JP2001319858A - Alignment-mark position measuring method, pattern exposure system, semiconductor device manufacturing method, semiconductor manufacturing plant, and pattern exposure system maintaining method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To immediately remove a measurement result or to measure an alternative position when an error measurement occurs or a predetermined measuring accuracy deteriorates. SOLUTION: In an alignment mark position measuring method for sequentially measuring positions of a plurality of alignment marks on an object necessary for aligning the object, every time the positions of one or a predetermined number of alignment marks are measured (step S3), an error measurement or the presence or absence of deterioration of a predetermined measuring accuracy is detected (step S9).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applicable to position measurement of a wafer, a mask, a part (a stage, etc.) of a semiconductor exposure apparatus for projecting and exposing an electronic circuit pattern onto a semiconductor substrate. Alignment mark position measurement method used for precise alignment and the like such as relative alignment of a mask, a mask and an apparatus reference position, apparatus parts, etc., an exposure apparatus using the same, a semiconductor device manufacturing method, a semiconductor manufacturing plant, and a semiconductor manufacturing method The present invention relates to a method for maintaining the exposure apparatus installed in a factory.

[0002]

2. Description of the Related Art Methods and apparatuses for precisely measuring the position of an object are used in various fields such as machine tools and robots, and further improvements in accuracy are required. For example,
2. Description of the Related Art In semiconductor exposure apparatuses, in recent years, the degree of integration of semiconductors typified by DRAMs has become increasingly higher, and the pattern dimensions formed on semiconductor elements have become finer. From such a background, in a semiconductor exposure apparatus, position measurement (alignment) between a reticle serving as an original plate and a wafer serving as a substrate is an indispensable technique, and further improvement in accuracy is an important issue.

FIG. 2 shows a conventional semiconductor exposure apparatus. In the figure, R is a reticle which is an original plate, W is a wafer which is a substrate on which a pattern of the reticle R is exposed, and 1 is a projection optical system which projects the pattern of the reticle R onto the substrate W. G is a positioning optical system for positioning the wafer W, and includes a positioning illumination unit 2, a beam splitter 3, an imaging optical system 4, and an imaging unit 5. Reference numeral 6 denotes A / D conversion means for converting the output of the imaging means 5 into a digital signal, 7 denotes integration means for integrating the output of the A / D conversion means 6, 8 denotes the position of the alignment mark based on the output of the integration means 7. 9 is a control means for controlling each part of the apparatus, 10 is a stage driving means, 11 is an XY that is driven by the stage driving means 10 and is movable in two dimensions.
The stage.

Although FIG. 2 shows only the positioning optical system G for detecting the position in the x direction, a similar positioning optical system for detecting the position in the y direction (not shown) is also provided. ing. Further, the integrating means 7, the position detecting means 8, and the control means 9 can be realized by a board computer or a general-purpose computer, and the same device may be shared. Of course, each may be realized by a dedicated electronic circuit.

[0005] This exposure apparatus for manufacturing a semiconductor device uses a reticle R
After the relative positioning of the wafer and the wafer W, exposure light is irradiated from an exposure illumination light source (not shown), and the electronic circuit pattern formed on the reticle R is transferred onto the XY stage 11 via the projection optical system 1. Is exposed on the wafer W placed on the wafer. FIG.
FIG. 1 shows an example of an exposure area on a wafer. FIG. 4 shows exposure areas S1 to S6 (hereinafter, referred to as measurement shots) as examples of exposure areas used for measurement.

FIG. 5 is a flowchart showing a procedure of a process of performing relative exposure between a reticle R and a wafer W by a global alignment method in the apparatus shown in FIG. When the process starts, first, in step S
In 1, a wafer W roughly positioned in advance is placed on an XY stage 11 by a wafer transfer device (not shown). Next, in step S2, the control means 9 controls the position of the alignment mark M1x formed on the first measurement shot S1 in FIG. To drive the XY stage 11.

Next, in step S3, the position of the alignment mark M1x is measured in the following procedure. First, the alignment mark M1x is illuminated by the beam emitted from the positioning illumination device 2 that emits non-exposure light via the beam splitter 3, the reticle R, and the projection optical system 1. The alignment mark M1x is, for example, as shown in FIG.
As shown in the figure, the frame is composed of four rectangular mark portions having the same shape. The light beam reflected by the alignment mark M1x again reaches the beam splitter 3 via the projection optical system 1 and the reticle R, is reflected there, and is aligned on the imaging surface of the imaging device 5 via the imaging optical system 4. M1x
Is formed. The image of the alignment mark M1x is photoelectrically converted by the imaging device 5, and is converted into a two-dimensional digital signal sequence by the A / D converter 6. Further, a processing window Wp is set in the integrating device 7 as shown in FIG. 6 with respect to the alignment mark image WM converted into a digital signal, and an addition process is performed in the Y direction in the window. It is converted into a one-dimensional digital signal sequence S (x). For each alignment mark of the digital signal sequence S (x), the position detection device 8 performs pattern matching using a template pattern stored in advance, and S (x) having the highest similarity with the template pattern. Is output to the control means 9. This output signal is output to the imaging device 5
Since the position of the alignment mark is based on the imaging surface of the reticle R, the control unit 9 determines the amount of deviation of the alignment mark M1x from the reticle R from the relative position of the imaging device 5 and the reticle R obtained in advance by a method (not shown). Is calculated. Thus, the displacement amount in the x direction of the first measurement shot has been measured. Next, the control means 9 sets the y-direction measurement alignment mark M of the first measurement shot S1.
The XY stage 11 is driven so that 1y falls within the field of view of the y-direction alignment optical system. Here, the displacement amount in the y direction is measured in the same procedure as in the x direction measurement. Above,
The measurement in the measurement shot S1 ends.

In the same manner, steps S2 and S3 are repeated until it is determined in step S4 that the predetermined number of measurement shots has been measured, and the measurement positional deviation amount in each measurement shot is measured.

Next, in steps S5 and S6,
The relative position of the wafer W with respect to the reticle R is adjusted according to the following procedure based on the amount of displacement in each measurement shot measured in step S3, and exposure is performed. That is, in step S5, a statistical calculation is performed based on the design alignment mark position in each measurement shot and the positional deviation amount in each measurement shot measured in step S3, so that the wafer position for performing alignment is determined. Correction amount, ie, x
And the parallel displacement in the y direction, the elongation in the x and y directions, and the rotational displacement in the x and y axes. Then, in step S6, the XY stage 11 is driven based on the wafer position correction amount obtained in step S5 under the control of the control means 9, and all the shots formed on the wafer W are exposed.

Next, in step S7, the wafer W is discharged from the XY stage 11 by a wafer transfer device (not shown). Further, the operations in steps S1 to S7 are
In step S8, the process is repeated until it is determined that the exposure process has been completed for all wafers to be processed.

The semiconductor exposure apparatus and the wafer alignment method have been described above. Here, wafer position measurement has been described as an example of the alignment mark position measurement method. However, such an alignment mark position measurement method is also applicable to position measurement of a mask (or a reticle) or a part of a semiconductor exposure apparatus such as a stage. The present invention is also applicable to a relative alignment between a mask (or a reticle) and an apparatus reference position or between apparatus parts.

On the other hand, an alignment mark used in a semiconductor exposure apparatus or the like may have unevenness in the level of the alignment mark generated in a semiconductor manufacturing process or unevenness in the thickness of a photoresist applied on the alignment mark. In some cases, the shape of the mark waveform obtained by imaging the alignment mark may be deformed, thereby causing erroneous measurement or deterioration of measurement accuracy. A similar phenomenon also occurs in rough wafer positioning performed before the wafer is placed on the XY stage 11, and the alignment mark may be sent out of the measurement range of the alignment mark position measurement to cause erroneous measurement. On the other hand, in the above-described conventional example, an erroneous measurement or a measurement shot whose measurement accuracy has deteriorated during the statistical processing in step S5 is detected and excluded from the statistical processing, or a substitute measurement shot is measured again to improve the accuracy. Deterioration is prevented.

[0013]

However, according to the above-mentioned prior art, erroneous measurement and deterioration of accuracy cannot be detected unless measurement is performed using predetermined measurement shots and statistical processing is performed. It takes time to perform operations such as exclusion from statistical processing and remeasurement of a substitute measurement shot.

In recent years, there has been a tendency to reduce the number of measurement shots for the purpose of improving productivity, and the effect of preventing the deterioration of accuracy has been limited only by the statistic processing. Furthermore, new semiconductor manufacturing techniques such as CMP have been introduced, and from the viewpoint of alignment mark measurement, erroneous measurement and accuracy deterioration are likely to occur.

Accordingly, the present invention provides an alignment mark position measurement method, an exposure apparatus, a semiconductor device manufacturing method, a semiconductor manufacturing factory, and a maintenance method for an exposure apparatus, which eliminates a measurement result when an erroneous measurement or a predetermined measurement accuracy deterioration occurs. Another object of the present invention is to improve productivity by enabling immediate or alternative position measurement.

[0016]

In order to solve this problem, a first alignment mark position measuring method according to the present invention is to sequentially measure the positions of a plurality of alignment marks on an object necessary for alignment of the object. The method for measuring the position of an alignment mark to be performed is characterized in that, for each position measurement of one or a predetermined number of alignment marks, the presence or absence of erroneous measurement or deterioration of a predetermined measurement accuracy is detected.

The second alignment mark position measuring method is the same as the first alignment mark position measuring method,
The position measurement of the alignment mark is performed based on an image signal obtained by imaging the alignment mark, and the detection of the erroneous measurement or the deterioration of the measurement accuracy is performed based on the image signal.

A third alignment mark position measuring method is the same as the second alignment mark position measuring method,
The detection of the erroneous measurement or the deterioration of the measurement accuracy is performed by comparing the contrast of a mark portion of the alignment mark with another portion of the image signal.

In a fourth alignment mark position measuring method, in the second or third alignment mark position measuring method, the presence or absence of the erroneous measurement or the deterioration of the measurement accuracy is determined by detecting the presence or absence of the mark portion between the mark portions of the alignment mark in the image signal. Is performed on the basis of the interval.

In a fifth alignment mark position measuring method, in any one of the second to fourth alignment mark position measuring methods, the presence or absence of the erroneous measurement or the deterioration of the measurement accuracy is determined by integrating the image signals in a predetermined direction. The method is characterized in that it is performed based on the degree of symmetry of a portion corresponding to each mark portion of the alignment mark in a one-dimensionally obtained waveform.

According to a sixth alignment mark position measuring method, in any one of the first to fifth alignment mark position measuring methods, the object is aligned by a global alignment method, and an exposure target substrate is exposed. It is characterized by being.

The seventh alignment mark position measuring method is the same as the sixth alignment mark position measuring method,
When the erroneous measurement or the deterioration of the predetermined measurement accuracy is detected, the position measurement result of the alignment mark of the shot accompanied by the detected alignment mark is not used for the alignment.

According to an eighth alignment mark position measuring method, in the sixth or seventh alignment mark position measuring method, when the erroneous measurement or the predetermined measurement accuracy deterioration is detected, the detection is immediately performed. It is characterized in that position measurement is performed on an alignment mark of a shot that substitutes for a shot accompanied by the alignment mark.

Further, the first exposure apparatus of the present invention employs any one of the first to eighth alignment mark position measuring methods to align and expose a substrate to be exposed. It is characterized by comprising means for measuring the position of the alignment mark.

The second exposure apparatus is the same as the first exposure apparatus, except that a display, a network interface,
A computer for executing network software, wherein maintenance information of the exposure apparatus can be data-communicated via a computer network.

The third exposure apparatus is the second exposure apparatus, wherein the network software is connected to an external network of a factory where the exposure apparatus is installed and is provided by a vendor or a user of the exposure apparatus. A user interface for accessing a database is provided on the display, and information can be obtained from the database via the external network.

Further, according to the method of manufacturing a semiconductor device of the present invention, a manufacturing apparatus group for various processes including the first exposure apparatus is installed in a semiconductor manufacturing factory, and a plurality of processes are performed by using the manufacturing apparatus group. And a step of manufacturing a semiconductor device.

According to a second method of manufacturing a semiconductor device, in the first method of manufacturing a semiconductor device, a step of connecting the group of manufacturing apparatuses via a local area network, and a step of connecting the local area network to an external network outside the semiconductor manufacturing plant. At least one of the manufacturing equipment
Data communication of information about the platform.

According to a third semiconductor device manufacturing method, in the second semiconductor device manufacturing method, a database provided by a vendor or a user of the exposure apparatus is accessed via the external network to maintain the manufacturing apparatus by data communication. The method is characterized in that information is obtained or data is communicated between the semiconductor manufacturing factory and another semiconductor manufacturing factory via the external network to perform production management.

Further, the semiconductor manufacturing plant of the present invention comprises a group of manufacturing apparatuses for various processes including the first exposure apparatus, a local area network connecting the group of manufacturing apparatuses,
It has a gateway that enables access from the local area network to an external network outside the factory, and enables data communication of information on at least one of the manufacturing apparatus groups.

The maintenance method for an exposure apparatus according to the present invention is the maintenance method for the first exposure apparatus installed in a semiconductor manufacturing plant, wherein a vendor or a user of the exposure apparatus
Providing a maintenance database connected to an external network of a semiconductor manufacturing plant, allowing access to the maintenance database from within the semiconductor manufacturing plant via the external network, and maintenance stored in the maintenance database Transmitting information to the semiconductor manufacturing factory via the external network.

In the configuration of the present invention, every time the position of one or a predetermined number of alignment marks is measured, the presence or absence of an erroneous measurement or a predetermined deterioration in measurement accuracy is detected. According to this, after measuring the position of all the alignment marks necessary for alignment, and then detecting whether there is any erroneous measurement or deterioration of the measurement accuracy, the measurement result is excluded or the position of the alternative alignment mark is measured. Compared with the related art, the elimination of the measurement result and the position measurement of the alternative alignment mark in the case of erroneous measurement or deterioration of the measurement accuracy are immediately performed, and the alignment is performed quickly. Therefore, the productivity of the exposure apparatus to which the present invention is applied is improved.

[0033]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a preferred embodiment of the present invention, erroneous measurement or deterioration of measurement accuracy is detected when measuring the position of each alignment mark by the following three detection methods 1 to 3. As a result, before performing statistical calculations based on all position measurement results, it is possible to delete measurement shots that have caused erroneous measurement or measurement accuracy deterioration from statistical calculations, or to measure alternative measurement shots ,
It is possible to reduce a decrease in productivity due to erroneous measurement or deterioration of measurement accuracy.

(Detection Method 1) In a configuration similar to that shown in FIG. 2, the contrast of the waveform of the detected mark portion is compared with the contrast of the waveform of the portion having no mark to detect erroneous measurement or deterioration of measurement accuracy. That is, as described above, the XY stage 11
If an error occurs in the positioning of the rough wafer performed before the wafer is placed on the alignment mark, the alignment mark is sent out of the measurement range of the alignment mark position measurement, and FIG.
The erroneous measurement shown in FIG. FIG. 7A shows the waveform of the signal sequence S (x) obtained by the integrating device 7 when the measurement is performed normally, and FIG.
Indicates the measurement position of each mark part constituting the alignment mark. In addition, as shown in FIG. 8, an alignment mark having an extremely low contrast of the waveform of the mark portion is largely affected by the base of the alignment mark, and the measurement accuracy may be deteriorated. On the other hand, in the present detection method, as shown in FIG. 9, the contrast of each mark portion and the contrast of a portion having no mark are compared to detect erroneous measurement or deterioration of measurement accuracy. For example, a case where the minimum value of the contrast of the mark part is smaller than the maximum value of the contrast of the part without the mark is detected as erroneous measurement or deterioration of measurement accuracy.

(Detection method 2) Erroneous measurement or deterioration of measurement accuracy is detected based on the distance between the positions of the measured mark portions. That is, when erroneous measurement of the alignment mark or deterioration of the measurement accuracy occurs, it is considered that the interval between the mark portions shown in FIG. 10 is different from the design value. From this, erroneous measurement or deterioration of measurement accuracy is detected based on the interval between mark portions. For example, a case where the difference between the measured interval between mark portions and the design value is larger than a preset threshold value is detected as erroneous measurement or measurement accuracy deterioration.

(Determination Method 3) Deterioration of measurement accuracy is detected from the asymmetricity of the waveform of the mark portion. In other words, if there is unevenness in the level of the alignment mark or unevenness in the thickness of the photoresist applied on the alignment mark, the situation shown in FIG.
As shown in FIG. 1, it is known that the waveform shape of each mark portion is left-right asymmetric and measurement errors occur. From this, the symmetry of the waveform of the mark portion is calculated, and the measurement accuracy deterioration is detected.

Any of these detection methods may be used alone or in combination. When used in combination, it can be detected, for example, as follows according to the allowable range of accuracy deterioration. If erroneous measurement or measurement accuracy deterioration is detected by any of the methods, it is regarded as erroneous measurement or measurement accuracy deterioration. When erroneous measurement or measurement accuracy deterioration is detected by any of the methods, erroneous measurement or measurement accuracy deterioration is determined.

As described above, in one embodiment of the present invention, in a semiconductor exposure apparatus or the like, when measuring the position of each alignment mark, erroneous measurement or deterioration of measurement accuracy is detected by one or more methods using the measurement position. And an erroneous measurement detecting step.

[0039]

[Embodiment 1] FIG. 1 is a flow chart showing the alignment and exposure processing procedure according to the first embodiment when the present invention is applied to the semiconductor manufacturing exposure apparatus of FIG. In this example, erroneous measurement or deterioration of measurement accuracy is detected by comparing the contrast of the measured mark part with the contrast of the part without the mark. The processing in steps S1 to S8 in FIG. 1 is the same as that in steps S1 to S8 in FIG.

As shown in FIG. 1, when the position measurement in step S3 is completed, in step S9, FIG.
In this method, erroneous measurement or measurement accuracy deterioration is detected. That is, in step S101, the contrast between the marked part shown in FIG. 9 and the part without the mark is measured. For example, the contrast between the marked part and the part without the mark is calculated from the difference between the maximum value and the minimum value of each part, the variance of the value of each part, and the like.

Next, in step S102, erroneous measurement or deterioration of measurement accuracy is determined based on the contrast between the mark portion and the mark-less portion measured in step 101. For example, when any of the following equations 1 to 4 is satisfied, it is determined that the measurement is erroneous or the measurement accuracy is deteriorated. One of the judgment formulas is selected and applied in advance according to the allowable range of the measurement accuracy deterioration.

[0042]

(Equation 1)

[0043]

(Equation 2)

[0044]

(Equation 3)

[0045]

(Equation 4)

Thereafter, in step S10, it is determined whether or not erroneous measurement or deterioration of measurement accuracy has been detected in step S9. As a result, if it is determined that erroneous measurement or measurement accuracy deterioration has been detected, the process proceeds to step S11.
The process proceeds to step 2 in order to exclude the measurement result of No. 3 from the statistical processing and to measure another measurement shot again. If it is determined that erroneous measurement or deterioration of measurement accuracy has not been detected, the process proceeds to step S4 as usual. Note that the method of this embodiment may be used in combination with the methods of other embodiments.

[Embodiment 2] As a second embodiment, another alignment and exposure processing procedure when the present invention is applied to the semiconductor manufacturing exposure apparatus of FIG. 2 will be described. In this example, erroneous measurement or measurement accuracy deterioration is detected from the interval between the measured mark positions.

Although the processing procedure of this embodiment is as shown in FIG. 1, only the processing of step S9 is different from that of the first embodiment. In step S9, erroneous measurement or deterioration of measurement accuracy is detected by the method shown in FIG. That is, first, in step S201, the interval between the positions of the mark portions measured in step S3 is calculated. For example, when the positions of four mark portions are measured, the interval between the first and second lines from the left, the interval between the second and third lines from the left, and the interval between the third and fourth lines from the left are calculated. Next, step S2
In 02, erroneous measurement or deterioration of measurement accuracy is determined based on the interval between the mark portions calculated in step S201. For example, a comparison is made with a design value of the interval between the mark portions, and if the difference between the design value and the interval between any of the mark portions is equal to or greater than a preset threshold value, it is determined that an erroneous measurement or a deterioration in measurement accuracy has occurred. Note that the method of this embodiment may be used in combination with the methods of other embodiments.

[Embodiment 3] As a third embodiment, still another alignment and exposure processing procedure when the present invention is applied to the semiconductor manufacturing exposure apparatus of FIG. 2 will be described. In this example, erroneous measurement or measurement accuracy deterioration is detected from the symmetry of the mark waveform.

Although the processing procedure of this embodiment is as shown in FIG. 1, only the processing of step S9 is different from that of the first embodiment. In step S9, erroneous measurement or deterioration of measurement accuracy is detected by the method shown in FIG. That is, first, in step S301, for each of the mark portions measured in step S3, the signal train S
Based on the waveform (x), the degree of symmetry of the waveform of the mark portion is calculated. For example, as shown in FIG. 11, a processing window is set on the left and right around the measured mark position, and the average symmetry and the contrast symmetry are calculated by the following equations.

[0051]

(Equation 5) Next, in step S302, erroneous measurement or deterioration of measurement accuracy is determined from the target degree of the mark waveform calculated in step 301. For example, the average symmetry and the contrast symmetry are compared with a preset threshold, and if either symmetry is smaller than the threshold, erroneous measurement or measurement accuracy deterioration is determined. Note that the method of this embodiment may be used in combination with the methods of other embodiments.

<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. 15 shows the entire system cut out from a certain angle. In the figure, reference numeral 101 denotes a business establishment of a vendor (apparatus supply maker) that provides a semiconductor device manufacturing apparatus. As an example of a manufacturing apparatus, a semiconductor manufacturing apparatus for various processes used in a semiconductor manufacturing plant, for example,
Pre-process equipment (lithography equipment such as exposure equipment, resist processing equipment, etching equipment, heat treatment equipment, film formation equipment,
It is assumed that flattening equipment and the like and post-processing equipment (assembly equipment, inspection equipment, etc.) are used. In the business office 101, a host management system 10 for providing a maintenance database of manufacturing equipment
8. It has a plurality of operation terminal computers 110 and a local area network (LAN) 109 connecting these to construct an intranet. Host management system 10
Reference numeral 8 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 semiconductor manufacturers as users 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, a local area network (LAN) 111 connecting them to construct an intranet, and a host management unit as a monitoring apparatus for monitoring the operation status of each manufacturing apparatus 106. A system 107 is provided. Each factory 10
The host management systems 107 provided in 2 to 104 are:
It has 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 from the LAN 111 of each factory to the host management system 108 on the vendor 101 side via the Internet 105 is possible, and only users limited by the security function of the host management system 108 are permitted to access. More specifically, the factory notifies the vendor of status information (for example, symptoms of the manufacturing apparatus in which a trouble has occurred) indicating the operating status of each manufacturing apparatus 106 via the Internet 105.
Response information corresponding to the notification (for example, information instructing a coping method for a trouble, software and data for coping), and maintenance information such as the latest software and help information can be received from the vendor. Each factory 10
For data communication between the vendors 2 to 104 and the vendor 101 and data communication on the LAN 111 in each factory, a communication protocol (TCP) generally used on the Internet is used.
/ IP) is used. 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 user factories.

FIG. 16 is a conceptual diagram showing the entire system according to the present embodiment cut out from a different 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 is connected to a management system of each of the plurality of manufacturing equipments 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 plant of a manufacturing apparatus user (semiconductor device manufacturer), and a manufacturing line for performing various processes, for example, an exposure apparatus 202, a resist processing apparatus 203;
A film forming apparatus 204 is introduced. Although only one manufacturing factory 201 is illustrated in FIG. 16, 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, each business establishment of a vendor (apparatus maker) such as an exposure apparatus maker 210, a resist processing apparatus maker 220, and a film forming apparatus maker 230 has a host management system 2 for performing remote maintenance of the supplied equipment.
11, 221 and 231, which comprise a maintenance database and an external network gateway as described above. The host management system 205 that manages each device in the user's manufacturing factory and the management systems 211, 221, and 231 of the vendors of each device are connected to the external network
Internet or a dedicated line network. In this system, if a trouble occurs in any of a series of manufacturing equipment in the manufacturing line, the operation of the manufacturing line is stopped, but remote maintenance is performed from the vendor of the troubled equipment via the Internet 200. 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 includes a display, a network interface, and a computer that executes network access software and apparatus operation software stored in a storage device. Examples of the storage device include a built-in memory, a hard disk, and a network file server. The network access software includes a dedicated or general-purpose web browser, and provides, for example, a user interface having a screen as shown in FIG. 17 on a display. The operator who manages the manufacturing equipment in each factory refers to the screen and refers to the manufacturing equipment model (401), serial number (402), trouble subject (403), date of occurrence (404), and urgency (40).
5), symptom (406), coping method (407), course (40)
8) Input information such as in the 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. Further, the user interface provided by the web browser further realizes a hyperlink function (410 to 412) as shown in the figure, so that the operator can access more detailed information of each item or use the software library provided by the vendor for the manufacturing apparatus. The latest version of software to be extracted can be extracted, and an operation guide (help information) can be extracted for reference by a factory operator. Here, the maintenance information provided by the maintenance database includes information on the features of the present invention described above, and the software library also provides software for realizing the features of the present invention.

Next, a manufacturing process of a semiconductor device using the above-described production system will be described. FIG. 18 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 is a process of forming a semiconductor chip using the wafer produced in step 4, and assembly such as an assembly process (dicing and bonding) and a packaging process (chip encapsulation). Process. 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. 19 shows a detailed flow of the above 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.

[0059]

As described above, according to the present invention, 1
In addition, the presence or absence of erroneous measurement or degradation of measurement accuracy is detected every time the position of a predetermined number of alignment marks is measured. Measurement can be performed immediately, and positioning can be performed quickly.
Therefore, the productivity of the exposure apparatus and the like to which the present invention is applied can be improved.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a registration and exposure processing procedure according to a first embodiment of the present invention.

FIG. 2 is a schematic view of a semiconductor exposure apparatus to which the present invention can be applied.

FIG. 3 is a view showing an exposure area of a wafer in the apparatus shown in FIG. 2;

FIG. 4 is a view showing a measurement shot on the wafer of FIG. 3;

FIG. 5 is a flowchart showing a conventional example of a wafer alignment method in the apparatus of FIG. 2;

FIG. 6 is a view for explaining an example of an alignment mark on the wafer of FIG. 3;

FIG. 7 is a diagram for explaining a mark waveform at the time of erroneous detection in the device of FIG. 2;

FIG. 8 is a diagram for explaining a low-contrast mark waveform in the apparatus of FIG. 2;

FIG. 9 is a diagram for explaining the contrast of a mark waveform in the apparatus of FIG. 2;

FIG. 10 is a diagram for explaining mark intervals in the apparatus of FIG. 2;

FIG. 11 is a diagram for explaining the degree of symmetry of a mark waveform in the apparatus of FIG. 2;

FIG. 12 is a flowchart showing step S in the flowchart of FIG. 1;
9 is a flowchart showing the process of No. 9.

FIG. 13 is a flowchart illustrating an alignment mark position measuring method according to a second embodiment of the present invention.

FIG. 14 is a flowchart illustrating an alignment mark position measuring method according to a third embodiment of the present invention.

FIG. 15 is a conceptual diagram of a semiconductor device production system viewed from a certain angle.

FIG. 16 is a conceptual diagram of a semiconductor device production system viewed from another angle.

FIG. 17 is a diagram illustrating a specific example of a user interface.

FIG. 18 is a diagram illustrating a flow of a device manufacturing process.

FIG. 19 is a diagram illustrating a wafer process.

[Explanation of symbols]

1: Projection optical system, 2: Alignment illumination means, 3: Beam splitter, 4: Imaging optical system, 5: Imaging means, 6: A /
D conversion means, 7: integration means, 8: position measurement means, 9: control means, 10: stage driving means, 11: XY stage, 101: business office, 102 to 104: manufacturing plant, 10
5: Internet, 106: manufacturing equipment, 107: host management system, 108: host management system, 10
9: local area network, 110: operation terminal computer, 111: local area network, 2
00: external network, 201: manufacturing factory, 202:
Exposure apparatus, 203: resist processing apparatus, 204: film formation processing apparatus, 205: host management system, 206: LA
N, 210: exposure apparatus maker, 211, 21 and 23
1: Host management system, 220: Resist processing apparatus maker, 230: Film forming apparatus maker, G: Alignment optical system, M1x to M6x: x-direction measurement alignment marks, M1y to M6y: y-direction measurement alignment marks, R: reticle, S (x): mark waveform, S1 to S
6: measurement shot, W: wafer, WM: alignment mark, Wp: processing window.

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Claims (16)

[Claims] 1. An alignment mark position measuring method for sequentially measuring the positions of a plurality of alignment marks on an object necessary for the alignment of the object, wherein an erroneous measurement is performed every time one or a predetermined number of alignment marks are measured. Alternatively, a method for measuring the position of an alignment mark, comprising detecting whether or not a predetermined measurement accuracy has deteriorated. 2. The method according to claim 1, wherein the position measurement of the alignment mark is performed based on an image signal obtained by imaging the alignment mark, and the detection of the erroneous measurement or the deterioration of the measurement accuracy is performed based on the image signal. The alignment mark position measuring method according to claim 1. 3. The alignment according to claim 2, wherein the detection of the erroneous measurement or the deterioration of the measurement accuracy is performed by comparing the contrast of a mark portion of the alignment mark with another portion of the image signal. Mark position measurement method. 4. The alignment mark according to claim 2, wherein the detection of the erroneous measurement or the deterioration of the measurement accuracy is performed based on an interval between each mark portion of the alignment mark in the image signal. Position measurement method. 5. The detection of the presence or absence of erroneous measurement or deterioration of measurement accuracy is performed by integrating the image signal in a predetermined direction and converting the one-dimensional waveform into a one-dimensional waveform to determine the degree of symmetry of a portion corresponding to each mark portion of the alignment mark. The alignment mark position measurement method according to claim 2, wherein the alignment mark position measurement is performed based on the information. 6. The apparatus according to claim 1, wherein the object is a substrate to be exposed, on which the alignment is performed by a global alignment method and exposure is performed.
Alignment mark position measurement method described in section. 7. When the erroneous measurement or the deterioration of the predetermined measurement accuracy is detected, a result of position measurement of an alignment mark of a shot accompanied by the detected alignment mark is not used for the alignment. The alignment mark position measuring method according to claim 6, wherein: 8. When the erroneous measurement or the predetermined measurement accuracy deterioration is detected, position measurement is immediately performed on an alignment mark of a shot that substitutes for a shot accompanied by the detected alignment mark. The alignment mark position measuring method according to claim 6 or 7, wherein the alignment mark position is measured. 9. An alignment mark position measuring method according to any one of claims 1 to 8, further comprising means for measuring a position of an alignment mark on the substrate to be exposed, in order to align and expose the substrate to be exposed. An exposure apparatus comprising: 10. The exposure apparatus according to claim 9, further comprising a display, a network interface, and a computer executing network software, and performing data communication of maintenance information of the exposure apparatus via a computer network. Exposure equipment made possible. 11. The network software,
Provided on the display is a user interface for accessing a maintenance database provided by a vendor or a user of the exposure apparatus connected to an external network of a factory where the exposure apparatus is installed, and from the database via the external network. 11. The device according to claim 10, which makes it possible to obtain information. 12. A step of installing a group of manufacturing apparatuses for various processes including the exposure apparatus according to claim 9 in a semiconductor manufacturing plant, and a step of manufacturing a semiconductor device by a plurality of processes using the group of manufacturing apparatuses. A method for manufacturing a semiconductor device, comprising: 13. A method for connecting said group of manufacturing apparatuses via a local area network, and performing data communication between said local area network and an external network outside said semiconductor manufacturing factory, the information relating to at least one of said group of manufacturing apparatuses. 13. The method of claim 12, further comprising the step of: 14. A semiconductor manufacturing factory different from the semiconductor manufacturing factory by accessing a database provided by a vendor or a user of the exposure apparatus via the external network to obtain maintenance information of the manufacturing apparatus by data communication. 14. The method according to claim 13, wherein data is communicated with the device via the external network to control production. 15. A group of manufacturing apparatuses for various processes including the exposure apparatus according to claim 9, a local area network connecting the group of manufacturing apparatuses, and an external network outside the factory can be accessed from the local area network. A gateway, and at least one of the manufacturing equipment groups
A semiconductor manufacturing plant that enables data communication of information about a table. 16. The semiconductor device according to claim 9, which is installed in a semiconductor manufacturing plant.
An exposure apparatus maintenance method according to the above, wherein a vendor or user of the exposure apparatus provides a maintenance database connected to an external network of a semiconductor manufacturing plant,
Allowing access to the maintenance database from the semiconductor manufacturing plant via the external network, and transmitting maintenance information stored in the maintenance database to the semiconductor manufacturing plant via the external network. A method of maintaining an exposure apparatus, comprising: