JPH085585A - Particle inspection equipment - Google Patents

Abstract

PURPOSE:To detect a particle with high reproducibility in a short time without requiring mechanical shift of a sample by turning a plurality of switches, disposed at least on the driving side or the output side of each inspection unit, ON/OFF. CONSTITUTION:A plurality of semiconductor switches 81, 82, for example, are connected between the driving section 50 for an inspection unit 20 and the electronic scanning system 30 for the unit 20, and between the secondary electron detection system 40 for the unit 20 and the operation control section 60. When the switches 81, 82 connected with an inspection unit An-1, for example, are switched through a switching control section 63, electrons are emitted from the electron source of the unit An-1 and raster scanning is effected on the surface of a sample opposing the unit An-1. Other switches 81, 82 are released at that time. When a plurality of units 20 are operated sequentially as the inspection time elapses, the front face of the sample facing the unit 20 can be scanned in a short time without requiring any mechanical shift of the sample.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a particle inspection apparatus for inspecting particles with an electron beam, and more particularly to a particle inspection apparatus for inspecting particles existing on a sample surface such as a semiconductor wafer.

[0002]

2. Description of the Related Art Conventionally, as an apparatus for inspecting particles existing on the surface of a sample, a scanning electron microscope (SEM: Scanning Electron Microscope, hereinafter referred to as SEM) using a low acceleration electron beam has been used.

Generally, the electron beam of the SEM and the detector are single, and in order to enlarge the observation area, the electron beam is scanned by a raster scan system using M rasters as shown in FIG. As shown in FIG. 12, the sample to be inspected is mechanically moved relative to the electron beam of the SEM to change the scan area to expand the observation area.

[0004]

However, in the above-mentioned SEM, since a detection signal is obtained by using a single electron beam and a detector, a large number of inspection target points such as a semiconductor wafer, for example, at least 100 inspection points. When inspecting particles existing on the surface of a sample having more than one portion to be inspected, it is necessary to mechanically move the sample relative to the electron beam of the SEM, which causes the following time problems. And have a connection problem of the field of view.

First of all, as a time-related problem, mechanical movement generally requires much more time than an electronic processing method.
There is a problem that the total inspection time becomes enormous by repeating this.

For example, the field of view of the SEM is 1 mm square and 1
A 00-times 100 mm square sample is to be observed. S
If one scan of the raster scan of the EM field of view takes 0.1 seconds and 100 scans are required, the scanning time of one field of view of the SEM becomes 10 seconds, and the movement of the field of view, that is, the movement time of the electron beam is If it is 5 seconds, the total observation time is (10 + 5) × 100 ² = 1.5 × 10 ⁵ seconds, which requires a great deal of time for inspection.

Further, in the system in which the scan areas are mechanically moved and the scan areas are connected to enlarge the field of view, the position of the end of the field of view depends on the accuracy of the moving mechanism, and therefore, the position of each observation area is increased. In addition, there is a problem that the continuous state of the visual field changes and the reproducibility of the observed image is lost.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a particle inspection apparatus for obtaining an observation image for particle inspection with good reproducibility in a short time.

[0009]

To achieve the above object, the present invention provides a fine electron source, an electronic scanning system for scanning an electron beam emitted from the electron source, and a scanning by this electronic scanning system. Particles in which a plurality of inspection units consisting of secondary electron detection systems that detect the particles by secondary electrons generated from the particles when the irradiated electron beam is irradiated on the particles on the sample surface and output this detection signal are arranged In the inspection device,
Drive means for driving each of the inspection units, a plurality of switch means disposed on at least one of the drive means side or the output side of each inspection unit driven by the drive means, and the plurality of switch means A switching control means for switching is provided.

Further, the particle inspection apparatus of the present invention is characterized in that the switching control means switches a plurality of switch means with the passage of time, and the inspection unit is driven with the passage of time to inspect.

Further, in the particle inspection apparatus of the present invention, the switching control means switches the plurality of switching means for each predetermined area,
It is characterized in that the inspection unit is driven for each predetermined area for inspection.

Further, according to the present invention, a fine electron source, an electron scanning system for scanning an electron beam emitted from this electron source, and an electron beam scanned by this electron scanning system irradiates particles on a sample surface. Particles are detected by secondary electrons generated from particles when the particles are inspected, and in a particle inspection device in which a plurality of inspection units consisting of a secondary electron detection system that outputs this detection signal are arranged, the above inspection units are collectively It is characterized in that it comprises drive means for driving in parallel, and the above-mentioned inspection unit collectively inspects in parallel.

Further, the particle inspection apparatus of the present invention is characterized in that arithmetic processing means for arithmetically processing the detection signal output from the inspection unit is provided, and the detection signal is arithmetically processed and output.

Further, the particle inspection apparatus of the present invention comprises a plurality of switch means provided on the output side of either the inspection unit or the arithmetic processing means, and a switching control for switching the plurality of switch means for every predetermined number. And means.

Further, in the particle inspection apparatus of the present invention, only the inspection unit corresponding to the detected particles is driven by making the scanning density by the electronic scanning system dense, and the particles detected by the driven inspection unit are driven. It is characterized in that it is provided with an observation means for observing an enlarged image of.

[0016]

In the particle inspection apparatus of the present invention, the sample is mechanically moved by switching the plurality of switch means arranged on at least one of the drive means side and the output side of each inspection unit by the switching control means. Instead, it becomes possible to inspect particles on the entire surface of the sample by a method of electrically switching the inspection unit, and it is possible to perform particle inspection with good reproducibility in a short time.

Further, in the particle inspection apparatus of the present invention, the switching control means switches a plurality of switch means with the passage of time, and the inspection unit is driven with the passage of time for inspection, so that the inspection time is shortened and the entire surface of the sample is reduced. Can be inspected for particles.

Further, in the particle inspection apparatus of the present invention, the switching control means switches the plurality of switching means for each predetermined area,
Since the inspection unit is driven and inspected for each predetermined area,
A search function for a specific pattern or a defect can be provided.

Further, in the particle inspection apparatus of the present invention, since the inspection units collectively inspect in parallel, the inspection time is greatly shortened, and the particles on the entire surface of the sample can be inspected in an extremely short time.

Further, since the particle inspection apparatus of the present invention is provided with the arithmetic means for arithmetically processing the detection signal output from the inspection unit, the existence of particles can be found in the inspection unit.

Further, since the particle inspection apparatus of the present invention is provided with the switching control means for switching the plurality of switch means provided on the output side of either the inspection unit or the arithmetic means for every predetermined number, the inspection Even if the number of units exceeds hundreds, without moving the sample mechanically,
Particles on the entire surface of the sample can be inspected by electrically switching the inspection unit.

Further, in the particle inspection apparatus of the present invention, only the inspection unit corresponding to the detected particles is driven with a high scanning density by the electronic scanning system, and the particles detected by the driven inspection unit are enlarged. Since the observation means for observing the image is provided, the detected particles can be observed easily and in detail.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The basic construction of the present invention will be described below with reference to the drawings.

FIG. 1 is a view showing the basic arrangement of a particle inspection apparatus according to the present invention. This particle inspection apparatus is a mounting table (not shown).
An inspection unit 20 that emits an electron beam toward a sample 10 such as a semiconductor wafer mounted thereon and detects backscattered electrons or secondary electrons from the sample 10, and supplies drive power to the inspection unit 20. Drive unit 50 and inspection unit 20
An operation control unit 60 for controlling the operation of the entire apparatus such as the drive unit 50 and the drive unit 50, and for processing the detection signal output from the inspection unit 20, and a mounting table on which the inspection unit 20 and the sample 10 are mounted. A vacuum chamber that can be stored and vacuum exhausted inside
70 and. The arithmetic control unit 60 includes an input unit 61 including a console for inputting an instruction such as an inspection start by the inspection unit 20 from the outside, image information obtained based on a detection signal output from the inspection unit 20, and the like on the screen. A display unit 62 including a CRT display and the like for displaying is connected.

