JP4403862B2 - Pellicle sticking position measuring device - Google Patents

Description

  The present invention relates to a pellicle sticking position measuring device for a photomask with a pellicle used in a photolithography process of a manufacturing process of a semiconductor integrated circuit, a liquid crystal display element and the like.

  In general, in the manufacturing process of a semiconductor integrated circuit and a liquid crystal display element, a pattern formed on a photomask is projected onto a substrate coated with a photosensitive agent such as a photoresist when various patterns are manufactured in a photolithography process. A projection exposure method is used in which exposure is carried out at the same time. In recent years, with the miniaturization of the pattern shape, the exposure light used tends to be shortened in wavelength. Instead of the mercury lamps that have been mainstream so far, KrF excimer laser (wavelength 248 nm) and ArF excimer laser (wavelength 193 nm). ) Has been put into practical use, and a considerable number of photomasks with a pellicle are used in the manufacturing process of semiconductor integrated circuits and liquid crystal display elements.

  An example of a photomask with a pellicle is shown in FIG. A photomask 90 with a pellicle is formed on a photomask 70 (see FIG. 4) in which a mask pattern 72 is formed of a light-shielding thin film made of chromium and chromium oxide on a transparent substrate 71 such as quartz glass. In order to prevent adhesion to the surface of the mask 70, a pellicle 80 (see FIG. 5) having a pellicle film 82 attached to a pellicle frame 81 is attached via an adhesive 91 or the like. A photomask with a pellicle is mainly used in the projection exposure method. Even if dust adheres to the pellicle film, the projection optical system is focused on the mask pattern on the photomask surface. Is not formed as an image on the exposed surface as a dust pattern and is not formed as a defect pattern.

When the pellicle 80 having the pellicle film 82 affixed to the pellicle frame 81 is affixed on the photomask 70, it is necessary to affix it to a predetermined position of the photomask 70 set in advance. Since the misalignment between the photomask 70 and the pellicle 80 does not cause a pattern misalignment of the photomask 70, strict accuracy as in the alignment mark is not required. However, the position of the photomask 70 and the pellicle 80 is not required. If the deviation is large, problems may occur due to automatic conveyance in the exposure process, setting in the exposure apparatus, and the like.
In order to improve the efficiency of the bonding operation, a method of bonding a pellicle to a photomask with a confirmation mark has been proposed (see, for example, Patent Document 1).

  As a method for confirming the accuracy of the position of the pellicle 80 in the photomask 90 with pellicle, the distance from the end surface of the photomask 70 to the pellicle frame 81 is measured using a caliper. Judgment / confirmation of whether it is out of alignment or within the standard.

As a method for confirming the accuracy of the position where the pellicle 80 is attached to the photomask 70, there are the following problems when measuring using a caliper.
(1) The variation of measured values is large (measurement reproducibility is poor).
(2) The variation (バ ラ, how to read) by the measurer is large.
(3) In order to perform measurement by bringing the caliper into contact with the end face of the photomask and the pellicle frame at the time of measurement, contact marks (scratches, foreign matter adhesion) are made on the photomask or the pellicle frame. (4) Since a person reads, records, and manually calculates a caliper value in the determination of the measured value, a human error such as an entry error or a calculation error may occur.
JP 11-237729 A

  The present invention was made in view of the above problems, and when measuring the pellicle sticking position accuracy of a photomask with a pellicle, the measurement by the measurer is eliminated, without causing scratches or foreign matter on the photomask and pellicle, It is an object of the present invention to provide a pellicle sticking position measuring device for a photomask with a pellicle that is excellent in measurement accuracy and measurement reproducibility.

To achieve the above object in the present invention, in the first claim 1, the measuring unit 10 consisting of a mounting jig 12 which is provided on at least the rotation stage 11 noncontact distance measuring device 15 for, the The pellicle sticking position measuring apparatus is characterized by comprising a determination / control unit 20 that feeds back the determination result of the pellicle sticking position measurement data of the photomask with pellicle measured by the measuring unit .

Further, in claim 2, the measurement unit 10 including at least the mounting jig 12 provided on the rotary stage 11 and the non-contact distance measuring device 15, and the pellicle sticking of the photomask with a pellicle measured by the measurement unit A pellicle sticking position measuring apparatus comprising a determination / control unit 20 that feeds back a determination result of position measurement data and a transfer unit 30 that moves a photomask with a pellicle between processes It is.

Furthermore, in claim 3, at least a pellicle attaching unit 50 for producing a photomask with a pellicle by bonding a photomask and a pellicle, a transfer unit 30a for moving the photomask with a pellicle between processes, and a rotary stage 11 is a measurement unit 10 composed of a mounting jig 12 provided on 11 and a non-contact distance measuring device 15, and a determination for feeding back the determination result of the pellicle application position measurement data of the photomask with a pellicle measured by the measurement unit. The pellicle sticking position measuring apparatus includes the control unit 20 and a transfer unit 30b that moves the photomask with pellicle between processes .

