JP2003028801A - Monitoring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable to provide a method having superior spatial resolution and time resolution in monitoring a plasma state with the use of an optical method. SOLUTION: In the optical method using a laser light, it is so constituted that the laser light is spread to propagate an entire coordinate space of a measuring object and detected with the use of a two-dimensional light-receiving element, thus permitting satisfying both the spatial resolution and the time resolution. Although the constitution requires correcting an optical system related to irregularities of an anticipation angle and sensitivity characteristics of the light-receiving element or the like, correcting in relation to a light intensity distribution of an excitation light and correcting in relation to a dependency of an emission intensity on an excitation light intensity, a reference signal is obtained therefor by, for example, sweeping a sheet-shaped excitation light relatively in a j direction.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a monitoring method using light. In particular, the present invention relates to a method of monitoring a plasma state using a laser induced fluorescence method or an absorption spectroscopy method.

[0002]

2. Description of the Related Art At present, in the manufacturing process of semiconductors and liquid crystal devices, surface treatment of a substrate using high frequency plasma such as thin film formation, doping and dry etching has been extensively performed. Along with this, demands for plasma processes are becoming more sophisticated every day, and efforts have been made to analyze and control plasmas using various plasma diagnostic methods. If a simple and essential method can be established, plasma monitoring / feedback control can be performed even in a production apparatus.

[0003]

There are various methods of plasma diagnosis, but the optical method is a noncontact method that does not disturb the plasma itself, and a monitoring method if essential species in the plasma can be detected. As is ideal.
In the past, plasma emission spectroscopy has been used as a method essential for plasma diagnostic research, and has also been used in a simple form for the purpose of detecting the end point of etching.

However, the species and sensitivity in plasma that can be detected by plasma emission spectroscopy are limited, and the laser-induced fluorescence method and laser absorption spectroscopy are used to detect important species. These methods are less common.

The laser-induced fluorescence method is a method in which plasma is excited by a laser having a wavelength peculiar to a species, and luminescence emitted when the species transits from an excited state to a ground state is detected. In addition, the laser absorption spectroscopy is a method in which plasma is excited by a laser having a wavelength peculiar to a species, and the light absorption absorbed when the species transits from a ground state to an excited state is detected.

Although these methods are difficult to handle, for example, they require a relatively high-power short-wavelength laser, but in recent years, high-power tunable lasers and high-sensitivity two-dimensional CCDs have been used.
As cameras have been developed, their functionality has improved significantly.

The present invention is intended to be used for plasma diagnostic research and further for plasma monitoring and control by improving the spatially resolved and time resolved measurement functions in the laser induced fluorescence method and the laser absorption spectroscopy method.

The laser-induced fluorescence method detects light emission from a region in a plasma through which a laser passes. Basically, the spatial resolution is high, and the laser light irradiation region is moved relatively and detected by a two-dimensional light receiving element. By doing so, it is basically possible to perform spatially resolved measurement of the plasma state.

Further, the laser absorption spectroscopy detects absorption by a seed when the laser light passes through the plasma, and has no resolution in the propagation direction of the laser light, but it is a space in a plane perpendicular to the propagation direction. It is basically possible to perform resolution measurement.

In either case, however, when attempting spatially resolved measurement, it takes time to relatively move or sweep the laser light, and therefore time resolved measurement is difficult or incompatible. is there.

Therefore, it is an object of the present invention to provide a monitoring method that can easily achieve both space-resolved measurement and time-resolved measurement.

[0012]

According to the present invention, instead of sweeping the laser light, the laser light is used in a plane perpendicular to the propagation direction or in the uniaxial direction by using a lens system to measure the laser light. The excitation light or the probe light is propagated at the same time in the entire coordinate space, and the two-dimensional light receiving element is configured to simultaneously monitor the light emission from each coordinate space or the transmitted light.

With this configuration, the measurement time or the time-resolved measurement function can be improved significantly.

However, in order to secure the quantification property, or at least the relative quantification property, in the case of the laser-induced fluorescence method, it relates to the correction of the optical system related to the variation of the solid angle and the sensitivity characteristic of the light receiving element, and the light intensity distribution of the excitation light. It is necessary to make a correction and a correction relating to the dependence of the emission intensity on the excitation light intensity. In the case of laser absorption spectroscopy, the optical system correction relating to the solid angle and the distribution of the sensitivity characteristics of the two-dimensional light receiving element, etc., and the probe Correction related to the light intensity distribution of light is necessary. Therefore, we propose a means and algorithm for efficient data calibration that enables real-time monitoring.

The amount of light incident on the detector (pixel of CCD) may be affected by various optical systems such as the solid angle of the light source and the shielding by the optical window or the end of the sample table. .

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention is
Two-dimensional coordinate space x _ij (i = 0 to k−1, j = 0 to 1−
1) When the time change of the physical quantity _nij distributed above is monitored (measured) using an optical method, the sheet-shaped excitation light spread in the j direction is propagated in the i direction based on the laser-induced fluorescence method. By doing so, the light emission emitted in the direction perpendicular to the _ij plane depending on the physical quantity n _ij and the intensity distribution I _ij of the excitation light is detected by using the two-dimensional light receiving element p _ij , and its time change is tracked. It is characterized by doing. by this,
It becomes possible to easily achieve both space-resolved measurement and time-resolved measurement.

However, in this configuration, in order to secure the quantification property, or at least the relative quantification property, the correction of the optical system related to the variation of the solid angle and the sensitivity characteristic of the light receiving element, the correction related to the light intensity distribution of the excitation light, And a correction related to the dependence of the emission intensity on the excitation light intensity is required.
In the described invention, as a method for easily obtaining the calibration data,
It is proposed in advance to obtain a reference signal by relatively sweeping sheet-shaped excitation light in the j direction. This enables real-time monitoring.

Further, as concrete means for obtaining the reference signal, in claims 3 and 4, in the same coordinate space as the monitored object or in a coordinate space optically equivalent to the monitored object,
It is proposed to uniformly fill the luminescent material or substance and measure the luminescence or scattered light emitted from these materials. In these configurations, it is premised that a linear excitation light intensity dependency is obtained.

The invention according to claim 5 of the present invention is a two-dimensional seat.
Standard space x_ijMin on (i = 0 to k-1, j = 0 to l-1)
Physical quantity to be clothed n_ijChange over time using an optical method.
When measuring (measuring), based on laser absorption spectroscopy, i
-Probe light spread on the j-plane, which is perpendicular to the i-j plane
Transmitted light obtained by propagating in the two-dimensional direction _ij
It is characterized by detecting and using the change over time.
is doing. This allows spatially resolved measurements and time resolved
It is possible to easily make both measurements compatible.

Also in this configuration, in order to secure the quantitativeness, or at least the relative quantitativeness, it is necessary to correct the optical system related to the variation in the solid angle and the sensitivity characteristic of the light receiving element, and the correction related to the light intensity distribution of the probe light. Therefore, claim 6
In the described invention, as a method for easily obtaining the calibration data,
It is proposed that the same coordinate space as the monitor target or the coordinate space that is optically equivalent to the monitor target be placed in a vacuum state or filled with a substance transparent to the probe light, and the transmitted light passing through these be measured. is doing. This enables real-time monitoring.

Hereinafter, embodiments of the present invention will be described with reference to the drawings, taking a plasma dry etching apparatus as an example.

(First Embodiment) FIG. 1 is a schematic diagram showing the structure of a plasma processing apparatus according to a first embodiment of the present invention. This apparatus is composed of a plasma generation chamber 1 of the inductive coupling system, and in the case of reactive gas, for example, oxide film etching, CHF ₃ (50%) / C ₄ F ₈ (5
Generating a plasma 6 by applying a high frequency power from a high frequency power source 5 via a matching circuit 4 to a coil 3 attached to the upper part of the chamber in a state where a mixed gas (0%) is flown from a gas inlet 2. You can 11 is C
_{A 4} F ₈ mass flow controller, 12 is a CHF ₃ mass flow controller, and 13 is a cylinder box.

The wafer 7 to be the sample is placed on the sample table, that is, the lower electrode 8 and bias power is supplied from the high frequency power source 10 through the matching circuit 9 so that the ions in the plasma are incident on the surface of the sample. Etching proceeds. In addition, optical windows 14, 15 and 16 are installed in this apparatus so that optical measurement can be performed.

For this device, laser-induced fluorescence (laser in
In the duced fluorescence (hereinafter, LIF) method, as shown in FIG.
It is assumed that the light is incident from the optical window 14 perpendicularly to No. 4. The incident laser light 17 propagates in the plasma 6 and is emitted from the optical window 15. At this time, species such as radicals existing in the passage region in the plasma 6 are excited in accordance with the wavelength of the laser light 17. , Light emission occurs in the relaxation process.

Of these, the light emitted from the optical window 16 is selected by the optical filter 18 or the like, and the two-dimensional light receiving element 1 is selected.
9. Capture as a two-dimensional image with a CCD camera, for example. In the present embodiment, a wavelength tunable dye laser excited by an excimer laser is used as the excitation laser, and a wavelength of 2
An example will be described in which an important species in plasma, CF ₂ radical, is detected with light of 34.2 nm.

Now, as shown in the coordinates of FIG. 3A, the two-dimensional coordinate space that can be expected from the optical window 16 is defined as x _ij (i = 0 to k).
-1, j = 0~l-1) , the density of the CF ₂ radicals distributed thereon, as shown in the measurement object in FIG (b), defined as a measurement target physical quantity n _ij, further the As shown in the two-dimensional light receiving element of FIG. 6C, the pixel p _ij of the corresponding two-dimensional light receiving element 19 is defined.

In the usual laser induced fluorescence method, since a point beam having a spot diameter of about 1 to 2 mm is used,
As shown by the point beam in FIG. 4A, in one shot, only information corresponding to the j-th row component of the laser light traveling in the i direction is obtained. Therefore, in order to obtain the information of the entire spatial distribution, that is, the i-j plane,
LIF optical measurement under point beam scanning in (b)
As shown in (a _ij ), the laser beam is swept in the j direction and the measurement is repeated while scanning (j = 0 to l−1), and the pixel p _ij of the two-dimensional light receiving element 19 is synchronized with this each time. The LIF signal a _ij (i = 0 to k−1, j = 0 to l−1) on the entire surface is obtained by cutting and collecting the output corresponding to the j-th row component.
Can be obtained.

At this time, a _ij is proportional to the physical quantity n _ij ,
In general, the correction coefficient k _ij of the optical system, which is proportional to the function f (I ₀ ) of the laser light intensity I ₀ and is related to the solid angle, the distribution of the light receiving element sensitivity characteristics, and the like, is incorporated,

[0029]

[Equation 1]

It can be expressed as

The correction coefficient k _{ij at} this time can be obtained by a separate reference signal measurement as shown in the reference signal measurement (b _ij ) under the point beam scan in FIG. 4C. Specifically, the same system (same coordinate space as the monitor target)
Or, in the same optical system (coordinate space equivalent to the monitor target), while sweeping the laser light in the j direction,
It can be determined by taking a method such as (a) filling a suitable gas to about atmospheric pressure to measure Rayleigh scattered light, or (b) filling a luminescent gas or liquid to measure luminescence. The reference signal b _ij (i obtained at this time
= ₀ to k−1, j = 0 to 1−1) is proportional to the correction coefficient k _ij and the laser light intensity I ₀ , and the proportional coefficient is r,

[0032]

[Equation 2]

Can be written as Therefore, from the equations (1) and (2), the physical quantity _nij is

[0034]

[Equation 3]

It is obtained as follows. Here, since rI ₀ / f (I ₀ ) can be regarded as a constant, the physical quantity n _ij is a relative value a _ij / b
It can be obtained from _ij .

As described above, in the LIF method,
When a normal point beam is used as the excitation laser light source, the physical quantity n is obtained by sweeping the laser light.
_Although the spatial distribution of _ij can be obtained, it is not suitable for measuring the temporal change of _ij because it takes time to sweep.