FIG. 2 is a view showing the structure of an inspection unit 20 composed of a total of N micro SEMs manufactured on the surface of a silicon wafer. One unit has both sides of lx and ly as shown in FIG. 2 (a). The silicon wafer 21 has a length of, for example, 10 μm to 1 mm square and is formed in a matrix on the entire surface of the silicon wafer 21 having a diameter of 6 to 8 inches.

The structure of the inspection unit 20 is shown in FIGS. 2 (b) and 2 (c). 2 (b) and 2 (c)
Is an inspection unit An-1 or An of an arbitrary area in the inspection unit 20 manufactured on the surface of the silicon wafer 21.
, An + 1.

The inspection unit 20 is an electron source that emits electrons.
31 and an electron beam 32 that emits electrons emitted from this electron source 31.
The electron scanning system 30 which radiates the sample 10 to form the spot S on the sample 10 and the secondary electron detection system 40 which detects the backscattered electrons or secondary electrons 33 from the surface of the sample 10 are regarded as one unit. N units are manufactured in a matrix on the entire surface of the wafer 21. As shown in FIG. 2 (b),
The electron beam 32 emitted from the electronic scanning system 30 collides with the surface of the sample 10 arranged facing the inspection unit 20, and its reflected electrons and secondary electrons 33 are detected by the adjacent secondary electron detection system 40.

The electron scanning system 30 includes an extraction electrode 34 for extracting electrons from a cone-shaped electron source 31 to form an electron beam 32, a focusing electrode 35 for focusing a spot S of the electron beam 32 on the sample 10, and an electron. A deflection electrode 36 for deflecting the beam 32 in an arbitrary direction is provided. The deflection electrode 36 is composed of two pairs of positive and negative electrodes which are formed in a quadrant so as to face each other in the direction orthogonal to the electron beam 32, and the deflection angle of the electron beam 32 is changed depending on the level of the potential difference between the two electrodes. The scanning range can be controlled so that raster scanning can be performed.

Further, as shown in FIG. 2 (c), the electronic scanning system 30 has a substantially concentric circular hole centered on the tip of the electron source 31 projecting in a cone shape on the silicon wafer 21. The respective electrode layers of the extraction electrode 34 and the converging electrode 35 are sequentially laminated with the insulating film 37 interposed therebetween, and the upper layer thereof has a gap at a position above the circular hole with the insulating film 37 interposed therebetween to form a four-divided shape. Deflection electrode
36 are formed.

The secondary electron detection system 40 is adjacent to the same silicon wafer 21 as the electronic scanning system 30 and is centered on the tip of the electron source 31, like the extraction electrode 34, the focusing electrode 35, and the deflection electrode 36. Are formed in a substantially concentric ring shape, for example, an electrode that attracts secondary electrons 32 when a voltage is applied, a scintillator that converts the rushed electrons into photons, a light pipe that allows the photons to pass, and a photon to increase into electrons. It is composed of a photomultiplier tube for multiplying, detects backscattered electrons and secondary electrons 33 from the surface of the sample 10, and outputs a detection signal reflected on the surface of the sample 10 to the arithmetic control unit 60. The arithmetic control unit 60 analyzes this detection signal to obtain image information, and outputs this image information to the display unit 62 for visualization.

The drive unit 50 for supplying drive power to the inspection unit 20 is controlled by the arithmetic control unit 60 to control the electronic scanning system 30.
And a voltage control circuit 51 for controlling the drive power supply to the secondary electron detection system 40, and a first control circuit 51 controlled by the voltage control circuit 51 to supply drive power to the electronic scanning system 30 and the secondary electron detection system 40, respectively. Power source 52 and second power source 53 of the extraction electrode 34, the focusing electrode 35, the deflection electrode 36, and the secondary electron detection system.
The voltage value supplied to 40 is controlled by the voltage control circuit 51.

Next, scanning of the electron beam 32 in each inspection unit 20 will be described.

