JP5572428B2 - Inspection apparatus and inspection method - Google Patents

Description

  The present invention relates to a semiconductor inspection apparatus and a semiconductor inspection method for inspecting, measuring, and observing a semiconductor substrate (semiconductor wafer), a semiconductor device, a photomask (exposure mask), a liquid crystal panel, and the like.

  Various semiconductor devices (semiconductor integrated circuits) such as semiconductor memories and microcomputers are used in computers and various electrical products. Cleaning process, ion implantation process, diffusion process, exposure process, lithography process, etching process, heat treatment The circuit pattern formed on the photomask is transferred and formed by repeating various processes such as processes. In a semiconductor device, the manufacturing yield is reduced due to defects such as foreign matter contamination, pattern shape defects, and poor electrical characteristics such as non-conduction and short circuit in each manufacturing process. Here, the defect is a factor that causes processing abnormality in each manufacturing process, such as foreign matter, pattern shape defect, and electrical characteristic defect.

  As semiconductor processes have evolved in recent years, pattern sizes have become finer and denser, and defect sizes have become finer. In order to detect such fine and diverse defects at an early stage or in advance, observation, measurement, and pass / fail judgment of patterns formed on photomasks, semiconductor substrates (semiconductor wafers), or liquid crystal panels are carried out in each manufacturing process. Has been.

  As described above, the defects to be detected are miniaturized with the progress of the semiconductor process. For this reason, in the semiconductor inspection apparatus, it is possible to detect a fine defect by reducing the diameter of the primary electron beam irradiated to the inspection object. However, according to this method, the time until the scanning of the sample is completed increases, and the inspection speed is lowered. As a method for solving this problem, Patent Document 1 (Japanese Patent Laid-Open No. 10-73424) describes “a charged particle beam optical system that irradiates a charged particle beam to a pattern-formed sample, and charged particles from the sample”. A defect inspection apparatus for inspecting a defect of the pattern, the charged particle beam forming means for forming a plurality of the charged particle beams, and the plurality of charged particle beams. A charged particle beam scanning means for scanning; a sample stage on which the sample is placed; a position measuring means for measuring the position of the sample stage; and the charged particle beam scanning means based on the measurement result of the position measuring means. And a first control means for controlling the defect inspection apparatus (claims).

  A multi-beam scanning electron microscope irradiates a sample with a plurality of primary electron beams, and detects a plurality of secondary electron beams generated from the sample with a plurality of detectors. In order to inspect with high accuracy, it is necessary to adjust the beam position and the focus for all the secondary electron beams so that the secondary electron beam generated from the sample can be efficiently detected by the detector. As a method for realizing this, Patent Document 2 (Japanese Patent Laid-Open No. 2003-346698) describes “a primary electron optical system for irradiating a sample with primary electrons and a detection system for detecting a secondary electron beam emitted from the sample surface”. An electron beam apparatus for evaluating a sample surface, wherein the primary electron optical system is a multi-beam generator, a scanning deflector that simultaneously scans the multi-beam on the sample, and the multi-beam is decelerated and irradiated to the sample And an objective lens for accelerating the secondary electron beam, and a secondary electron beam separator for deflecting a plurality of secondary electron beams that have passed through the objective lens to the detection system, and the detection system is formed on a single silicon substrate An "electron beam device including a plurality of detectors (Claims)" is disclosed. Patent Document 3 (Japanese Patent Application Laid-Open No. 2009-9882) discloses a method for adjusting a secondary electron beam as follows: “From the image acquired as an image of the reference mark on the stage, the amount of deviation from the ideal state of the reference mark. Measure and correct by adjusting the primary electron optical system, etc., and adjust the position where multiple secondary beams are irradiated to the secondary beam detector at the same time using the output of the secondary beam detector to perform calibration. "Applied charged particle beam application apparatus (summary)" is disclosed.

Japanese Patent Laid-Open No. 10-73424 JP 2003-346698 A JP 2009-9882 A

  Patent Document 2 discloses a method of detecting a plurality of secondary electron beams with a detector formed of a single silicon in a multi-beam scanning electron microscope. Adjustment is easy. However, it is necessary to adjust each beam in advance so that all the secondary electron beams can be detected by a detector formed of a single silicon. However, Patent Document 2 discloses a specific method thereof. Absent.

  Further, depending on the charged particle beam application apparatus disclosed in Patent Document 3, it is necessary to change the secondary electron beam control parameters until the detector output becomes maximum, and it is a problem that adjustment takes time.

  An object of the present application is to provide a semiconductor inspection apparatus and a defect inspection method capable of efficiently performing a plurality of secondary electron beam adjustments in a semiconductor inspection apparatus, particularly a multi-beam scanning electron microscope. To do.

  In order to achieve the above object, the outline of typical ones of the inventions disclosed in the present application will be described as follows.

  (1) An irradiation optical system for irradiating a target object with a plurality of irradiation lights, a detection optical system for detecting a plurality of lights irradiated by the irradiation optical system and emitted from the target object, and the detection A comparison unit that compares signal intensities based on a plurality of lights detected by the optical system; a position of the plurality of lights based on a result of comparison by the comparison unit; and a detection position of the plurality of lights in the detection optical system. A correction amount calculation unit that calculates a deviation amount of the signal, and an arithmetic processing unit including a processing unit that processes the signals based on the plurality of lights and inspects the inspection target object, and the detection optical system includes: The inspection apparatus further includes a control unit that adjusts the irradiation optical system based on the deviation amount calculated by the correction amount calculation unit.

  ADVANTAGE OF THE INVENTION According to this invention, the semiconductor inspection apparatus and semiconductor inspection method which can implement multiple secondary electron beam adjustment efficiently can be provided.

It is the schematic of the 1st Example of the semiconductor inspection apparatus which concerns on this invention. It is a display part of the 1st Example of the semiconductor inspection apparatus which concerns on this invention. It is a flowchart which shows the secondary electron beam adjustment method of the 1st Example of the semiconductor inspection apparatus which concerns on this invention. It is a figure which shows the relationship between the incident range to the detection element of a secondary electron beam, and a detection element visual field. It is a figure which shows the relationship between the incident range to the detection element of a secondary electron beam, and a detection element visual field. It is a figure which shows the relationship between the incident range to the detection element of a secondary electron beam, and a detection element visual field. It is a figure which shows the relationship between the incident range to the detection element of a secondary electron beam, and a detection element visual field. It is a figure which shows the relationship between the incident range to the detection element of a secondary electron beam, and a detection element visual field. It is a figure which shows the relationship between the incident range to the detection element of a secondary electron beam, and a detection element visual field. It is the figure which showed the incident position from which a secondary electron beam differs. It is a figure which shows the mixing state to the adjacent element of a secondary electron beam. It is explanatory drawing for calculating | requiring the mixing area to the adjacent element of a secondary electron beam. It is a graph which shows the relationship between a secondary electron beam position shift amount and the mixing rate to an adjacent element. It is the figure which showed the relationship between the parallel position shift of a secondary electron beam, and a detection element. It is the flowchart which showed the calculation procedure of the parallel position shift amount of a secondary electron beam. It is the schematic which shows the structural example of a semiconductor inspection apparatus. It is the schematic which shows the structural example of a semiconductor inspection apparatus. It is a flowchart which shows the calculation procedure of the rotational deviation amount in case the secondary electron beam has produced rotational deviation. It is a flowchart which shows the procedure which calculates the center space | interval deviation | shift amount of a secondary electron beam. It is a flowchart which shows the procedure which calculates the center axis position shift amount of a secondary electron beam. It is explanatory drawing which shows the relationship between a focus shift and a detection element. It is explanatory drawing which shows the relationship between a focus shift and a detection element. It is explanatory drawing which shows the relationship between the secondary electron beam a and a detection element visual field. It is explanatory drawing which shows the relationship between the secondary electron beam a and a detection element visual field. It is explanatory drawing which shows the relationship between the secondary electron beam a and a detection element visual field. It is a figure which shows the relationship between a secondary electron beam radius and the mixing rate to an adjacent element. It is a flowchart which shows the procedure which calculates the defocus amount of a secondary electron beam. It is a modification of the method of calculating the center axis position of the secondary electron beam. It is a flowchart which shows a center axis position calculation procedure. It is a flowchart which shows a secondary electron beam adjustment procedure. It is the figure which showed the relationship of a secondary electron beam, a detection element, and contamination. It is a modification of the detection system of a semiconductor inspection apparatus. It is a figure which shows the positional relationship of a detection element visual field and a secondary electron beam. It is explanatory drawing of the Example of the detection system of a semiconductor inspection apparatus.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In all the drawings for explaining the embodiments, the same symbols are attached to the same elements, and the repeated explanation thereof is omitted.

  In the following, observation, measurement, and pass / fail determination are collectively referred to as “inspection”, and unless otherwise noted, any or all of observation, measurement, and pass / fail determination are included. Unless otherwise specified, a semiconductor inspection apparatus refers to an apparatus including any or all of observation, measurement, and quality determination.

  Further, in the following examples, the inspection object (sample) is described as an example of a semiconductor substrate. However, the inspection object is not limited to a semiconductor substrate, but a semiconductor device, a photomask (exposure mask), a liquid crystal panel, etc. Any object related to a semiconductor that can be inspected by this type of inspection apparatus may be used.

  In addition, although an example using an electron beam as the first energy and a secondary electron beam as the second energy will be described, the first and second energies are not limited. For example, the laser is applied to the first energy. When photon beams such as infrared rays, X-rays, and γ rays are used, the second energy is reflected light, scattered light, transmitted light, photoelectrons, Auger electrons, luminescence, ions, phonons, and the like. In addition, when an electron beam is used as the first energy, the second energy is reflected electrons, scattered electrons, transmitted electrons, absorbed electrons, secondary electrons, Auger electrons, secondary ions, characteristic X-rays, etc. When an ion beam is used as the first energy, the second energy is scattered ions, secondary ions, neutral atoms, neutral molecules, secondary electrons, Auger electrons, and the like. Furthermore, the structure which applied several energy may be sufficient.

  In the present embodiment, the detection element is described as having a square field of view, but the field of view is not limited to a square, and may be any shape.

  First, an outline of a general inspection method of a semiconductor substrate in this type of semiconductor inspection apparatus will be described. Here, the inspection object (sample) is described as an example of a semiconductor substrate. However, the inspection object is not limited to a semiconductor substrate, and may be a semiconductor device, a photomask (exposure mask), a liquid crystal panel, or the like. Absent.

  First, a semiconductor substrate is irradiated with a first beam from a beam irradiation source. A second beam generated from the semiconductor substrate by irradiation is detected by a detector (sensor), converted into an electrical signal, and data processing is performed. The inspection result is not only the display of the results such as the type and number of defects and the measurement value, but also the display of the defect map, the shape and defects of the semiconductor substrate, etc. ”And display. These displays are based on the results of data processing.

  Here, a plurality of types of applications can be considered for the first energy and the second energy, and physical characteristics such as the pattern shape and material of the semiconductor substrate, the type and size of foreign matter and defects to be inspected, A configuration that detects the second energy by irradiating a suitable first energy for each manufacturing process, depending on the inspection purpose such as defect inspection or shape observation, or measurement of dimensions on the semiconductor substrate such as pattern width The semiconductor inspection apparatus is used. The combination of the first energy and the second energy is as described above. One or a plurality of second energy generated from the semiconductor substrate by the first energy irradiation is detected by one or a plurality of detectors. Electrons and ions are sometimes collectively referred to as charged particles.

  Here, the first energy in the semiconductor inspection apparatus is not limited to one, and the semiconductor substrate may be configured to irradiate the semiconductor substrate with a plurality of types of first energy. Similarly, the second energy to be detected is not limited to one, and may be configured to detect a plurality of second energies.

In the following, a semiconductor inspection apparatus using an electron beam as the first energy and a secondary electron beam generated by irradiating the inspection object (sample) with the electron beam as the second energy, particularly scanning the electron beam on the inspection object. A scanning electron microscope (SEM) that detects a secondary electron beam will be described as an example.
<Example 1>
An example of an embodiment of a semiconductor inspection apparatus according to the present invention will be described with reference to FIG. The semiconductor inspection apparatus shown in FIG. 1 includes a primary electron beam irradiation source 11, a primary electron beam condenser lens 12, a primary electron beam aperture array 13, a primary electron beam lens 14, a primary electron beam deflector 15, and an objective lens 16. A secondary electron beam deflector (ExB deflector) 21, a secondary electron beam deflector 22, a secondary electron beam deflection control unit 42, a secondary electron beam lens 24, two A detection optical system including a secondary electron beam lens control unit 41, secondary electron beam detectors (detection elements) 25a to 25c, A / D (analog-digital) conversion units 31a to 31c, a signal intensity comparison unit 33, An arithmetic processing unit 32 including a secondary electron beam position / focus calculation unit 34, a secondary electron beam correction amount calculation unit 35, and a signal processing unit 39, an overall control unit 51, an input unit 52, and a table It is constituted by a part 53.

  In the semiconductor inspection apparatus in FIG. 1, the inspection of the semiconductor substrate 1 that is the object to be inspected is performed as follows. First, the primary electron beam irradiation source 11 irradiates the semiconductor substrate 1 with a primary electron beam that is a charged particle beam. The irradiated electron beam is changed to a parallel beam by the primary electron beam condenser lens 12, and a plurality of primary electron beams are generated by the primary electron beam aperture array 13. The plurality of primary electron beams are changed into non-parallel beams 17a to 17c by the primary electron beam lens 14, and after passing through the primary electron beam deflector 15 for scanning the primary electron beam irradiated on the semiconductor substrate 1, The semiconductor substrate 1 is irradiated by the objective lens 16.

  Here, the semiconductor substrate 1 which is an object to be inspected is a substrate for secondary electron beam adjustment in which a primary electron beam irradiation region is uniformly formed. From the semiconductor substrate 1 irradiated with the primary electron beams 17a to 17c, secondary electron beams which are reflected charged particles according to the pattern of the irradiated position and the shape of the defect are emitted. The emitted secondary electron beam is separated by a secondary electron beam deflector (ExB deflector) 21 acting only on the secondary electron beam to become a secondary electron beam 20, and then the secondary electron beam deflection. After being shaped by the detector 22 and the secondary electron beam lens 24, it is incident on a secondary electron beam detector (detection element) 25 (25a to 25c).

  Here, an example in which three primary electron beams are irradiated has been described, but the configuration of the present invention is not limited to the case of three primary electron beams.

  The secondary electron beam 20 emitted from the semiconductor substrate 1 is converted into an analog electric signal corresponding to the amount of charged particles by a secondary electron beam detector 25 (25a to 25c), and an A / D converter 31 (31a to 31c). ) Is converted into a digital signal. The signal strength of the digital signals converted by the A / D converters 31a to 31c is compared by the signal strength comparison unit 33.

  The secondary electron beam position / focus calculation unit 34 calculates the position and focus of the secondary electron beam incident on the secondary electron beam detectors 25a to 25c by a method described later.

  In the secondary electron beam correction amount calculating unit 35, the secondary electron beam deflectors 21 and 22 are arranged so that the secondary electron beam incident on the secondary electron beam detectors 25a to 25c has a desired position or focus. And a control correction amount of the secondary electron beam lens 24 is calculated.

  The overall control unit 51 receives the control correction amount of the secondary electron beam deflector 22 and the secondary electron beam lens 24 calculated by the calculation processing unit 32 from the calculation processing unit 32, and each controls the deflection control for the secondary electron beam. To the unit 42 and the secondary electron beam lens control unit 41. The secondary electron beam deflection control unit 42 and the secondary electron beam lens control unit 41 are respectively based on the control correction amount transmitted from the overall control unit 51, and the secondary electron beam deflectors 21 and 22 and the secondary electron beam. The signal input to the beam lens 24 is changed, whereby the secondary electron beam is adjusted.

  The overall control unit 51 performs beam control such as control of irradiation conditions of the irradiation optical system for irradiating the primary electron beam and control of detection conditions of the detection optical system for detecting the secondary electron beam emitted from the semiconductor substrate 1, An arithmetic processing unit 32 for arithmetic processing of signals detected by the secondary electron beam detectors 25a to 25c, an input unit 52 such as a keyboard and a mouse, a display unit 53 for displaying detected images and various setting values, and the like are integrated. Control.

  In the display unit 53, not only the acquired inspection image of the semiconductor substrate 1 but also the results of data processing according to the purpose of observation, measurement, defect inspection, foreign matter inspection of the semiconductor substrate 1, and in some cases, design data and Comparisons with past inspection images can also be displayed.

FIG. 2 is an explanatory diagram of the display unit 53 of the first embodiment of the semiconductor inspection apparatus according to the present invention, and an example of a secondary electron beam adjustment screen 61 displayed on the display unit 53 during secondary electron beam adjustment. Indicates.
On the screen, a current output value table 64 of each of the detection elements a to d (detectors), an output image diagram 63, and a list 65 of current setting parameters of the semiconductor inspection apparatus are displayed. An adjustment start button 62 for starting secondary electron beam adjustment is also provided, and secondary electron beam adjustment can be started by an input from the input unit 52.

  FIG. 3 is a flowchart showing a secondary electron beam adjusting method of the first embodiment of the semiconductor inspection apparatus according to the present invention.

Secondary electron beam adjustment is started by selecting the adjustment start button 62 on the secondary electron beam adjustment screen 61 of the display unit 53 (step 801). First, the control value (initial value) of the secondary electron beam is set by the overall control unit 51 (step 802). At this time, the irradiation conditions of the irradiation optical system that irradiates the primary electron beam with the control value of the secondary electron beam (irradiation position such as irradiation angle and irradiation height, beam wavelength, number of beams, type of beam, etc.), etc. The control value may be set.
Next, the control value of the secondary electron beam set in step 802 is transferred to the secondary electron beam lens control unit 41 and the secondary electron beam deflection control unit 42. Therefore, the secondary electron beam lens control unit 41 and the secondary electron beam deflection control unit 42 use the signal (control value) transferred from the overall control unit 51 for the secondary electron beam lens 24 or the secondary electron beam. It outputs to the deflectors 21 and 22 (step 803).
Thereafter, irradiation of the primary electron beam to the semiconductor substrate 1 is started based on the control value set by the overall control unit 51 (step 804). At this time, the control value may be an irradiation condition of an irradiation optical system for irradiating the primary electron beam, or may be controlled by the secondary electron beam lens control unit 41 and the secondary electron beam deflection control unit 42. It may be the control value (initial value) of the secondary electron beam output to the secondary electron beam lens 24 or the secondary electron beam deflectors 21 and 22.

Then, the semiconductor substrate 1 is irradiated with the primary electron beam by the irradiation optical system, and the secondary electron beams emitted from the semiconductor substrate 1 are detected by the plurality of secondary electron beam detectors 25 (step 805). At this time, each of the plurality of secondary electron beam detectors 25 converts each of the plurality of secondary electron beams into an analog electric signal corresponding to the amount of charged particles, and outputs a plurality of analogs output from the secondary electron beam detector 25. The electrical signal is converted into a digital signal by the A / D converter 31 (31a to 31c). In this case, an output signal from the A / D conversion unit 31 is input to the arithmetic processing unit 32.
Next, a signal based on the secondary electron beam detected by each of the secondary electron beam detectors 25 a to 25 c is input to the arithmetic processing unit 32. The signal intensity comparison unit 33 of the arithmetic processing unit 32 compares the output signal intensity of the signal based on the secondary electron beam input to the arithmetic processing unit 32 (step 806).

Next, the signal intensity comparison unit 38 transmits the comparison result of the output signal intensity of the signal based on the secondary electron beam to the secondary electron beam position / focus calculation unit 34. In the secondary electron beam position / focus calculation unit 34, The current position (height, angle, etc.) or focal position of the secondary electron beam is calculated (step 807).
The secondary electron beam position / focus calculation unit 34 determines whether the position or focus of the secondary electron beam calculated by the secondary electron beam position / focus calculation unit 34 satisfies an appropriate state set before the start of adjustment. (Step 808). The determination as to whether or not the appropriate state is satisfied may be made by the secondary electron beam correction amount calculation unit 35, or the secondary electron beam position / focus calculation unit 34 and the secondary electron beam correction amount calculation unit 35 Another calculation unit may be provided between them to perform the calculation.

If the secondary electron beam position / focus calculation unit 34 determines that the state is appropriate, the adjustment ends at that point (step 812). In this case, the signal processing unit 39 performs signal processing based on the signal based on the secondary electron beam transmitted from the secondary electron beam position / focus calculation unit 34 to inspect the semiconductor substrate 1. Thereby, the inspection of the semiconductor substrate 1 is completed.
Here, the result of the signal processing performed in the signal processing unit 39 can be transmitted to the overall control unit 51 and displayed on the display unit 53.

When the secondary electron beam position / focus calculation unit 34 determines that the state is inappropriate, the calculation result in the secondary electron beam position / focus calculation unit 34 is transmitted to the secondary electron beam correction amount calculation unit 35, and A correction amount of the secondary electron beam is calculated from the amount of deviation between the position and focus of the determined secondary electron beam in the proper state and the position or focus of the secondary electron beam actually detected by the detection optical system (step 809). ).
In step 808, if the secondary electron beam correction amount calculation unit 35 determines whether or not the appropriate state is satisfied, the secondary electron beam correction amount calculation unit 35 directly uses the secondary electron beam correction amount calculation unit 35 in the inappropriate state. The beam correction amount may be calculated. In addition, when another calculation unit determines whether or not the appropriate state is satisfied, the determination result is transmitted to the secondary electron beam correction amount calculation unit 35, and the secondary electron beam correction amount is calculated based on the transmission result. The unit 35 may calculate the secondary electron beam correction amount.

The secondary electron beam correction amount calculation unit 35 transmits the secondary electron beam control value (change value) changed based on the correction amount calculated by the secondary electron beam correction amount calculation unit 35 to the overall control unit 51 (step). 810).
The changed control value of the secondary electron beam is transferred from the overall control unit 51 to the lens control unit 41 for the secondary electron beam and the deflection control unit 42 for the secondary electron beam, and based on the control value of the secondary electron beam. The signal output to the secondary electron beam lens 24 or the secondary electron beam deflectors 21 and 22 is changed (step 811).
Thereafter, the semiconductor substrate 1 is again irradiated with the primary electron beam based on the changed control value, and the secondary electron beam emitted from the semiconductor substrate 1 is detected again by the secondary electron beam detectors 25a to 25c (step 805). .

By repeating these operations (steps 805 to 811) until the secondary electron beam is determined to be in an appropriate state in the arithmetic processing unit 38 (secondary electron beam position / focus calculation unit 34), a predetermined appropriate state is satisfied. The secondary electron beam can be detected by the detection optical system, and the adjustment of the plurality of secondary electron beams obtained by irradiating the plurality of primary electron beams can be performed efficiently.
Thus, when a plurality of secondary electron beams are detected by the detector, a shift between each detector and the center position of each secondary electron beam, a focus shift, and the like are reduced, so that the two straddles a plurality of detection elements. It is possible to prevent the deterioration of accuracy due to detection of the secondary electron beam and the like and to detect with high accuracy.

4 to 9 are diagrams illustrating the relationship between the incident range of the secondary electron beam to the detection element and the field of view of the detection element. These figures show the relationship between the visual fields 72a to 72d of the detection elements (a to d) and the incident ranges 71a to 71d, 712a to 712d, and 713a to 713d where the secondary electron beam is incident on the detection elements. . Here, FIG. 4 shows an example in which the position and focus of the secondary electron beam are appropriate, and FIGS. 5 to 9 show an inappropriate state.
In the following description, an example is described in which four circular secondary electron beams are incident on the fields of view 72 a to 72 b of the detection element having four square fields of view. In addition, the four detection elements 72a to 72b are arranged two each on the top, bottom, left, and right, and two secondary electron beams are also arranged on each of the top, bottom, left, and right. 4 to 9 show the case where there are four secondary electron beams and detection elements, the present embodiment is not limited to four.

  In FIG. 4, the centers of the visual fields 72a to 72d of the respective detection elements coincide with the central axes of the incident secondary electron beams 71a to 71d, and the incident range of the secondary electron beams to the detection elements is detected. It shows a case where the secondary electron beam is within the field of view 72a to 72d of the element, that is, the secondary electron beam is in focus. In this case, all the charged particles of each secondary electron beam can be detected by each detection element without leakage, and highly accurate detection is possible. Furthermore, the secondary electron beams 71a to 71d and the detection elements a to d have a one-to-one correspondence with each other without any secondary electron beam being mixed into adjacent elements, and the separation accuracy between the detection elements. Can be said to be in a high state.

FIG. 5 shows an inappropriate state in the case where the central axes of the four secondary electron beams 71a to 71 and the centers of the visual fields 72a to 72d of the four detection elements do not match. At this time, a part of the charged particles of the secondary electron beam is not in the field of view 72a to 72d of the detection element, and not only a part of the charged particles cannot be detected, but also one secondary electron beam includes a plurality of detection elements. , The degree of separation between the detection elements is poor, and the detection accuracy deteriorates.
For example, the secondary electron beam 71a extends in and out of the field of view 72a of the detection element, and the secondary electron beam 71c is detected across all the fields of view 72a to 72d of the detection element. Therefore, as shown in FIG. 5, when the center positions of the secondary electron beams 71a to 71d and the centers of the regions of the detection elements a to d do not coincide with each other, the secondary electrons are detected in order to detect the secondary electron beam with high accuracy. It is necessary to adjust the beam.

FIG. 6 shows an inappropriate state in which the center axis positions of the four secondary electron beams 71a to 71d are rotated with respect to the centers of the four detection elements 72a to 72d. In this case, all the secondary electron beams 71a to 71d are within the visual fields 72a to 72d of the four detection elements, but are mixed into the adjacent detection elements.
For example, if the secondary electron beam 71a is in an appropriate state, it is necessary to be entirely within the visual field 72a of the detection element a, but a part of the secondary electron beam is incident on the visual field 72b of the detection element b. Even when the adjacent detection element is mixed as described above, it is necessary to adjust the secondary electron beam.

FIG. 7 shows a case where the center axis intervals of the four secondary electron beams 71a to 71d do not coincide with the center intervals of the four detection element visual fields 72a to 72d, which is an inappropriate state.
The secondary electron beams 712a to 712d are examples in which the center axis interval of the secondary electron beam is wider than the center interval of the detection element visual fields 72a to 72d. In this case, the secondary electron beam is not mixed into the adjacent detection element as shown in FIG. 6, but there is also a secondary electron beam outside the field of view 72a to 72d of the detection element. -D cannot be detected, the detection element output is reduced, and the measurement accuracy is deteriorated. That is, in order to prevent the measurement accuracy from deteriorating, it is necessary to narrow the interval between the central axes of the secondary electron beams so as to be within the detection element visual field.
The secondary electron beams 713a to 713d are examples in which the secondary electron beam central axis interval is narrower than the central interval of the detection element visual fields 72a to 72d. In this case, similarly to FIG. 6, the secondary electron beam is mixed into the adjacent detection element, and the degree of separation of the secondary electron beam is lowered, so that the measurement accuracy is deteriorated. In other words, it is necessary to widen the center axis interval of the secondary electron beam so as not to be mixed into adjacent elements.

FIG. 8 shows a case where the center axis of one secondary electron beam 714b out of the four secondary electron beams 71a, 714b, 71c, 71d is shifted. The secondary electron beam 714b shows the case where the beam center axis position deviates from the detection element visual field 72b. In this case, the detection signal of the detection element b is lowered, and the detection accuracy is deteriorated.
Further, the secondary electron beam 715b shows a case where the beam center axis position deviates from the detection element visual field 72b, and a part of the secondary electron beam 715b is mixed into the visual field 72c of the detection element c. In this case, the detection accuracy is deteriorated due to the mixing of the secondary electron beam 715b into the detection element c.

  FIG. 9 shows a case where the secondary electron beams 71a to 71d are out of focus. In this figure, the center axis of each secondary electron beam coincides with the center of each detection element visual field 72a to 72d, but the secondary electron beam incident range is wider than the detection element visual field because it is not focused. Not all of the secondary electron beams can be detected by the corresponding detectors, and since they are mixed into adjacent elements, the detection accuracy deteriorates.

  Next, a method of calculating the positional deviation amount of the secondary electron beam central axis will be described with reference to FIGS. Here, an example in which one secondary electron beam is incident on four detection elements a to d will be described.

FIG. 10 is a diagram showing different incident positions of the secondary electron beam. The secondary electron beam 718 is an example in which the beam is incident on all the fields of view 72 a to 72 d of the four detection elements. Since the output value of each detection element changes in proportion to the amount of charged particles detected by each detection element, in this example, the detection element a, the detection element b, the detection element d, This is in the order of the detection element c.
Next, the secondary electron beam 717 is an example in which the beam center position is located at the upper left of the detection element a. The outputs of the detection elements b to d at this time are zero, and an output is generated only in the detection element a. However, since the secondary electron beam incident area protrudes outside the visual field 72a of the detection element a, the output value of the detection element a is such that the beam is within the visual field of the detection element a as in the secondary electron beam 716. It is smaller than (the sum of output values detected by the detection elements a to d in the case of the secondary electron beam 718). That is, the center axis position of the secondary electron beam can be estimated by comparing the detection output values of the detection elements.

  FIG. 11 is a diagram showing a mixed state in adjacent elements, and shows an example in which the secondary electron beam 71 is incident across the detection element visual field 72a and the detection element visual field 72b.

で計算できる。 FIG. 12 is an explanatory diagram for obtaining the mixed area of the secondary electron beam mixed into the adjacent element, where the radius of the secondary electron beam is r, and it is shifted by s in the x-axis direction with respect to the central axis of the secondary electron beam. It is assumed that there is a boundary between the detection element a and the detection element b at the position. At this time, the area 711b of the secondary electron beam incident on the detection element b is compared with the total beam area. The area 711b can be obtained by subtracting the area of a triangle having a base length 2t and a height s from a fan-shaped area having a radius r and an angle 2θ.
(Equation 1)

It can be calculated with

  FIG. 13 shows the ratio of the distance s from the center of the secondary electron beam to the boundary between the detection elements a and b with respect to the secondary electron beam radius r and the secondary electron beam incident on the detection element b with respect to the total beam area S71. It is a figure which shows the relationship with the ratio of beam area S711b. Here, the distance from the center of the secondary electron beam to the boundary between the detection elements a and b is the boundary position s, and the area of one secondary electron beam is the total beam area S71.

Here, assuming that the charged particle density distribution in the secondary electron beam is constant, the intensity of the secondary electron beam detected by the detection element is proportional to the area of the secondary electron beam incident on the detection element. The center axis position of the secondary electron beam is calculated by taking the ratio of the detection element output value (signal intensity) when detected by one element and the detection element output value (signal intensity) when there is a positional shift. It is possible.
For example, when the output ratio is 0.5, it means that s / r = 0, that is, the detection element boundary is at the center of the secondary electron beam, and when the output ratio is 0.2, s / r = 0. .5, that is, the detection element boundary is located at a position shifted by r / 2 from the center axis position of the secondary electron beam.

  As described above, it is possible to calculate the secondary electron beam position from the comparison of the intensity of the output signal (detection element output value) based on the secondary electron beam incident on each detection element.

  Note that the configuration example of the semiconductor inspection apparatus according to the present invention shown in FIG. 1 is a configuration diagram describing only indispensable components according to the present invention, and is not limited to the illustrated configuration. For example, the energy irradiation source 1 and the detector 25 may be disposed at any location in the apparatus, and the number of the energy irradiation sources 1 and the detectors 25 is not limited. Further, the arrangement of a plurality of primary electron beams and secondary electron beams and the arrangement of the detector 25 are not limited. FIG. 2 is also a diagram illustrating only necessary display elements according to the present invention, and is not limited to the illustrated ones. The display arrangement may be different, and further, the necessary inspection results are not illustrated. The element may be displayed.

2 shows the case where the number of detection elements is four, the number of detection elements is not limited to four, and the display may be changed according to the number of detection elements.
The secondary electron beam adjustment procedure shown in FIG. 3 is not limited to this. For the same purpose, the order of steps, addition of steps, etc. may be changed.
Also in the diagrams showing the secondary electron beam and the detection element field of view shown in FIGS. 4 to 12, the number of secondary electron beams and the number of detection elements are not limited, and the arrangement thereof is not limited. Also, the secondary electron beam central axis position calculation method shown in FIGS. 11 to 13 does not limit the number of secondary electron beams and the number of detection elements, and the arrangement thereof is not limited. The number of detection elements to which the secondary electron beam is incident is not limited to four elements, and the center axis position can be calculated in the same manner even in the case of more than four detection elements. The same applies to the embodiments described below.

  Next, as shown in FIG. 5, the secondary electron beam adjustment procedure when the center axis positions of the secondary electron beams 71a to 71d are shifted in parallel vertically and horizontally with respect to the center of the visual field 72a to 72d of the detection element will be described. To do.

  FIG. 14 is a diagram showing the field of view 72a to 72d of each detection element and the detection element incidence range of the secondary electron beam when there is a position shift parallel to the secondary electron beam. A part 711a of four secondary electron beams is incident on the upper left detection element a. Here, the four secondary electron beams are shifted in parallel to the upper left direction with respect to the centers of the visual fields 72a to 72d of the detection element. Therefore, the total area of incident secondary electron beams is equal to the area of one secondary electron beam. On the other hand, the right-side two secondary electron beams 711b are incident on the upper-right detection element b. Here, considering the case where the boundary between the left and right detection elements is shifted from the central axis of the secondary electron beam by a distance s in the left direction, the area 711b of the secondary electron beam incident on the detection element b is hatched in FIG. It is equal to the area of the secondary electron beam incident on the detection element b shown. Here, r is the radius of the secondary electron beam. Assuming that the beam area is proportional to the output value of the detection element, the ratio between the output value of the detection element a and the output value of the detection element b is taken, and from the boundary position and output ratio graph shown in FIG. A secondary electron beam shift amount can be calculated. Further, by taking the ratio of the output value of the detection element d and the output value of the detection element a by the secondary electron beam 711d incident on the detection element d, the amount of deviation in the vertical direction can be calculated in the same manner.

FIG. 15 is a flowchart summarizing the above-described deviation amount calculation procedure.
First, four secondary electron beams are detected by each detection element (step 822). Here, the semiconductor substrate 1 is irradiated with a primary electron beam by the irradiation optical system shown in FIG. 1, and the secondary electron beams emitted from the semiconductor substrate 1 are detected by a plurality of detection elements.
Of the detection elements that have detected the secondary electron beam in step 822, the detection element that maximizes the detection output of the secondary electron beam is searched for (step 823). This may be performed by the signal intensity comparison unit 33 of the arithmetic processing unit 32, or a maximum detection element search unit is provided between the A / D conversion unit 31 and the signal intensity comparison unit 33 so that the detection output is maximized. You may look for the detection element which becomes. At this time, the maximum detection element search unit is included in the arithmetic processing unit 32.

  Next, the output value of the detection element adjacent in the left-right direction of the detection element with the maximum detection output extracted in step 823 is compared with the output value of the detection element with the maximum output (step 824). As described above, by comparing the output values (signal intensity) of adjacent detection elements, the center axis position and focus of the secondary electron beam can be detected. In other words, the beam area S711b is calculated by the mathematical formula described in (Equation 1), and using the correspondence table shown in FIG. 13 created based on the calculation result, the output value (signal intensity) of the adjacent detection element compared is calculated as two. Next electron beam position is calculated. In this step, for example, the output value comparison processing of the detection element is performed by the signal intensity comparison unit 33, and the secondary electron beam position calculation processing is performed by the secondary electron beam position / focus calculation unit 34.

  Next, based on the comparison result in step 824, the amount of deviation of the secondary electron beam in the left-right direction is calculated (step 825). Specifically, the ideal secondary electron beam position (relative relationship between the center of the detection element and the central axis of the secondary electron beam) determined in advance and the actual secondary electron beam position calculated in step 824 are obtained. The difference is calculated and the amount of deviation of the secondary electron beam in the left-right direction is calculated. This step is performed by, for example, the secondary electron beam correction amount calculation unit 35. Here, the ideal secondary electron beam position may not be determined in advance, and for example, a position calculated at an arbitrary timing from the position of the detection element may be used. Thereby, the deviation | shift amount of the secondary electron beam of the left-right direction is computable.

  Next, the output value of the detection element adjacent in the vertical direction of the detection element having the maximum detection output extracted in step 823 is compared with the output value of the detection element having the maximum output (step 826). Similar to step 824, the beam area S711b is calculated by the mathematical expression described in (Equation 1), and the output values (signals) of the adjacent detection elements compared with each other using the correspondence table shown in FIG. 13 created based on the calculation result. The secondary electron beam position is calculated from the intensity. In this step, for example, the output value comparison processing of the detection element is performed by the signal intensity comparison unit 33, and the secondary electron beam position calculation processing is performed by the secondary electron beam position / focus calculation unit 34.

  Based on the comparison result in step 826, the amount of deviation of the secondary electron beam in the vertical direction is calculated (step 827). As in step 825, the ideal secondary electron beam position (relative relationship between the center of the detection element and the central axis of the secondary electron beam) determined in advance and the actual secondary electron beam position calculated in step 826 And the difference is calculated and the amount of vertical displacement of the secondary electron beam is calculated. This step is performed by, for example, the secondary electron beam correction amount calculation unit 35. Here, the ideal secondary electron beam position may not be determined in advance, and for example, a position calculated at an arbitrary timing from the position of the detection element may be used. Thereby, the amount of deviation of the secondary electron beam in the vertical direction can be calculated.

Here, after calculating the amount of displacement of the secondary electron beam in the left-right direction in step 824, the amount of displacement in the up-down direction is calculated in step 827. The amount of deviation may be calculated. Further, after the signal comparison processing in step 824 and step 826 is processed in parallel by the same signal intensity comparison unit 33 and in parallel by the same secondary electron beam position focus calculation unit 34, the shift between step 825 and step 827 is performed. The amount calculation process may be performed in parallel by the same secondary electron beam correction amount calculator 35.
Further, in order to calculate the amount of secondary electron beam deviation in each of the horizontal direction and the vertical direction of the detection element, a configuration may be provided in which a plurality of arithmetic processing units are provided. In that case, the maximum detection element search unit that searches for the detection element that maximizes the detection output of the secondary electron beam is shared, and the other signal intensity comparison unit, the secondary electron beam position / focus calculation unit, and the secondary electron beam It is good also as an arithmetic processing part provided with two correction amount calculation parts.

  Next, a method for changing the number of secondary electron beams incident on the detection element will be described.

  FIG. 16 is a schematic configuration example of a semiconductor inspection apparatus that changes the number of secondary electron beams incident on the detection elements 25a to 25c. The difference from FIG. 1 is that a secondary electron beam deflector 23 for moving an arbitrary secondary electron beam out of the field of view of the detection element is added. In the figure, the secondary electron beam deflector 23 is controlled by the secondary electron beam change control unit 42 so that only 201 of the secondary electron beams 201 and 202 is incident on the detection element 25b. The secondary electron beam 202 is moved out of the detection element. The secondary electron beam deflector 22 is mainly used for fine adjustment of the secondary electron beam.

FIG. 17 is a schematic configuration diagram of a modified example of the semiconductor inspection apparatus that changes the number of secondary electron beams incident on the detection elements 25a to 25c. The difference from FIG. 1 is that an aperture array 131 for the primary electron beam whose numerical aperture can be changed so that only an arbitrary primary electron beam 171 can be selected and transmitted among the plurality of primary electron beams 172 and 172 can be obtained. This is the point used.
As a result, the number of primary electron beams applied to the semiconductor substrate 1 can be changed, and the number of secondary electron beams generated from the semiconductor substrate can be changed. As a result, the number of secondary electron beams incident on the secondary electron beam detection elements 25a to 25c can be changed. In the figure, only the primary electron beam 171 can pass through the aperture array 131, the two primary electron beams 172 are blocked by the aperture array 131, and only the secondary electron beam 201 is incident on the detection element 25b.
<Example 2>
In the present embodiment, as shown in FIG. 6, the secondary electron beam adjustment procedure when the center axis position of the secondary electron beam is rotated with respect to the centers of the four detection elements a and b will be described.

In order to adjust the rotational deviation shown in FIG. 6, the central axis position of the secondary electron beam is calculated, and the rotational deviation amount is calculated based on the result, whereby the rotational deviation amount can be corrected.
Only one secondary electron beam 71a shown in FIG. 6 is incident on the detection element, and each of the detection elements a and b detects it. As described in Embodiment 1, the position of the central axis of the secondary electron beam can be calculated by comparing the output intensities of the detection elements. Therefore, by calculating the center axis positions of all the secondary electron beams 71a to 71d, it is possible to determine whether there is a rotational deviation with respect to the detection element. Angle) can be calculated.

  FIG. 18 is a flowchart showing a calculation procedure of the rotational deviation amount when the secondary electron beam causes rotational deviation.

First, in order to calculate the incident position of each secondary electron beam to the detection element, for example, the number of secondary electron beams is adjusted by the method described above, and only one secondary electron beam is incident on the detection element (step 832).
Next, the secondary electron beam incident in step 832 is detected by each detection element (step 833).
A detection element that maximizes the signal output of the secondary electron beam detected by each detection element in step 833 is searched (step 834).
The output value of the detection element adjacent in the left-right direction of the detection element with the maximum signal output found in step 834 is compared with the detection element output value with the maximum signal output (step 835).
The position of the secondary electron beam in the left-right direction is calculated (step 836). Here, instead of the position of the secondary electron beam in the horizontal direction, the horizontal displacement (relative positional relationship) between the ideal secondary electron beam position and the actual secondary electron beam position is calculated. Also good.
Next, the output value of the detection element adjacent in the vertical direction of the detection element with the maximum signal output is compared with the detection element output value with the maximum signal output (step 837).
The position of the secondary electron beam in the vertical direction is calculated (step 838). Here, instead of the vertical secondary electron beam position, the vertical displacement (relative positional relationship) between the ideal secondary electron beam position and the actual secondary electron beam position is calculated. Also good.

  Here, the steps 834 to 838 have almost the same contents as the steps 823 to 827 in FIG.

Steps 832 to 838 are performed for all the secondary electron beams, and it is determined whether or not the position calculation has been completed for all the secondary electron beams (step 839).
If completed (calculation of secondary electron beam positions for all secondary electron beams), the secondary electron beam is calculated from the secondary electron beam positions calculated in step 836 and step 838. Is calculated (step 840).
Through these steps, calculation of the rotational deviation amount is completed (step 841).
If it is determined in Step 839 that the electron beam is not completed, the secondary electron beam incident on the detection element is changed (Step 832), and Steps 832 to 839 are performed until calculation of the incident positions of all the secondary electron beams is completed. repeat. With the above procedure, the amount of rotational deviation when the secondary electron beam rotates can be calculated.

In the above description, the case where the secondary electron beam is incident on the detection element one by one has been described. However, the secondary electron beam position may be calculated while a plurality of secondary electron beams are simultaneously incident on the detection element. Absent.
In addition, the method of calculating the vertical position shift after calculating the horizontal position shift of the secondary electron beam has been described. However, the vertical position shift is calculated first, and then the horizontal position shift is calculated. May be. Further, the horizontal position shift in step 836 and the vertical position shift calculation in step 838 may be processed in parallel.

Similarly to FIG. 15, the processing for comparing the signal output intensities of the adjacent detection elements in steps 835 and 837 is performed by the signal intensity comparison unit 33 in FIG. 1, and the position of the secondary electron beam in steps 836 and 838 is determined. The calculation process may be performed by the secondary electron beam position / focus calculation unit 34 or the secondary electron beam position / focus calculation unit 35 of FIG.
<Example 3>
In this embodiment, as shown in FIG. 7, the secondary electron beam adjustment procedure when the distance between the central axes of the secondary electron beams is deviated from the visual field center distance of the detection element will be described. Adjustment is possible by irradiating the detection elements one by one with the secondary electron beam and comparing the output values of the detection elements.

First, a description will be given of a beam adjustment method in the case where the secondary electron beam center axis interval is wider than the visual field center interval of the detection element as in the secondary electron beams 712a to 712d shown in FIG. In this case, with respect to all of the four secondary electron beams, a part of the secondary electron beam falls outside the field of view of the detection element, so that the detection element output decreases. In order to calculate the amount of deviation to the outside of the detection element, the detection element corresponding to the beam in FIG. 12 is set as the detection element b, and the secondary electron beam region incident on the element is set as a region 711b (shaded portion).
Further, an area outside the detection element is considered as a field of view of the detection element a in FIG. 12, and a secondary electron beam area outside the detection element is considered as an area 711a. At this time, the area of the secondary electron beam region 711b incident on the detection element corresponding to the beam can be calculated by (Equation 1), which is proportional to the detection element output value assuming that the secondary electron beam density is constant. From this, by taking the ratio of the maximum value of the detection element output when all the secondary electron beams are detected by the detection element and the detection element output value when the secondary electron beam is shifted outside the detection element, 13 can be used to calculate the amount of deviation of the secondary electron beam out of the detection element.

Next, a description will be given of a method of adjusting the beam when the secondary electron beam center axis interval is narrower than the visual field center interval of the detection element as in the secondary electron beams 713a to 713d shown in FIG. In this case, for all the four secondary electron beams, a part of the beam is mixed in the adjacent detection element, so that an output is generated in the adjacent detection element. In order to calculate the shift amount of the secondary electron beam to the adjacent detection element, in FIG. 12, the detection element corresponding to the beam is defined as a detection element a, and the secondary electron beam region incident on the element is defined as a region 711a.
Further, an adjacent element is considered as a detection element b in the figure, and a secondary electron beam mixed region is considered as a region 711b (shaded portion). At this time, the area of the secondary electron beam region 711b incident on the adjacent element can be calculated by (Equation 1), which is proportional to the output value of the detection element assuming that the secondary electron beam density is constant. Thus, by taking the ratio of the maximum value of the detection element output when all the secondary electron beams are detected by the detection element a and the output value of the adjacent detection element generated by mixing the secondary electron beam, FIG. 13 is obtained. By using this, it is possible to calculate the amount of deviation of the secondary electron beam toward the adjacent element.

  FIG. 19 is a flowchart showing a procedure for calculating the center interval deviation amount of the secondary electron beam.

First, a secondary electron beam is incident on the detection element one by one (step 852).
The output value detected by each detection element is stored (step 853). This may be stored, for example, in the arithmetic processing unit 32 in FIG. 1, or may be configured to include a storage unit that stores the outputs from the detection elements 25 a to 25 c in addition to the arithmetic processing unit 32.
It is determined whether the detection is completed for all the secondary electron beams (step 854). If incomplete (there are secondary electron beams for which detection has not been completed), steps 852 to 854 are repeated until completion (detection is completed for all secondary electron beams). If completed, go to Step 855.

Next, it is determined whether or not all the secondary electron beams are mixed into adjacent detection elements (step 855). The secondary electron beam region 711a incident on the detection element a and the secondary electron beam region 711b incident on the detection element b are calculated, and the detection element output when all the secondary electron beams are detected by the detection element a By comparing with the maximum value, it can be determined whether or not the adjacent detection element is mixed. This step is performed by, for example, the secondary electron beam position / focus calculation unit 34 in FIG.
When all the secondary electron beams are mixed in the adjacent element, the secondary electron beam center axis is shifted inward, so the secondary electron beam center is calculated from the ratio of the secondary electron beam mixed into the adjacent element. The amount of deviation to the inside of the shaft is calculated (step 856). Specifically, the output value of the adjacent detection element calculated based on the area of the secondary electron beam region 711b calculated in (Equation 1) and the detection element output when all the secondary electron beams are detected by the detection element a. By comparing the maximum value with the ratio, the amount of deviation of the secondary electron beam toward the adjacent element can be calculated. This step is performed by, for example, the secondary electron beam correction amount calculation unit 35 in FIG.

  On the other hand, if at least one or more secondary electron beams are not mixed in the adjacent detection element in step 855, the next determination is made in step 857. In step 857, it is determined whether or not the current output value is lower than the output value of the detection element corresponding to each secondary electron beam compared to the output value when all the secondary electron beams are incident on the detection element. When the detection element outputs of all the secondary electron beams are reduced, the secondary electron beam center axis is shifted to the outside. The amount of deviation is calculated (step 858). This step is performed by, for example, the secondary electron beam correction amount calculation unit 35 in FIG.

  If the output of at least one detection element has not decreased in step 857, it is determined in step 859 that there is no deviation in the center axis spacing of the secondary electron beam or there is a deviation other than the center axis spacing. By the above procedure, it is possible to calculate the amount of gap deviation between the central axes of the secondary electron beams.

In the above description, the case where the secondary electron beam is incident on the detection element one by one has been described. However, the secondary electron beam position may be calculated while a plurality of secondary electron beams are simultaneously incident on the detection element. Absent.
<Example 4>
In this embodiment, as shown in FIG. 8, the secondary electron beam adjustment procedure when the center axis position is shifted by only one secondary electron beam will be described. Adjustment is possible by irradiating the detection elements one by one with the secondary electron beam and comparing the output values of the detection elements.

In FIG. 8, a beam adjustment method when one secondary electron beam 714b is shifted out of the field of view of the detection element 72b will be described. In this case, since only the output of the corresponding detection element is reduced, the deviation amount of the secondary electron beam central axis can be calculated from the reduction amount. In order to calculate the deviation amount outside the detection element, in FIG. 12, the detection element corresponding to the beam is set as the detection element b, and the secondary electron beam region incident on the element is set as a region 711b (shaded portion).
Further, an area outside the detection element is considered as a field of view of the detection element a in FIG. 12, and a secondary electron beam area outside the detection element is considered as an area 711a. At this time, the area of the secondary electron beam region 711b incident on the detection element corresponding to the beam can be calculated by (Equation 1), which is proportional to the detection element output value assuming that the secondary electron beam density is constant. From this, by taking the ratio of the maximum value of the detection element output when all the secondary electron beams are detected by the detection element and the detection element output value when the secondary electron beam is shifted outside the detection element, 13 can be used to calculate the amount of deviation of the secondary electron beam out of the detection element.

Next, referring to FIG. 8, a beam adjustment method when one secondary electron beam 715b is mixed in the adjacent detection element 72c will be described. In this case, the output of the detection element 72b corresponding to the secondary electron beam 715b decreases, and an output value is generated in the adjacent detection element 72c mixed with the beam. The amount of deviation of the central axis of the secondary electron beam can be calculated from the amount of decrease or the amount of mixing of adjacent elements. In order to calculate the shift amount of the secondary electron beam to the adjacent detection element, in FIG. 12, a secondary electron beam region incident on the detection element corresponding to the beam is defined as a region 711a.
Further, a secondary electron beam mixed region of an adjacent element is considered as a region 711b (shaded portion). At this time, the area of the secondary electron beam region 711b incident on the detection element can be calculated by (Equation 1), which is proportional to the output value of the detection element, assuming that the secondary electron beam density is constant. Thus, by taking the ratio of the maximum value of the detection element output when all of the secondary electron beams are detected by the detection element a and the output value of the adjacent detection element generated by mixing the secondary electron beam, FIG. 13 is obtained. By using this, it is possible to calculate the amount of deviation of the secondary electron beam toward the adjacent element.

  FIG. 20 is a flowchart showing a procedure for calculating the amount of deviation of the center axis position of the secondary electron beam.

First, a secondary electron beam is incident on the detection element one by one (step 862).
The output value detected by each detection element is stored (step 863). This may be stored, for example, in the arithmetic processing unit 32 in FIG. 1, or may be configured to include a storage unit that stores the outputs from the detection elements 25 a to 25 c in addition to the arithmetic processing unit 32.
It is determined whether there is a secondary electron beam mixed in the adjacent detection element among the stored output values (step 864). Whether or not the secondary electron beam is mixed into the adjacent detection element may be determined in the same manner as in step 855 in FIG. This is performed, for example, by the secondary electron beam position / focus calculation unit 34 in FIG.

If there is contamination, the amount of deviation of the secondary electron beam toward the adjacent detection element is calculated (step 865), and the process proceeds to the next step 869. The amount of shift of the secondary electron beam in the direction of the adjacent detection element may be calculated in the same manner as steps 825 and 827 in FIG. This is performed, for example, by the secondary electron beam correction amount calculator 35 in FIG.
If it is determined in step 864 that there is no mixture in the adjacent detection element, the output of the detection element corresponding to the secondary electron beam is the output value when all the secondary electron beams are incident on the detection element. It is determined whether or not it is lower than (step 866).

If the element output has decreased, the amount of deviation to the outside of the secondary electron beam central axis is calculated from the rate of decrease in the detection element output (step 867). This is performed, for example, by the secondary electron beam correction amount calculator 35 in FIG.
Proceed to the next Step 869. On the other hand, if it is determined in step 866 that the detection element output has not decreased, it is determined that there is no deviation of the secondary electron beam (step 868), and the process proceeds to the next step 869.

  In step 869, it is determined whether or not the calculation of the shift amount has been completed for all the secondary electron beams, and if not completed, steps 862 to 869 are repeated until the calculation is completed. In the case of completion, the calculation of the secondary electron beam center axis deviation amount ends (step 870). By the above procedure, it is possible to calculate the deviation amount of the central axis of the secondary electron beam.

In the above description, the case where the secondary electron beam is incident on the detection element one by one has been described. However, the secondary electron beam position may be calculated while a plurality of secondary electron beams are simultaneously incident on the detection element. Absent.
<Example 5>
In this embodiment, as shown in FIG. 9, the secondary electron beam adjustment procedure when the focus of the secondary electron beam is shifted will be described.

  When there is a defocus, as shown in FIG. 9, the secondary electron beam is mixed in the adjacent detection element and protrudes outside the detection element. The defocus amount is calculated by determining these.

21 and 22 are explanatory diagrams showing the relationship between the defocus and the detection element. As shown in FIGS. 21 and 22, the radius of the secondary electron beam at the incident surface of the detection element is r, and the field length of the detection element is 2L in both length and width. Based on the relationship between L and r, a method of obtaining the defocus calculation from the area where the beam is mixed into the adjacent element will be described by dividing into two cases of L ≦ r ≦ 2 ^1/2 L and 2 ^1/2 L <r.

First, in the case of L ≦ r ≦ 2 ^1/2 L, the defocus is as shown in FIG. That is, regions where no secondary electron beam is incident remain at the four corners of each detection element. Here, using the upper left secondary electron beam a as a representative, the area of the beam mixed with the adjacent detection element b by the secondary electron beam a is obtained.

次に、２^１／２Ｌ＜ｒの場合には、焦点ずれは図２２に示すようになり、二次電子ビームは一つの検出素子視野をはみ出して入射される。ここで左上の二次電子ビームａを代表として、二次電子ビームａが隣接する検出素子ｂに混入するビームの面積を求める。 FIG. 23 is an explanatory diagram showing the relationship between the secondary electron beam a and the detection element field of view. If the area of the beam region 711b to be mixed into the field of view 72b of the detecting element b (the hatched portion) is denoted as _{S 711b, S 711b} is equal when the s = L In Equation 1, the following equation.
(Equation 2)

Next, in the case of 2 ^1/2 L <r, the defocus becomes as shown in FIG. 22, and the secondary electron beam enters one detection element field of view and enters. Here, using the upper left secondary electron beam a as a representative, the area of the beam mixed with the adjacent detection element b by the secondary electron beam a is obtained.

次に、図２５の横縞模様で示したビーム領域７５の面積Ｓ_７５を求める。この面積はビーム半円の面積から数３で求めたＳ_７4の面積を引き、さらにそれを半分にして求めることができ、
（数４）

となる。検出素子ｂに混入するビーム面積をＳ_７１１ｂは、数４で求めた面積Ｓ_７５から一辺長Ｌの正方形面積を引き、さらにそれを倍にすれば求めることができ、
（数５）

で計算することができる。 24 and 25 are explanatory diagrams showing the relationship between the secondary electron beam a and the detection element field of view. A region of the secondary electron beam a mixed in the visual field 72b of the detection element b is a hatched portion 711b in FIG. Here, this area is expressed as S _711b, and this area is obtained. In order to obtain the area, as shown in FIG. 25, the beam region of the secondary electron beam a is divided into two parts. First, an area S ₇₄ of the beam region 74 shown by the lattice pattern in FIG. 25 is obtained. This area S ₇₄ is equal to the case where s = L in Equation 1, and is given by the following equation.
(Equation 3)

Next, an area S ₇₅ of the beam region 75 indicated by the horizontal stripe pattern in FIG. 25 is obtained. This area can be obtained by subtracting the area of S ₇₄ obtained from Equation 3 from the area of the beam semicircle and then halving it.
(Equation 4)

It becomes. The beam area mixed in the detection element b S _{711 b} can be obtained by subtracting a square area of one side length L from the area S ₇₅ obtained by _Equation 4 and further doubling it.
(Equation 5)

Can be calculated with

図２６は、二次電子ビーム半径と隣接素子への混入率の関係を示す図である。二次電子ビーム半径ｒに対する検出素子の一辺の半分の長さＬの比と、検出素子ｂに入射されるビームの面積と全ビーム面積との比、あるいは、検出素子ｂの出力とビーム全領域が検出された時の最大出力の比である。
このグラフより、検出素子ｂで検出される出力からビーム半径を求めることができる。例えば、出力比０．１のときのビーム半径ｒは１．４５Ｌであることがグラフより読み取れる。以上より、隣接検出素子への混入の割合からビーム半径を求めることができ、これより焦点ずれ量を算出できる。 When the charged particle density in the secondary electron beam is constant, the detection element output is proportional to the area of the secondary electron beam incident on the detection element. When the detection element output obtained when the entire area of the secondary electron beam is detected by the detection element is 1, the output when a part of the beam is incident on the detection element is incident on the entire beam area and the detection element. It can be calculated by the ratio of the area. That is, as shown in FIG. 23 and FIG. 24, the output V _b of the detection element b when the secondary electron beam a is mixed into the detection element _b is the beam mixing area S _711b obtained by _Expression 2 or _{Expression 5.} And the ratio of the total beam area.
(Equation 6)

FIG. 26 is a diagram showing the relationship between the radius of the secondary electron beam and the mixing rate into adjacent elements. The ratio of the length L of the half of one side of the detection element to the secondary electron beam radius r and the ratio of the area of the beam incident on the detection element b to the total beam area, or the output of the detection element b and the entire beam area Is the ratio of the maximum output when is detected.
From this graph, the beam radius can be obtained from the output detected by the detection element b. For example, it can be seen from the graph that the beam radius r when the output ratio is 0.1 is 1.45L. From the above, the beam radius can be obtained from the mixing ratio into the adjacent detection element, and the defocus amount can be calculated from this.

  FIG. 27 is a flowchart showing a procedure for calculating the defocus amount of the secondary electron beam.

First, a secondary electron beam is incident on the detection elements one by one (step 872), and the output value detected by each detection element is stored (step 873). This may be stored, for example, in the arithmetic processing unit 32 in FIG. 1, or may be configured to include a storage unit that stores the outputs from the detection elements 25 a to 25 c in addition to the arithmetic processing unit 32.
Next, it is determined whether or not the detection is completed for all the secondary electron beams (step 874). If the detection is not completed, steps 872 to 874 are repeated until the detection is completed for all the secondary electron beams. . If completed, go to Step 875.

  In step 875, it is determined for all the secondary electron beams whether there is any mixture of secondary electron beams into the adjacent detection elements. If there is mixing, the process proceeds to step 876, and if there is no mixing, the process proceeds to step 877. Whether or not the secondary electron beam is mixed into the adjacent detection element may be determined in the same manner as in step 855 in FIG. This is performed, for example, by the secondary electron beam position / focus calculation unit 34 in FIG.

  In step 876, for each secondary electron beam, the total output of each detection element is calculated, and it is determined whether or not the total is one. Here, the output 1 is an output generated when all the secondary electron beams are detected by the detection element. When the total output is 1, the process proceeds to step 877. When the total is not 1, the process proceeds to step 878. This may be performed, for example, by the signal intensity comparison unit 33 or the secondary electron beam position / focus calculation unit 34 in FIG.

  Step 878 is a case where a defocus has occurred. The radius of the secondary electron beam and the amount of defocus are calculated from the mixing ratio of the secondary electron beam to the adjacent elements, and the process is terminated (step 879). . The radius of the secondary electron beam and the defocus amount may be calculated by the above-described method, and this step is performed by, for example, the secondary electron beam correction amount calculating unit 35 in FIG.

  On the other hand, step 877 is a case where there is no defocus, and the defocus calculation is terminated as it is (step 879). The defocus amount of the secondary electron beam can be calculated by the above procedure.

In the above description, the case where the secondary electron beam is incident on the detection element one by one has been described. However, the secondary electron beam position may be calculated while a plurality of secondary electron beams are simultaneously incident on the detection element. Absent.
<Example 6>
The present embodiment provides a method for calculating the center axis position of the secondary electron beam. The center axis position calculation method described with reference to FIGS. 10 to 13 in the first embodiment calculates the current center axis deviation amount from the amount of secondary electron beam mixed into the adjacent element, and detects the center of the detection element from the deviation amount. This is a method of moving the position of the central axis of the secondary electron beam so as to match.

  FIG. 28 is a modification of the method for calculating the center axis position of the secondary electron beam. As shown in FIG. 28, the secondary electron beam central axis position is moved to a position where the outputs of all the detection elements are equal (center positions of the four detection elements), and the central axis position is calculated from the movement amount. Yes, highly accurate position calculation is possible.

  FIG. 29 is a flowchart showing a central axis position calculation procedure.

First, a secondary electron beam is incident on the detection element one by one (step 882).
The output value detected by each detection element is stored (step 883). This may be stored, for example, in the arithmetic processing unit 32 in FIG. 1, or may be configured to include a storage unit that stores the outputs from the detection elements 25 a to 25 c in addition to the arithmetic processing unit 32.
Next, it is determined whether or not the signal output intensities of the detection elements are all equal (step 884). The comparison of the signal output intensity is performed by, for example, the signal intensity comparison unit 33 in FIG.

  If it is determined in step 884 that they are not equal, it is determined whether or not a secondary electron beam has been detected by two or more detection elements (step 885). This is performed, for example, by the signal intensity comparison unit 33 in FIG.

  When two or more elements are detected, as indicated by a beam 718 in FIG. 10, the secondary electron beam is incident on a plurality of detection elements. A movement amount for moving the next electron beam to the center of the four elements is calculated (step 886). This amount of movement can be calculated by using a correspondence table as shown in FIG. 13 based on the detection results of a plurality of detection elements that have detected the secondary electron beam. This is performed, for example, by the secondary electron beam correction amount calculation unit 35 of FIG.

  If it is determined in step 885 that two or more elements are not detected, the current secondary electron beam is positioned at a position where the beam protrudes from one detection element as indicated by a beam 717 in FIG. I understand that there is. At this time, in order to bring the secondary electron beam closer to the center of the four elements, ½ of the length of one side of the detection element visual field is set as the movement amount (step 887). For example, the movement amount may be set by the secondary electron beam correction amount calculation unit 35 in FIG.

  The beam is moved based on the movement amount of the secondary electron beam set in step 886 or 887, and the output of each detection element is detected again in step 883. These operations from step 882 to 887 are repeated until it is determined in step 884 that the outputs of the respective detection elements are equal. If it is determined in step 884 that they are equal, as shown in FIG. 28, since the current secondary electron beam position is located at the center of the four elements, the target position after beam position correction is determined from this position. Is calculated (step 888). For example, the movement amount may be calculated by the secondary electron beam correction amount calculation unit 35 of FIG.

  In step 889, it is determined whether or not the movement amount has been calculated for all the secondary electron beams. If it is not completed, the operations in steps 882 to 889 are repeated. If completed, the calculation ends (step 890). The positional deviation of the secondary electron beam is corrected by the above procedure.

In the above description, the case where the secondary electron beam is incident on the detection element one by one has been described. However, the secondary electron beam position may be calculated while simultaneously causing a plurality of secondary electron beams to be incident on the detection element. .
<Example 7>
The present embodiment provides a secondary electron beam adjusting method in the case where the secondary electron beam deviations shown in FIGS. First, alignment is performed for each secondary electron beam, and then focusing is performed. This is performed for all secondary electron beams.

  FIG. 30 is a flowchart showing a secondary electron beam adjustment procedure. Steps 902 to 908 in the figure are procedures for beam alignment, and steps 909 to 912 are procedures for beam focusing.

First, a secondary electron beam is incident on the detection elements one by one (step 902), and the output value detected by each detection element is stored (step 903). Next, it is determined whether or not the outputs of the detection elements are all equal (step 904). If it is determined that they are not equal, it is determined whether or not secondary electron beams are detected by two or more detection elements (step 905). ). When two or more elements are detected, the secondary electron beams are incident on a plurality of detectors as indicated by the secondary electron beam 718 in FIG. The movement amount for moving the secondary electron beam to the center of the four elements is calculated from the output ratio (step 906).
If it is determined in step 905 that two or more elements are not detected, the beam is in a position protruding from one detection element as indicated by a beam 717 in FIG. At this time, in order to bring the secondary electron beam closer to the center of the four elements, a half of the length of one side of the detection element visual field is set as the movement amount (step 907). The beam is moved based on the movement amount of the secondary electron beam set in step 906 or 907, and the output of each detection element is detected again in step 903. These operations in steps 902 to 907 are repeated until it is determined in step 904 that the outputs of the detection elements are equal.
If it is determined in step 904 that they are equal, the current secondary electron beam position is located at the center of the four elements as shown in FIG. The amount of movement is calculated and the beam is moved (step 908). At this time, the secondary electron beam is at a position indicated by a beam 716 in FIG. 10 (in the case of the beam a).

Next, the output value detected by each detection element is stored again (step 909). Thereafter, it is determined whether or not the secondary electron beam is mixed into the adjacent detection element (step 910). If there is mixing, the radius of the secondary electron beam is determined from the ratio of the secondary electron beam mixed into the adjacent element. The beam radius is calculated and adjusted so as to be within the detection element (step 911). Thereafter, the output of each detection element is detected again and stored (step 909). These steps 909 to 911 are repeated until it is determined in step 910 that there is no mixing in adjacent elements.
If it is determined that there is no contamination, it is determined that the image is in focus (step 912), and the process proceeds to the next step 913.

  In step 913, it is determined whether or not the adjustment has been completed for all the secondary electron beams. If the adjustment has not been completed, the operations in steps 902 to 913 are repeated until the adjustment is completed. If completed, the adjustment is completed (step 914). By the above procedure, secondary electron beam adjustment can be performed when various general secondary electron beam deviations coexist.

  In the above description, the case where the secondary electron beam is incident on the detection element one by one has been described. However, the secondary electron beam position may be calculated while a plurality of secondary electron beams are simultaneously incident on the detection element. Absent.

Also, here, an example of performing beam adjustment by combining an example of beam alignment and beam focusing has been shown. For example, FIG. 6 is an adjustment flow when the central axis position of the secondary electron beam in FIG. 6 rotates. 18. When the distance between the center axes of the secondary electron beams in FIG. 7 is shifted from the center distance of the visual field of the detection element. When the position of the center axis is shifted in only one secondary electron beam in FIGS. 20 and FIG. 21, which is the secondary electron beam adjustment flow of FIG. 21, and the secondary electron beam adjustment in which the secondary electron beam adjustment flows of FIG. May be performed. In this case, the adjustment flow may be combined according to user instruction, or the type of secondary electron beam deviation having a higher fatality is selected, and the adjustment flow according to the type of secondary electron beam deviation is selected. Adjustments may be made based on this.
<Example 8>
The present embodiment provides a method for suppressing a decrease in detection sensitivity due to contamination (foreign matter, defects, etc.) adhering to the detection element surface.

  FIG. 31 is a diagram showing a relationship between a secondary electron beam, a detection element, and contamination. As shown in FIG. 31, the secondary electron beam 71 is moved to a position avoiding the contamination 73 adhering to the detection element surface 72 to suppress a decrease in detection sensitivity. Hereinafter, a method for avoiding contamination will be described. In order to avoid contamination, the secondary electron beam is moved, and the beam irradiation position where the output of the detection element is maximized is determined. At this time, it is desirable that the secondary electron beam to be moved is moved within a range in which the adjacent detection element is not mixed. However, if contamination is near the center of the element and mixing into the adjacent element is unavoidable, mixing is not possible. In consideration of the amount, the beam may be moved to a position where it is mixed into an adjacent element in order to maximize the detector output.

Further, if the position of contamination is known in advance, it is possible to adjust the beam to a position avoiding contamination in the secondary electron beam adjustment of the present invention.
<Example 9>
In this embodiment, another configuration example from the detection element to the A / D conversion unit and a secondary electron beam adjusting method in the configuration will be described.

  FIG. 32 is a modification of the detection system of the semiconductor inspection apparatus. The switches 36A to 36D are connected to the outputs of the detection elements 25A to 25D, and after these are connected to the adder 37, the signal is input to the A / D converter 31. In this configuration, one or a plurality of secondary electron beams are incident on the detection elements 25A to 25D to obtain an output value of a detection signal.

Here, the detection accuracy is considered in relation to the noise-to-noise ratio (S / N ratio). When a sufficient amount of beams are incident on all the detection elements, the output generated by all the detection elements is large and the SN ratio is good. However, in the output of the detection element with a small amount of beam incidence, the noise component of the detection element or the like is more dominant than the signal component of the beam, and the SN ratio is deteriorated.
In such a case, since the outputs of all the detection elements including the detection element output having a poor SN ratio are added, it is expected that the SN ratio of the added signal is deteriorated. As a result, the detection accuracy deteriorates, which causes a problem. In order to solve this problem, by switching the switch connected to the output of the detection element and selecting the output of the detection element to be added, accuracy degradation can be suppressed, and highly accurate detection is possible.
For example, consider a case where the beam is incident only on the upper left detection element as indicated by the secondary electron beam 716 in FIG. If the detection element corresponding to the upper left of FIG. 10 is the detection element 25a of FIG. 32, the outputs of the other detection elements 25b to 25d are only noise components, and these noises are added, so that the measurement accuracy is high. Getting worse.
Therefore, in order to remove these noises, the switches 36 to 36 are opened so that the noise of the detection elements Ro to D is not added to the output of the adder.

  A procedure for adjusting the secondary electron beam in such a configuration will be described. By switching the switches 36a to 36d, it is possible to obtain the output of any detection element. That is, it is possible to obtain a detection element output by a secondary electron beam for each detection element. Using this feature, the incident position of the secondary electron beam can be calculated by comparing the output values of the respective detection elements measured while switching the switches. Similarly, focusing is possible.

Note that in the semiconductor inspection apparatus using the detection system shown in FIG. 32, a single detection system may be configured for one secondary electron beam, or a plurality of detection systems may be provided. good. Further, the number of secondary electron beams is not limited to one.
FIG. 33 is a diagram showing the positional relationship between the detection element field of view and the secondary electron beam, and FIG. 34 is an explanatory diagram of an example of four detection systems. For example, when four secondary electron beams are configured by four sets of detection systems, four detection elements are configured as one set of detection systems as shown in FIG. 33, and four sets of measurement systems are configured as shown in FIG. .
The incident range 71a of the secondary electron beam a on the detection element surface is detected by the visual fields 72a to 72d of the four detection elements 25a to 25d. The detected signals pass through the switches 36a to 36d, are added by the adder 37a, and are input to the A / D converter 31a. Similarly, the beams 71b to 71d are also detected by the detection elements 25b to 25d, added by the adders 37b to 37d after passing through the switches 36b to 36d, and detected by the A / D converters 31b to 31d.

  Thus, by having a configuration including four sets of detection systems, it is possible to improve the S / N ratio of the detection signal. In the various semiconductor inspection apparatuses described above, the detector output can be improved by making the center axis of the secondary electron beam coincide with the center of the detection field of the detection element, or by making the focal point coincide with the surface of the detection element. In addition, mixing of beams into adjacent detection elements can be suppressed, and the degree of separation between the detection elements can be improved. Further, by moving the secondary electron beam to a position avoiding contamination adhered to the detection element surface, it is possible to suppress a decrease in detection sensitivity due to contamination. Accordingly, the secondary electron beam can be efficiently received by the detector, and the detection accuracy can be improved by improving the contrast of the inspection image.

DESCRIPTION OF SYMBOLS 1 Semiconductor substrate, 11 Primary electron beam irradiation source, 12 Primary electron beam condenser lens, 13 Primary electron beam aperture array, 14 Primary electron beam lens, 15 Primary electron beam deflector, 16 Objective lens, 17 Primary electron beam , 20 Secondary electron beam, 21 Secondary electron beam deflector (ExB deflector), 22, 23 Secondary electron beam deflector, 24 Secondary electron beam lens, 25 Secondary electron beam detector (detection element) ), 31 A / D conversion unit, 32 arithmetic processing unit, 33 signal intensity comparison unit, 34 secondary electron beam position / focus calculation unit, 35 secondary electron beam correction amount calculation unit, 41 secondary electron beam lens control unit 42 secondary electron beam deflection control unit 51 overall control unit 52 input unit 53 display unit 61 secondary electron beam adjustment screen 62 Sei start button, 63 detecting element output image view, the table 64 detecting element output values, 65 configuration parameter values list, 71 the incident range of the secondary electron detection elements, the field of view of 72 sensing elements

Claims (16)

An irradiation optical system for irradiating the object to be inspected with a plurality of irradiation lights;
A detection optical system for detecting a plurality of lights emitted by the irradiation optical system and emitted from the inspection object;
A comparison unit that compares signal intensities based on a plurality of lights detected by the detection optical system, and a beam position / focal point that calculates at least one of the position and the focus of the plurality of lights based on the comparison result of the comparison unit The calculation unit compares at least one of the plurality of light positions or focal points calculated by the beam position / focus calculation unit with a detection position of the detection optical system that is a predetermined detection position, and shifts. An arithmetic processing unit comprising: a correction amount calculating unit that calculates an amount; and a processing unit that processes the signals based on the plurality of lights and inspects the inspection target object;
A control unit that adjusts the detection optical system based on the deviation amount calculated by the correction amount calculation unit;
Inspection device having The inspection device according to claim 1,
The inspection apparatus controls the beam deflection for shaping a plurality of lights emitted from the object to be inspected and a beam lens for adjusting the focal points of the plurality of lights. The inspection apparatus according to claim 1 or 2,
The inspection optical system detects the plurality of lights by a plurality of detectors. The inspection device according to claim 3,
Further, either an output image of detection signals detected by the plurality of detectors, a setting parameter that determines irradiation conditions of the irradiation optical system, or an output value of detection signals detected by the plurality of detectors. An inspection apparatus comprising a display unit for displaying the above. The inspection apparatus according to any one of claims 1 to 4,
The inspection apparatus further includes an overall control unit that receives an output result from the arithmetic processing unit and transmits a control signal to the control unit of the detection optical system. The inspection device according to claim 3,
The comparison unit of the arithmetic processing unit compares the output intensity of the signal based on the light detected by each of the plurality of detectors,
In the correction amount calculation unit of the arithmetic processing unit, from the output intensity of the signal detected by an arbitrary detector selected from the plurality of detectors based on the comparison result in the comparison unit, the position of the plurality of detectors An inspection apparatus that calculates a positional deviation amount of the plurality of lights. The inspection apparatus according to claim 6,
2. The inspection apparatus according to claim 1, wherein the correction amount calculation unit calculates a horizontal shift amount and a vertical shift amount of the plurality of lights. The inspection apparatus according to claim 6,
The inspection apparatus according to claim 1, wherein the correction amount calculation unit calculates rotational deviation amounts of the plurality of lights with respect to the positions of the plurality of detectors. An irradiation step of irradiating the object to be inspected with a plurality of irradiation lights;
A detection step of detecting a plurality of lights emitted in the irradiation step and emitted from the inspection object;
Based on the comparison result of the signal intensities based on the plurality of lights detected in the detection step and the comparison result of the signal intensities in the comparison step, at least one of the positions or the focal points of the plurality of lights is calculated. In the beam position / focus calculation step and the correction amount calculation step, at least one of the plurality of light positions or focal points calculated in the beam position / focus calculation step is compared with a predetermined ideal detection position. An arithmetic processing step including a correction amount calculating step for calculating a deviation amount, and a processing step for processing the signals based on the plurality of lights to inspect the inspection target object,
A control step of adjusting the irradiation conditions in the irradiation step based on the deviation amount calculated in the correction amount calculation step;
Inspection method having The inspection method according to claim 9,
In the control step, a beam deflection for shaping a plurality of lights emitted from the object to be inspected and a beam lens for adjusting the focus of the plurality of lights are controlled. The inspection method according to claim 9 or 10, wherein
In the detection step, the plurality of lights are detected by a plurality of detectors. The inspection method according to claim 11,
Display either the output image of the detection signals detected by the plurality of detectors, the setting parameter that determines the irradiation conditions in the irradiation step, or the output value of the detection signals detected by the plurality of detectors An inspection method characterized by comprising a display step. An inspection method according to any one of claims 9 to 12,
Receiving an amount of deviation calculated in the correction amount calculating step, and transmitting to the control unit, the overall control step,
In the control step, the amount of deviation transmitted in the overall control step is received and the irradiation condition is adjusted. The inspection method according to claim 11,
In the comparison step, the output intensity of the signal based on the light detected by each of the plurality of detectors is compared,
In the correction amount calculating step, the plurality of lights with respect to the positions of the plurality of detectors based on an output intensity of a signal detected by an arbitrary detector selected from the plurality of detectors based on a comparison result in the comparison step. An inspection method characterized by calculating the amount of positional deviation. The inspection method according to claim 14,
In the correction amount calculating step, the amount of shift in the left-right direction and the amount of shift in the up-down direction of the plurality of lights are calculated. The inspection method according to claim 14,
In the correction amount calculating step, an amount of rotational deviation of the plurality of lights with respect to the positions of the plurality of detectors is calculated.

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