Therefore, in the present invention, first, as shown in FIG. 5, the point beam propagating in the i direction is expanded in the j direction by using the cylindrical concave lens 20 and the cylindrical convex lens 21, and the one-shot two-dimensional coordinate space x is obtained.
_ij (i = 0 to k−1, j = 0 to l−1) The entire region is propagated.

Output c _ij of the two-dimensional light receiving element p _ij at this time
(I = 0 to k−1, j = 0 to 1−1) includes information from the entire ij plane, and the sheet beam at this time is the sheet beam of FIG. Since there is generally a light intensity distribution as shown in Fig. 6, by measuring the LIF light under the sheet beam as shown in Fig. 6 (b), the LIF light measurement under the sheet beam (c _ij ). , And the light intensity at the coordinate x _ij is I _ij , c _ij is

[0039]

[Equation 4]

It can be expressed as The correction coefficient k _{ij at} this time can be obtained in advance from the reference signal measurement result expression (2) using the point beam in FIG. 4C. On the other hand, the reference signal measurement under the seat beam of FIG.
_ij ), the output d _ij (i = 0) of the two-dimensional light receiving element p _ij is measured by measuring the reference signal under the sheet beam.
~ K-1, j = 0 to l-1) is

[0041]

[Equation 5]

Which can be expressed as
From the equation, the laser light intensity distribution I _ij is

[0043]

[Equation 6]

Can be relatively calculated as However, as shown in the equation (4), generally, the sheet beam has a light intensity distribution, and the LIF signal intensity is a non-linear function of the light intensity. Therefore, from the above information alone, the physical quantity n You cannot ask for _ij .

First, in the simplest case, the light intensity is LI.
In a region having a proportional relationship with the F signal intensity, that is, when it is possible to write f (I _ij ) = α · I _ij using the proportional constant α,
Equation (4) is

[0046]

[Equation 7]

Then, according to equations (2) and (6),

[0048]

[Equation 8]

It becomes At this time, since r / α can be regarded as a constant, the physical quantity n _ij can be obtained as a relative value from c _ij / d _ij .

Next, in the general case, that is, when the light intensity is
Consider a case where the LIF signal strength has a non-linear relationship. This
Here, the light intensity distribution I_ijBetween LIF signal strength and f
(I_ijProcedure for obtaining the LIF reference signal for
First, the LIF under the sheet beam sweep of FIG.
Reference signal light measurement (e_ij) As shown in FIG.
Consider sweeping in the direction. When sweeping the seat beam
Then, the two-dimensional light receiving element p _ijOne row with j₀Line component
Sheet beam light intensity I at_ijTurn off the output corresponding to
E_ij(I = 0 to k-1, j = 0 to
l-1). That is,

[0051]

[Equation 9]

Can be expressed as At this time, from equation (9),

[0053]

[Equation 10]

And

[0055]

[Equation 11]

From equations (10) and (11),

[0057]

[Equation 12]

Is

[0059]

[Equation 13]

Can be written as On the other hand, from equation (6),

[0061]

[Equation 14]

Then,

[0063]

[Equation 15]

And

[0065]

[Equation 16]

Both can be obtained as a value relative to the j ₀ row component in the i ₀ column. These 7, by obtaining a master curve can be plotted to determine the f (I _ij) uniquely as a function of I _ij. At this time, from equations (2), (4), and (6),

[0067]

[Equation 17]

And the physical quantity _nij is a relative value,
It can be obtained from b _ij , c _ij , d _ij and e _ij and FIG. 7.

Although the above procedure is slightly complicated, if the i-direction distribution of the light intensity distribution I _ij can be ignored, that is,
If it can be written that I _ij = I _j , it can be simplified. This corresponds to adjusting the cylindrical concave lens 20 and the cylindrical convex lens 21 to obtain parallel light. At this time, equation (4) is

[0070]

[Equation 18]

From the equations (9) to (12), f
(I _j ) is

[0072]

[Formula 19]

Since it is expressed as follows, it can be obtained as a relative value to the j ₀ row component in the i ₀ column, that is, it can be offset. That is, (2), (15), (16)
From the formula,

[0074]

[Equation 20]

Is obtained. At this time,

[0076]

[Equation 21]

Can be regarded as a constant, so the physical quantity _nij is a relative value.

[0078]

[Equation 22]

It can be obtained from

As described above, when the sheet beam is used, in addition to the correction of the optical system related to the solid angle and the distribution of the sensitivity characteristic of the light receiving element, the correction associated with the light intensity distribution is necessary. The calibration data can be obtained by measuring the reference signal in advance, and it is possible to deal with time-space resolved measurement and the like, and real-time monitoring is possible.

(Second Embodiment) Using the same apparatus as that used in the first embodiment and shown in FIG. 1, laser absorption spectroscopy (lase
The case of using the absorption spectroscopy, hereinafter LAS) method will be described. As shown in FIG. 8, laser light 1
7 is incident on the plasma generation chamber 1 perpendicularly to the optical window 14. The incident laser beam 17 propagates in the plasma 6 and is emitted from the optical window 15. At this time, the species such as radicals existing in the passage region in the plasma 6 are excited in accordance with the wavelength of the laser light 17, and absorption occurs. At this time, the light transmitted through the optical window 15 is captured as a two-dimensional image by the two-dimensional light receiving element 19, for example, a CCD camera. In this embodiment, an infrared laser is used as a laser, and a case where CF ₂ radicals, which are important species in plasma, are detected with light having a wave number of 1096 cm ⁻¹ will be described as an example.

Now, as in FIG. 3, the two-dimensional coordinate space that is perpendicular to the laser incident direction and can be seen from the optical window 15 is x.
_ij (i = 0 to k−1, j = 0 to l−1), and the pixel of the two-dimensional light receiving element 19 corresponding thereto is defined as p _ij . Corresponding to these, the average value of the density of CF ₂ radicals distributed in the laser propagation direction is defined as a physical quantity _nij .

In the ordinary laser absorption spectroscopy, FIG.
As shown in the point beam, the spot diameter is 1-2 mm
Since one point shot is used, only one shot can obtain information corresponding to one point in the ij plane.

When a laser beam is incident on the coordinate x _ij with an incident light intensity I ₀ , the propagation distance of the laser is d, the absorption coefficient of the CF ₂ radical is β, and the pixel of the two-dimensional light receiving element 19 is the output f of p _ij . _ij is proportional to the transmitted light intensity (the proportional coefficient is γ
Incorporating the correction coefficient h _ij of the optical system relating to the solid angle and the distribution of the light receiving element sensitivity characteristics,

[0085]

[Equation 23]

Can be written as

To obtain information on the entire spatial distribution, that is, on the ij plane, as shown in the transmitted light measurement (f _ij ) under the point beam scan of FIG. The measurement is repeated while sweeping and scanning in the direction (i = 0 to k−1, j = 0 to l−1), and the output f _ij of the pixel p _ij of the two-dimensional light receiving element 19 is synchronized with this every time.
By collecting and collecting the signal f _ij (i = 0 to k)
-1, j = 0 to 1-1) can be obtained.

The correction coefficient h _{ij at} this time can be obtained by a separate reference signal measurement as shown in the reference signal measurement (g _ij ) under the point beam scan in FIG. In an equivalent optical system, a method such as measuring the transmitted light while sweeping the laser light in the i and j directions by setting it in a vacuum state or filling it with a medium transparent to the wavelength of the laser light can be adopted. it can. Reference signals g _ij (i = 0 to k-1, j = 0 to l-1) obtained at this time
Is

[0089]

[Equation 24]

From equations (18) and (19), the physical quantity _nij is

[0091]

[Equation 25]

It is obtained as follows. Since αd can be regarded as a constant,
The physical quantity n _ij can be obtained as a relative value from g _ij / f _ij .

As described above, also in the LAS method, when a normal point beam is used as the laser light source, the physical quantity n _{ij is} obtained by sweeping the laser light.
Although it is possible to obtain the spatial distribution of, it is not suitable for measuring the temporal change thereof, because it takes time to sweep.

Therefore, also in the present invention, as in the case of FIG. 5, the sheet beam is used to perform sweeping in only one direction, and further, as shown in FIG. 10, it propagates perpendicularly to the ij plane. The point beam is expanded in the ij direction using the concave lens 22 and the convex lens 23 to form a cylindrical beam, and the two-dimensional coordinate space x _ij (i = 0
˜k−1, j = 0˜l−1) The whole area is transmitted. However, in the case of the LAS method, the physical quantity _nij is exactly i-
In order to reflect the average value in the laser propagation direction perpendicular to the j-plane, it is necessary to adjust the lens system so as to obtain parallel light with no change in light intensity in the propagation direction.

At this time, that is, as shown in the transmitted light measurement (q _ij ) under the cylindrical beam in FIG. 11B, the output q _ij (i = 0 to k−1) of the two-dimensional light receiving element p _ij. ,
(j = 0 to l-1) includes information from the entire ij plane, and the cylindrical beam at this time has the same shape as that shown in FIG. ), There is a light intensity distribution in the i-j plane, so that the light intensity at the coordinate x _ij is I _ij
q _ij is

[0096]

[Equation 26]

It can be expressed as The correction coefficient h _{ij at} this time can be obtained from the reference signal measurement result (19) using the point beam in FIG. 9C, but on the other hand,
Reference signal measurement under the cylindrical beam of FIG. 11 (c)
As shown in (r _ij ), the output r _ij (i = 0 to k−1, j of the two-dimensional light receiving element p _ij is measured by measuring the reference signal under the cylindrical beam, as in FIG. 9C. = 0 to 1
-1) is

[0098]

[Equation 27]

It can be expressed as Eventually, from equations (21) and (22), h _ij · γ · I _ij are canceled out, and the physical quantity n _ij immediately becomes

[0100]

[Equation 28]

Is obtained. Since αd can be regarded as a constant,
The physical quantity n _ij can be obtained as a relative value from r _ij / q _ij .

As described above, when the cylindrical beam is used, in addition to the correction of the optical system related to the solid angle and the distribution of the sensitivity characteristic of the light receiving element, the correction associated with the light intensity distribution is necessary. The calibration data can be obtained by measuring the reference signal in advance, and it is possible to support time-space resolved measurement and the like, and thus real-time monitoring is possible.

In addition to the radical density, the physical quantity to be monitored may be the number of fine particles, the number of gas molecules, the number of metastable atoms, the electric field strength, and the like.

[0104]

As described above, according to the present invention, the laser light is spread in the plane perpendicular to the propagation direction or in the uniaxial direction by using the lens to generate the excitation light or the probe light. All coordinate spaces to be measured are propagated in one shot at the same time, and the two-dimensional light receiving element is configured to simultaneously monitor the light emitted from each coordinate space or the transmitted light. It is possible to easily achieve both time-resolved measurement.

Further, in the present configuration, in the case of the laser induced fluorescence method, the correction of the optical system relating to the variation of the solid angle and the sensitivity characteristic of the light receiving element, the correction relating to the light intensity distribution of the excitation light,
It is necessary to make a correction for the dependence of the emission intensity on the excitation light intensity. In the case of laser absorption spectroscopy, the solid angle and
It is necessary to correct the optical system related to the distribution of the sensitivity characteristics of the three-dimensional light receiving element, and the correction related to the light intensity distribution of the probe light, but since a means for efficient data calibration and an algorithm are also devised. Real-time monitoring is possible.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a configuration of a plasma processing apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a device configuration using a monitoring method according to an embodiment of the present invention.

FIG. 3 is a schematic diagram showing a relationship of variables defined by the monitoring method according to the embodiment of the present invention.

FIG. 4 is a schematic diagram showing a monitoring method in the embodiment of the present invention.

FIG. 5 is a schematic diagram showing an apparatus configuration using the monitoring method in the embodiment of the present invention.

FIG. 6 is a schematic diagram showing a monitoring method in the embodiment of the present invention.

FIG. 7 is a schematic diagram showing a characteristic curve in the monitoring method according to the embodiment of the present invention.

FIG. 8 is a schematic diagram showing an apparatus configuration using the monitoring method in the embodiment of the present invention.

FIG. 9 is a schematic diagram showing a monitoring method in the embodiment of the present invention.

FIG. 10 is a schematic diagram showing an apparatus configuration using the monitoring method in the embodiment of the present invention.

FIG. 11 is a schematic diagram showing a monitoring method in the embodiment of the present invention.

[Explanation of symbols]

1 Plasma Generation Chamber 2 Gas Inlet 3 Coil 4 Matching Circuit 5 High Frequency Power Supply 6 Plasma 7 Sample Wafer 8 Lower Electrode 9 Matching Circuit 10 High Frequency Power Supply 11 Mass Flow Controller (C ₄ F ₈ ) 12 Mass Flow Controller (CHF ₃ ) 13 Tank Box 14 Optical window 15 Optical window 16 Optical window 17 Laser light 18 Filter 19 Two-dimensional light receiving element (CCD camera) 20 Cylindrical concave lens 21 Cylindrical convex lens 22 Concave lens 23 Convex lens

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2G043 AA01 AA03 CA02 CA07 DA01                       EA10 EA13 FA03 GA07 GB21                       KA01 KA03 KA09 NA01                 2G059 AA05 BB16 EE01 EE06 EE07                       FF04 GG01 HH01 HH03 HH06                       JJ02 JJ11 KK04 MM01 MM03                       MM14                 5F004 AA16 BA04 CB02 CB09 DA01                       DA16

Claims (6)

[Claims] 1. A two-dimensional coordinate space x _ij (i = 0 to k−1,
The time variation of the physical quantity n _ij distributed to j = 0 to L-1) on to a monitoring method for monitoring using optical method, to propagate a sheet-like excitation light spread in the j direction in the i direction Thereby, the light emission emitted in the direction perpendicular to the _ij plane depending on the physical quantity _nij and the intensity distribution _Iij of the excitation light is detected by using the two-dimensional light receiving element _pij. Monitoring method. 2. A correction of an optical system related to a solid angle and a distribution of sensitivity characteristics of the two-dimensional light receiving element, a correction related to a light intensity distribution of the excitation light, and a correction related to a dependence of emission intensity on the excitation light intensity. The monitoring method according to claim 1, wherein the reference signal is obtained by relatively sweeping the sheet-shaped excitation light in the j direction in order to carry out. 3. When obtaining the reference signal, the two-dimensional coordinate space or a coordinate space optically equivalent to the two-dimensional coordinate space is filled with a uniform illuminant exhibiting linear excitation light intensity dependence, The monitoring method according to claim 2, wherein the emitted light is emitted as the reference signal. 4. When obtaining the reference signal, the two-dimensional coordinate space or a coordinate space optically equivalent to the two-dimensional coordinate space is filled with a uniform substance, and scattered light emitted from this is filled with the reference signal. 3. The method according to claim 2, wherein
The monitoring method described. 5. A two-dimensional coordinate space x _ij (i = 0 to k−1,
j = 0~l-1) the time change of the physical quantity n _ij distributed on, a monitoring method for monitoring using optical techniques, ij surface probe light spread ij plane direction by propagating in a direction perpendicular to, the physical quantity n _ij
A method of monitoring, wherein the intensity of transmitted light depending on is detected using a two-dimensional light receiving element p _ij . 6. The two-dimensional coordinate space or the two-dimensional coordinate space for correcting the optical system relating to the solid angle, the distribution of the sensitivity characteristics of the two-dimensional light receiving element, and the like, and the light intensity distribution of the probe light A coordinate space optically equivalent to the dimensional coordinate space is in a vacuum state or in a state filled with a substance transparent to the probe light, and a signal due to transmitted light at this time is obtained as a reference signal. The monitoring method according to claim 5.