In the pellicle sticking position measuring apparatus of the present invention, since the pellicle sticking position measurement is performed by non-contact measurement using a laser displacement meter or the like, scratches and foreign matter are not attached to the photomask and the pellicle frame.
Further, in the pellicle sticking position measuring device of the present invention, since the pellicle sticking position measurement, transport and storage can be performed automatically from the introduction of the photomask with pellicle, by setting the measurement point in advance, The data measured by the measurement unit is taken into the judgment / control unit, and the results of calculation and judgment processing are displayed on the display or printed out, so the pellicle attachment position is excellent in measurement accuracy and measurement reproducibility without human intervention. Measurement becomes possible.
In addition, each unit of the pellicle sticking position measuring apparatus of the present invention can be set to various environmental conditions, so that a series of operations from taking out a photomask with a pellicle from the case, measurement and storage in the case is clean. It becomes possible.

In addition, since the pellicle sticking position measuring apparatus of the present invention is provided with a pellicle sticking unit, the pellicle sticking to the photomask, the sticking position measurement, and the judgment of the sticking position state are performed by inserting the photomask and the pellicle. And a series of operation | movement to the accommodation to a case can be performed automatically. Further, by feeding back the measurement result of the pellicle sticking position to the pellicle sticking unit, it is possible to manufacture a photomask with a pellicle with excellent sticking position accuracy.

Hereinafter, embodiments of the present invention will be described.
As shown in FIG. 1, the pellicle sticking position measuring apparatus according to the first aspect of the present invention includes a measuring unit 10 including a mounting jig 12 provided on a rotary stage 11 and a non-contact distance measuring device 15, It consists of a determination / control unit 20 that feeds back the determination result of the measurement data of the pellicle attachment position measurement data of the photomask with pellicle measured by the measurement unit. It can be measured.

Specifically, first, a pellicle-equipped photomask 90 (see FIG. 6) in which a pellicle 80 is bonded onto the photomask 70 is placed on the mounting jig 12 provided on the rotary stage 11.
Here, the rotational position of the rotary stage 11 can be digitally controlled, and is controlled by the determination / control unit 20.

Next, the specified end face of the photomask 70 of the photomask with pellicle 90 and the pellicle according to the measurement points set in advance by the non-contact distance measuring device 15 including the sensor 13 such as a laser displacement meter moving up and down and left and right. The distance measurement to 80 designated end faces is sequentially performed.
Here, the measurement position is programmed in advance in the determination / control unit 20 for each product type, and by specifying the product type each time, the position control of the sensor 13 and the rotation control of the rotary stage 11 are performed, and a series of measurement is performed. Can be done.
In addition, the non-contact distance measuring device 15 shows an example of a sensor provided with a laser displacement meter as an example. However, the non-contact distance measuring device 15 is not particularly limited thereto. Can be used.

The measured distance measurement data is taken into the determination / control unit 20 and converted as position data of the pellicle 80 on the photomask 70, and a determination process is performed to determine whether the pasting position is within a preset reference. The determination result is displayed on the display or printed out.
Further, the determination / control unit 20 has a database function that records and stores a history of measurement data for each product type, and can arbitrarily read past pasted photomask-attached photomask-attached photomask and determination results. .

As shown in FIG. 2, the pellicle sticking position measuring apparatus according to the second aspect of the present invention includes a measuring unit 10 including a mounting jig 12 provided on a rotary stage 11 and a non-contact distance measuring device 15; Consists of a determination / control unit 20 that feeds back the determination result of the pellicle attachment position measurement data of the photomask with pellicle measured by the measurement unit, and a transfer unit 30 that moves the photomask with pellicle between processes. Fully automatic pellicle sticking position measuring device that automatically takes out the photomask with pellicle stored in the container, automatically measures the pellicle sticking position, and then stores the photomask with pellicle in the container. Is to provide.

Specifically, first, a storage container (SMIF-Pod) stored in a photomask with a pellicle.
) Is set in the case insertion port 40.
This mask storage container (SMIF-Pod) is a SMIF (Standard Mechanical Interface) -Pod (standard mechanical interface mechanism mask box) that can be filled with an inert gas such as nitrogen. Here, the standard mechanical interface mechanism means that a bottom portion, a lid lock, a take-out mechanism and the like adapted to the standard mechanical interface SMIF system are provided.

  Next, the lid 42 of the storage container (SMIF-Pod) is lifted by the lid opening / closing mechanism from the SMIF-Pod main body 41 and used as an arm of the transfer robot 31 (for example, a cylindrical coordinate robot) of the transfer unit 30. Then, the pellicle-equipped photomask 90 is gripped, and the pellicle-equipped photomask 90 is placed on the mounting jig 12 provided on the rotary stage 11 of the measurement unit 10.

Next, the specified end face of the photomask 70 of the photomask with pellicle 90 and the pellicle according to the measurement points set in advance by the non-contact distance measuring device 15 including the sensor 13 such as a laser displacement meter moving up and down and left and right. The distance measurement to 80 designated end faces is sequentially performed.
Here, the measurement position is programmed in advance in the determination / control unit 20 for each product type, and by specifying the product type each time, the position control of the sensor 13 and the rotation control of the rotary stage 11 are performed, and a series of measurement is performed. Can be done.
In addition, the non-contact distance measuring device 15 shows an example of a sensor provided with a laser displacement meter as an example. However, the non-contact distance measuring device 15 is not particularly limited thereto. Can be used.

The measured distance measurement data is taken into the determination / control unit 20 and converted as position data of the pellicle 80 on the photomask 70, and a determination process is performed to determine whether the pasting position is within a preset reference. The determination result is displayed on the display or printed out.
In addition, the determination / control unit 20 has a database function that records and stores a history of measurement data for each product type and can arbitrarily read past pasted photomask-attached photomask-attached photomask and determination results. Yes.

The pellicle-equipped photomask 90 for which the pasting position has been measured is held by the arm of the cylindrical coordinate robot 31 of the transfer unit 30 and placed on the main body 41 of the storage container (SMIF-Pod) of the case insertion port 40. Then, the lid 42 is returned to the original position by the lid opening / closing mechanism, nitrogen purge is performed, the storage container (SMIF-Pod) is taken out from the case insertion port 40, and the pellicle application position of the photomask 90 with pellicle is measured. finish.
Here, a series of operation instructions for taking out the photomask 90 with a pellicle 90 from the storage container (SMIF-Pod), moving, transporting, measuring the pellicle application position and storing it in the storage container (SMIF-Pod) are determined and measured. This is performed by the unit 20 and programmed for each type of photomask 90 with a pellicle.

  As shown in FIGS. 2 (a) and 2 (b), the pellicle sticking position measuring apparatus of the present invention includes gate valves 32a and 32b between each unit, and an exhaust device and a gas inlet are provided for each unit. By providing each unit, the inside of each unit can be purged with nitrogen, and a series of processes from taking out the photomask 90 with a pellicle from the storage container (SMIF-Pod), measuring the pasting position, and storing it in the storage container (SMIF-Pod) Operation is possible in a clean state, and contamination and foreign matter can be prevented from adhering.

As shown in FIG. 3, the pellicle sticking position measuring apparatus according to the third aspect of the present invention includes a pellicle sticking unit 50 for producing a photomask with a pellicle by sticking the photomask and the pellicle, and a process using the photomask with the pellicle. A transfer unit 30a that moves in between, a measurement unit 10 that includes a mounting jig 12 and a non-contact distance measuring device 15 provided on the rotary stage 11, and a pellicle of a photomask with a pellicle measured by the measurement unit The judgment / control unit 20 that feeds back the judgment result of the pasting position measurement data, and the transfer unit 30b that moves the photomask with a pellicle between processes. The photomask with a pellicle is attached to the photomask and the pellicle. After making and automatically measuring the pellicle sticking position, pellicle attached There is provided a pellicle attaching position measuring device automates a series of operations until accommodating the photomask container.

  Specifically, first, in the pellicle attaching unit 50, a photomask 70 (see FIG. 4) in which a mask pattern 72 is formed of a light-shielding thin film made of chromium and chromium oxide on a transparent substrate 71 such as quartz glass. In order to prevent foreign matter such as dust from adhering to the surface of the photomask 70, the pellicle film 82 pasted on the pellicle frame 81 is bonded to the pellicle 80 (see FIG. 5), and the photomask 90 with pellicle (see FIG. 6) and place it at a predetermined position.

  Next, the pellicle-attached photomask 90 placed on the pellicle pasting unit 50 is held by the arm of the transfer robot 31 (for example, a cylindrical coordinate robot) of the transfer unit 30a, and the rotation stage 11 of the measurement unit 10 is held. A photomask 90 with a pellicle is placed on the mounting jig 12 provided above.

Next, the specified end face of the photomask 70 of the photomask with pellicle 90 and the pellicle according to the measurement points set in advance by the non-contact distance measuring device 15 including the sensor 13 such as a laser displacement meter moving up and down and left and right. The distance measurement to 80 designated end faces is sequentially performed.
Here, the measurement position is programmed in advance in the determination / control unit 20 for each product type, and by specifying the product type each time, the position control of the sensor 13 and the rotation control of the rotary stage 11 are performed, and a series of measurement is performed. Can be done.
In addition, the non-contact distance measuring device 15 shows an example of a sensor provided with a laser displacement meter as an example. However, the non-contact distance measuring device 15 is not particularly limited thereto. Can be used.

The measured distance measurement data is taken into the determination / control unit 20 and converted as position data of the pellicle 80 on the photomask 70, and a determination process is performed to determine whether the pasting position is within a preset reference. The determination result is displayed on the display or printed out.
The determination result of the pasting position is fed back to the pellicle pasting unit 50 and can be used as pasting position correction data. By repeating this, a photomask with a pellicle with excellent pasting position accuracy is produced. be able to.
In addition, the determination / control unit 20 has a database function that records and stores a history of measurement data for each product type and can arbitrarily read past pasted photomask-attached photomask-attached photomask and determination results. Yes.

The pellicle-equipped photomask 90 for which the pasting position measurement has been completed is held by the arm of the transfer robot 31 (for example, a cylindrical coordinate robot) of the transfer unit 30b, and the lid 42 is lifted by the lid opening / closing mechanism. Then, it is placed on the main body 41 of the storage container (SMIF-Pod) of the storage port 60. The lid 42 is returned to the original position by the lid opening / closing mechanism, nitrogen purge is performed, the storage container (SMIF-Pod) is taken out from the case insertion port 40, and the measurement of the pellicle sticking position of the photomask 90 with pellicle is completed. .
Here, a series of operation instructions for manufacturing, moving, transporting, measuring the pellicle application position and storing in the storage container (SMIF-Pod) of the photomask 90 with pellicle is performed by the determination / control unit 20 and the pellicle is attached. It is programmed for each type of photomask 90.

  As shown in FIG. 3, the pellicle sticking position measuring device of the present invention includes gate valves 32a, 32b, 32c and 32d between the units, and by providing an exhaust device and a gas inlet for each unit. Each unit can be set to various environments (for example, nitrogen purged state), and a series of operations from production of a photomask 90 with a pellicle to measurement and storage in a storage container (SMIF-Pod) is clean. It is possible to prevent contamination and foreign matter from adhering.

(A) is a typical block diagram which shows one Example of the pellicle sticking position measuring apparatus of this invention which concerns on Claim 1. FIG.

(B) is a schematic side view showing an embodiment of a pellicle sticking position measuring apparatus of the present invention according to claim 1.
(A) is a schematic block diagram which shows one Example of the pellicle sticking position measuring apparatus of this invention which concerns on Claim 2. FIG.

(B) is a schematic side view showing an embodiment of a pellicle sticking position measuring apparatus of the present invention according to claim 2.
It is a schematic block diagram which shows one Example of the pellicle sticking position measuring apparatus of this invention concerning Claim 3. It is explanatory drawing which shows an example of a photomask. It is explanatory drawing which shows an example of a pellicle. It is explanatory drawing which shows an example of the photomask with a pellicle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Measuring unit 11 ... Rotary stage 12 ... Mounting jig 13 ... Sensor 15 ... Non-contact type distance measuring machine 20 ... Judgment / control unit 30, 30a, 30b ... Transfer unit 31 ... Transfer Loading robot 32a, 32b, 32c, 32d ... Gate valve 40 ... Case loading port 41 ... SMIF-Pod main body 42 ... Lid 50 ... Pellicle sticking unit 60 ... Storage port 70 ... Photo mask 71 ... Transparent substrate 72 ... Mask pattern 80 ... Pellicle 81 ... Pellicle frame 82 ... Pellicle film 90 ... Photomask with pellicle 91 ... Adhesive

Claims (3)

A measurement unit (10) comprising at least a mounting jig (12) provided on the rotary stage (11) and a non-contact distance measuring device (15), and a pellicle sticking of a photomask with a pellicle measured by the measurement unit A pellicle sticking position measuring device comprising: a determination / control unit (20) for performing feedback of a determination result of position measurement data . A measurement unit (10) comprising at least a mounting jig (12) provided on the rotary stage (11) and a non-contact distance measuring device (15), and a pellicle sticking of a photomask with a pellicle measured by the measurement unit A pellicle sticking position measurement comprising a determination / control unit (20) for feeding back a determination result of position measurement data and a transfer unit (30) for moving a photomask with a pellicle between processes. apparatus. A pellicle attaching unit (50) for producing a photomask with a pellicle by attaching at least a photomask and a pellicle, a transfer unit (30a) for moving the photomask with a pellicle between processes, and a rotating stage (11) A measurement unit (10) comprising a provided mounting jig (12) and a non-contact distance measuring device (15), and feedback of determination results of pellicle attachment position measurement data of a photomask with a pellicle measured by the measurement unit A pellicle sticking position measuring apparatus comprising: a determination / control unit (20) that performs the above and a transfer unit (30b) that moves a photomask with a pellicle between processes .

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