 is shown in FIG. Here, the positional information of each irradiation point Ki (i = 1, 2,...) Indicates the irradiation order of the irradiation point Ki, the irradiation timing based on the first irradiation point K1, the first irradiation point K1. It is stored in association with the reference angular position and the like.

2-2. Flow of processing>
The flow of processing executed in the laser induced analyzer 10a will be described with reference to FIG. 7 in addition to FIGS. FIG. 7 is a diagram showing the series of flows.

  First, the sample 9 is prepared by an appropriate method and placed on the stage 1 (step S21).

  Next, the surface measuring unit 61a causes the surface sensor 5 to measure the positions of the plurality of irradiation points K1, K2,... On the surface of the sample 9 (step S22).

  Specifically, the surface measurement unit 61a first causes the surface sensor 5 to measure the position of the point Po on the line in a state where the stage 1 is disposed at a predetermined initial rotation position (step S221). Here, the point Po on the line when the stage 1 is arranged at the initial rotational position is taken as the first irradiation point K1. Therefore, the surface measuring unit 61a describes the position information obtained by the measurement in the position information table 602 as the position information of the first irradiation point K1.

  Subsequently, the surface measuring unit 61a controls the rotation mechanism 7 to rotate the stage 1 by a predetermined angle (an angle interval up to the next irradiation point K2, which is 18 ° in the example of FIG. 6) (rotation The speed is, for example, 3 rpm (step S222). As a result, the second irradiation point K2 coincides with the line Po. In this state, the surface measuring unit 61a causes the surface sensor 5 to measure the position of the point Po on the line again (step S221). Then, the position information obtained by the measurement is described in the position information table 602 as the position information of the second irradiation point K2.

  When the predetermined number of pieces of position information are acquired by repeating the processing of step S221 to step S222 a predetermined number of times (20 times in the case of the example of FIG. 6) (that is, all irradiation points in position information table 602). When positional information of each Ki (i = 1, 2,...) Is described (YES in step S223), the process proceeds to step S23.

  In step S23, the irradiation control unit 63a controls the rotation mechanism 7 to rotate the stage 1, and intermittently emits laser light from the light source unit 3 a plurality of irradiation points K1, K2, and so on. A laser beam is irradiated to each of.

  Specifically, the irradiation control unit 63a first controls the rotation mechanism 7 as needed, rotates the stage 1 appropriately, and places the stage 1 at a predetermined initial rotation position. As a result, the first irradiation point K1 coincides with the line Po (FIG. 5 (a)). Also, in parallel with this, the focusing unit 62a reads the focusing point position information 601 stored in the storage device 60a, and reads the position information of the first irradiation point K1 from the position information table 602, The elevation mechanism 2 is controlled to move the stage 1 up and down by the difference (FIG. 5 (b)). As a result, the position of the irradiation point K1 and the position of the condensing point P are in agreement. That is, under the control of the irradiation control unit 63a and the focusing unit 62a, the stage 1 is lifted and lowered while being rotated, so that the position of the first irradiation point K1 matches the position of the condensing point P ( Step S231).

  Thereafter, the irradiation control unit 63a causes the light source unit 3 to emit a laser beam (step S233). The emitted laser light is condensed at the first irradiation point K1, and the emission spectrum of the light generated at this time is acquired by the analyzer 4.

  Subsequently, the irradiation control unit 63a controls the rotation mechanism 7 to rotate the stage 1 by a predetermined angle (an angle interval up to the next irradiation point K2, 18 ° in the example of FIG. 6), The second irradiation point K2 coincides with the point Po on the line. Also, in parallel with this, the focusing unit 62a reads the position information of the second irradiation point K2 from the position information table 602, calculates the difference between this and the position information of the first irradiation point K1, and moves up and down the mechanism 2 is controlled to raise and lower the stage 1 by the difference. As a result, the position of the irradiation point K2 matches the position of the focusing point P. That is, by moving up and down while the stage 1 is rotated, the position of the second irradiation point K2 and the position of the focusing point P coincide with each other (FIG. 5 (c)) (step S231).

  Thereafter, the irradiation control unit 63a causes the light source unit 3 to emit laser light again (step S233). The emitted laser light is condensed at the second irradiation point K2, and the emission spectrum of the light generated at this time is acquired by the analyzer 4.

  By repeating the process of steps S231 to S232 a predetermined number of times (20 times in the case of the example of FIG. 6), the emission spectra of all the irradiation points Ki (i = 1, 2,...) Are acquired And (YES in step S233), the process proceeds to step S24.

  In step S24, the control unit 6a performs predetermined arithmetic processing on the plurality of emission spectra obtained in step S23. Specifically, for example, the plurality of emission spectra are integrated (or averaged). By integrating or averaging a plurality of emission spectra, the influence of noise can be reduced and the S / N ratio can be increased. The data obtained by the calculation is stored in the storage device 60a. Also, it is displayed on the display unit as necessary. The analyst can specify the type and amount of elements contained in the sample 9 by, for example, specifying the position (wavelength) and intensity of the peak appearing in the data.

<3. Third embodiment>
<3-1. Device configuration>
The laser induced analyzer according to the third embodiment will be described with reference to FIG. FIG. 8 is a view schematically showing a configuration example of the laser induced analyzer 10b. In the following, only differences from the above-described embodiments will be described. The same elements as those of the laser induced analyzers 10 and 10a according to the above-described embodiments are denoted by the same reference numerals and the description thereof will be omitted.

  The laser induced analyzer 10b is the same element as the laser induced analyzer 10 according to the second embodiment (the stage 1, the lift mechanism 2, the light source unit 3, the analyzer 4, the surface sensor 5, the controller 6b, and the pivot A mechanism 7) is provided.

  The irradiation control unit 63b intermittently emits laser light from the light source unit 3 a plurality of times while controlling the rotation mechanism 7 to rotate the stage 1 as in the irradiation control unit 63a according to the second embodiment. The laser light is irradiated to each of a plurality of irradiation points K1, K2,.

  The surface measuring unit 61b causes the surface sensor 5 to measure the positions of the plurality of irradiation points K1, K2,... On the surface of the sample 9. Specifically, the surface measurement unit 61b causes the surface sensor 5 to measure the position of the point Po on the line at timings alternate with the timings at which the laser light is emitted under the control of the irradiation control unit 63b, thereby a plurality of irradiations. The position information of each of the points K1, K2,.

<3-2. Flow of processing>
The flow of processing performed in the laser induced analyzer 10b will be described with reference to FIGS. 5 and 9 in addition to FIG. FIG. 9 is a diagram showing the series of flows.

  First, the sample 9 is prepared by an appropriate method and placed on the stage 1 (step S31).

  Next, the surface measuring unit 61b causes the surface sensor 5 to measure the position of the point Po on the line in a state where the stage 1 is disposed at a predetermined initial rotational position (FIG. 5A) (step S32). The position information obtained by the measurement is notified to the focusing unit 62b as the position information of the first irradiation point K1.

  Subsequently, the focusing unit 62b reads the focusing point position information 601 stored in the storage device 60b, calculates the difference between this and the position information of the first irradiation point K1 acquired in step S32, and moves up and down. The mechanism 2 is controlled to raise and lower the stage 1 by the difference (FIG. 5B) (step S33). As a result, the position of the irradiation point K1 and the position of the condensing point P are in agreement.

  Subsequently, the irradiation control unit 63b causes the light source unit 3 to emit a laser beam (Step S34). The emitted laser light is condensed at the first irradiation point K1, and the emission spectrum of the light generated at this time is acquired by the analyzer 4.

  After that, the irradiation control unit 63b controls the rotation mechanism 7 to rotate the stage 1 by a predetermined angle (an angle interval to the next irradiation point K2), and the second irradiation point K2 coincides with the point Po on the line The state is set (step S35).

  Then, the processes of steps S32 to S35 are performed again. That is, the surface measuring unit 61b causes the surface sensor 5 to measure the position of the point Po on the line, and notifies the focusing unit 62b of the position information obtained by the measurement as the position information of the second irradiation point K2 Step S32), the focusing unit 62b controls the elevation mechanism 2 based on the difference between the position information of the second irradiation point K2 and the condensing point position information 601 to raise and lower the stage 1, and the position of the irradiation point K2 And the position of the condensing point P are made to coincide (FIG. 5 (c)) (step S33). Then, the irradiation control unit 63b causes the light source unit 3 to emit a laser beam (step S34). The emitted laser light is condensed at the second irradiation point K2, and the emission spectrum of the light generated at this time is acquired by the analyzer 4. After that, the irradiation control unit 63b controls the rotation mechanism 7 to rotate the stage 1 by a predetermined angle (the angular interval to the next irradiation point K3), and the third irradiation point K3 coincides with the point Po on the line The state is set (step S35).

  When the emission spectrum of each of all the irradiation points Ki (i = 1, 2,...) Is acquired by repeating the processing of steps S32 to S35 a predetermined number of times (YES in step S36), the processing of step S37 Go to The process of step S37 is the same as the process of step S24 according to the second embodiment.

<4. Fourth embodiment>
<4-1. Device configuration>
The laser induced analyzer according to the fourth embodiment will be described with reference to FIGS. 10 and 11. FIG. FIG. 10 is a view schematically showing a configuration example of the laser induced analyzer 10c. FIG. 11 is a diagram for explaining the focusing operation performed by the laser induced analyzer 10c. In the following, only differences from the above-described embodiments will be described. The same elements as those of the laser induced analyzers 10, 10a, and 10b according to the above-described embodiments are denoted by the same reference numerals, and the description thereof is omitted.

  The laser induced analyzer 10c is added to the same elements as the laser induced analyzer 10 according to the first embodiment (the stage 1c, the lift mechanism 2, the light source unit 3, the analyzer 4, the surface sensor 5, and the controller 6c). And a linear motion mechanism 8 is provided. Further, in the control unit 6c, a radiation desired position reception unit 64c is realized as a functional block.

  The linear movement mechanism 8 is a mechanism for moving the stage 1c along each of two linear axes which are parallel to the upper surface (here, the horizontal mounting surface) and are orthogonal to each other. Now, assuming that the horizontal axis parallel to any side of the stage 1c is the "X axis", the linear motion mechanism 8 moves the stage 1c along the X axis and the Y axis which is a horizontal axis orthogonal to this. Drive mechanism (X drive mechanism 81 and Y drive mechanism 82).

  Specifically, the X drive mechanism 81 can be configured to include, for example, a screw shaft extending in the X direction, a drive motor for rotating the same, a guide shaft extending parallel to the X direction, and the like. Similarly, the Y drive mechanism 82 can be configured to include a screw shaft extending in the Y direction, a drive motor for rotating the same, a guide shaft extending parallel to the Y direction, and the like. In any of the drive mechanisms 81 and 82, the drive motor is configured by a numerically controllable motor, and the drive motor is rotated by the rotation angle instructed from the control unit 6c (that is, numerically controlled). The stage 1 c moves in the X direction or the Y direction by the designated distance.

  In the vicinity of the stage 1c, sensors (X sensor 801 and Y sensor 802) for detecting the X position and Y position respectively are disposed (see FIG. 11A). Each of the sensors 801 and 802 is, for example, an optical displacement sensor, and measures the position of the surface on the optical axis. For example, the X sensor 801 is disposed such that the optical axis thereof coincides with an imaginary line parallel to the X axis and passing through the light collection point P. Similarly, the Y sensor 802 is disposed, for example, such that its optical axis coincides with an imaginary line parallel to the Y axis and passing through the focusing point P.

  The stage 1 c is a member in which a flat and horizontal mounting surface is formed on the upper surface, and the sample 9 is mounted on the mounting surface. A scale 11 is provided on the side surface of the stage 1 c so that an arbitrary position in the mounting surface of the stage 1 c can be designated in the XY coordinate system defined by the scale 11. Therefore, for example, the analyst specifies the position of the point (desired irradiation point) D to which the laser light is desired to be irradiated in the sample 9 placed on the stage 1 c by reading the scale 11 in the XY coordinate system. be able to.

  The irradiation desired position reception unit 64c receives an input of positional information of the irradiation desired point D from the analyst prior to the irradiation of the laser light, and controls the linear motion mechanism 8 based on the input positional information to thereby perform the stage 1c. To move the irradiation desired point D to the point Po on the line.

<4-2. Flow of processing>
The flow of processing executed in the laser induced analyzer 10c will be described with reference to FIG. 12 in addition to FIGS. FIG. 12 is a diagram showing the series of flows.

  First, the sample 9 is prepared by an appropriate method and placed on the stage 1c (step S41).

  Subsequently, the analyst specifies the position information of the irradiation desired point D in the sample 9 placed on the stage 1 c by reading the scale 11 of the stage 1 c, for example, and inputs this via the input unit. When position information of the irradiation desired point D is input from the analyst, the irradiation desired position receiving unit 64c receives the input, and based on this, the linear motion mechanism 8 is controlled, and the irradiation point PL is desired to be irradiated. The stage 1c is moved to a position where it passes the point D (step S42). That is, the irradiation desired point D is made to coincide with the point Po on the line.

  Specifically, the desired radiation position receiving unit 64c first controls the linear motion mechanism 8 to set a predetermined initial position (for example, the origin of XY coordinates defined by the scale 11 by the focusing point passing line PL). The stage 1c is moved to a position where it passes (FIG. 11 (b)). That is, the irradiation desired position reception unit 64c controls the X drive mechanism 81 while detecting the X position of the stage 1c with the X sensor 801 to move the stage 1c to a predetermined initial X position, and the Y sensor 802 detects the stage 1c. The Y drive mechanism 82 is controlled while detecting the Y position of to move the stage 1 c to a predetermined initial Y position. Thereafter, the desired radiation position receiving unit 64c further moves the stage 1c in the X direction and the Y direction according to the positional information on the desired radiation point D received from the analyst, and the desired light point passing line PL is irradiated The stage 1c is moved to such a position as to pass the point D (FIG. 11 (c)).

  Thereafter, processing similar to that of step S12 to step S14 in the first embodiment is performed (step S43 to step S45). That is, the surface measurement unit 61c causes the surface sensor 5 to measure the position of the point Po on the surface of the sample 9 on the stage 1c in a state where the irradiation desired point D coincides with the point Po on the line 1 (step S43). Subsequently, the focusing unit 62c reads the focusing point position information 601 stored in the storage device 60c, calculates the difference between this and the position information of the point Po obtained at step S43, The stage 1c is moved up and down by the difference by control (step S44). Thereby, the position of the irradiation point K1 of the point Po on the line Po, which is the irradiation desired point D, coincides with the position of the condensing point P (FIG. 11 (d)). Thereafter, the irradiation control unit 63c causes the light source unit 3 to emit a laser beam (step S45). The emitted laser light is condensed at the desired irradiation point D, and the light emission spectrum of the light generated at this time is acquired by the analyzer 4.

<5. Other Embodiments>
In each of the above-described embodiments, the elevating mechanism 2 moves (lifts) the stages 1 and 1c in the vertical direction, but the elevating mechanism 2 moves the stages 1 and 1c in any direction crossing the surface thereof What is necessary is to move it.

  In the laser induced analyzers 10a and 10b according to the second and third embodiments, the linear motion mechanism 8 may be provided, and in the laser induced analyzer 10c according to the fourth embodiment, the pivot mechanism 7 is provided. It is also good. That is, the laser induced analyzer may be provided with both the pivoting mechanism 7 and the linear motion mechanism 8.

  In the fourth embodiment, the irradiation control unit 63c controls the linear motion mechanism 8 to move the stage 1c along a predetermined trajectory defined in the XY plane (for example, in the main scan in the X direction and in the Y direction) The laser light is emitted from the light source unit 3 intermittently (typically at a constant cycle) a plurality of times while alternately performing double scanning, and a plurality of irradiation points K1, K2,. Each of the may be irradiated with a laser beam. In this case, as in the second embodiment, the surface measurement unit 61c moves the stage 1c along the predetermined trajectory before the laser beam is emitted a plurality of times, and the surface sensor 5 moves the stage 1c along the predetermined trajectory. The position may be intermittently measured a plurality of times to acquire positional information of each of the plurality of irradiation points K1, K2,. Alternatively, as in the third embodiment, the surface measurement unit 61c causes the surface sensor 5 to measure the position of the point Po on the line alternately by repeating the emission of the laser beam while the emission of the laser beam is performed a plurality of times. Thus, positional information of each of the plurality of irradiation points K1, K2,... May be acquired.

  In the second to fourth embodiments, although integrated data and / or average data are acquired from a plurality of emission spectra, it is not necessary to acquire these data. For example, among the plurality of emission spectra, the one which detects the largest peak at a predetermined wavelength may be selected, and the content of the substance or the like may be specified from the single emission spectrum.

DESCRIPTION OF SYMBOLS 10, 10a, 10b, 10c ... Laser induction analysis apparatus 1, 1c ... Stage 2 ... Elevation mechanism 3 ... Light source unit 4 ... Analyzer 5 ... Surface sensor 6, 6a, 6b, 6c ... Control part 601 ... Focusing point position information 602 Position information table 61, 61a, 61b, 61c Surface measurement unit 62, 62a, 62b, 62c Focusing unit 63, 63a, 63b, 63c Radiation control unit 64c Radiation desired position reception unit 7 Rotation mechanism 8 linear motion mechanism 801 X sensor 802 Y sensor 81 X drive mechanism 82 Y drive mechanism 9 sample D desired irradiation point K1, K2, ... irradiation point P condensing point PL condensing point Passing line Po ... point on the line

Claims (9)

A laser induced analyzer which collects laser light and irradiates the surface of a sample, and analyzes the sample based on an emission spectrum of light generated by the irradiation,
A stage on which the sample is placed;
A drive mechanism for moving the stage in a predetermined movement direction intersecting the upper surface thereof;
A surface sensor that measures the position of the surface on a line parallel to the moving direction through the focusing point of the laser light;
A focusing unit that controls the drive mechanism such that the position measured by the surface sensor coincides with the position of the focusing point;
, A laser induced analyzer. The laser induced analyzer according to claim 1, wherein
An in-plane drive mechanism for moving the stage in a plane parallel to the upper surface thereof;
The laser induced analyzer further comprising The laser induced analyzer according to claim 2, wherein
The in-plane drive mechanism is
A rotation mechanism for rotating the stage around a rotation axis orthogonal to the upper surface thereof;
, A laser induced analyzer. The laser induced analyzer according to claim 2 or 3, wherein
The in-plane drive mechanism is
A translation mechanism for moving the stage along each of two linear axes parallel to the upper surface and nonparallel to each other;
, A laser induced analyzer. The laser induced analyzer according to any one of claims 2 to 4, wherein
An irradiation control unit that emits a laser beam a plurality of times while moving the stage by controlling the in-plane drive mechanism;
The laser induced analyzer further comprising A laser induced analysis method of collecting laser light and irradiating the surface of a sample, and analyzing the sample based on an emission spectrum of light generated by the irradiation,
Placing the sample on a stage;
Measuring a position of a surface on a line parallel to a predetermined direction crossing the top surface of the stage, passing through the focusing point of the laser light;
A focusing step of moving the stage in the predetermined direction to align the position measured in the surface measurement step with the position of the focusing point;
Laser induced analysis method. The laser induced analysis method according to claim 6, wherein
Repeatedly irradiating the laser beam a plurality of times while moving the stage along a predetermined trajectory defined in a plane parallel to the upper surface of the stage;
The laser induced analysis method, further comprising The laser induced analysis method according to claim 7, wherein
While the repeated irradiation process is performed, the surface measurement process is repeated alternately with the emission of the laser light.
Laser induced analysis method. The laser induced analysis method according to claim 7, wherein
Before the repetitive irradiation process, the surface measurement process is repeated several times while moving the stage along the predetermined trajectory.
Laser induced analysis method.

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