JPS6211147A - Apparatus for inspecting foreign matter - Google Patents

Abstract

PURPOSE:To effectively perform the inspection of foreign matter containing visual observation, by preliminarily storing the correspondence table of the results of automatic inspection and visual observation in the inspection of foreign matter by polarizing laser in a table. CONSTITUTION:A foreign matter inspection apparatus is constituted so that the surface to be inspected of a wafer 30 is irradiated with laser beams of S-polarizing laser oscillators 32, 34, 36, 38 to automatically inspect foreign matter. The reflected laser beam from the surface of the wafer 30 reaches a 45 deg. prism 60 through the optical system common to a detection system 50 detecting foreign matter and a microscope 52 for the visual observation of the wafer 30, that is, an objective lens 54, a half mirror 56 and a prism 58. A means wherein the information of the visual observation result of foreign matter indicated by a means, which stores at least the positional information of the foreign matter detected on the basis of reflected beam in the table on the memory so as to correspond to each foreign matter and indicates the detected arbitrary foreign matter, is written in the aforementioned table so as to correspond to said foreign matter is provided and the memory content of said table is outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial Utilization" This invention applies to
This invention relates to a foreign matter inspection device that automatically tests for the presence or absence of foreign matter. More specifically, this invention not only irradiates a light beam such as a polarized laser beam onto a surface to be inspected and automatically scans the surface of an object on the surface to be inspected based on the reflected light, but also uses a microscope to The present invention relates to a foreign matter inspection device that allows visual observation of surfaces.

[Prior Art] Conventionally, foreign matter inspection equipment for LSI wafers uses an Printed out using a Y plotter. According to such a foreign object map, the location and size of the foreign object can be known, but the nature or type of the foreign object cannot be determined. In order to analyze the cause of foreign matter, information on the nature or type of the foreign matter is required.

In order to investigate the nature or type of foreign matter, the wafer after the foreign matter inspection is placed under a microscope and the foreign matter is observed with an IJ vision.

[Problem to be solved] Finally, it is necessary to create a table or the like that correlates the results of this 1" visual observation with the results of the automatic inspection. However, conventional foreign object inspection equipment does not require the creation, storage, and storage of such correspondence tables.
Unable to print. In addition, conventional foreign object inspection devices cannot manage automatic inspection results and visual inspection results all at once, making it difficult to manage their correspondence, making it inconvenient to manage inspection result data. .

[Purpose of the Invention] This invention was made in view of the above-mentioned problems, and its purpose is to create, save, and output a correspondence table that correlates the results of automatic inspection and the results of visual observation. The object of the present invention is to provide a foreign matter inspection device that can collectively manage the results of automatic inspection and visual observation.

[L Stage for Solving Problems] In order to achieve such a 1:1 ratio, in the present invention, the inspection target is In a foreign object inspection device configured to automatically detect foreign objects on the inspection surface and to enable visual observation of the surface to be inspected using a microscope, information on at least the position of the foreign object detected based on the reflected light is associated with each foreign object. means for storing the corresponding foreign matter in a table on the memory; means for determining an arbitrary foreign object detected based on the reflected light; and means for inputting information on the visual observation result of the specified foreign object. and a means for writing input visual inspection result information of a foreign object into the table in association with the foreign object, and a means for outputting the stored contents of the table.

[Function] In the same device, a correspondence table between the results of automatic inspection and visual observation can be created, stored in the table, and output. In this way, the creation of the correspondence table becomes easier than before, and the efficiency of inspection is improved. Furthermore, the results of both tests can be managed collectively in the form of a table, making it possible to prevent errors in the correspondence between the results of both tests.

[Embodiment] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a simplified schematic diagram showing the configuration of the optical system and other parts of the wafer foreign matter inspection apparatus according to the present invention. Second
The figure is a schematic diagram of the signal system and processing control system of the device.

First, in FIG. 1, reference numeral 10 denotes an X stage supported by a base 12 so as to be slidable in the X direction. This X stage 1
A screw 16 directly connected to the rotating shaft of the stepping motor 14 is screwed into the stepping motor 1.
4, the X stage 10 can be moved forward and backward in the X direction. 18 is a linear encoder that generates a code signal corresponding to the position X of the X stage 10 in the X direction.

On the X stage lO, the Z stage 20 moves in the Z direction +
It is attached to 1J Noh. Its transportation means are omitted in the figure. The Z stage 20 rotatably supports a rotation stage 22 on which a wafer 30 as an object to be inspected is placed. This rotation stage 22 is driven by a DC motor 2
4 are connected and can be rotated by operating them. This DC motor 24 has a built-in rotary encoder that outputs a code signal corresponding to its rotation angle position 0.

Note that the wafer 30 is positioned and fixed on the rotation stage 22 by negative pressure suction, but means for this purpose are omitted in the figure.

This foreign matter inspection device uses polarized laser light to
This is a device that automatically inspects foreign objects on wafer 30.
The upper surface (surface to be inspected) of is irradiated with S-polarized laser light.

For that purpose, an S-polarized laser oscillator 32.34.38.3
8 is provided.

A pair of S-polarized laser oscillators 32 and 34 generate S-polarized laser light with a wavelength of λI, for example, with a wavelength of 830.
This is a 0 angstrom semiconductor laser oscillator. The S-polarized laser light is irradiated onto the wafer from the X direction at an irradiation angle of, for example, 2 degrees.

Since the irradiation angle is thus small, when a beam of S-polarized laser light having a circular cross section is irradiated, the spot on the wafer extends in the X direction, making it impossible to obtain a sufficient irradiation density. Therefore, in this embodiment, a cylindrical lens 40.42 is placed in front of the S-polarized laser oscillator 32.34, and the S-polarized laser beam is turned into a beam with a flat cross-sectional shape collapsed in the Z direction and irradiated onto the wafer. , the spot shape is made closer to a circle to increase the irradiation density.

The other S-polarized laser oscillator 38.38 has an S polarization laser oscillator with a wavelength of λ2.
It generates polarized laser light, for example, the wavelength is 6330.
This is an Angstrom He-N e laser oscillator. The S-polarized laser beam is transmitted through a cylindrical lens 44.
48 in two directions, and then from the Y direction, for example, 2
The wafer is irradiated with an irradiation angle of °.

If the wafer is microscopically smooth, the reflected laser light of the S-polarized laser light irradiated onto the wafer will contain only the S-polarized light component. For example, if a pattern exists, it is microscopically considered to be a smooth part, and therefore the reflected laser light can be considered to have only an S-polarized component.

On the other hand, if a foreign material is present on the wafer, the surface of the foreign material generally has minute irregularities, so the irradiated S-polarized laser light is scattered and the polarization direction changes. As a result, the reflected laser light contains a considerable amount of P-polarized light component in addition to S-polarized light component.

Based on this phenomenon, the presence or absence of a foreign object and the size of the foreign object are detected based on the level of the P-polarized light component contained in the reflected laser light. This is the detection principle of this foreign object inspection device.

Referring again to FIG. The reflected laser light from the S-polarized laser light irradiation area of the wafer 30 is incident on a common optical system of a detection system 50 for detecting foreign matter according to the above principle and a microscope 52 for visual observation of the wafer 1. That is, the reflected laser light reaches the 45-degree prism 60 via the objective lens 54, the half mirror 56, and the prism 58.

A lamp 70 is also provided for visual observation.

The visible light emitted from this lamp 70 causes the half mirror 5 to
6 and an objective lens 54, the wafer image is exposed.

60 degree prism 62 and field lens 64
, passes through the relay lens 66 in order and enters the eyepiece lens 68. Therefore, through the eyepiece lens 68, the wafer can be observed with a 1-minute higher magnification. View in this case! The S-polarized laser beam irradiation area of the wafer falls within IIf.

The wafer 30 can also be observed at low magnification through the prism 58.

The reflected laser light that has entered the detection system side via the prism 60 passes through two apertures 4 provided in the slit 72.
A and 74B, it reaches the dichroic mirror 76 for wavelength separation, and is separated into a reflected laser beam with a wavelength λl and a reflected laser beam with a wavelength λ2.

The separated reflected laser beam of wavelength λ is passed through a sharp cut filter 78 and an S polarization cut filter (polarizing plate) 8.
0 and only its P polarized component is extracted. The extracted P-polarized laser beam is incident on the separation mirror 82, the portion that has passed through the aperture 4A of the slit 72 is incident on the photomultiplier 84A, and the portion that has passed through the aperture 4B is incident on the photomultiplier 84B.

Similarly, the wavelength-separated reflected laser beam of wavelength λ2 is S
The light is passed through a polarization cut filter (polarizing plate) 86, and only the P polarized light component is extracted. The extracted P-polarized laser light enters the separation mirror 88, and the portions that pass through the apertures 4A and 74B of the slit 72 are photomultipliers 90''A, respectively.

90B.

Each photomultiplier 84A, 84B, 90A.

90B outputs a detection signal having a value proportional to the amount of incident light. As described later, the photomultiplier 8
The detection signals of photomultipliers 84B and 90B are added together. As described later, based on the level of this added signal,
The presence or absence of foreign matter (details will be described later) in the S-polarized laser beam irradiation region is determined, and if foreign matter is present, the particle size of the foreign matter is determined based on the confidence level.

Here, the foreign matter inspection is performed while rotating the wafer 1 and feeding it in the X direction ('t' X direction) as described above.

According to such movement of the wafer 30, the S-polarized light irradiation area 30A moves spirally from the outside toward the center of the sea urchin/X 30, as shown at 7J in FIG. The field of view of the apertures 4A and 74B of the slit 72 is located within the S-polarized laser beam irradiation area 30A. That is, Ueno 1
The object is scanned spirally.

Further, the fields of view 74a and 74b of the apertures 4A and 74B of the slit 72 on the wafer are as shown in FIG. Each dimension in this figure is, for example, l, = 2X
12-α, and each aperture overlaps by α in a direction perpendicular to the scanning direction (O direction), that is, in the X direction. Further, 11 is larger than the feeding pitch of the wafer in the X direction, that is, in the radial direction. Therefore, the wafer will be scanned partially overlappingly.

In this way, the aperture of the slit 72 is divided into two,
The reason why each field of view is shifted in the X direction is as follows.

The signal output from the photomultiplier includes, in addition to the signal component related to the foreign object, background noise determined by the condition of the spinal surface to be examined. In order to increase the signal-to-noise ratio of the signal and make it possible to detect minute foreign objects, it is necessary to reduce the aperture of the slit. However, when there is only one aperture, if the aperture is small, the scanning line pitch (feeding pitch in the X direction) must be made small, which increases the time required to scan the entire surface to be inspected. Therefore, in this embodiment, l)'1
As mentioned above, by providing two apertures (generally more than one aperture) and shifting the field of view of each in the X direction to expand the overall field of view in the X direction, the inspection time can be shortened when the aperture is made sufficiently small. I'm trying.

In order to eliminate detection errors due to the anisotropy of foreign objects, the output signals of each photomultiplier that detects 116 scattered lights emitted from different directions are added, as will be described later.

Next, the signal processing control system of this foreign matter inspection apparatus will be explained with reference to FIG.

The output signals of the photomultipliers 84A and 90A are summed and amplified by a summing amplifier 100, and then sent to a level comparison circuit 1.
02 is input. Similarly, photomultiplier 84B
, 90B are summed and amplified by an amplifier 104 and input to a level comparison circuit 106.

Here, there is a relationship as shown in FIG. 5 between the particle size of the foreign matter on the wafer and the output signal level of the photomultiplier 84, 90. In this figure, Lt + L21
La is a threshold value of the level comparison circuits 102 and 106.

The level comparison circuits 102 and 108 compare the level of each input signal with each threshold value, and send out an output signal corresponding to the logic level threshold value according to the comparison result. That is, the threshold values Ll, L2 . Output signal Ot + 02 corresponding to LJ
The logic level of vOJ becomes "1" when a signal with a level higher than the threshold is input, and becomes "0" when the Daikai No. 5 level is less than the threshold. Therefore, for example, if the input signal level is less than the threshold (lI'fL1,
All the output signals become 0'', and if the large power immediate level is 1- or more than the threshold L2 and less than the threshold L3, the output signal y) is O.
l and 02 become "1", and 03 becomes "0".

In this way, the output signals o, , o2 . o3 is a binary code indicating the result of level comparison of input signals.

Level comparison circuit 102. Corresponding signals of the toe output signals are wired-ORed and input as code L (binary code with 0 as the least significant bit) to the interface circuit 108 of the data processing system 118. This interface circuit 108 also receives a signal (binary code) indicating information about the rotation angle position 0 and the X direction (radial direction) position X at each time point from the rotary encoder and the linear encoder.
2. These input codes are taken into a certain register inside the interface circuit 108 at regular intervals and are temporarily held there.

Also, inside the interface circuit 10g, a stepping motor 14 and a TDM motor 24 are installed from the processing control system.
There are also registers in which control information is set. According to the control information set in this register, the motor controller 118 controls the stepping motor 14 and the DC motor 24.
drive control is performed.

Data processing system 118 includes microprocessor 12
0. It consists of a ROM 122, a RAM 1 24, a floppy disk device 12B, an X-Y plotter 127, a CRT display device 128, a keyboard 130, and the like. 1
32 is a system bus, and a microprocessor 120
, ROM 122, RAM 124, and the interface circuit 108 are directly connected.

The keyboard 130 is used by an operator to input various commands and data, and is connected to the system bus 132 via an interface circuit 134. The floppy disk device 126 stores an operating system, various processing programs, test result data, etc., and is connected to the system bus 132 via a floppy disk controller 136.

When this material inspection device is started, the operating system is transferred from the floppy disk device 12B to the RAM 12.
4 is loaded into the system area 124A. Thereafter, one or more necessary processing programs among the various processing programs stored in the floppy disk device 126 are loaded into the program area 124B of the RAM 124 and executed by the microprocessor 120. Data that is being processed is temporarily stored in the work area of the RAM 124. The processing result data is finally transferred to and stored in the floppy disk device 126.

The ROM 122 stores dot patterns such as letters, numbers, and symbols.

The CRT display device 128 is used to display various messages for interaction with the operator, a foreign object map, and other data, and the display data is expanded into a bit map in the video RAM 138.

140 is a video controller, and the video RAM 13
In addition to controlling the writing and reading operations of 8, it also generates video signals according to dot patterns, generates cursor patterns, etc. The video controller 140 is connected to the system bus 132 via an interface circuit 142. A cursor address pointer 140A for controlling the address of the cursor is provided in the video controller 140, and this pointer is incremented or decremented according to the cursor column signal from the keyboard 130, and
20.

The X-Y plotter 127 is used to print out foreign matter maps and the like, and is connected to the system bus 132 via a plotter controller 137.

Next, please refer to the flowchart in Figure 6 for processing on the object surface! t(l This will be explained while referring to L. Here, jobs such as automatic foreign object inspection, 11-view observation, and printing are specified by the operator, but this is just an example.

With the wafer 30 set at a predetermined position on the rotary stage 22, when four operators command the start of inspection from the keyboard 130, the inspection processing program is transferred from the floppy disk device 126 to the program area 12 of the RAM 124.
Loaded to 4B and started running.

First, the microprocessor 120 performs initialization processing. Specifically, the X stage lO and the rotation stage 22
Motor control information for positioning the motor to the initial position is set in an internal register of the interface circuit 108. According to this motor control information, motor controller 1
16 controls the steering wheel, pumping motor 14, and DC motor 24 to move each stage to its initial position. The microprocessor 120 also operates tables, counters, etc., which will be described later.
Storage areas (see FIG. 2) for test data buffers, etc. are secured in the RAM 124J- (those storage areas are cleared).

A conceptual diagram of the above table (created in the table area 124D) is shown in FIG. Each entry in this table 150 includes the number of the foreign object (the order in which it was detected), the position of the foreign object (detected scanning position X, 0), and its type or property (1-
(investigated by one-view observation), and size information.

After the initialization, a job menu is displayed on the CRT display device 128, and the system waits for job designation from the operator.

The flow of processing when an "automatic inspection" job is designated will be described with reference to the flowchart in FIG. 6(A).

When the autotest code is entered into microprocessor 120 through keyboard 130, microprocessor 120 begins the autotest process. First, the microprocessor 120 instructs the motor controller 116 to start scanning through the interface circuit 108 (step 210). Upon receiving this instruction, the motor controller 116 controls the stepping motor 14 and the DC motor 24 so as to carry out the spiral scanning at a constant speed as described above.
to drive.

The microprocessor 120 includes an interface circuit l
The contents of certain internal registers of O8, i.e. wafer 3
0 scanning position X+ (7 code and level comparison circuit 10
The input data consisting of code L, which is the result of the level comparison by 2. The data is written to the upper power buffer y124c (step 215).

The microprocessor 120 compares the captured scanning position information with the position information of the position of the scanning cotton 1 to determine the end of scanning (step 220).

If the result of this determination is No (scanning is in progress), the microprocessor 120 determines that the loaded code L is zero (step 225). If L2000, no foreign matter exists at that scanning position.

If L≠000, foreign matter exists.

If the determination result in step 225 is YES, step 21
Return to 5. If the determination result in step 225 is No, the microprocessor 120 stores the acquired position information (X,
O) and position information of other detected foreign objects stored in the table 150 (X.

0) (step 230).

If the position information is correct, the current foreign object can be considered to be the same as another foreign object, so the process returns to step 215.

If the location information does not match, it can be assumed that a new foreign object has been detected. Therefore, the microprocessor 120
A counter N, which is an area 124E secured on the RAM 124, is incremented by 1 (step 235).

Then, the position information (X, 0) of the foreign object and the code L (as size information) are entered into the Nth entry of the table 150 (step 240).

Similar processing is repeated until the scanning of the wafer 30 is completed.

When it is determined in step 220 that scanning has ended, the master 12
0 sends a 1° scan stop instruction to the motor controller 11B through the interface circuit 108 (step 250). In response to this instruction, the motor controller tte stops driving the stepping motor 14 and the DC motor 24.

Next, the microprocessor 120 refers to the table 150 and calculates the total number of foreign substances with a code L of 12 - l number TL1%, the total number of foreign substances with a code L of 32 TL2, and the total number of foreign substances with a code L of 72 TLa. , the total number of foreign objects data, R
Specific areas 124F, 124G, 124H on AM124
(step 251). And table 1
The stored contents of 50 and the foreign matter total data are transferred to the floppy disk device 12B with a wafer number added thereto and stored therein (step 252).

This completes the automatic inspection job 1'L, and a job menu is displayed on the screen of the CRT display device 128.

Next, the flow of the "visual observation" process will be explained using flowcharts shown in FIGS. 6(B) to 811(E).

The visual inspection includes a sequential mode, a number specification mode, and a cursor specification mode, depending on the method of specifying the foreign object to be observed, and can be specified using the keyboard 130.

When the job and mode of visual observation are specified, the microprocessor 120 causes the dot pattern data of the outline image of the wafer 1 to be transferred from the flow disk device 12B to the video RAM 138 (step 28).
5). The activation control of this transfer is performed by the microprocessor 120.
However, subsequent transfer control is performed by the video controller 140 and the floppy disk controller 13.
6. The door) pattern data in the video RAM 138 is sequentially read out by the video controller 140, converted into a video signal, and sent to the CRT display device 128 for display.

Next, the microprocessor 120 reads the stored contents of the table 150 stored in the floppy disk device 126 and the total number of foreign objects data, with the number of the wafer to be observed (entered from the keyboard 130 when selecting a job) added, and 8 is written into the corresponding area of the RAM 124 (step 290).

The microprocessor 120 sequentially reads the position information and size information (L code) of each foreign object from the table 150 on the RAM 124, reads the dot pattern data corresponding to the L code from the ROM 122, and sets the address of the video RAM 138 corresponding to the position information. It is transferred along with the information to the video controller 140 and written into the video RAM 138 (step 295). Through this process, the foreign object map stored in the table 150 is displayed on the screen of the CRT display device 128.

Next, the microprocessor 120 instructs the motor controller 11B to position the scanning position to the initial position via the interface circuit 108 (step 30
0). The following processing differs depending on the specified mode.

If sequential mode is specified, the microprocessor 12
0 is 1 in counter M (area 124J of RAM 124)
is set (step 320), and the data of the foreign object (the foreign object detected at M number 1) stored in the M-th entry of the table 150 is read (step 325). Then, control information for moving the scanning position to a position corresponding to the position information (X + θ) is sent to the motor controller 116 via the interface circuit 108.
j, er (step 330). Motor controller 11
6 controls the stepping motor 14 and the DC motor 24, and when the scanning position is determined, the M number [I
foreign body is located.

The microprocessor 120 generates a foreign object pattern corresponding to the Mth foreign object code and a Pth foreign object pattern (P is the RAM 124
The foreign object pattern corresponding to the foreign object code (the value of the counter P) is read out from the ROM 122 in the area 124, and the P-th foreign object pattern is left as it is, the M-th foreign object pattern is inverted, and the foreign object pattern is sent to the video controller 140 along with the address information. sequentially transfer those patterns to the video RA
The corresponding address of M is calculated (step 335).

Now, only the Mth foreign object on the foreign object map displayed on the screen of the CRT display device 128 is displayed as an inverted pattern, and is visually distinguished from other foreign objects.

The microprocessor 120 includes an interface circuit 1
The positional information is sequentially taken in through 08 and compared with the positional information of the Mth foreign object to determine whether positioning is complete (step 340). Once the positioning is complete, the microprocessor 120 sends a message to the video RAM that it can be viewed.
138 and displayed on the screen of the CRT display device 128 (step 345). Then, it waits for a key input (step 350).

The operator visually observes the foreign object, identifies the nature or type of the foreign object, and inputs a code for the nature or type from the keyboard 130. In practice, by specifying a visual observation job, the CRT display device 1
A table of properties or types of foreign objects and numbers is displayed on the screen 28, and the corresponding number from the table is input.

If the input code is a code for the nature or type of foreign object (step 352), microprocessor 120 writes that code into the Mth entry of table 150 (step 352).
step 355). However, if the input code is another code such as a tab, step 355 is skipped.

Next, the microprocessor 120 operates counters M, P
is incremented by 1 (step 360), and a comparison is made between counter M and counter N (this value is the total number of detected foreign objects) (step 365).
. If M is N, the process returns to step 325.

Also, if M≧N, table 150 in RAM 138
In step 37, the memory contents and the total number of foreign particles are transferred to the floppy disk device 126 along with the wafer number.
0), return to the job menu screen state.

In this way, in the sequential mode, foreign objects to be observed are automatically designated in the order of detection.

On the other hand, if a>j and the designation mode is designated, the microprocessor 120 waits for the operator to input a foreign object number (step 410). When a keystroke is made,
It is determined whether the input code is a foreign object number (step 415). If it is not a foreign object number, wait for key input.

When the foreign object number is keyed in, the microprocessor 12
0, the foreign object number is set in the counter M (step 420), and the process proceeds to step 325.

Thereafter, in step 357, the value of the counter M is changed to the value of the counter P.
In the next step 400, it is determined whether the current mode is a number designation mode or a cursor designation mode. Since the mode is number designation mode here, the process returns to step 410.

In the same way, by key-inputting the foreign object number,
The designated foreign object is automatically positioned approximately at the center of the field of view of the microscope 52, visually observed, and the result of the visual observation is written into the corresponding entry in the table 150.

Thus, in this mode, the foreign object to be observed is specified by key-inputting the foreign object number.

Although not shown in the flowchart, if the end key of the keyboard 130 is input at any time, the number designation mode ends, and after the process of step 370, the screen returns to the three-b menu screen.

The cursor specification mode will be explained. In the cursor specification mode, the operator operates the cursor operation keys provided on the keyboard 130 to
Cursor address pointer 1 through cursor control signal
40A, move the cursor displayed on the screen of the CRT display device 128 to the position of the target foreign object also displayed on the screen, and press the cursor read key on the keyboard 130 to make the observation. Specify the foreign object that should be removed.

In this mode, the microprocessor 120 waits for a key input (step 430), and when a key input is made, it determines whether it is a code for a cursor read key (step 435). If the determination result is NO, the process waits for key input.

If the judgment result is YES, the microprocessor 120
reads the contents (cursor address) of the cursor address pointer 140A (step 440). and,
The cursor address is converted into the corresponding scanning position, that is, the foreign object position (step 445).

Next, the table 150 is searched, the obtained foreign object position is compared with the position of each foreign object stored in the table 150, the nearest foreign object is searched (step 450), and the number of the foreign object is set in the counter M. (Step 455)
. Then, the process advances to step 325.

In this way, the foreign object designated by the cursor is automatically positioned in the field of view of the microscope, and the observation result is entered into the corresponding entry in the table 150.

Although not shown, if the end key of the keyboard 130 is pressed, the process branches to step 370, and after the end of step 370, the job selection screen is displayed.

As explained above, by visual observation, a table is obtained in which the results of visual observation and the results of automatic inspection are integrated.

Note that during visual observation, the foreign object being observed is displayed on the CRT display device 128 on the foreign object map 1-
, the operator (
The observer) can easily confirm the foreign object being observed using the object marker or button.

If "print" is specified on the job selection screen, the test results can be printed out from the X-Y plotter 127.

When printing is specified, as shown in FIG. 6(F),
Microprocessor 120 reads wafer contour image data from floppy disk device 126 and transfers it to the plotter controller (step 465).

Next, the microprocessor 120 sequentially reads out the stored contents of the table 150 stored in the floppy disk drive 126 and the total number of materials, to which the number of the wafer to be printed (input from the keyboard 130 when selecting a job) is added. , is transferred to the plotter controller 137 (step 470).

In this way, the foreign matter map, the table contents (table), the total number of foreign matter data, and the wafer number are printed by the X-Y plotter 127.

When printing is completed, the screen returns to the job selection screen.

Below-1-1 Examples of this invention have been described,
This invention is not limited to this, but can be implemented with appropriate modifications.

For example, there are not necessarily two vessels in which the scanning position of the detection system is always within the field of view of the microscope, and it is sufficient that the scanning position and the field of view can maintain a constant positional relationship. However, if the above embodiment is adopted, processing such as identification of foreign objects during visual observation is easy.

Instead of the photomultiplier, other suitable photoelectric elements can be used.

The scanning is not limited to spiral scanning, but may be linear scanning, for example. However, since linear scanning stops at the scanning edge, the scanning time tends to increase, and when scanning a circular spinal surface such as a wafer, position control at the scanning edge tends to become complicated. There is. Therefore, for foreign object inspection, such as wafers, helical scanning is generally advantageous.

The slit may have one aperture, or three or more apertures.

Furthermore, it goes without saying that the present invention can be similarly applied to an apparatus for inspecting foreign body surfaces other than wafers. Further, the present invention is also applicable to similar foreign matter inspection apparatuses that utilize light beams other than polarized laser light.

[Effects of the Invention (1) As explained above, according to the present invention, it is possible to automatically detect a foreign object on the examined spinal surface based on the reflected light from the examined spinal surface irradiated with a light beam. At the same time, in the foreign body inspection device configured to allow visual observation of the spinal surface to be examined using a microscope, information on at least the position of the foreign body detected based on the reflected light is stored in a memory table by associating it with each foreign body. means for storing, means for specifying any foreign object detected based on the reflected light, means for inputting information on the visual observation result of the specified foreign object, and information on the L1 visual observation result of the input foreign object. It is provided with means for writing in the table in correspondence with the foreign matter, and an L stage for outputting the stored contents of the table.

Therefore, at the end of the visual inspection, a correspondence table of the results of automatic inspection and visual observation is automatically obtained as the stored contents of the table. It is also possible to save and output a correspondence table between the results of automatic inspection and 1Tf visual observation, which facilitates analysis of the cause of foreign matter generation, and allows the results of automatic inspection and visual inspection to be managed all at once.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a schematic diagram of the optical system etc. of the foreign matter inspection device according to the present invention, FIG. 2 is a schematic block diagram showing the signal system and processing control system of the foreign matter inspection device, and FIG. An explanatory diagram of the spinal surface scan to be examined, Fig. 4 is an explanatory diagram of the slit aperture, and Fig. 5 is a graph showing the relationship between the particle size of the foreign object and the output signal of the photomultiplier, and the relationship with the threshold value for level comparison. ,
6(A) to 6(F) are flowcharts of the inspection process, and FIG. 7 is a conceptual diagram of tables related to the inspection process. 10...X stage, 14...Stepping motor, 22...Rotating stage, 24...DC motor, 3
0... Wafer, 32.34, 38.38... S polarization laser oscillator 1.50... Detection system, 52... Microscope, 72... Slit, 76... Dichroic mirror, 80... ... S polarization cut filter, 82 ... Separation mirror, 84A, 84B ... Photomultiplier, 8
6... S polarization cut filter, 88... Separation mirror, 90A, 90B... Photomultiplier, 100,
104...Summing amplifier, 102.106...Level comparison circuit, 108...Interface circuit, IIQ
...Mode controller, 120...Microprocessor, 122...ROM, 124...RAM11
2B...Floppy disk device, 127...X-
Y plotter, 128...CRT display device, 1
30...Keyboard, 138...Video RAM, 1
50...table.

Claims (1)

[Claims] (1) In a foreign matter inspection device configured to automatically detect foreign matter on the surface to be inspected based on the reflected light from the surface to be inspected that has been irradiated with a light beam, and to visually observe the surface to be inspected using a microscope. , means for storing information on at least the position of a foreign object detected based on the reflected light in a table on a memory in association with each foreign object; means for specifying any foreign object detected based on the reflected light; means for inputting information on visual observation results of designated foreign objects; means for writing input information on visual observation results of foreign objects into the table in association with the foreign objects; and means for outputting the stored contents of the table. A foreign matter inspection device comprising: