JPH09115975A - Foreign substance inspecting equipment and manufacture of device using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain foreign substance inspecting equipment capable of detecting the presence/absence of foreign substances on an inspection plane, such as a reticle plane and a pellicle plane with accuracy, and a method for the manufacture of devices using the equipment. SOLUTION: Two beams of light flux, different in frequency and the state of polarization of light from each other, from a light source means 1 are passed through a scanning lens 14 by means of a scanning means 13, and are, after the passage through the scanning lens, divided into two beams of light flux by means of a light dividing member 61. Scattered light produced at an inspection plane 2 when the inspection plane is scanned using one of the two beams of light flux, and the other beam are, after the other beam is passed through a scattering structure 62, multiplexed using a multiplexer 63 to cause optical heterodyne interference. A signal based on the heterodyne interference is detected using a detecting means 29, and a signal from the detecting means is used to obtain information on the presence/absence of foreign substances on the inspection plane. At this time, information on the position of the inspection plane is detected, and at least one of a plurality of elements placed in the optical path extending from the scanning lens to the detecting means is displaced according to the positional information.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foreign substance inspection apparatus and a device manufacturing method using the same, and for example, on a master plate such as a reticle or a photomask on which a circuit pattern used in a semiconductor device manufacturing apparatus is formed, or / Also, when foreign matter such as impermeable dust adheres to the pellicle protective film surface when the pellicle protective film is attached to the original plate, it is suitable for accurately detecting the presence or absence of the foreign matter and its position. It is something.

[0002]

2. Description of the Related Art Generally, in an IC manufacturing process, an exposure circuit pattern formed on an original plate such as a reticle or a photomask is transferred onto a resist-coated wafer surface by a semiconductor printing apparatus (stepper or mask aligner). Is being manufactured.

At this time, if a foreign matter such as a pattern defect or dust is present on the surface of the original plate, the foreign matter is also transferred at the same time when the circuit pattern is transferred, which causes a reduction in the yield of IC manufacturing.

In particular, when a reticle is used and a circuit pattern is repeatedly printed on the wafer surface by the step-and-repeat method, if one harmful foreign substance is present on the reticle surface, the foreign substance is printed on the entire surface of the wafer. This causes the yield of the IC process to be greatly reduced.

Therefore, it is indispensable to detect the presence of foreign matter on the substrate in the IC manufacturing process, and various inspection methods have been conventionally proposed.

Generally, a method is widely used which utilizes the property that foreign matter isotropically scatters light.

For example, the applicant of the present invention has disclosed Japanese Patent Laid-Open Nos. 6-18431, 7-43313, and 7-43.
In Japanese Patent No. 92093, there is proposed a foreign matter inspection apparatus which is obtained by detecting the presence or absence of foreign matter such as dust adhering to the surface of a reticle or pellicle by using heterodyne interference to detect scattered light generated when the foreign matter is irradiated with light. doing.

[0008]

Generally, the presence or absence of foreign matter such as dust and dirt on the inspection surface is detected with high accuracy by utilizing scattered light generated when the foreign matter is irradiated with a light beam. In order to achieve this, it is important to perform optical scanning with a good spot light on the inspection surface and efficiently detect scattered light generated from the inspection surface by the detection means, thereby obtaining a signal with a high S / N ratio. come.

For example, in the method of detecting the presence / absence of foreign matter on the inspection surface by utilizing optical heterodyne interference, the position of the inspection surface (particularly in the vertical direction) is displaced during measurement by the shaking of the stage holding the inspection surface. If so, it becomes difficult to obtain an accurate beat signal, and as a result, the detection accuracy of the foreign substance presence / absence information decreases. Particularly, in the foreign matter inspection using the heterodyne interference, the presence or absence of the foreign matter is detected from the magnitude of the beat signal, so that the displacement of the inspection surface is a major factor of lowering the detection accuracy.

According to the present invention, when the presence or absence of foreign matter on the inspection surface such as the reticle or pellicle surface is detected by the optical heterodyne method in the IC manufacturing process, the stage system holding the inspection surface sways and the inspection surface A foreign matter inspection apparatus capable of highly accurately detecting the presence / absence information of a foreign matter on an inspection surface by displacing at least one optical element among a plurality of optical elements provided in an optical path even if the position is displaced. An object of the present invention is to provide a device manufacturing method using.

[0011]

In the foreign matter inspection apparatus of the present invention, (1-1) two light fluxes having different frequencies and polarization states from a light source means are passed through a scanning lens through a scanning lens, and the scanning lens After passing through, the light is split into two light beams by the light splitting member, and when one light beam of the two light beams scans the inspection surface, the scattered light generated from the inspection surface and the other light beam of the two light beams. After passing through the scattering structure, the light is multiplexed by a multiplexer to cause optical heterodyne interference, a signal based on the heterodyne interference is detected by a detection unit, and a foreign matter on the inspection surface is used by using the signal from the detection unit. When determining the presence / absence information, the position information of the inspection surface is detected, and at least one of the plurality of elements provided in the optical path from the scanning lens to the detection means is displaced based on the position information. It is characterized by that.

In particular, (1-1-1) the scattering structure is a diffraction grating. (1-1-2) The light splitting member is a polarization beam splitter. (1-1-3) The at least one element is displaced so that the two light fluxes combined by the multiplexer are adjusted by the detection means. And so on.

The device manufacturing method of the present invention includes (2-1) a step of exposing the substrate after inspecting the relics on the substrate by using the foreign substance inspection apparatus described in the constituent feature (1-1) above. It is characterized by that.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic view of a main part of a first embodiment of the present invention, and FIG. 2 is a sectional view of a part of FIG. In the figure, reference numeral 1 denotes a Zeeman laser as a light source means, which is a two-frequency laser having a predetermined frequency difference in which polarization directions are orthogonal to each other.

In this embodiment, the P-polarized light LP having the frequency f1 and the S-polarized light LS having the frequency f2 are oscillated. A collimator optical system 4 collimates the laser light from the Zeeman laser 1. Reference numeral 13 is a polygon mirror as a scanning means, which is rotating at a constant speed around a rotary shaft 13a,
The laser light from the collimator optical system 4 is reflected and deflected. Reference numeral 14 denotes an f-θ lens system as a scanning lens,
The laser light reflected and deflected by the polygon mirror 13 is guided to a polarization beam splitter 61 as a light splitting member. The polarization beam splitter 61 splits the incident light into two polarized lights orthogonal to each other.

In the present embodiment, the P-polarized light LP having the frequency f1 is reflected as the reference light, and the diffraction grating 6 as the scattering structure is formed.
It is incident on the point AP above 2. The S-polarized light LS having the frequency f2 is transmitted as signal light and is made incident on a point AS on the reticle 22 as the surface to be inspected.

Here, the point AP on the diffraction grating 62 and the point AS on the reticle 22 are in a conjugate relationship with each other with respect to the polarization beam splitter 61. The diffraction grating 62 is P-polarized L
P is diffracted and scattered in a predetermined direction. An actuator 53 is attached to the diffraction grating 62.

Reference numeral 20 is a scanning spot formed on the surface of the reticle 22 by the S-polarized light LS. 24 is a foreign substance such as dust or dust on the surface of the reticle 22. Reference numeral 25 is a stage hand on which the reticle 22 is placed. A stage system 23 drives the stage hand 25 and the like in a predetermined direction. Reference numeral 63 denotes a half mirror as an optical multiplexer, which scatters light from the reticle 22 and diffracted light from the diffraction grating 62 (P
The polarized light LP) is multiplexed to form a beat signal. 2
Reference numeral 6 denotes a detection optical system, which collects a beat signal by two light fluxes of scattered light and diffracted light combined by the half mirror 63.

Reference numeral 27 denotes a polarizer, which allows the light flux of a predetermined polarization component from the detection optical system 26 to pass therethrough. Reference numeral 28 denotes an aperture that allows only a predetermined light flux to pass therethrough. 29
Is a photoelectric detector (detection means), which detects a beat signal. A signal processing system 30 uses the beat signal detected by the photoelectric detector 29 to detect the foreign matter 24 on the surface of the reticle 22.
I have gotten information about whether or not. A displacement sensor 51 detects the displacement of the reticle 22 in the Z direction. A signal processing system 52 obtains position information on the surface of the reticle 22 using a signal from the displacement sensor 51.

In the present embodiment, the scanning spot 20 on the surface 22 to be inspected (recticle) is rotated by the rotation of the polygon mirror 13.
Is scanning in the Y direction. The scanning stage system 23 moves the stage hand 25 in the X direction to move the surface 22 to be inspected.
The upper part is two-dimensionally scanned by the scanning spot 20.

In this embodiment, the displacement of the stage system 23 is detected by the displacement sensor 51, and the position of the optical component (optical element) necessary for causing the heterodyne interference is finely moved, or the stage 25 and the optical component are separated from each other. By incorporating in an integrated unit, the scattered light from a foreign substance or defect on the inspection surface and the diffracted light from the grating 62 are caused to coherently heterodyne to determine the presence or absence of the foreign substance or defect, its size, etc. Is characterized by.

Next, the features of this embodiment will be described.
In the present embodiment, first, the displacement sensor 51 detects the position information of the stage hand 25 in the Z direction as the movement of the stage system 23, and the signal processing system 52 processes the position signal.
Next, the signal processing system 52 sends the position signal to the actuator 53 attached to the grating 62. Then, for example, when the stage hand 25 moves upward in the Z direction as shown in FIG.
The actuator 53 is moved in the direction opposite to the direction in which the stage hand 25 has moved by the same distance as the stage hand 25 has moved (downward in the Z direction in this case).

As a result, in this embodiment, even if the stage hand 25 shakes, the half mirror 6 reflects the scattered light from the foreign matter or defect on the inspection surface 22 and the diffracted light from the grating 62.
At 3 the waves are combined accurately. Then, the combined light flux is detected by the photoelectric detector 29 via the detection optical system 26,
Thereby, the heterodyne interference signal is obtained as described later.

Next, a method of detecting the presence / absence information of foreign matter on the surface 22 to be inspected in this embodiment will be described. A light beam incident on the diffraction grating (grating) 62 is diffracted and scattered, where P: grating pitch θ: diffraction angle λ: wavelength m: diffraction order, Psin θ = ± mλ.

Therefore, the diffracted light (frequency f1) is diffracted in the angle θ direction. The diffracted light beam is reflected by the half mirror 63 and travels toward the photoelectric detector 29. On the other hand, the surface 22 to be inspected
The scattered light (frequency f2) from the foreign matter 24 or the circuit pattern above is scattered in the 2π space, but a part of the scattered light is scattered in the direction of the photoelectric detector 29 whose polarization plane is rotated by 90 degrees (depolarization).

Therefore, the detection optical system 2 in front of the photoelectric detector 29
6 the diffraction scattered light from the grating 62 and the surface 2 to be inspected
The scattered light from 2 is synthesized and condensed. And the polarizer 27
By passing through, the diffracted and scattered light (frequency f1) from the grating 62 and the depolarized light wave (frequency f2) from the surface 22 to be inspected cause a beat (frequency f2-f1), and the beat signal at this time is photoelectrically converted. It is detected by the detector 29.

Next, generation of scattered light and detection of beat signals will be described. The s-polarized laser Ls incident on the surface 22 to be inspected and the p-polarized laser Lp incident on the grating 62.
If the electric fields of are respectively E1 and E2, they can be expressed as follows.

Ls: E1 = Es · exp {j (f2t + θ1)} (1) Lp: E2 = Ep · exp {j (f1t + θ2)} (2) At this time, diffraction scattering from the grating 62 is performed. The light Rp and the p-polarized light Fp transmitted through the polarizer 27 out of the scattered light by the foreign matter 24 can be written as follows, where R1 and F1 are respectively.

Fp: F1 = αEp · exp {j (f2t + θ′1)} (3) where α: Scattering efficiency Rp: R1 = βEp · exp {j (f1t + θ′2)} (4) where β Diffraction efficiency At this time, the intensity I of the combined beat signal detected by the photoelectric detector 29 can be written as follows.

I = | F1 + R1 | ^ 2 = (α ^ 2 + β ^ 2) Ep ^ 2 + 2αEp · βEp · cos {(f2-f1) t + θ′2-θ′1} (6) Equation (6) Of these, the first term is the DC component and the second term is the AC component required here.

Next, the beat signal detected by the photoelectric detector 29 will be described. FIG. 3 is a schematic diagram showing the detected beat signal. FIG. 4 shows scanning spots 20 and 2.
It is explanatory drawing about the scattered light when a foreign substance exists in 0 '. In FIG. 3, the horizontal axis 301 represents the time, the vertical axis 302 represents the intensity of the detected signal, 306 is the detected beat signal, 303 is the DC component of the beat signal 306, and 304 is the AC of the beat signal 306. The component, 305, represents the time width in which the beat signal is detected.

As shown in FIG. 4, if there is no foreign matter defect in the scanning spot 20, no beat signal is detected.
When there is a foreign matter defect, a beat signal of frequency Δω as shown by 306 in FIG. 3 is generated during the time width Δt.

Time width Δt (305) in which the beat signal occurs
Is determined by the size of the scanning spot 20 and the speed at which the scanning spot 20 scans the surface 22 to be inspected, as shown in FIG. By performing signal processing on this beat signal by the signal processing system 30, the foreign matter defect on the surface 22 to be inspected is increased by S.
/ N ratio is detected.

Next, a method of distinguishing the scattered light from the foreign matter and the circuit pattern will be described. In foreign matter detection, the diameter of the scanning spot is usually several tens of μm, and the size of the foreign matter is 1/10 or less of that. Therefore, the time when the scattered light is generated is approximately the same as the time when the spot passes over the foreign matter.

On the other hand, the circuit pattern is usually composed of a repetitive pattern, and is usually larger than the scanning spot 20 as shown in FIG. 5, for example. For example, it is assumed that both the foreign matter 24 and the circuit pattern 71 exist on the spot scan as shown in FIG. At that time, the detection signal by the photoelectric detector 29 is as shown in FIG.

Here, the horizontal axis represents time and the vertical axis represents the detection voltage of the photoelectric detector 29. The scattered light from the foreign matter depolarizes as described above, and the light wave of frequency f1 due to p-polarization and the light wave of frequency f2 due to p-polarization resulting from depolarization of s-polarization interfere with each other to cause a beat.

On the other hand, since the scattered light from the circuit pattern does not cause depolarization, the beat hardly occurs. Therefore, the amplitude of the predetermined beat frequency in the signal of the scattered light output from the photoelectric detector has a higher amplitude ay for a foreign substance than the amplitude ap for a circuit pattern. Therefore, this difference is used to distinguish between the foreign matter and the circuit pattern.

FIG. 8 shows the case of a foreign signal for the processing of the beat signal, which is formed from the beat signal as described above into its envelope. This is processed in the same way in the case of the circuit pattern.

In the first step (A) of FIG. 8, the DC component is removed by the high pass filter. Next, in the second step (B), the voltage generated by the slice level generator removes a voltage equal to or lower than a predetermined voltage. Next, in the third stage (C), the low pass filter circuit shapes the envelope of the beat signal. This processing is performed by the signal processing system 30.

FIG. 9 shows a signal processing system 20 according to this embodiment.
It is a principal part block diagram of. In the figure, the presence / absence information of the foreign matter is obtained by distinguishing between the foreign matter on the surface to be inspected and the circuit pattern. That is, as described with reference to FIG. 8, it has a function of converting a beat signal into its envelope, and a block for determining the presence or absence of a foreign matter defect by distinguishing it from a circuit pattern from the envelope.

In this embodiment, the beat signal is shaped into its envelope, and after holding the maximum signal level in the peak hold circuit, it is compared with a predetermined signal level from the foreign substance / circuit threshold value generator in the comparison circuit. The circuit pattern and the foreign matter are distinguished from each other to determine the foreign matter. Then, the scanning spot 2 is perpendicular to the scanning direction of the scanning spot 20.
The entire surface of the surface 22 to be inspected is inspected by the scanning stage system 23 that moves 0 and the surface 22 to be inspected relative to each other.

FIG. 10 is a schematic view of the essential portions of Embodiment 2 of the present invention. In this embodiment, a memory 54 is newly provided as compared with the first embodiment of FIG. 1, position information of the stage hand 25 obtained by the signal processing system 52 is stored in the memory 54, and the memory 54 stores the position information. The difference is that the actuator 53 drives the diffraction grating 62 using the above-described position information, and the other configurations are the same.

In the present embodiment, first, the surface 22 to be inspected
Stage system 2 from the top position to the end position
Move 3 The amount of shaking (positional information) of the stage hand 25 at this time is detected by the displacement sensor 51, passed through the signal processing system 52, and then temporarily stored in the memory. Then move the stage system 23 again to move the stage hand 25.
Return to the position where the inspection started. Then, the foreign matter defect on the surface 22 to be inspected is detected by moving the grating 62 based on the position information stored in the memory.

FIG. 11 is a schematic view of an essential part of Embodiment 3 of the present invention, and FIG. 12 is a sectional view of an essential part of FIG. In the figure, 55 is an actuator for moving the polarization beam splitter 61, and 56 is an actuator for moving the half mirror 63. This embodiment is based on position information from the signal processing system 52 when the stage hand 25 moves upward in the Z direction as shown in FIG. A point in which the grating 62, the polarization beam splitter 61, and the half mirror 63 are moved by using the respective actuators 53, 55, and 56 by the same distance as the direction in which the stage hand 25 moves (upward in this case) and the same direction. Are different,
Other configurations are the same.

According to this embodiment, even if the stage hand 25 shakes, scattered light from foreign matters or defects and the grating 62 are generated.
The diffracted light from the can be combined by the half mirror 63, and these light fluxes are detected by the photoelectric detector 29 via the detection optical system 26 to obtain the heterodyne interference signal.

FIG. 13 is a schematic view of the essential portions of Embodiment 4 of the present invention. This embodiment is a combination of the second embodiment of FIG. 10 and the third embodiment of FIG. 11, and the other configurations are the same as those of the third embodiment of FIG.

That is, the position information of the stage hand 25 obtained by the signal processing system 52 is temporarily stored in the memory 54. Then, using the position information from the memory 54, the actuators 53, 55, 56 use the grating 62,
The polarization beam splitter 61 and the half mirror 63 are driven, respectively, whereby the photoelectric detector 20 obtains a good heterodyne interference signal.

FIG. 14 is a schematic view of the essential portions of Embodiment 5 of the present invention. In the figure, 25 'is a stage hand on which the reticle 22, the polarization beam splitter 61, the grating 62, and the half mirror 63 are all mounted.

In this embodiment, all the optical components required for the heterodyne interference are made to move integrally. This ensures that the heterodyne signal can be stably obtained in any case. The other basic configuration is the same as that of the first embodiment shown in FIG.

FIG. 15 is a schematic view of an essential part of a method for manufacturing a semiconductor device according to the present invention.

The present embodiment shows a case where the circuit pattern provided on the original plate such as a reticle or a photomask is printed on a wafer and applied to a manufacturing system for manufacturing a semiconductor device. The system roughly includes an exposure apparatus, an original plate storage device, an original plate inspection device (corresponding to a different inspection device in FIG. 1), and a controller, which are arranged in a clean room.

In FIG. 15, 901 is a far-ultraviolet light source such as an excimer laser, and 902 is a unitized illumination system. P. The original plate 903 set to the above is simultaneously illuminated from above with a predetermined NA (numerical aperture). Reference numeral 909 denotes a projection lens which converts a circuit pattern formed on the original plate 903 into a wafer 9 such as a silicon substrate.
It is projected and printed on 10. During projection printing, the wafer 910 moves 1
The exposure is repeated while shifting each shot. An alignment system 900 aligns the original plate 903 and the wafer 910 with each other prior to the exposure operation. Alignment system 9
00 has at least one original plate observing microscope system. An exposure apparatus is configured by the above members.

Reference numeral 914 is an original plate accommodating device which accommodates a plurality of original plates. Reference numeral 913 is an inspection device (foreign substance inspection device) for detecting the presence or absence of foreign matter on the original plate, and includes the configuration shown in each of the above embodiments. This inspection device 913
When the selected original plate is pulled out from the storage device 914, the exposure position E. P. Inspection of foreign material on the original plate is performed before setting.

The principle and operation of the foreign matter inspection at this time are the same as those described in the first embodiment. The controller 918 controls the sequence of the entire system,
It controls the operation commands of the storage device 914 and the inspection device 913, and the sequence of basic operations of the exposure apparatus, such as alignment, exposure, and step feed of the wafer.

The manufacturing process of a semiconductor device using the system of this embodiment will be described below. First, the original plate 903 to be used is taken out from the storage device 914, and the inspection device 9
Set to 13.

Next, the inspection apparatus 913 inspects the foreign matter on the original plate 903. As a result of inspection, it is confirmed that there is no foreign matter. P. Set to. Next, a semiconductor wafer 910 as an object to be exposed is set on the moving stage 911. Then, according to the step feed of the moving stage 911 by the step & repeat method, the original plate pattern is reduced and projected onto each region of the semiconductor wafer 910 while shifting each shot and exposed. This operation is repeated.

After the exposure of the entire surface of one semiconductor wafer 910 is completed, the semiconductor wafer 910 is accommodated and a new semiconductor wafer is supplied, and similarly, the exposure of the original pattern is repeated by the step & repeat method.

The exposed wafer which has been exposed is subjected to known predetermined processing such as development and etching by an apparatus provided separately from the present system. Thereafter, semiconductor devices are manufactured through assembly processes such as dicing, wire bonding, and packaging.

According to this embodiment, it is possible to manufacture a highly integrated semiconductor device having a very fine circuit pattern, which has been difficult to manufacture in the past.

FIG. 16 is a block diagram showing an embodiment of an original plate cleaning / inspection system for manufacturing a semiconductor device. The system roughly has an original plate storage device, a cleaning device, a drying device, an inspection device, and a controller, which are arranged in a clean chamber.

In FIG. 16, reference numeral 920 denotes an original plate accommodating device which accommodates a plurality of original plates and supplies the original plates to be cleaned. Reference numeral 921 denotes a cleaning device for cleaning the original plate with pure water. A drying device 922 dries the washed original plate. Reference numeral 923 denotes an original plate inspection device, which includes the configuration of the previous embodiment and inspects foreign substances on the cleaned original plate. A controller 924 controls the sequence of the entire system.

The operation will be described below. First, an original plate to be washed is taken out of the original plate storage device 920 and supplied to the cleaning device 921. The original plate cleaned by the cleaning device 921 is sent to the drying device 922 to be dried. After the drying, it is sent to the inspection device 923, and the inspection device 923 inspects the foreign material on the original plate by using the method of the above embodiment.

If no foreign matter is found as a result of the inspection, the original plate is returned to the storage device 920. If foreign matter is confirmed,
This original plate is returned to the cleaning device 921 for cleaning, and the drying device 9
After the drying operation is performed at 22, the inspection device 923 performs a re-inspection, and this is repeated until the foreign matter is completely removed. Then, the completely cleaned original plate is returned to the storage device 920.

Thereafter, the cleaned original plate is set in an exposure apparatus, and a circuit pattern of the original plate is printed on a semiconductor wafer to manufacture a semiconductor device. As a result, a highly integrated semiconductor device having a very fine circuit pattern, which has been conventionally difficult to manufacture, can be manufactured.

[0065]

As described above, according to the present invention, when the presence or absence of foreign matter on the inspection surface such as the reticle or pellicle surface is detected by using the optical heterodyne method, the stage system holding the inspection surface sways. A foreign matter inspection apparatus capable of detecting a foreign matter on the inspection surface with high accuracy by displacing at least one optical element among a plurality of optical elements provided in the optical path even if the position of the inspection surface is displaced; A device manufacturing method using the same can be achieved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a main part of a first embodiment of the present invention.

FIG. 2 is a sectional view of a main part of a part of FIG. 1;

FIG. 3 is an explanatory diagram of a signal obtained by the detection means according to the present invention.

FIG. 4 is an explanatory diagram on the inspection surface of FIG.

5 is an explanatory diagram on the inspection surface of FIG.

6 is an explanatory diagram on the inspection surface of FIG.

FIG. 7 is an explanatory diagram of a signal obtained by the detection means according to the present invention.

FIG. 8 is an explanatory diagram of a signal obtained by the detection means according to the present invention.

9 is an explanatory diagram of the signal processing system of FIG.

FIG. 10 is a schematic view of the essential portions of Embodiment 2 of the present invention.

FIG. 11 is a schematic view of the essential portions of Embodiment 3 of the present invention.

FIG. 12 is a cross-sectional view of essential parts of a third embodiment of the present invention.

FIG. 13 is a schematic view of the essential portions of Embodiment 4 of the present invention.

FIG. 14 is a schematic view of the essential portions of Embodiment 5 of the present invention.

FIG. 15 is a schematic view of a main part of a method for manufacturing a semiconductor device according to the present invention.

FIG. 16 is a block diagram of an original plate cleaning inspection system.

[Description of Reference Signs] 1 light source means 2 collimator optical system 13 scanning means 14 scanning lens 22 inspection surface (reticle) 61 light splitting member 62 scattering structure 63 optical combiner 29 detection means 51 displacement sensor 30, 52 signal processing system

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Minoru Yoshii 53 Imaiuemachi, Nakahara-ku, Kawasaki-shi, Kanagawa Canon Inc. Kosugi Plant

Claims (5)

[Claims] 1. A light flux from a light source means having two different frequencies and different polarization states is passed through a scanning lens through a scanning means, and after passing through the scanning lens, is split into two light rays by a light splitting member. When the inspection surface is scanned by one of the light fluxes, the scattered light generated from the inspection surface and the other light flux of the two light fluxes are combined by a multiplexer and then combined by a multiplexer to generate light. When the heterodyne interference, the signal based on the heterodyne interference is detected by the detection means, and when the presence / absence information of the foreign matter on the inspection surface is obtained using the signal from the detection means,
Foreign object inspection characterized by detecting position information of the inspection surface and displacing at least one of a plurality of elements provided in an optical path from the scanning lens to the detecting means based on the position information. apparatus. 2. The foreign matter inspection apparatus according to claim 1, wherein the scattering structure is a diffraction grating. 3. The foreign matter inspection apparatus according to claim 1, wherein the light splitting member is a polarization beam splitter. 4. The foreign matter inspection apparatus according to claim 1, wherein the at least one element is displaced so that the two light fluxes combined by the multiplexer are adjusted by the detection means. . 5. A device manufacturing method, which comprises the step of exposing a substrate after inspecting the relics on the substrate by using the foreign substance inspection apparatus according to claim 1.