JP2002134400A - Image-processing unit, mark-measuring device and apparatus for manufacturing semiconductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the accuracy of measuring a mark, using an interlacing type storage area sensor. SOLUTION: The mark measuring device obtains the brightness of even numbered fields and odd numbered fields of an image time-divided and stored in the even numbered fields and the odd numbered fields, obtains a constant for correcting the deviations of the brightnesses, and corrects the brightnesses of the even numbered fields and the odd numbered fields by the constant. The mark is measured by using the corrected images.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the processing of an image stored in an even / odd field in a time-division manner, such as the NTSC system. Such image processing is suitably applied when measuring the mark by imaging the reflected light from the mark illuminated with the light output from the illumination device with an interlaced storage area sensor, and in particular, It is suitable for use in mark measurement in a semiconductor manufacturing apparatus.

[0002]

2. Description of the Related Art In a semiconductor manufacturing apparatus for manufacturing a high-density memory or a high-spec CPU, the required exposure resolution is 0.20 μm or less. Therefore, in order to transfer a finer pattern, Kr is used as an exposure light source.
F laser (248 nm), ArF laser (193n)
m), and an F2 laser (157 nm). On the other hand, it is necessary to precisely measure the positional relationship between the position of the reticle or the position of the reticle stage on which the reticle is set and the wafer stage as a part of the alignment method of the semiconductor manufacturing apparatus. The most advantageous method for measuring the positional relationship between the reticle stage and the wafer stage is a TTR for simultaneously measuring the reticle stage and the wafer stage.
Measurement. In the TTR measurement, a mark on the reticle stage and a mark position on the wafer stage are measured via a projection lens existing between the reticle stage and the wafer stage. The illumination light source used in the TTR measurement is optimally exposure light. The reason is that the aberration (such as chromatic aberration) of the projection lens is adjusted to the exposure light. As a result, marks on the reticle stage and marks on the wafer stage existing at conjugate positions can be measured simultaneously.

By the way, excimer lasers and the like are the mainstream illumination devices for semiconductor manufacturing devices which can emit light of high energy and short wavelength today. The light generation method of the excimer laser is pulse emission.

A device for illuminating a reticle and a mark image on a wafer stage illuminated with a pulsed laser beam has been devised as disclosed in JP-A-3-226187 and JP-A-4-26011. ing. An outline is shown below.

[0005] 1) Irregularity of the laser is suppressed by the swinging means in the illumination device. 2) The laser is synchronized with a video synchronizing signal input to the image capturing device so that the number of pulses during light accumulation becomes the same. Control 3) Integrate the captured electric signals to reduce uneven illuminance. 4) Synchronize the cycle of the oscillating means with the cycle of image capture. Using these methods, an image with less uneven illuminance was created. .

FIG. 2 shows a configuration of a semiconductor manufacturing apparatus which is a conventional example and is also an example to which the present invention is applied. In the apparatus shown in the figure, the light of the pulse laser 15 is averaged by a swinging means 7 such as a wedge, and the mark 3 on the stage is illuminated through the projection lens 2. To image. CCD camera 8
Are output from the synchronization signal generator 13. The synchronization signal is also sent to the oscillating means 7 and the laser 15 at the same time, and the CCD camera 8, the oscillating means 7 and the laser 15 are synchronized.

Since the CCD camera 8 is of the NTSC type, FIG.
As shown in (1), light is accumulated at even / odd timings. The output image is e
The image is composed of the image of the scanning line of ven and the image of the scanning line of odd, and the image of even / odd is captured with a time lag.

FIG. 3 shows the relationship between image capture and laser pulse emission. The swing cycle is adjusted to be a cycle that is an integral multiple of the even / odd field.
In the conventional example, the accumulated image data is integrated by the image addition device 12 in FIG. 2, and in the case of FIG. 3, images of three to six frames are combined to produce a measurement image.

[0009]

Since the scanning exposure using the pulse laser has been performed, it has become necessary to synchronize the swinging means with the scanning speed. That is, the scan exposure irradiates the resist of the wafer with the light of the pulse laser as if the slit were scanning over the wafer. In order to perform exposure without uneven illuminance in the scan area, pulse light for one cycle of the oscillating means or n cycles (n: natural number) must be exposed while a certain point on the wafer moves through the slit width. No. Therefore, as the scan speed increases, it is necessary to increase the swing frequency of the swing means. On the other hand, scan speed
It is inversely proportional to the amount of energy for exposing the resist on the wafer. To increase the energy amount, more laser pulses are required. Since the laser oscillation frequency is fixed (usually the maximum value), the amount of exposure energy can be increased by lowering the scan speed. As described above, the oscillating frequency of the oscillating means must be changed according to the scan speed (exposure amount).

On the other hand, when pulse light is accumulated by a CCD camera of the NTSC system, the exposure time is limited to 1/60 second. Time-divided into even / odd specific to NTSC,
Moreover, in order to prevent the unevenness of the illuminance and the occurrence of the even / odd difference in the interlaced imaging in which the accumulation time is limited, the swing means must be adjusted to an integral multiple of 1/60 second.

When the oscillation frequency is adjusted according to the scan speed, but the oscillation frequency is adjusted for the measurement, the control of the oscillation means occurs every time the measurement is performed.
To change the speed of a fast moving object,
A control time of about several seconds is required. To reduce this time to a few milliseconds, high-performance control means must be used. On the other hand, if there is a swing unit dedicated to measurement, it is not necessary to change the swing frequency. However, in this case, the problem is that the lighting device becomes large and the optical member becomes
It is a point that is required twice. In addition, a part of the light must be guided to the optical system dedicated for measurement, and in the worst case, the illuminance for pattern exposure may be reduced. Therefore, it is the most suitable configuration to use a part of the illumination system of the scan exposure system without forming a dedicated optical system.

The TTR measurement is used for calibration of a stage position and a reticle position or calibration of a projection lens. The measurement is performed during a wafer exchange or the like. This is because if the measurement is completed in parallel with the wafer exchange, the wafer processing time will not be increased.
However, in recent years, the exposure apparatus has minimized the wafer exchange time and has increased the throughput (wafer processing capacity per unit time). The time required for the rocking means to stabilize for the measurement performed at the time of wafer exchange uses a wasteful time of the apparatus.

In the conventional method, the swing means must be controlled for capturing an image for measurement, which has a problem that the throughput of the apparatus is affected.

When a camera of the type that performs even / odd field light accumulation at different times and synthesizes even / odd field images to produce one image is used as an image capturing device, such as the NTSC system.
Brightness differences (illuminance differences) may occur between n / odd fields. The causes of the illuminance difference include: 1) an error in laser energy between the accumulation period of the even field and the accumulation period of the odd field (particularly, the amount of laser energy at the first pulse of the light emission start is higher) 2) Unevenness of the oscillating means Is mentioned.

The above 1) will be supplemented with reference to FIG.
FIG. 5 shows time on the horizontal axis and the amount of laser energy on the vertical axis. The section surrounded by the arrow above the graph is even
The light accumulation period of the / odd field is shown. even / o
The time for taking in dd switches every 16.6 msec. The amount of laser energy is high in the initial four pulses of the start of laser emission, and is gradually stabilized. In the case of FIG. 5, the amount of light entering the even field is higher than the amount of light entering the odd field. Therefore, the image of the even field is od
Brighter than d field. This phenomenon does not cause a problem when light is emitted continuously, but becomes remarkable when it oscillates intermittently after a few seconds. As described above, the TTR measurement is performed at a timing when the wafer is not directly exposed, such as when the wafer is replaced. Usually, the laser is turned off for a few seconds. Therefore, this phenomenon must be considered in measurement using laser light.

An adverse effect of the occurrence of the illuminance difference is that the measurement accuracy of the captured image is deteriorated. For example, in measurement that quantifies the amount of defocus based on the contrast of a captured signal, accurate measurement cannot be performed unless the amount of light is constant. This is because the contrast value fluctuates depending on the brightness. When a change as shown in FIG. 5 occurs as the laser oscillation energy, the light amount stored in the even field becomes larger than the light amount stored in the odd field. In this case, when a window WRY1 is set on the RY1 mark of the mark shown in FIG. 1 and the projection (integration) process is performed in the direction of dx, a signal as shown in FIG. 1B is obtained. In other words, even pixels and odd pixels have different brightness due to the influence of the illumination intensity, resulting in a jagged signal. Note that the X mark (RX1, RX2, WX mark) has no even / odd effect. This is because the projection direction is the dy direction orthogonal to the scanning lines, so that the illuminance difference between the scanning lines acts uniformly on all pixels.

In order to improve the measurement accuracy, it is necessary to reduce the illuminance difference. Conventionally, there are a method of increasing the time (number of times) for integrating the captured electric signals and a method of discarding an image initially captured by the camera. However, the problem with these measures is that the time for capturing images is lengthened.

As another countermeasure, there is a method of synchronizing the start of capturing and the origin of the oscillating means for each even / odd field. The problem with this method is that not only the time taken for image capture becomes longer, but also the control of the oscillating means and the control of capture become complicated.

In summary: 1: The swinging means cannot be adjusted to the image capturing cycle in a short time. If they are adjusted over a long period of time, the throughput will be affected. 2: When capturing images in NTSC format, even / o
Irregularities in the amount of illumination occur between the dd fields, which affects measurement accuracy.

An object of the present invention is to provide an image processing apparatus capable of performing suitable image processing even when the brightness of an even field and the odd field of an interlaced image are different.

Further, when a mark illuminated with light output from the illuminating device is picked up by an interlaced pick-up means, an image can be accurately measured even if there is an illuminance difference between an even field and an odd field. It is an object of the present invention to provide a mark measuring device capable of performing the above.

[0022]

In order to solve the above problem, an image processing apparatus according to the present invention obtains the brightness of an even field and an odd field of an image temporally divided and stored in an even field and an odd field. A constant for correcting the deviation of the brightness is obtained, and the brightness of the even field and the odd field is corrected by the constant.

Further, the first mark measuring device of the present invention comprises:
In an apparatus for measuring the mark by capturing the reflected light from the mark illuminated with the light output from the illumination device with an interlaced storage area sensor, an even field of the image captured by the storage area sensor is used. The brightness of the odd field is obtained, a constant for correcting the deviation of the brightness is obtained, and the mark measurement is performed using the image signal obtained by correcting the brightness of the even field and the odd field by the constant. .

According to a second mark measuring device of the present invention, there is provided an apparatus for measuring reflected light from a mark illuminated by light output from an illuminating device using an interlaced storage area sensor to measure the mark. A processing window is set on the image captured by the accumulation type area sensor, one-dimensional information integrated in the scanning line direction is created, and the brightness of even-numbered pixels and odd-numbered pixels in the one-dimensional information is obtained. A constant for correcting a deviation in brightness is obtained, and the mark is measured using the one-dimensional information corrected by the constant. Such a deviation between the signal levels of the even field and the odd field occurs, for example, when the light quantity output from the lighting device changes during the timing when the area sensor accumulates (images) the light quantity of the even field and the odd field.

[0025]

As described above, according to the present invention, image capture using an interlaced storage area sensor is performed by
Even if there is an illuminance difference between the en field and the odd field, noise due to the illuminance difference can be corrected, and stable mark measurement accuracy can be maintained by using the corrected image. Therefore, in the manufacture of semiconductors, it is possible to contribute to the improvement of the yield by increasing the accuracy of measurement.

[0026]

In a first preferred embodiment of the present invention, reflected light from a mark illuminated by light output from a lighting device is picked up by an interlaced storage area sensor, and the mark is imaged. In the measuring device, the brightness of the even field and the odd field is obtained, the constant for correcting the brightness of at least one of the even field and the odd field is obtained, and the mark is measured using the image corrected by the constant described on the left.

According to a second preferred embodiment of the present invention, there is provided an apparatus for measuring reflected light from a mark illuminated with light output from a lighting device by an interlaced storage area sensor and measuring the mark. A processing window is set in the captured image, and 1 is integrated in the scanning line direction.
Creates dimensional information, and the even pixel and od in the one-dimensional information
The brightness of the d pixel is obtained, and the even pixel and o
A constant for correcting the brightness of at least one of the dd pixels is obtained, and the mark is measured using the one-dimensional information corrected by the constant described on the left.

Here, a pulse generator such as an excimer laser can be used as the illumination device. Further, a CCD camera can be used as the accumulation type area sensor.

According to a third preferred embodiment of the present invention, in a semiconductor manufacturing apparatus for projecting a mask pattern on a mask stage onto a wafer on a wafer stage via a projection lens, an alignment mark on the mask stage and the wafer stage Either or both of the alignment marks are measured by using the mark measuring device according to the first or second embodiment.

In a fourth preferred embodiment of the present invention, in a semiconductor manufacturing apparatus for projecting a mask pattern on a mask stage onto a wafer on a wafer stage via a projection lens, a contrast measurement mark on the mask stage and a wafer on the wafer stage are projected. And / or one of the contrast measurement marks is measured using the mark measurement device according to the first or second embodiment.

According to the second embodiment, the swing frequency of the swing means is not adjusted in accordance with the image capture, and even
Regarding the mark detection in the direction orthogonal to the scanning line for the image in which the illuminance difference of the n / odd field occurs, after integrating in the scanning line direction, the illuminance difference of the even / odd field is measured from the image before detection, Even / odd is added to the pixel of the even field or the pixel of the odd field.
The signal or image is corrected by multiplying by a constant that corrects the difference.
High-precision mark detection is performed based on the corrected signal on the left.

Originally, the reflectance on the substrate cannot change every 1/60 sec. Only the amount of illumination changes. Therefore, the illuminance at the time of the even field accumulation and the illuminance at the time of the odd field accumulation are measured from a position of uniform reflectance in the image, an illuminance correction value is obtained from the illuminance described on the left, and the illuminance correction value is determined by the pixel of the even field or
By multiplying the pixels of the odd field, the even field pixels and the odd field pixels in the image can be corrected.

Therefore, an accurate calculation can be performed on an image captured for measurement without synchronizing the swinging means with the image capturing time and without discarding the initially captured image data. Therefore, without using a complicated illumination system, it is possible to acquire an image at high speed with an NTSC camera and detect a mark.

[0034]

FIG. 2 is a block diagram of a semiconductor manufacturing apparatus according to one embodiment of the present invention, in which a mark on a reticle stage and a mark on a wafer stage are observed by the TTR method, and both or any one is measured. Is shown. The measured values include mark brightness, mark contrast (defocus amount), mark position, and the like. In the present invention, the details of the method of measuring brightness, contrast, and mark position are not important. Even if an illuminance difference of an even / odd field occurs in a captured image, mark brightness,
The subject is an illuminance difference correction method that enables measurement of contrast and mark position. Therefore, in the present embodiment, detailed description of the mark measurement method is omitted.

In FIG. 2, 1 is a reticle (reticle reference plate), 2 is a projection lens, 3 is a stage reference plate, 4 is a wafer stage, 5 is a mirror, 6 is a half mirror, 7 is a swing means, and 8 is a CCD. Camera, 10 is a reticle mark (reticle side mark), 11 is an AD converter, 12 is an image adding device, 13 is a synchronization signal generator, 14
Is an image processing device, 15 is an excimer laser (pulse laser), 16 is an exposure device control device, 17 is a swing control device,
Reference numeral 18 is a stage control device, and 19 is an interferometer.

The excimer laser 15 is composed of KrF, ArF, F
2 is a light source for generating pulsed laser light by a gas laser in which gas is sealed. The pulse light generated here enters the rocking means 7. The oscillating means 7 is an optical system for oscillating the incident beam in the output at the circumference, and is realized by, for example, rotating a wedge by a motor. The beam oscillated by the oscillating means 7 passes through the half mirror 6, is reflected by the mirror 5, and reaches the reticle side mark 10 on the reticle stage. Further, the light passes through the projection lens 2 and irradiates the reference mark 3 on the wafer stage 4.

The emission pulse light of an excimer laser generally has greater illuminance unevenness in a beam than continuous light such as a mercury lamp. If the exposure is performed while the beam is fixed, the illuminance unevenness on the wafer cannot be suppressed within an allowable range even if the exposure is performed by using a plurality of pulses. Therefore, in this embodiment,
The excimer laser emits light while oscillating the beam circumferentially by the oscillating means 7.

On the other hand, in FIG. 2, the beam reflected by the reference mark 3 passes through the projection lens 2 and the reticle side mark 1, is reflected by the mirror 5 and the half mirror 6, and is incident on the imaging surface of the CCD camera (Cam) 8. I do. For this reason, the stage reference mark 3 and the reticle side mark 10 can be observed simultaneously by the CCD camera 8, and by processing this image, the relative position of the wafer stage and the reticle stage or the brightness and contrast of each mark can be known. .

The image capture will be described with reference to FIG. Incorporation is described in JP-A-3-226187 and JP-A-4
As disclosed in Japanese Patent No. 26011, the swinging means is rotated in synchronization with a synchronization signal (Sync) for image capture. Image capture is 1/60 in case of NTSC system
Light is accumulated in the even / odd field every second. The laser is controlled so that each field always contains the same number of laser pulses. FIG. 3 shows that three frames of images are captured when the swinging means makes one rotation. The image of the first frame composed of the even / odd fields is converted from voltage (analog signal) to digital data by the AD converter 11 in FIG.
2 is stored. The images of the second and third frames are AD
While being converted into digital data by the converter 11, the digital data is added and synthesized with the image stored in the adding device 12. In the case of FIG. 3, the swinging means makes two rotations, and adds six frames. Increasing the number of added frames reduces illuminance unevenness, but increases the capture time. It is desirable that the number of additions be the maximum number allowed by the system.

Next, from the captured image, even / od
A method for measuring the brightness of the d-field will be described.

FIG. 1 shows a state in which the mark 1 on the reticle plate and the mark 3 on the stage plate captured by the CCD camera 8 are simultaneously imaged. A window WRY1 is set for the reticle mark RY1, and projection processing is performed in the direction of dx. The signal subjected to the projection processing is as shown in FIG. The obtained pixels in the even field are projected to the even pixels in the signal, and the pixels in the odd field are projected to the odd pixels in the signal. Since there is an illuminance difference between the even / odd fields, the odd pixels are brighter than the even pixels. The reticle mark is produced by depositing chrome or the like on a glass surface. And, the reflectance is controlled and manufactured so as to be uniform. Therefore, the projection data of the tops (peaks and valleys) of the signal SRY1 all indicate the brightness of the reflected light on the reticle chrome surface. For example, if the mountain is e
The brightness of the ven pixel and the valley are the brightness of the odd pixel. Therefore, the brightness of the even pixel and the odd pixel at the top of SRY1 is extracted, and the brightness E of the even pixel is calculated by the following equation.
The brightness Os of the s and odd pixels is obtained. N is a predetermined number of pixels, and S is obtained from the mark center position.

[0042]

(Equation 1)

[0043]

(Equation 2)

As a method of obtaining S, for example, the center position of the RY1 mark is roughly detected from the signal SRY1 to obtain RY1C, and a position shifted by RY1C-N / 2 pixels from the position is set as S.

Next, the illuminance correction of the even pixel and the odd pixel will be described. The illuminance correction of the even pixel and the odd pixel may be performed by adjusting the darker pixel to the lighter pixel, or conversely, adjusting the lighter pixel to the darker pixel or to the average value. Here, an example is shown in which the color is adjusted to the brighter one. Using Es and Os obtained by the above formula,

[0046]

(Equation 3)

When the above operation is performed, if the even pixel is bright, the odd pixel is brightened, and its coefficient is set to Ko. The brightness is corrected by multiplying all odd pixels by Ko. Also, if the odd pixels are bright, K is assigned to all even pixels.
The brightness is corrected by multiplying by e. The signal corrected in this manner is the signal SRY1 'shown in FIG. FIG.
The signal is smoother than that of FIG.

The above coefficients Ko and Ke are calculated based on the window WWY.
And WRY2 can also be used for signals produced by projection processing, and even / o
The brightness correction of the dd pixel is performed.

When the mark position of the reticle plate and the mark position of the stage plate are obtained using the signal in which the illuminance difference between the even / odd pixels has been corrected as described above,
Measurement results independent of illuminance can be obtained. Also in the measurement of the light amount and the measurement of the signal contrast, the same processing is performed, and then, for example, the mark light amount is obtained from the maximum value of the SRY1 'signal, and the contrast is obtained from the differential value of SRY1'.

In this embodiment, the correction characteristic of the present invention is performed on the projected signal. However, the correction may be performed on the entire captured image. In that case, Equation 4 is extended as follows.

[0051]

(Equation 4)

In equation (4), when the above operation is performed, if the even field is bright, the odd field is brightened, and its coefficient is set to Ko. The pixels in all odd fields are multiplied by Ko to correct the brightness. Also, when the odd field is bright, K is assigned to all the even field pixels.
The brightness is corrected by multiplying by e.

In this embodiment, the brightness of the even / odd field is measured by using the measurement mark.
(A) The brightness of the even / odd field may be measured by capturing an image of a dedicated mark composed of a uniform reflective surface shown in the LM. The dedicated mark only needs to be present in a range that does not affect the mark measurement in the visual field. The arrangement of the dedicated mark may be on the stage reference mark 3 side or on the reticle side mark 10. The use of a dedicated mark eliminates the need to determine the mark position. Even with special mark
The brightness of the / odd field is measured by the following equation.

[0054]

(Equation 5)

A one-dimensional signal or a two-dimensional image is corrected using Es and Os obtained by Equations 5 and 6, and Equations 3 and 4.

In this embodiment, an example in which a device for generating pulsed light is used as an illumination device has been described. This is because the temporal change in illuminance is large. However, when a temporal change in illuminance occurs even in a lighting device that emits light continuously, the present correction method and measurement method are effective.
For example, a temporal change in illuminance occurs in a discharge-type lamp or the like.

<Example of Semiconductor Production System> Next, an example of a production system for semiconductor devices (semiconductor chips such as ICs and LSIs, liquid crystal panels, CCDs, thin-film magnetic heads, micromachines, etc.) will be described. This includes maintenance services such as troubleshooting and periodic maintenance of manufacturing equipment installed in semiconductor manufacturing plants, and software provision.
This is performed using a computer network outside the manufacturing factory.

FIG. 6 shows the whole system cut out from a certain angle. In the figure, reference numeral 101 denotes a vendor that supplies a semiconductor device manufacturing apparatus (apparatus supplier).
Is a business establishment. Examples of manufacturing equipment include semiconductor manufacturing equipment for various processes used in semiconductor manufacturing factories, for example, pre-processing equipment (lithography equipment such as exposure equipment, resist processing equipment, etching equipment, heat treatment equipment, film formation equipment, planarization). Equipment) and post-process equipment (assembly equipment, inspection equipment, etc.). A host management system 1 that provides a maintenance database for manufacturing equipment in the business office 101
08, a plurality of operation terminal computers 110, and a local area network (LAN) 109 connecting these to construct an intranet. Host management system 1
Reference numeral 08 includes a gateway for connecting the LAN 109 to the Internet 105, which is an external network of the business office, and a security function for restricting external access.

On the other hand, reference numerals 102 to 104 denote manufacturing factories of a semiconductor device manufacturer as a user of the manufacturing apparatus. The manufacturing factories 102 to 104 may be factories belonging to different manufacturers or factories belonging to the same manufacturer (for example, a factory for a pre-process, a factory for a post-process, etc.). In each of the factories 102 to 104, a plurality of manufacturing apparatuses 106 and a local area network (LAN) 111 connecting them to construct an intranet are provided.
And a host management system 107 as a monitoring device for monitoring the operation status of each manufacturing apparatus 106. Host management system 1 provided in each factory 102 to 104
Reference numeral 07 includes a gateway for connecting the LAN 111 in each factory to the Internet 105 which is an external network of the factory. As a result, access to the host management system 108 on the vendor 101 side from the LAN 111 of each factory via the Internet 105 is possible, and only a limited user is permitted access by the security function of the host management system 108. Specifically, each manufacturing apparatus 1 is connected via the Internet 105.
In addition to notifying the vendor of the status information (for example, the symptom of the manufacturing apparatus in which the trouble has occurred) indicating the operation status of No. 06, the response information (for example,
(Information instructing how to cope with a trouble, software and data for coping), and maintenance information such as the latest software and help information can be received from the vendor side. A communication protocol (TCP / IP) generally used on the Internet is used for data communication between each of the factories 102 to 104 and the vendor 101 and data communication with the LAN 111 in each of the factories. Instead of using the Internet as an external network outside the factory, it is also possible to use a dedicated line network (such as ISDN) that cannot be accessed by a third party and has high security. Further, the host management system is not limited to the one provided by the vendor, and a user may construct a database and place it on an external network, and permit access to the database from a plurality of factories of the user.

FIG. 7 is a conceptual diagram showing the whole system of the present embodiment cut out from another angle from FIG.
In the above example, a plurality of user factories each having a manufacturing device and a management system of a vendor of the manufacturing device are connected via an external network, and the production management of each factory and at least one device are connected via the external network. The data of the manufacturing apparatus was communicated. On the other hand, in this example, a factory equipped with manufacturing equipment of a plurality of vendors and a management system of each vendor of the plurality of manufacturing apparatuses are connected via an external network outside the factory, and maintenance information of each manufacturing equipment is stored. It is for data communication. In the figure, reference numeral 201 denotes a manufacturing factory of a manufacturing apparatus user (semiconductor device manufacturer), and a manufacturing apparatus for performing various processes is provided on a manufacturing line of the factory, for example, an exposure apparatus 202, a resist processing apparatus 203, and a film forming processing apparatus. 204 have been introduced. Although only one manufacturing factory 201 is illustrated in FIG. 7, a plurality of factories are actually networked similarly. Each device in the factory is connected by a LAN 206 to form an intranet, and the host management system 205 manages the operation of the production line. On the other hand, the exposure apparatus maker 210,
Resist processing equipment maker 220, deposition equipment maker 2
Each of the offices of vendors (equipment suppliers) such as 30 includes host management systems 211, 221, and 231 for remote maintenance of the supplied equipment, and as described above, these include a maintenance database and an external network gateway. Is provided. The host management system 205 that manages each device in the user's manufacturing plant and the management systems 211, 221, and 231 of the vendors of each device are connected by the external network 200, ie, the Internet or a dedicated line network. In this system, if a trouble occurs in any of a series of manufacturing equipment on the manufacturing line, the operation of the manufacturing line is stopped, but remote maintenance is performed via the Internet 200 from a vendor of the troubled equipment. As a result, quick response is possible, and downtime of the production line can be minimized.

Each of the manufacturing apparatuses installed in the semiconductor manufacturing factory has a display, a network interface, and a computer that executes network access software and apparatus operation software stored in a storage device. The storage device is a built-in memory, a hard disk, a network file server, or the like. The network access software includes a dedicated or general-purpose web browser,
For example, a user interface having a screen as shown in FIG. 8 is provided on the display. The operator who manages the manufacturing equipment at each factory refers to the screen and refers to the manufacturing equipment model (401), serial number (402), trouble subject (403), date of occurrence (404), urgency (405), Information such as a symptom (406), a coping method (407), and a progress (408) is input to input items on the screen. The input information is transmitted to the maintenance database via the Internet, and the resulting appropriate maintenance information is returned from the maintenance database and presented on the display. The user interface provided by the web browser further includes a hyperlink function (410 to 41) as shown in the figure.
2), the operator can access more detailed information of each item, extract the latest version of software used for the manufacturing device from the software library provided by the vendor, and operate the operation guide ( Help information). Here, the maintenance information provided by the maintenance database includes information relating to correction of the illuminance deviation between the even field (or pixel) and the odd field (or pixel) of the mark image data described above. The latest software to realize mark measurement including correction is also provided.

Next, a process for manufacturing a semiconductor device using the above-described production system will be described. FIG. 9 shows a flow of the whole semiconductor device manufacturing process. In step 1 (circuit design), the circuit of the semiconductor device is designed. Step 2 is a process for making a mask on the basis of the circuit pattern design. Step 3
In (wafer manufacture), a wafer is manufactured using a material such as silicon. Step 4 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer by lithography using the prepared mask and wafer. The next step 5 (assembly) is called a post-process, and step 4
Is a process of forming a semiconductor chip using the wafer produced by the above-described process, and includes an assembly process such as an assembly process (dicing and bonding) and a packaging process (chip encapsulation). In step 6 (inspection), inspections such as an operation confirmation test and a durability test of the semiconductor device manufactured in step 5 are performed. Through these steps, a semiconductor device is completed and shipped (step 7). The pre-process and the post-process are performed in separate dedicated factories, and maintenance is performed for each of these factories by the above-described remote maintenance system. Further, information for production management and apparatus maintenance is also communicated between the pre-process factory and the post-process factory via the Internet or a dedicated line network.

FIG. 10 shows a detailed flow of the wafer process. Step 11 (oxidation) oxidizes the wafer's surface. Step 12 (CVD) forms an insulating film on the wafer surface. Step 13 (electrode formation) forms electrodes on the wafer by vapor deposition. In step 14 (ion implantation), ions are implanted into the wafer. Step 1
In 5 (resist processing), a photosensitive agent is applied to the wafer. Step 16 (exposure) uses the above-described exposure apparatus to print and expose the circuit pattern of the mask onto the wafer. Step 17 (development) develops the exposed wafer. In step 18 (etching), portions other than the developed resist image are removed. In step 19 (resist stripping), unnecessary resist after etching is removed. By repeating these steps, multiple circuit patterns are formed on the wafer. Since the manufacturing equipment used in each process is maintained by the remote maintenance system described above, troubles can be prevented beforehand, and if troubles occur, quick recovery is possible. Productivity can be improved.

[0064]

As described above, according to the present invention, even when there is an illuminance difference between the even field and the odd field, the noise caused by the illuminance difference is corrected by the image capturing using the interlaced storage area sensor. By using the image after the correction, stable mark measurement accuracy can be maintained. Therefore, in the manufacture of semiconductors, it is possible to contribute to the improvement of the yield by increasing the accuracy of measurement.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an embodiment of the present invention.

FIG. 2 is a configuration diagram of a semiconductor manufacturing apparatus which is an example of an application target of the present invention.

FIG. 3 is a diagram for explaining timing of oscillation means, laser emission, and image accumulation.

FIG. 4 is a diagram showing an interlaced image capture.

FIG. 5 is a diagram showing variations in laser pulse energy.

FIG. 6 is a conceptual view of a semiconductor device production system viewed from a certain angle.

FIG. 7 is a conceptual diagram of a semiconductor device production system viewed from another angle.

FIG. 8 is a specific example of a user interface.

FIG. 9 is a diagram illustrating a flow of a device manufacturing process.

FIG. 10 is a diagram illustrating a wafer process.

[Description of Signs] 1: reticle (reticle reference plate), 2: projection lens, 3: stage reference plate, 7: swing means, 8: C
CD camera, 12: image adding device, 13: synchronous signal generator, 14: image processing device, 15: excimer laser (pulse laser), 16: exposure device control device, 17: swing control device, 18: stage control device , 19: interferometer.

 ──────────────────────────────────────────────────続 き Continuing on the front page F term (reference) 2F065 AA20 BB27 CC20 EE03 FF04 FF42 GG05 GG08 JJ03 JJ26 LL00 LL13 MM26 NN02 NN17 PP12 QQ03 QQ13 QQ24 QQ27 QQ28 QQ36 QQ42 5B047 AA12 FA02 CB04 BA03 CB04 FA10 FA16 FB06 FC04

Claims (16)

[Claims] 1. A method for determining the brightness of an even field and an odd field of an image stored temporally separated into an even field and an odd field, obtaining a constant for correcting a deviation of the brightness, and obtaining the constant of the even field and the odd field. An image processing apparatus, wherein the brightness of a field is corrected by the constant. 2. An apparatus for measuring reflected light reflected from a mark illuminated with light output from a lighting device by capturing the reflected light from the mark using an interlaced storage area sensor.
The brightness of the even field and the odd field of the image captured by the accumulation type area sensor were obtained, a constant for correcting the deviation of the brightness was obtained, and the brightness of the even field and the odd field were corrected by the constant. A mark measuring device, wherein the mark is measured using an image signal. 3. An apparatus for measuring reflected light reflected from a mark illuminated by light output from a lighting device by capturing the reflected light from the mark using an interlaced storage area sensor.
A processing window is set on the image captured by the accumulation type area sensor, one-dimensional information integrated in the scanning line direction is created, and the brightness of even-numbered pixels and odd-numbered pixels in the one-dimensional information is obtained. A mark measuring device, wherein a constant for correcting a deviation in brightness is obtained, and the mark is measured using one-dimensional information corrected by the constant. 4. The illumination device outputs light whose light quantity changes with time, and a deviation of a signal level between the even field and the odd field is caused by a change in the light quantity between timings at which the even field and the odd field are imaged. The mark measuring device according to claim 2 or 3, wherein 5. The mark measurement device according to claim 2, wherein the illumination device is a pulse light generation device. 6. The mark measuring apparatus according to claim 5, wherein the pulse light generator is an excimer laser. 7. The mark measuring device according to claim 2, wherein the accumulation type area sensor is a CCD camera. 8. A semiconductor manufacturing apparatus for projecting a mask pattern on a mask stage onto a wafer on a wafer stage via a projection lens, wherein at least one of an alignment mark on the mask stage and an alignment mark on the wafer stage is A semiconductor manufacturing apparatus that performs position measurement using the mark measuring apparatus according to claim 2. 9. A semiconductor manufacturing apparatus for projecting a mask pattern on a mask stage onto a wafer on a wafer stage via a projection lens, wherein at least one of a contrast measurement mark on the mask stage and a contrast measurement mark on the wafer stage is Any one of claims 2 to 7
A semiconductor manufacturing apparatus characterized in that measurement is performed using the mark measuring apparatus described in (1). 10. A step of installing a manufacturing apparatus group for various processes including the semiconductor manufacturing apparatus according to claim 8 in a semiconductor manufacturing factory, and manufacturing a semiconductor device by a plurality of processes using the manufacturing apparatus group. And a method of manufacturing a semiconductor device. 11. A step of connecting the group of manufacturing apparatuses via a local area network, and data communication between at least one of the group of manufacturing apparatuses between the local area network and an external network outside the semiconductor manufacturing plant. 11. The method of claim 10, further comprising the step of: 12. A database provided by a vendor or a user of the semiconductor manufacturing apparatus is accessed via the external network to obtain maintenance information of the manufacturing apparatus by data communication, or a semiconductor manufacturing apparatus different from the semiconductor manufacturing factory. The method according to claim 11, wherein data is communicated with a factory via the external network to control production. 13. A group of manufacturing apparatuses for various processes including the semiconductor manufacturing apparatus according to claim 8, a local area network connecting the group of manufacturing apparatuses, and an external network outside the factory from the local area network. A semiconductor manufacturing plant having a gateway for enabling access and capable of performing data communication of information on at least one of the manufacturing apparatus groups. 14. The semiconductor device according to claim 8, which is installed in a semiconductor manufacturing plant.
Or a maintenance method for a semiconductor manufacturing apparatus according to 9, wherein
A step of providing a maintenance database connected to an external network of a semiconductor manufacturing plant by a vendor or a user of the manufacturing apparatus, and a step of permitting access to the maintenance database from the inside of the semiconductor manufacturing factory via the external network. Transmitting the maintenance information stored in the maintenance database to the semiconductor manufacturing factory via the external network. 15. The semiconductor manufacturing apparatus according to claim 8, further comprising a display, a network interface, and a computer for executing network software, wherein maintenance information of the semiconductor manufacturing apparatus is transmitted via a computer network. Semiconductor manufacturing equipment that enables data communication. 16. The network software,
Provided on the display is a user interface for accessing a maintenance database provided by a vendor or user of the semiconductor manufacturing apparatus connected to an external network of a factory where the semiconductor manufacturing apparatus is installed, and providing the user interface via the external network. 16. The device according to claim 15, which makes it possible to obtain information from a database.