In an arbitrary inspection unit 20, for example, the inspection unit An, as shown in FIG. 3, the inspection area facing the inspection unit An in the inspection area of the sample 10 in a state where the electron beam 32 is not deflected. The electron beam 32 forms a spot S at a substantially central portion of An. Further, when the voltage of the sawtooth wave is applied to the deflection electrode 36 under the control of the voltage control circuit 51, the electron beam 32 is deflected by the deflection electrode 36, and the spot S is rastered in the entire inspection area An for the raster L1 of one scanning time τ. , L2, ..., Lm−1, Lm, a two-dimensional scan (raster scan) consisting of M rasters is performed. The scanning of the electron beam 32 makes it possible to observe the inspection area An of the sample 10 facing the inspection unit An. That is, by performing the two-dimensional scanning of the electron beam 32 in all the inspection units 20, it becomes possible to observe the surface state of the sample 10 arranged facing the inspection units 20.

Therefore, when observing the sample 10,
The entire surface of the sample 10 facing the inspection unit 20 can be observed without moving the inspection unit 20 composed of the micro SEM arranged facing the sample 10 relatively. Hereinafter, each example of the present invention will be described.

First, a first embodiment of the present invention will be described with reference to FIGS. 4 and 5. In the figure showing the configuration, the power supply line from the drive unit 50 is shown as one line, and the input unit 61 is also provided.
Are omitted, and the same applies to the second and subsequent embodiments.

In FIG. 4, reference numeral 81 denotes a drive unit 50 for supplying drive power of a predetermined voltage to the inspection unit 20 and the inspection unit 20.
Of the electronic scanning system 30, specifically, the drive unit 50 and the electron source 31.
And a plurality of first switches made of a semiconductor or the like provided between the first switch 81 and the first switch 81. The first switch 81 is controlled by the arithmetic control unit 60 to control ON / OFF of the plurality of first switches 81. It is controlled by the control unit 63 to connect / disconnect in a time division manner. Reference numeral 82 denotes a plurality of second switches made of a semiconductor or the like provided between the secondary electron detection system 40 of the inspection unit 20 and the arithmetic control unit 60 that controls the operation of the entire apparatus. Similarly to the first switch 81, the switches 82 are also controlled by the switching control unit 63 to connect / disconnect in sequence as the inspection time elapses, and to the first switch 81 connected to the same inspection unit 20. Connect and disconnect simultaneously at the same time.

For example, when the first and second switches 81 and 82 connected to the inspection unit An-1 are connected by the switching control unit 63, electrons are emitted from the electron source 31 of the inspection unit An-1. , Electron beam 32 inspection unit An-
The raster scan shown in FIG. 3 of the surface of the sample 10 facing 1 is performed. At this time, the other first and second switches 81 and 82 are released, and the sawtooth wave voltage is also applied to the deflection electrode 36 of the other inspection unit 20, but the electron source 31
Since no electron is emitted from the electron beam 32, the electron beam 32 and the secondary electron 33 accompanying it are not generated.

The first connected to the inspection unit An-1
And the second switch 81,82 are connected, and the inspection unit An-1
According to FIG. 3, rasters L1, L2 for one scan time τ,
..., M raster scans of Lm-1 and Lm are performed,
After the detection signal of the secondary electron detection system 40 is output to the arithmetic control unit 60, the first and second units connected to the inspection unit An-1 are connected.
Switches 81 and 82 are released, the first and second switches 81 and 82 connected to the inspection unit An are connected, and the raster scan by the inspection unit An is similarly performed.
When the raster scan by the inspection unit An is completed, the first and second switches 81 and 82 connected to the inspection unit An + 1 are connected, and the raster scan by the inspection unit An + 1 is similarly performed. FIG. 5 shows a detection signal output from the secondary electron detection system 40 to the arithmetic control unit 60 at this time.

If particles such as dust are present on the sample 10, secondary electrons 33 are generated from the particles when the particles are irradiated with the electron beam 32. Depends on the amount of. That is, a detection signal having a peak value corresponding to the amount of particles existing on the sample 10 is output from the secondary electron detection system 40 as shown in FIG. 5, for example, and the arithmetic control unit 60 analyzes this detection signal. Sample 10
The display unit 62 displays the image information that reflects the surface state of the.

Here, the first and second parts are controlled by the arithmetic and control unit 60 based on the input from the input unit 61, and only the portion where particles are detected, for example, the inspection unit An is connected to the inspection unit An. By connecting and driving the switches 81 and 82, detailed observation of the particle image becomes possible. That is, the individual inspection unit 20 is used as the SEM, the deflection width of the raster scan is reduced to make the scanning density higher than that during the inspection, and the observation image of the particles is enlarged, thereby enabling detailed observation of the particle image. .

As described above, by sequentially operating the N inspection units 20 as the inspection time elapses, the entire surface of the sample 10 facing the inspection units 20 can be electronically scanned. At this time, the time T required for the whole surface scanning is T = N × M × τ. Here, N, M, and τ are set to N as in the conventional technique.
= 100 ² , M = 100, τ = 0.1 seconds, T = 100 ² × 100 × 0.1 = 10 ⁵ seconds, which can be shortened to 2/3 of the conventional total observation time. .

Therefore, according to the first embodiment, it is possible to inspect the particles on the entire surface of the sample without mechanically moving the sample, and it is possible to perform the reproducible particle inspection in a short time.

Next, a second embodiment of the present invention will be described with reference to FIGS. 6 and 7. The same parts as those in FIG. 4 are designated by the same reference numerals, and detailed description thereof will be omitted.

In the first embodiment shown in FIG. 4, the N inspection units 20 are sequentially operated in a time division manner, while in FIG.
The second embodiment shown in (a) is a system in which N inspection units 20 are simultaneously operated and the entire inspection units 20 are collectively scanned. In this method, all the electron sources 31 emit electrons, and the electron beams 32 are simultaneously scanned at the same angle. At this time, since the spot S of each inspection unit 20 exists at the same position relatively in the corresponding area of the sample 10, the spot S obtained from each inspection unit 20 shown in FIG.
Detection signal S composed of raster signal Li as shown in (a)
, SAn-1, SAn, ..., SAN (hereinafter collectively referred to as detection signals SAn) are independently obtained and input to the arithmetic control unit 60 via, for example, a connector. Sample at this time
The time T required to scan the entire surface of 10 is one inspection unit
It is the same as the time required for 20 scans, and T = 100 × 0.1 = 10 seconds, which is about 1/10 of the total observation time of the related art.
It is possible to greatly reduce the number to ⁴ , and it is possible to inspect particles on the entire surface of the sample in an extremely short time.

By the way, the detection signal SAn can be output in parallel to the arithmetic control unit 60 through a connector or the like until the number N of the inspection units 20 is about several hundreds. However, when the number N is several hundreds or more, the inspection unit 20 manufactured in a matrix is driven by the drive unit 50 in parallel in a group unit, for example, a column unit or a row unit, and the inspection time elapses. Controlled to scan the entire surface of the sample 10, and
A plurality of switches 83 made of semiconductor or the like is provided between the inspection unit 20 and the arithmetic control unit 60, and the plurality of switches 83 are arranged in parallel in column units or row units in the same manner as the drive unit 50 by the switching control unit 63. By connecting / disconnecting with the passage of inspection time, the detection signal SA of the inspection unit 20
It is possible to output n to the arithmetic control unit 60 in parallel.

Therefore, even if the number of the inspection units 20 exceeds several hundreds, the sample is not mechanically moved,
Particles on the entire surface of the sample can be inspected by electrically switching the driving state of the inspection unit 20.

If it is not necessary to directly reconstruct the raster signal Li obtained from the inspection unit 20 into an image on the display unit 62, an arithmetic processing circuit including, for example, an integrating circuit is provided on the output side of each inspection unit 20. 84 is provided, and the signal obtained by processing the detection signal SAn by the calculation processing circuit 84 can be output to the calculation control unit 60 in batch parallel using a connector or the like, or in a state via a plurality of switches 83. is there.

As a case where the detection signal SAn is arithmetically processed by the arithmetic processing circuit 84, for example, particles such as dust adhering to the sample 10 are found in the inspection unit 20 unit. That is, when the detection signal SAn shown in FIG. 7 (a) is subjected to, for example, an integration calculation process in the calculation processing circuit 84, an integrated value of the detection signal SAn shown in FIG. 7 (b) is obtained. Since the integrated value of SAn shows its magnitude according to the amount of particles existing in the region of the sample 10 facing the inspection unit 20, the particles are inspected in 20 units of the inspection unit by comparing the integrated value of the detection signal SAn. Can be found at.

In FIG. 7C, a plurality of switches 83 are provided in the subsequent stage of the arithmetic processing circuit 84, and the integrated value of each detection signal SAn obtained by batch scanning by the inspection unit 20 is connected to the switch 83.
The signal waveform of the integrated value of the detection signal SAn when the release is controlled by the switching control circuit 63 according to the detection time and is output to the arithmetic control unit 60 in time series is shown. In this way, the time T for obtaining the total detection signal SAn to be output to the arithmetic control unit 60 by performing the batch scanning → the arithmetic process → the switching process is T = M × τ + N × Δ. Here, N, M, and τ are set to N = 10 as in the above.
0 ² , M = 100, τ = 0.1 seconds, and each detection signal SA
When the output time of the integrated value of n is Δ = 1 msec, T = 100 × 0.1 + 100 ² × 10 ⁻³ = 10 + 10 =
The time is 20 seconds, and the inspection time can be greatly shortened, and the particles adhering to the sample 10 at an extremely high speed can be greatly reduced similarly to the method in which the entire inspection unit 20 is collectively scanned and each detection signal SAn is collectively output. It enables extremely high-speed inspection.

Here, if it is desired to obtain a detailed image of the detected particles after the inspection of the particles, a bypass wiring not having the arithmetic processing circuit 84 as shown in FIG. 6B is provided. The switch 83 'is connected to each other, and the particle images can be observed by using the individual inspection units 20 as SEMs as in the first embodiment.

Although the integrating circuit is exemplified as the arithmetic processing circuit 84, various circuits can be used depending on the form of the required signal. For example, a peak hold circuit may be used, or 2 with a comparator, etc.
A circuit that counts the binarized pulse signal may be used, and other arithmetic circuits that obtain various predetermined arithmetic values may be used.

Next, a third embodiment of the present invention will be described with reference to FIGS. The same parts as those in FIG. 4 are designated by the same reference numerals, and detailed description thereof will be omitted.

In the third embodiment, as shown in FIG. 8, the inspection unit 20 manufactured on the surface of the silicon wafer 21.
Inspection unit 20 located at a specific position in
A group, for example, inspection units An, Bn-1, Bn, Bn + 1, Cn arranged in a cross pattern are selected and electronically scanned, and the detection signals are integrated in the same manner as in the second embodiment. hand,
For example, it is compared with a reference value (pattern).

As shown in FIG. 9A, the inspection unit 20
A plurality of switches 85 made of a semiconductor or the like are provided between the driving unit 50 that supplies driving power of a predetermined voltage to the electron source 31 of the inspection unit 20, and the inspection units An and Bn-1 are arranged in a cross shape. , Bn, Bn + 1, Cn connected to switch 8
5 is selected by the switching control unit 63 to enter the connected state.

Selected inspection units An, Bn-1, Bn, B
At n + 1, Cn, a raster scan of the surface of the sample 10 by the electron beam 32 is performed, and this scan causes the scan of FIG.
Detection signals SAn, SBn-1, SBn, SB as shown in FIG.
n + 1, SCn are obtained. These detection signals SAn, SBn-1,
SBn, SBn + 1, SCn are integrated by an integrating circuit 86 provided at the subsequent stage of the inspection unit 20 to obtain integrated values as shown in FIG. 10 (b). In addition, in FIG.
The individual detection signals SAn, SBn, SCn and their integrated values are shown.

The five integrated values integrated by the integrating circuit 86 are output to the processing circuit 87 connected to the subsequent stage of the integrating circuit 86, and in the processing circuit 87, the five integrated values are
For example, if the parameter P is

[Equation 1] It is calculated based on. The calculated parameter P is output to the arithmetic control unit 60 connected to the subsequent stage of the processing circuit 87. Note that D _j represents a detection signal, and D ₁ = SAn, D _{2
= SBn-1, D 3 =} SBn, D 4 = SBn + 1, D 5 = S
Let Cn.

Subsequently, the switching control unit 63 calculates the address of the cross-shaped pattern in which the inspection unit 20 at the center of the cross-shaped pattern is changed from the inspection unit Bn to the inspection unit Bn + 1, and the five next cross-shaped patterns are calculated. Inspection unit An + 1, B
n, Bn + 1, Bn + 2, Cn + 1 are selected. The same processing as described above is performed on the five newly selected inspection units 20, and the parameter P is output to the arithmetic control unit 60.

By performing the above-described processing so that all the inspection units 20 are located at the center positions of the cross-shaped patterns, the electron beam 32 is scanned over the entire surface of the sample 10 facing the inspection units 20.

The arithmetic control unit 60 can analyze the input parameter P to find out the position of the pattern formed on the sample 10 or inspect a defective pattern which does not exist under normal conditions. The result can be displayed on the display unit 62.

The time T required for the above processing is given by T = (M × τ + δ) × N, where δ is the processing time of the parameter. Here, N, M, and τ are set to N = 10 as in the above.
Assuming that 0 ² , M = 100, τ = 0.1 seconds, and the parameter processing time δ is δ = 1 millisecond, T = (100 × 0.1 + 10 ⁻³ ) × 100 ² = about 10 ⁵
Seconds, which can be reduced to about 2/3 of the total observation time in the past.

Here, as in the second embodiment, as shown in FIG.
Bypass wiring not including the integrating circuit 86 and the processing circuit 87 as shown in (b) is provided, and the switch 85 'is switched.
By connecting to this bypass side by 63, the particle image can be observed by using each inspection unit 20 as an SEM as in the first embodiment.

The present invention is not limited to the above-mentioned embodiments, and can be variously modified.

[0063]

As described above in detail, according to the particle inspection apparatus of the present invention, the switching control means switches a plurality of switch means arranged on at least one of the drive means side and the output side of each inspection unit. As a result, it is possible to inspect particles on the entire surface of the sample by a method of electrically switching the inspection unit without mechanically moving the sample, and it is possible to perform particle inspection with good reproducibility in a short time.

Further, in the particle inspection apparatus of the present invention, the switching control means switches the plurality of switch means with the passage of time, and the inspection unit is driven with the passage of time to inspect, so that the inspection time is shortened and the entire surface of the sample is reduced. Can be inspected for particles.

Further, in the particle inspection apparatus of the present invention, the switching control means switches the plurality of switching means for each predetermined area,
Since the inspection unit is driven and inspected for each predetermined area,
A search function for a specific pattern or a defect can be provided.

Further, in the particle inspection apparatus of the present invention, the inspection units collectively inspect in parallel, so that the inspection time is greatly shortened and the particles on the entire surface of the sample can be inspected in an extremely short time.

Further, since the particle inspection apparatus of the present invention is provided with the arithmetic means for arithmetically processing the detection signal output from the inspection unit, the presence of particles can be found in the inspection unit.

Further, since the particle inspection apparatus of the present invention is provided with the switching control means for switching the plurality of switch means provided on the output side of either the inspection unit or the arithmetic means for every predetermined number, the inspection Even if the number of units exceeds hundreds, without moving the sample mechanically,
Particles on the entire surface of the sample can be inspected by electrically switching the inspection unit.

Further, in the particle inspection apparatus of the present invention, only the inspection unit corresponding to the detected particles is driven with a high scanning density by the electronic scanning system, and the particles detected by the driven inspection unit are enlarged. Since the observation means for observing the image is provided, the detected particles can be observed easily and in detail.

[Brief description of drawings]

FIG. 1 is a diagram showing a basic configuration of a particle inspection apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing an inspection unit, FIG. 2 (a) is a diagram showing the entire inspection unit, FIG. 2 (b) is a partially enlarged sectional view of the inspection unit, and FIG. 2 (c) is a bottom view thereof. is there.

FIG. 3 is a diagram showing a raster scan by an electron beam.

FIG. 4 is a diagram showing a schematic configuration of a first embodiment of the present invention.

FIG. 5 is a diagram showing a detection signal according to the first embodiment of the present invention.

FIG. 6 is a diagram showing a schematic configuration of a second embodiment of the present invention,
FIG. 6 (a) is a diagram without bypass wiring, and FIG. 6 (b).
FIG. 6 is a diagram in which bypass wiring is provided.

FIG. 7 is a diagram showing a signal waveform according to a second embodiment of the present invention, FIG. 7 (a) is a diagram showing a detection signal, FIG. 7 (b) is a diagram showing its integrated waveform, and FIG. ) Is a diagram showing an output state of an integrated waveform.

FIG. 8 is a diagram showing an outline of a third embodiment of the present invention.

FIG. 9 is a diagram showing a schematic configuration of a third embodiment of the present invention,
9 (a) is a diagram without bypass wiring, and FIG. 9 (b).
FIG. 6 is a diagram in which bypass wiring is provided.

FIG. 10 is a diagram showing a signal waveform according to a third embodiment of the present invention, FIG. 10 (a) is a diagram showing a detection signal, and FIG.
(B) is a figure which shows the integrated waveform.

FIG. 11 is an explanatory diagram showing a state of raster scanning.

FIG. 12 is an explanatory diagram showing connection of scan areas.

[Explanation of symbols]

 10 ... Sample 20 ... Inspection unit 30 ... Electronic scanning system 31 ... Electron source 32 ... Electron beam 33 ... Secondary electron 40 ... Secondary electron detection system 50 ... Driving part (driving means) 62 ... Display part (observation means) 63 ... Switching control section (switching control means) 81,82,83,85 ... Switch (switching means) 84 ... Preprocessing circuit (preprocessing means)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshiaki Akama 33 Shinisogocho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture

Claims (7)

[Claims] 1. A fine electron source, an electron scanning system for scanning an electron beam emitted from the electron source, and an electron beam scanned by the electron scanning system when a particle on a sample surface is irradiated with the electron beam. Particles are detected by secondary electrons generated from particles, and in a particle inspection device in which a plurality of inspection units each including a secondary electron detection system that outputs this detection signal are arranged,
Drive means for driving each of the inspection units, a plurality of switch means disposed on at least one of the drive means side or the output side of each inspection unit driven by the drive means, and the plurality of switch means A particle inspection apparatus comprising a switching control means for switching. 2. The particle inspection apparatus according to claim 1, wherein the switching control means switches a plurality of switching means with time, and the inspection unit is driven with time to inspect. 3. The particle inspection apparatus according to claim 1, wherein the switching control means switches a plurality of switch means for each predetermined area and drives the inspection unit for each predetermined area for inspection. 4. A fine electron source, an electronic scanning system for scanning an electron beam emitted from this electron source, and an electron beam scanned by this electronic scanning system when the particles on the sample surface are irradiated with the electron beam. Particles are detected by secondary electrons generated from particles, and in a particle inspection device in which a plurality of inspection units each including a secondary electron detection system that outputs this detection signal are arranged,
A particle inspection apparatus comprising drive means for driving the inspection units in parallel in parallel, and inspecting the inspection units in parallel in parallel. 5. The particle inspection apparatus according to claim 4, further comprising arithmetic processing means for arithmetically processing the detection signal output from the inspection unit, and arithmetically processing and outputting the detection signal. 6. A plurality of switch means provided on the output side of either the inspection unit or the arithmetic processing means, and a switching control means for switching the plurality of switch means for every predetermined number. The particle inspection apparatus according to claim 4 or claim 5. 7. An observing means for driving only the inspection unit corresponding to the detected particles while making the scanning density of the electronic scanning system dense and observing an enlarged image of the particles detected by the driven inspection unit. The particle inspection apparatus according to any one of claims 1 to 6, further comprising: