JPH07161676A - Self-cleanness diagnostic type substrate cleaning device - Google Patents

Abstract

PURPOSE:To diagnose the cleanness of a substrate route through which a test substrate passes by a method wherein the test substrate high in cleanness is used and made to pass a part of a processing route which corresponds to a process wherein either transfer processing or cleaning processing is carried out. CONSTITUTION:A test reticle high in cleanness and housed in a reticle library 11 is transferred to a foreign matter inspection section 12 through the intermediary of a transfer outer 17. When the reduction of the test reticle in cleanness is detected at the foreign matter inspection section 12, the reduction of the reticle library 11 or the transfer outer 17 in cleanness is confirmed. On the other hand, when the reduction of the test reticle in cleanness is not detected at the foreign matter inspection section 12, the cleanness of the reticle library 11 and the transfer route 17 is confirmed. When the reduction of a test reticle in cleanness is not detected, cleanness diagnosis is successively made with the same test reticle. By this setup, a region deteriorated in cleanness can be surely detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate cleaning apparatus, and more particularly to a cleaning apparatus for removing foreign matter (fine dust, stains or oil) attached to glass substrates such as reticles and photomasks used in semiconductor manufacturing processes. This is related to the diagnostic function of equipment cleanliness.

[0002]

2. Description of the Related Art If foreign substances such as dust adhered to a glass substrate such as a reticle or a photomask are left as they are, these foreign substances are transferred onto the wafer and cause defects in the manufactured wafer. Since there are various kinds of contaminants attached to the substrate, a cleaning apparatus has been proposed in which a plurality of cleaning tanks corresponding to the types of attached contaminants are incorporated in one chamber.

In the conventional substrate cleaning apparatus incorporating a plurality of cleaning tanks as described above, the substrate to be cleaned is taken out from the substrate library in which the substrates are stored, and is transferred to the foreign matter inspection unit via the transfer system. The cleanliness of the transported substrate is inspected by the foreign matter inspection unit. As a result, the substrate that has not reached the desired cleanliness passes through the plurality of cleaning tanks (including the drying tank) via the transport system according to a predetermined path.
The substrate that has undergone the cleaning process is again transported to the foreign matter inspection unit via the transport system, and its cleanliness is inspected. The first foreign matter inspection can be omitted.

[0004]

In the conventional substrate cleaning apparatus as described above, if the cleanliness of the substrate that has undergone the cleaning process has not reached the desired cleanliness, the cleaning process is repeated again. However, when the cleanliness of a part of the cleaning equipment, such as the transport system and the cleaning tank, is low and the cleaning performance of the equipment is low, the cleanliness of the substrate is desired even if the cleaning process is repeated. The cleanliness may not be reached.

When the cleanliness of the substrate does not reach the desired cleanliness even after repeating the cleaning process as described above, the fact that the cleanliness of the entire substrate cleaning apparatus is deteriorated indirectly from the cleanliness of the substrate after cleaning. Recognize. However, the conventional substrate cleaning apparatus does not have a function of detecting in which region of the apparatus the cleanliness is lowered. Specifically, it was not known whether the cleanliness of the transport system was low or the cleanliness of the cleaning tank was low. Further, it was not known which part the cleanliness of the transport system had deteriorated and which cleaning tank had the cleanliness of the cleaning tank. Therefore,
When the cleaning ability is deteriorated, it takes a lot of time and labor to find out the cause, and as a result, the throughput is deteriorated.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a substrate cleaning apparatus capable of self-diagnosing the cleanliness of each region.

[0007]

In order to solve the above problems, in the present invention, a storage means for storing a substrate, at least one cleaning means for cleaning the substrate, and a cleanliness of the substrate are provided. In a substrate cleaning apparatus provided with an inspection unit for inspecting and a substrate transfer system for interconnecting the storage unit, the cleaning unit, and the inspection unit, a high-cleanness test stored in the storage unit A control unit is provided for inspecting the cleanliness of the test substrate in the inspection unit after passing a part of a processing path corresponding to a process of performing at least one of a transfer process and a cleaning process on the substrate. Provided is a substrate cleaning apparatus.

According to a preferred embodiment, the control means is
The cleanliness of the first processing path and the first processing are sequentially checked by sequentially inspecting the cleanliness of the test substrate for the first processing path and the second processing path that partially overlaps with the first processing path. The cleanliness of the second processing route except the route is individually diagnosed. Further, it is preferable that the control means has a display means for displaying a result of the inspection means, and the display means displays a processing route region in which cleanliness is lowered and a required processing method.

[0009]

In the substrate cleaning apparatus of the present invention, a test substrate having a high degree of cleanliness is used, and the substrate is allowed to pass through a part of the processing route corresponding to the step of carrying out at least one of the carrying processing and the cleaning processing. After that, the cleanliness of the test substrate is diagnosed by inspecting the cleanliness of the test substrate. For example, if the cleanliness of the test substrate that first passed a part of the transport route A is lowered, it can be seen that the cleanness of the transport route A is lowered. After the cleanliness of the transport path A is confirmed, if the cleanliness of the test substrate that has passed through the transport path A and a specific cleaning tank B (which has undergone the cleaning process in the cleaning tank B) is lowered, It can be seen that the cleanliness of the cleaning tank B is lowered.

In this way, the test substrate is sequentially inspected for a processing path that partially overlaps with the processing path whose cleanliness has been confirmed in advance (in other words, the processing area in which at least one of the transfer processing and the cleaning processing is performed). By repeating, the cleanliness of each area of the device can be diagnosed.
The self-diagnosis of the cleanliness of such a device may be automatically performed based on a predetermined condition, or may be performed by an operator at any time.

[0011]

Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a block diagram schematically illustrating the overall configuration of a substrate cleaning apparatus according to an embodiment of the present invention. The apparatus shown in FIG. 1 is a computer 1 for interfacing with an operator.
Is equipped with. A floppy disk 2 having a cleanliness diagnostic program written therein can be installed in the interface computer 1.

The output of the interface computer 1 is connected to the input of the device operation control computer 3. The operation control computer 3 incorporates a cleanliness diagnostic operation sequence in addition to the normal cleaning operation sequence. The output of the operation control computer 3 is connected to the input of the substrate cleaning system 4. The output of the substrate cleaning system 4 is fed back to the operation control computer 3. In this way, the interface computer 1 and the operation control computer 3 form a control system and control the operation of the substrate cleaning system 4.

FIG. 2 is a diagram schematically showing the internal structure of the substrate cleaning system of FIG. The illustrated substrate cleaning system includes a reticle library 11 for storing a substrate such as a reticle. The reticle library 11 contains a reticle to be cleaned and a test reticle for diagnosing cleanliness. The illustrated substrate cleaning system also
A foreign matter inspection unit 12 for inspecting the cleanliness of the reticle is provided. As the foreign matter inspection unit 12, for example, there is an oblique incident light type foreign matter inspection apparatus that scans the surface of a reticle with a light beam obliquely incident and receives scattered light reflected by the foreign matter adhering to the reticle surface to inspect the foreign matter. Showa 57-1288
No. 34, etc.

The illustrated substrate cleaning system further includes a plurality of cleaning tanks. The first cleaning tank is an ultraviolet irradiation unit 13 that mainly irradiates the surface of the reticle with ultraviolet light in a clean air atmosphere to remove foreign matters. The second cleaning tank is a brush scrub cleaning tank 14 for mainly removing inorganic foreign matter by applying a physical force to the reticle surface by a pair of rotating brushes. Further, the third cleaning tank is an ultrasonic cleaning tank 15 for removing foreign matters on the surface of the reticle by immersing the reticle in the liquid to which ultrasonic vibration is applied. The fourth cleaning tank is the IPA drying tank 16 for drying the reticle by generating IPA (isopropyl alcohol) vapor.

Reticle library 11 and foreign matter inspection unit 1
2, the ultraviolet irradiation unit 13, the brush scrub cleaning tank 14, the ultrasonic cleaning tank 15, and the IPA drying tank 16 are connected to each other by a transport system (not shown). In a normal cleaning operation, the reticle is cleaned in the order of the ultraviolet irradiation unit 13, the brush scrub cleaning tank 14, the ultrasonic cleaning tank 15, and the IPA drying tank 16. Although the use of either cleaning tank can be omitted, since the reticle cleaned by the brush scrub cleaning tank 14 or the ultrasonic cleaning tank 15 is in a wet state, the drying processing in the IPA drying tank 16 (one of cleaning processing is performed). Section) is required.

The operation of the substrate cleaning apparatus according to this embodiment will be described with reference to FIGS. 1 and 2. First, the overall operation of the device will be described. In the substrate cleaning apparatus of this embodiment,
When any one of the predetermined conditions is satisfied during the operation, the cleanliness diagnosis is automatically executed. The predetermined condition is, for example, a lapse of a certain number of cleanings from the previous cleanliness diagnosis, a lapse of a certain cleaning time from the previous cleanliness diagnosis, a decrease in the average inspection pass rate for a certain period such as one week or one month.

Further, in response to a sudden decrease in cleaning ability,
The operator can also perform the cleanliness diagnosis at any time. The automatic cleanliness diagnosis is an interface that automatically responds to the cleaning frequency data and cleaning time data fed back from the operation control computer 3 and the foreign matter inspection data fed back from the substrate cleaning system 4 (actually, the foreign matter inspection unit 12). It is executed under the control of the operation control computer 3 based on the instruction of the program in the operation computer 1. On the other hand, the occasional cleanliness diagnosis by the operator is based on a command input to the interface computer 1 by the operator who responds to the foreign matter inspection output data of the substrate cleaning system, for example, based on a command input to the operation control computer 3 by the operator. It is executed via control. In either case, the cleanliness diagnostic operation is the same.

Next, the cleanliness diagnostic operation will be described. The test reticle with high cleanliness contained in the reticle library 11 is transported to the foreign matter inspection unit 12 via the transport path 17. If the foreign matter inspection unit 12 confirms that the cleanliness of the test reticle has decreased, it means that the cleanliness of the reticle library 11 or the transport route 17 has decreased. On the other hand, if the foreign matter inspection unit 12 does not confirm that the cleanliness of the test reticle has decreased, it means that the cleanliness of the reticle library 11 and the transport path 17 has been confirmed.

When it is confirmed that the cleanliness of the test reticle has decreased, the cleanliness diagnostic operation ends. This is because if the cleanliness of the reticle library 11 or the transport path 17 is low, it is highly likely that the reticle library 11 or the transport path 17 will be immediately contaminated even if it is replaced with a new test reticle, and there is no point in continuing diagnosis. On the contrary, when the deterioration of the cleanliness of the test reticle is not confirmed, the cleanliness diagnostic operation is continued using the same test reticle.

That is, once the reticle library 11
The test reticle that has returned to No. 2 is washed through the conveyance path 18 in the ultraviolet irradiation unit 13 and then conveyed to the foreign matter inspection unit 12. If the foreign matter inspection unit 12 confirms that the cleanliness of the test reticle has decreased, the ultraviolet irradiation unit 13 or the transport path 1
It was confirmed that the cleanliness of No. 8 was lowered. On the other hand, if the foreign matter inspection unit 12 does not confirm the decrease in cleanliness of the test reticle, it means that the cleanliness of the ultraviolet irradiation unit 13 and the transport path 18 has been confirmed.

In general, the transport route 17 and the transport route 18
Part (the part parallel to the transport path 17) is a common area, and when a decrease in cleanliness of the test reticle is confirmed,
It is confirmed that the cleanliness of the route other than the common area of the ultraviolet irradiation unit 13 or the transport route 18, that is, the horizontal route in the drawing, is lowered.

In this case, after the test reticle conveyed through the conveyance path 18 without being introduced into the ultraviolet irradiation section 13 is inspected by the foreign matter inspection section 12, the inside of the ultraviolet irradiation section 13 is washed again by the conveyance path 18. By inspecting the processed test reticle by the foreign matter inspection unit 12, it is possible to confirm the decrease in cleanliness of the ultraviolet irradiation unit 13 and the transport path 18 separately.

If a decrease in cleanliness of the test reticle is confirmed, a new test reticle contained in the reticle library 11 is used. If no decrease in cleanliness of the test reticle is confirmed, the same test reticle is used. Can be used to continue the cleanliness diagnostic operation. Actually, the reticle library 11 and the transport path 1 described above are used.
Unlike the case of No. 7, even if the cleanliness of the ultraviolet irradiation unit 13 and the transport path 18 is lowered, the cleanliness diagnosis operation can be performed for other processing paths without passing through this area.

A new test reticle taken out from the reticle library 11 or a test reticle that has once returned to the reticle library 11 is cleaned in the brush scrub cleaning tank 14 via the transfer path 19 and then to the foreign matter inspection section 12. Transport. If the foreign matter inspection unit 12 confirms that the cleanliness of the test reticle has decreased, it means that the cleanliness of the brush scrub cleaning tank 14 or the transport path 19 has decreased. On the other hand, if the foreign matter inspection unit 12 does not confirm that the cleanness of the test reticle has decreased, it means that the cleanliness of the brush scrub cleaning tank 14 and the transport path 19 has been confirmed.

Incidentally, the transfer path 17 and a part of the transfer path 19 (the part parallel to the transfer path 17) are common areas, and when it is confirmed that the cleanliness of the test reticle is lowered, the brush scrub cleaning tank 14 or the transfer path is transferred. It is confirmed that the cleanliness of the portion of the route 19 other than the common area is reduced. In addition, as described above, after the test reticle conveyed through the conveyance path 19 without being introduced into the brush scrub cleaning tank 14 is inspected by the foreign matter inspection unit 12, the brush scrub cleaning tank 14 is again conveyed through the conveyance path 19. By inspecting the test reticle that has been subjected to the cleaning process in the foreign matter inspecting section 12, it is possible to separately confirm the decrease in cleanliness of the brush scrub cleaning tank 14 and the transport path 19.

The surface of the test reticle which has passed through the brush scrub cleaning tank 14 is in a wet state due to the action of the cleaning liquid. Therefore, when the foreign matter inspection unit 12 is of a type that cannot inspect the test reticle in a wet state, after the cleaning process in the brush scrub cleaning tank 14, the IPA drying tank 1 is transferred via the transport path 21.
It is necessary to carry out the drying process in 6 and then convey it to the foreign matter inspection unit 12. In this case, if the foreign matter inspection unit 12 confirms that the cleanliness of the test reticle has decreased, it is confirmed that the cleanliness of the brush scrub cleaning tank 14, the IPA drying tank 16, the transport path 19 or the transport path 21 has decreased. Become. Unless the foreign matter inspection unit 12 confirms that the cleanliness of the test reticle is not deteriorated, the brush scrub cleaning tank 14, the IPA drying tank 16,
The cleanliness of the transport path 19 and the transport path 21 is confirmed.

As described above, the brush scrub cleaning tank 1
4. The foreign matter inspection unit 12 inspects the test reticle conveyed through the conveyance route 19 without introducing the same into the No. 4, and the foreign matter inspection unit detects the test reticle conveyed through the conveyance route 21 without being introduced into the IPA drying tank 16. Check at 12. Next, the test reticle that has been dried in the IPA drying tank 16 via the transfer path 21 is inspected by the foreign matter inspection unit 12, and is cleaned in the brush scrub cleaning tank 14 via the transfer path 19 and then transferred via the transfer path 21. The test reticle that has been dried in the IPA drying tank 16 is inspected by the foreign matter inspecting unit 12, and the decrease in cleanliness is individually confirmed for the brush scrub cleaning tank 14, the IPA drying tank 16, the transport path 19 and the transport path 21. can do.

The horizontal portions of the transport paths 19 and 21 in the figure are common areas, and when it is confirmed that the cleanliness of the test reticle is low only for the transport path 21, the areas other than the common area of the transport path 21 are confirmed. It was confirmed that the cleanliness of the product had decreased. If the foreign matter inspection unit 12 is of a type that can perform inspection of a wet test reticle, the remaining ultrasonic cleaning tank 15 and the transfer path 2
0, the IPA drying tank 16 and the transport path 2
For No. 1, the same operations as those for the brush scrub cleaning tank 14 and the transport path 19 described above are repeated. In the case where the foreign matter inspection unit 12 is of a type that cannot inspect a wet test reticle, the remaining ultrasonic cleaning tank 15 and the transport path 20 have the above-mentioned brush scrub cleaning tank 14, Transport path 19,
The same operations as the series of operations for the IPA drying tank 16 and the transport path 21 are repeated.

In this way, when a series of cleanliness diagnostic operations are completed, the area in which the cleanliness is lowered, necessary countermeasures, etc. are displayed on the screen of the interface computer. In the present embodiment, the substrate cleaning apparatus having a plurality of cleaning tanks has been described as an example, but the present invention is also applied to a substrate cleaning apparatus of a type that performs all cleaning / drying steps in one tank. be able to.

Further, in this embodiment, the test reticle is once returned to the reticle library every time the foreign matter inspection section inspects, but the test reticle may be directly conveyed from the foreign matter inspection section to the next stage area. Further, in the present embodiment, the processing route for which the cleanliness diagnosis is to be performed is selected according to the normal cleaning process, but as described above, the “processing route” corresponds to the process of performing at least one of the carrying process and the cleaning process. Since it is an arbitrary route to be performed, it is possible to select a treatment route according to a certain condition regardless of a normal cleaning process.

[0031]

As described above, in the substrate cleaning apparatus of the present invention, a test substrate having high cleanliness is used, and a step of inspecting the cleanliness of the test substrate after passing a part of the processing path through the substrate is performed. By repeating the process, the cleanliness of each area can be finally self-diagnosed. Therefore, it is possible to surely find the area where the cleanliness is lowered and to deal with it promptly, so that the throughput of the apparatus is significantly improved.

[Brief description of drawings]

FIG. 1 is a block diagram schematically illustrating an overall configuration of a substrate cleaning apparatus according to an exemplary embodiment of the present invention.

FIG. 2 is a diagram schematically showing an internal configuration of the substrate cleaning system of FIG.

[Explanation of symbols]

 1 Interface Computer 2 Floppy Disk 3 Operation Control Computer 4 Substrate Cleaning System 11 Reticle Library 12 Foreign Material Inspection Section 13 Ultraviolet Irradiation Section 14 Brush Scrub Cleaning Tank 15 Ultrasonic Cleaning Tank 16 IPA Drying Tank

Claims (3)

[Claims] 1. A storage means for storing a substrate, at least one cleaning means for cleaning the substrate, an inspection means for inspecting the cleanliness of the substrate, the storage means, the cleaning means and the inspection means. In a substrate cleaning apparatus having a substrate transfer system for connecting the two to each other, a high cleanliness test substrate stored in the storage means,
A control unit is provided for inspecting the cleanliness of the test substrate in the inspection unit after passing through a processing route corresponding to a process of performing at least one of a conveyance process and a cleaning process. Substrate cleaning equipment. 2. The first processing is performed by the control means sequentially inspecting the cleanliness of the test substrate for a first processing path and a second processing path that partially overlaps the first processing path. The substrate cleaning apparatus according to claim 1, wherein the cleanliness of the path and the cleanliness of the second processing path other than the first processing path are individually diagnosed. 3. The control means has a display means for displaying a result of the inspection means, and the display means displays a processing path area in which the cleanliness is lowered and a required coping method. The substrate cleaning apparatus according to claim 1.