JPH08250409A - Exposure apparatus - Google Patents

Abstract

PURPOSE: To improve a throughput without lowering a yield of a semiconductor device, etc., owing to foreign matter existing on a substrate holder. CONSTITUTION: A clean substrate holder 44 is stored in a storage part 104 beforehand, and the holder 44 stored in this storage part 104 is transported by a robot-hand 72 and a transport-arm 92 to a X-stage 42 and is exchanged for a dirty substrate holder 44 on the stage 42. Thus, the dirty holder 44 on the stage 42 and the clean holder 44 are exchanged in a short time during which the apparatus is stopped so that the holder 44 can always be kept in a clean state without stopping the apparatus for a long time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus, and more particularly, to exposure for exposing a mask pattern used on a photosensitive substrate such as a wafer, which is used in a photolithography process in the manufacturing process of semiconductor devices and the like. Regarding the device.

[0002]

2. Description of the Related Art When manufacturing a semiconductor device, a liquid crystal display device or the like by a photolithography process, an exposure apparatus is used which exposes a wafer whose surface is coated with a photosensitizer such as a photoresist with a pattern image of a mask or reticle. There is. In such a conventional exposure apparatus, in order to hold the wafer in a flat state so as not to move, a wafer holder mounted on the wafer stage sucks and holds the wafer.

However, if a wafer is adsorbed in a state where foreign matter such as dust or dirt exists between the wafer holder that holds the wafer and the wafer, the foreign matter deteriorates the flatness of the wafer exposed surface. The deterioration of the flatness of the exposed surface causes a positional deviation error in each shot area of the wafer,
It has been a major factor that deteriorates the yield when manufacturing SI and the like. Therefore, conventionally, the exposure is stopped at regular intervals, the wafer holder is moved to a position where the operator can reach, and the operator moves the wafer using a grindstone or a dust-free cloth so that The entire contact surface (hereinafter appropriately referred to as “upper surface”) was wiped.

[0004]

However, when the operator manually cleans the wafer holder as described above, it takes, for example, 30 minutes to 1 hour to wipe the entire surface of the wafer holder. Since the apparatus must be stopped during the cleaning work, there is an inconvenience that the exposure time per day is inevitably shortened and the throughput is lowered. Further, in such manual work, in addition to the inconvenience that the individual difference of the worker is likely to occur, dust generation (secondary dust generation) from the worker has been a problem.

On the other hand, the cleaning frequency of the wafer holder is set to 1 per day in order to prolong the exposure time per day.
When the number of times is set to about twice, the probability that the wafer is exposed while the foreign matter is adsorbed on the wafer holder increases, but this causes the foreign matter present on the upper surface of the wafer holder to distort the wafer and cause lateral deviation during baking. However, there is an inconvenience that the overlay accuracy may be deteriorated and the yield of semiconductor elements and the like may be deteriorated.

The present invention has been made in view of the inconveniences of the prior art, and an object thereof is not to reduce the yield of semiconductor elements or the like due to the presence of foreign matter existing on the substrate holder, but also to improve the throughput. An object is to provide an exposure apparatus that can be improved.

[0007]

According to the first aspect of the present invention,
An exposure apparatus for transferring a pattern formed on a mask onto a photosensitive substrate on a substrate holder, a stage for detachably supporting the substrate holder; an attachment / detachment mechanism for attaching / detaching the substrate holder to / from the stage; A storage unit capable of storing a substrate holder; a holder transfer system that transfers the substrate holder to and from each of the attachment / detachment mechanism and the storage unit, and transfers the substrate holder between the attachment / detachment mechanism and the storage unit. Have and.

According to a second aspect of the present invention, there is provided an exposure apparatus which transfers a pattern formed on a mask onto a photosensitive substrate on a substrate holder, and a stage which detachably supports the substrate holder; An attachment / detachment mechanism for attaching / detaching to / from the stage; a holder cleaning section for cleaning the substrate holder; a transfer of the substrate holder to / from each of the attachment / detachment mechanism and the holder cleaning section; and the attachment / detachment mechanism and the holder cleaning section. And a holder transport system for transporting the substrate holder between them.

According to a third aspect of the present invention, there is provided an exposure apparatus which transfers a pattern formed on a mask onto a photosensitive substrate on a substrate holder, and a stage which detachably supports the substrate holder; An attaching / detaching mechanism for attaching / detaching to / from the stage; a storage unit capable of storing the substrate holder;
A holder cleaning unit that cleans the substrate holder; a substrate cleaning unit that transfers the substrate holder to and from each of the attachment / detachment mechanism, the storage unit, and the holder cleaning unit, and between the attachment / detachment mechanism, the storage unit, and the holder cleaning unit. And a holder transport system for transporting the substrate holder.

[0010]

According to the first aspect of the invention, the holder transfer system transfers the substrate holder to and from each of the attachment / detachment mechanism and the storage unit, and transfers the substrate holder between the attachment / detachment mechanism and the storage unit. Therefore, for example, by storing a clean substrate holder in the storage unit in advance, the transport system transports the clean substrate holder stored in this storage unit to the attachment / detachment mechanism, and the dirty substrate holder on the stage Received
Hand a clean holder to the attachment / detachment mechanism. The attachment / detachment mechanism receives this clean holder and attaches it to the stage. According to this, since the dirty substrate holder and the clean substrate holder on the stage are exchanged while the device is stopped for a short time, the holder is always kept clean without stopping the device for a long time. It becomes possible to do.

According to the second aspect of the invention, the holder transfer system transfers the substrate holder to and from each of the attachment / detachment mechanism and the holder cleaning section, and transfers the substrate holder between the attachment / detachment mechanism and the cleaning section. Therefore, in the transfer system, the dirty substrate holder on the stage is received from the attachment / detachment mechanism, transferred to the cleaning unit, and transferred to the cleaning unit. The cleaning unit receives the dirty substrate holder, transfers it to the transport system after cleaning. In the transport system, the cleaned holder is transported to the attachment / detachment mechanism and passed to the attachment / detachment mechanism. The attachment / detachment mechanism receives the cleaned substrate holder and mounts it on the stage. According to this, when the substrate holder on the stage becomes dirty, it is mounted again on the stage after cleaning in the cleaning unit, so that the holder is always kept clean without stopping the device for more than the cleaning time. It becomes possible to do.

According to the third aspect of the present invention, the holder transfer system transfers the substrate holder between the attachment / detachment mechanism, the storage unit and the holder cleaning unit, and the substrate between the attachment / detachment mechanism, the storage unit and the holder cleaning unit. The holder is transported.
Therefore, for example, by storing a clean substrate holder in the storage unit in advance, the transport system transports the clean substrate holder stored in this storage unit to the attachment / detachment mechanism, and the dirty substrate holder on the stage And pass the clean holder to the attachment / detachment mechanism. The attachment / detachment mechanism receives this clean holder and attaches it to the stage. Further, in this case, in the transfer system, the dirty substrate holder received from the attachment / detachment mechanism is transferred to the cleaning unit and transferred to the cleaning unit. The cleaning unit receives the dirty substrate holder, transfers it to the transport system after cleaning. In the transfer system, the cleaned holder is transferred to the storage section and delivered to the storage section. The cleaned substrate holder delivered to the storage unit is stored in the storage unit. According to this, the dirty substrate holder and the clean substrate holder on the stage are exchanged while the device is stopped for a short time, and the substrate holder on which foreign substances are attached after the exchange is cleaned and stored again in the storage unit. Therefore, by preparing at least two substrate holders, it is possible to keep the holders in a clean state at all times without stopping the apparatus for a long time.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.
It will be described based on. 1 and 2 schematically show the overall configuration of an exposure apparatus 10 according to an embodiment.
FIG. 1 is a schematic vertical sectional view of the exposure apparatus 10.
FIG. 4 is a schematic cross-sectional view.

The exposure apparatus 10 comprises a chamber 12 and a chamber 14 which are independent of each other. The reason why the two chambers 12 and 14 are independent of each other is to prevent dust in the chambers 12 and 14, and in particular, it is necessary to keep the temperature and humidity constant in one chamber 12 as well. Is. The inside of the chamber 12 is constantly controlled to ± 0.1 ° C with respect to a set temperature, for example, 23 ° C. Further, these chambers 12 and 14 are provided with a minimum required number of doors required for IC manufacturing work and maintenance of the apparatus.

Inside the one chamber 12, there are housed various constituent parts which can be said to be the heart of this apparatus, including an exposure light irradiation optical system 16, a projection optical system 18, an XY stage device 20, and the like.

The irradiation optical system 16 includes a light source 24 such as a mercury lamp, a filter (not shown) that transmits only the exposure light (eg, g-line or i-line) emitted from the light source 24, and a fly as an optical integrator. It has an illumination optical system 26 including an eye lens (not shown), a diaphragm (not shown) for setting an exposure light irradiation region, and a folding mirror 28.

The bending mirror 28 is obliquely provided at an angle of about 45 degrees at a position substantially above the light source 24 vertically above the projection optical system 18 (above the optical axis direction).
A reticle 30 as a mask is arranged between the projection optical system 18 and the projection optical system 18 in the horizontal direction (the direction orthogonal to the optical axis). This reticle 30 has a horizontal plane (XY plane) of 2
It is held on a reticle stage 32 that is movable in the dimensional direction and is rotatable around a vertical axis (Z axis) within a minute angle range. A predetermined pattern area PA is provided on the lower surface of the reticle 30, and a circuit pattern to be exposed is formed in this pattern area PA.

On the other hand, below the projection optical system 18, a wafer 3 serving as a photosensitive substrate having a photoresist coated on its surface.
4 is held on the XY stage device 20 so that its surface is conjugate with the surface of the reticle 30 on which the pattern area PA is provided as described above with respect to the projection optical system 18.

Therefore, when the exposure light emitted from the light source 24 passes through the illumination optical system 26 and is applied to the reticle 30, the exposure light passes through the pattern area PA on the reticle 30 and reaches the projection optical system 18. An image of the pattern that is incident and reduced by the magnification of the projection optical system 18 is formed on the wafer 34.

Next, the XY stage device 20 will be described. The XY stage device 20 includes a base 38 fixed on a mount 36, a Y stage 40 movable on the base 38 in the left-right direction (Y-axis direction) in FIG.
An X stage 42 that is movable on the stage 40 in the direction orthogonal to the paper surface of FIG. 1 (X axis direction) is provided. Although not shown in FIG. 1 on the X stage 42, a stepped disk-shaped wafer holder (hereinafter referred to as “holder”) 44 as a substrate holder is used, but in reality, a vacuum suction means such as a vacuum chuck 140 is used. (See FIG. 8), and the wafer 34 is similarly attracted onto the holder 44.

In FIG. 3, the X stage 42 is shown with the holder 44 partially cut away. As shown in FIG. 3, a round hole 46 into which the bottom small diameter portion of the holder 44 can be fitted is formed in the X stage 42, and a circular guide hole is formed in the center of the inner bottom surface of the round hole 46. 48 is provided in the vertical direction. Inside the guide hole 48, a holder supporting member 50 that can move up and down along the guide hole 48 is inserted as indicated by arrows A and B. The holder supporting member 50 is a drive mechanism (not shown). It is designed to be moved up and down by. That is, in this embodiment, the guide hole 4
8, the holder support member 50, and a drive mechanism (not shown) constitute a holder vertical movement mechanism 144 (see FIG. 8) as an attachment / detachment mechanism.

A notch 52 having a substantially U-shaped cross section is formed at the upper end of the holder supporting member 50, so that when the holder 44 is replaced, the tip of a holder carrying arm described later is inserted through the notch 52. It can be inserted from one side to the other side in the X-axis direction in FIG. 1 (from the front side to the back side in the direction orthogonal to the paper surface in FIG. 3).

Further, on the inner bottom surface of the round hole 46, there are provided three vertical movement pins 54 which constitute a wafer vertical movement mechanism 146 (see FIG. 8) for supporting the wafer 34 at three points and moving it up and down during wafer exchange. It is provided in the vertical direction. In the state where the holder 44 is sucked and fixed on the X stage 42, the tip of each of the vertical movement pins 54 is attached to the holder 44 through a round hole (not shown) provided corresponding to the vertical movement pin 54. It is designed to move up and down in a penetrating state.

Now, returning to the description of FIG. 1, the oblique-incidence-type focusing mechanism (AF) is provided on both sides of the projection optical system 18.
The light transmitting system 56 and the light receiving system 58 that form the system) 134 (see FIG. 8) are arranged symmetrically with respect to the optical axis of the projection optical system 18.

In addition to the above, in one chamber 12, an alignment light source 60, a half mirror 62, a mirror 64, an alignment microscope 66, and the like, which is a TTL (through-the-lens) type alignment for superposing the wafers 34. Although not shown in the drawings, the sensor 68 and the interferometer system 136 for measuring the position of the X stage 42 (see FIG. 8).
(See) is also installed.

In the other chamber 14, as shown in FIGS. 1 and 2, an X guide 70 extending in the X-axis direction is installed at the center. A robot hand 72 capable of reciprocating in the X direction is provided on the X guide 70. The robot hand 72 has a moving portion 74 that can move in the X direction along the X guide 70, and the moving portion 74. A first rotating arm 76 is attached to the upper end of the first rotating arm 76 so as to be rotatable about a rotating shaft (not shown), and a base end of the first rotating arm 76 is attached to the tip (rotating end) of the first rotating arm 76. The second rotation arm 78 is rotatably attached to the second rotation arm 78, and the hand portion 80 is attached to the tip (rotation end) of the second rotation arm 78. That is, the first and second rotating arms 76 and 78 of the robot hand 72 are
The first rotation arm 76 is integrally rotatable around the rotation axis of the first rotation arm 76 and has a structure capable of expanding and contracting. Therefore, the hand portion 80 attached to the tip of the second rotating arm 78 is allowed to freely move horizontally within the area of a circle having a predetermined radius centered on the rotating shaft of the first rotating arm 76. Has become.

In FIG. 4, the vicinity of the tip of the hand portion 80 is shown enlarged. As shown in FIG. 4, the hand portion 80 has a mounting portion 82 and a tip portion 84, and the tip portion 84 is centered on an axis C extending in the longitudinal direction of the hand portion 80 with respect to the mounting portion 82. It is configured to be rotatable 180 degrees in the arrow D direction and the opposite direction. As a result, the holder 44 is held by the pair of holder grips 86 and 88 described later.
When holding, the direction of the holder 44 can be turned upside down while holding the holder 44. Tip 84
Is provided with the pair of holder holding portions 86, 88 formed of L-shaped cross-section members for sandwiching the side surface of the holder 44 so as to face each other.
A gripping surface 86 consisting of the upper facing surface of 88 in FIG.
A and 88A are formed as arcuate curved surfaces. Further, vacuum holes (not shown) are formed in contact surfaces 86B, 88B of the holder gripping portions 86, 88 with the back surface of the holder 44, and the holder 44 is sucked and fixed by vacuum suction means (not shown) through the vacuum holes. It is supposed to be done. Further, these holder grips 86, 88
Are configured to be movable along the guide grooves 84A and 84B in the directions toward and away from each other as indicated by arrows E and F. This is done in this way so that a plurality of types of holders 44 can be sandwiched, and a single type of holder 44
In the case where only the gripping surfaces 86A and 88A are used, the gripping surfaces 86A and 88A may be fixed at a position where they are separated by a distance that is substantially the same as the outer diameter of the large diameter portion of the holder 44.

Now, returning to the description of FIG. 2, the chamber 1
A Y guide 90 that extends in the Y direction while penetrating the two is provided between the chamber 2 and the chamber 14. The Y guide 90 is attached to the chamber 1 along the Y guide 90.
A holder transfer arm (hereinafter, appropriately referred to as “transfer arm”) 92 configured to be movable between the chamber 2 and the chamber 14 and movable in a predetermined distance range in the X direction is attached. The holder transfer arm 92 has the same structure as the hand part 80 of the robot hand 72 described above (see FIG. 4). It should be noted that only openings of a size corresponding to the Y guide 90 and the holder transfer arm 92 are formed on the side walls of the chambers 12 and 14 on the side where the chamber 12 and the chamber 14 are in contact with each other.

Further, as shown in FIG.
In the vicinity of the position where the X guide 70 and the Y guide 90 intersect with each other in 4, the holder transfer arm 92 and the robot hand 72 are provided.
A transfer table 94 for transferring the holder 44 to and from is installed. A holder holding member 98 having a notch 96 having a U-shaped cross section formed at the upper end portion thereof as shown in FIG. 1 is provided on the delivery table 94, as in the holder vertical movement mechanism 144 on the X stage 42 described above. A holder vertical movement / rotation mechanism 100 is provided. The holder vertical movement / rotation mechanism 100 has a cylindrical guide 102 whose upper end is partially exposed above the transfer table 94, and the holder holding member which slides vertically inside the cylindrical guide 102. And 98. The holder holding member 98 is rotatable in the range of 90 degrees around the rotation axis in the Z-axis direction from the position shown in FIG. This gives, for example,
As will be described later in detail, it becomes possible to transfer the holder 44 from the holder transfer arm 92 to the robot hand 72.

Further, in the present embodiment, as shown in FIG. 2, a holder storage unit (hereinafter referred to as "storage unit" as a storage unit) is provided on the side of the X guide 70 inside the chamber 14 opposite to the chamber 14. 104) and holder cleaning unit 10
6 is installed, and the holder 44 can be transferred by moving the robot hand 72 in front of the holder storage unit 104 or in front of the holder cleaning unit 106, as will be described later.

In FIG. 5, a right side view of the holder storage unit 104 in FIG. 1 is partially omitted. This storage unit 104 is for storing the clean holder 44,
It has a box-shaped outer case 108 and a plurality of stages of holder support shelves 110 vertically arranged at predetermined intervals on the inner surfaces of both side walls of the outer case 108. Each holder support shelf 110 has a pair of left and right shelf members 112A, 112 extending in the direction orthogonal to the paper surface (Y direction) of FIG.
It is composed of B. The holder storage unit 104 is supported by the column unit 114, and the column unit 114
Can be moved up and down via a vertical sliding guide (not shown) provided in the base portion 116 shown in FIG. 1, and the drive mechanism 154 built in the base portion 116 (see FIG. 8).
(See) to be moved up and down. This makes it possible to adjust the positional relationship in the height direction between the holder support rack 110 at a desired stage in the holder storage unit 104 and the hand unit 80 of the robot hand 72.

In this case, the holder 44 is preliminarily supported by the holder supporting shelves 110 of all the stages in the holder storage unit 104, and the holder 44 after cleaning is placed on the holder supporting shelves 110 of the same stage as the stage in which the holder 44 is unloaded. In order to carry out and carry in the holder 44 in advance, for example, from the top to the bottom or from the bottom to the top, the holder storage unit 104 is sequentially raised or lowered. Then, it is as if the new holder 44
This is the same as the case where the holder 44 is sequentially fed in the storage unit 104 every time the paper is loaded, and the oldest entered holder 44 is preferentially carried out. It should be noted that a mechanism that actually realizes such a forward feed of the holder 44 may be configured by a special belt conveyor.

As shown in FIG. 5, the holder 44 may be stored in the chamber 14 or the holder storage unit 104 in the upside down direction so that the contact portion with the wafer faces downward. It is desirable from the viewpoint of preventing foreign matter in the atmosphere from adhering to the contact portion due to falling. In this case, before the holder 44 after being washed in the state shown in FIG. 6A is carried into the holder storage unit 104, the tip end portion 84 of the hand unit 72 is inverted and the state shown in FIG. It may be carried in to the storage unit 104 in the state shown in FIG.

FIG. 7 is a schematic vertical sectional view of the cleaning unit 106 (right side sectional view in FIG. 2). As shown in FIG. 7, the cleaning unit 106 includes a water tank 118 containing a predetermined amount of pure water, a pair of side plates 120A and 120B provided in the water tank 118 so as to face each other, and these side plates. A pair of holder support members 122A, 122B made of L-shaped cross-section members that can move up and down along guide grooves (not shown) formed in 120A, 120B in the vertical direction, respectively, as shown by arrows G, H. And an ultrasonic wave generator 124 installed in the water tank 118.

In order to clean the holder 44 by the cleaning section 106, the holder gripping sections 86, 88 of the hand section 80 with the holder supporting members 122A, 122B slightly lowered.
The holder 4 whose both ends in the direction orthogonal to the paper surface of FIG.
4 is inserted from the front side to the back side of the paper surface of FIG. 7 by a predetermined amount, and in this state, the holder support members 122A and 122B are raised and the hand portion 80 is retracted, the holder support members 122A and 122B move the holder 44. The state shown in FIG. 7 is that it is supported from below. Next, the holder support member 122
The holders 44 are immersed in the pure water in the water tank 118 as A and 122B descend. In this state, when the ultrasonic wave generator 124 is activated, ultrasonic waves are generated and the holder 44 is cleaned in the same manner as cleaning eyeglasses. Instead of pure water, various kinds of solvents corresponding to possible foreign substances (chemicals such as resist) are prepared, and the holder 44 is sequentially installed.
After soaking, the drying may be repeated.
Further, when there is a foreign substance that cannot be removed only by dipping, the surface of the holder may be rubbed with a non-woven brush such as nylon. 1 and 2, reference numeral 39 indicates a wafer transfer system.

Next, the structure of the control system of the apparatus 10 of this embodiment will be described with reference to FIG. This control system mainly includes a first control unit 130 and a second control unit 132. These first and second control units 130 and 132 use the CP
It is configured by a so-called microcomputer or minicomputer including U, ROM, RAM, an input interface and an output interface. The first and second control units 130 and 132 are connected to each other via a system bus.

The AF system 1 is connected to the input side of the first controller 130.
34 and the interferometer system 136 are connected. Also,
The X stage 42 and the Y stage are provided on the output side of the first controller 130.
A stage drive system 138 for driving the stage 40, a vacuum chuck 140 for sucking the holder 44 on the X stage 42, a vacuum suction means 142 for sucking the holder 44 on the transfer arm 92, and a holder vertical movement mechanism on the X stage 42. 144, the wafer up-and-down moving mechanism 146 including the three up-and-down moving pins 54, the driving unit, and the transfer arm 92
A transfer arm drive system 148 that drives in a direction, a wafer loader drive system 150 that drives a load arm, an unload arm, and the like that form a wafer loader (not shown) are connected.

On the output side of the second control section 132, the holder vertical movement rotating mechanism 100 and each drive section (a vacuum suction means (not shown) communicating with a vacuum hole (not shown) of the hand section 80) constituting the robot hand are included. ) For controlling the robot hand control system 152, the drive mechanism 154 of the holder storage unit 104, and the support members 122A and 122B of the cleaning unit 106.
A support member drive system 156 for vertically driving and the ultrasonic generator 124 are connected.

Next, the main operation of the apparatus of this embodiment constructed as described above will be described with reference to the first and second control sections 130, 1
The control operation of 32 will be mainly described.

First, the control operation of the first controller 130 will be described with reference to the flowchart of FIG. 9 showing the main control algorithm. This control algorithm starts when a predetermined number of step-and-repeat exposures are completed and a test wafer having extremely high flatness is adsorbed on the holder 44 on the X stage 42. As a premise, a counter (not shown) indicating the number of the measurement area of the wafer (test wafer) described later is reset (count value n ← 0), and a flag indicating contamination of the holder 44 described later is also reset (F ← 0). It has been done.

First, in step 200, the processing of the subroutine "detection of dirt on the holder" is performed. In this subroutine, as shown in the flowchart of FIG. 10, in step 300, a counter (not shown) indicating the number of the measurement region is incremented by 1 (n ← n + 1), and then the process proceeds to step 302 to measure the nth measurement on the wafer. The area is positioned within the image field of the projection optics 18. This positioning is performed based on the coordinate position data of the measurement area and the output coordinate data of the interferometer system 136 stored in advance in the RAM.

At the next step 304, the output of the AF system 134 is fetched, and the routine proceeds to step 306 and step 304
It is determined based on the output of the AF system 134 taken in step 3 whether or not the positional shift amount (focus shift amount) of the wafer surface in the optical axis direction exceeds a predetermined threshold value. If the determination is negative, the process proceeds to step 308 to determine whether or not the count value n is equal to or more than the total number n _{0 of} measurement regions to be measured, thereby ending the measurement of defocus in all measurement regions. Judge whether or not. If the determination in step 308 is negative, the process returns to step 300 to repeat the processing and determination. On the other hand, when the determination in step 306 is affirmative, the routine proceeds to step 310, the aforementioned flag is set (F ← 1), and then the routine returns to step 202 of the main routine of FIG. Also, when the measurement of defocus in all the measurement regions is completed and the determination in step 308 is affirmative, the process returns to step 202 of the main routine.

In step 202 of the main routine, it is determined whether or not the holder 44 is dirty by determining whether or not the above-mentioned flag is "0". If the determination in step 202 is affirmative, that is, if the holder 44 is not dirty, the process proceeds to step 204, in which a wafer unload arm (not shown) is driven via the wafer loader drive system 150 to unload the test wafer. After that, the series of processes of this routine is finished. In this case, the normal exposure process is continued thereafter. The suction of the wafer is released when the wafer is unloaded.

On the other hand, if the determination in step 202 is negative, that is, if the holder 44 is dirty and foreign matter is attached, the process proceeds to step 206 and the vacuum chuck 14 is carried out.
After the suction of the holder 44 on the X stage 42 is released via 0, the routine proceeds to step 208, where the wafer loader drive system 1
The wafer unload arm is driven via 50 to unload the test wafer.

In the next step 210, the holder vertical movement mechanism 144 is driven upward. Thereby, the holder support member 5
0 rises and lifts a predetermined amount while supporting the holder 44 from below. At this time, it is assumed that the holder support member 50 is at a position where the position of the notch 52 is substantially the same as the height position of the transfer arm 92 waiting in front of the X stage 42.

At the next step 212, the transfer arm 92 is driven via the transfer arm drive system 148 to move the transfer arm 9
Holder support member 5 supporting the holder 44 at the tip of 2
It is inserted in the notch 52 of 0. At this time, the carrier arm 92 is inserted to a position where the holder 44 can be exactly seen between the gripping members in a plan view.

In the next step 214, the holder vertical movement mechanism 1
44 is driven downward, and suction (vacuum) of the holder 44 by the transfer arm 92 is started via the vacuum suction means 142. As a result, the support member 50 is attached to the holder 4
4, the holder 44 is sucked and held by the transfer arm 92.

In the next step 216, the transfer arm 92 holding the holder 44 is moved to above the transfer table 94 via the transfer arm drive system 148, and the holder 44 is sucked by the transfer arm 92 via the vacuum suction means 142 ( Vacuum). At this time, the transfer arm 92
Is a holder holding member 9 of the holder vertical movement / rotation mechanism 100.
It is at a position just corresponding to the notch 96 of 8, and when the holder holding member 98 rises, the holder 44 held by the transport arm 92 is at a position supported by the holder holding member 98 from below.

In the next step 218, the second controller 132
After notifying that the movement of the transfer arm 92 above the transfer table 94 is completed, the process proceeds to step 220, and the second controller 132 notifies that the raising / lowering drive of the holder vertical movement / rotation mechanism 100 is completed. Wait for

Next, the control operation of the second controller 132 will be described with reference to the flowchart of FIG. 11 showing the main control algorithm. The control algorithm starts when the first control unit 130 receives a notification from the first control unit 130 that the movement of the transfer arm 92 above the transfer table 94 is completed.

First, in step 400, the process of the "passage of the holder to the cleaning unit" subroutine is performed.

In this subroutine, as shown in the flowchart of FIG. 12, in step 500, the holder vertical movement / rotation mechanism 100 is lifted and the holder vertical movement / rotation mechanism 100 is lifted. 1
After notifying 30, the process proceeds to step 502 and waits for a notification from the first controller 130 that the withdrawal of the transfer arm 92 has been completed.

Here, the operation of the first controller 130 will be temporarily returned to. As described above, the first control unit 130 waits for the notification from the second control unit 132 that the upward movement of the holder vertical movement / rotation mechanism 100 is completed in step 220. By doing so, step 2
If the determination in step 20 is affirmative, the process proceeds to step 222, the transfer arm 92 is retracted to the front in the X-axis direction via the transfer arm drive system 148, and the second control unit 132 is notified that the retracting of the arm 92 is completed. After that, the routine proceeds to step 224, and waits until the second controller 132 notifies that the holder 44 is ready for delivery.

Here, the operation of the second controller 132 will be described again. As described above, the second control unit 132 waits for the notification from the first control unit 130 that the withdrawal of the transfer arm 92 has been completed in step 502. Is affirmed,
Proceeding to step 504, the holder vertical movement / rotation mechanism 100
Rotate 90 degrees. As a result, the holding member 98 rotates 90 degrees while holding the holder 44, and the holding member 9 is held.
The notch 96 of 8 faces the robot hand 72 at the height position of the hand portion 80 of the robot hand 72 waiting in front of the transfer table 94.

At the next step 506, the tip of the hand portion 80 is inserted into the notch 96 via the robot hand control system 152. At this time, the hand portion 80 is inserted to a position where the holder 44 held by the holding member 98 appears to be inserted between the holding members 86 and 88 in a plan view.

In the next step 508, the holder vertical movement / rotation mechanism 100 is driven downward, and the suction of the holder 44 by the hand portion 80 is started via the robot hand control system 152. As a result, the holding member 98 is separated from the holder 44, and the holder 44 is sucked and held by the hand portion 80.

In the next step 510, the robot hand 72 is moved to the front of the holder cleaning section 106 via the robot hand control system 152, and then the process proceeds to step 512, in which the robot hand 7 is moved via the robot hand control system 152.
2 to control the holder 44 held by the hand unit 80 to the holder support members 122A and 122B of the holder cleaning unit 106.
Move above.

In the next step 514, the suction of the holder 44 by the hand portion 80 is released via the robot hand control system 152, and then the process proceeds to step 516 to raise the holder support members 122A and 122B via the support member drive system 156. To drive. As a result, the holder 44 is supported from below by the holder support members 122A and 122B.

At the next step 518, the robot hand 72 is controlled via the robot hand control system 152 to retract the hand portion 80, and at step 520 the holder support members 122A, 122B are moved via the support member drive system 156. Move it down.

At the next step 522, the ultrasonic wave generator 12
After activating No. 4, the process returns to step 402 of the main routine of FIG.

In step 402, the robot hand 72 is moved to the holder storage unit 1 via the robot hand control system 152.
After moving to the position before 04, the process proceeds to the subroutine of “unloading the holder from the holder storage unit” in step 404.

In this subroutine, as shown in the flow chart of FIG.
The height of the holder storage unit 104 is adjusted via 56. Specifically, based on the count value of a counter (not shown) indicating the location of the holder support shelf 110 in the storage unit 104, the holder 44 stored in the holder support shelf 110 at the stage corresponding to the count value is stored in the hand unit 80. The height of the storage unit 104 is adjusted to be slightly lower.

At the next step 602, the hand unit 80 of the robot hand 72 is passed through the robot hand control system 152.
Is turned upside down, and the process proceeds to step 604, where the hand unit 80 is inserted above the target holder 44 in the storage unit 104 via the robot hand control system 152. Here, the hand portion 80 is inserted to a position most suitable for holding both ends of the holder 44 by the holding members 86 and 88.

In the next step 606, the holder storage unit 104 is driven upward by a predetermined amount via the drive mechanism 156, and in step 608, the suction of the holder 44 by the hand unit 80 is started via the robot hand control system 152. As a result, the holder 44 is sucked by the hand portion 80.

At the next step 610, the robot hand 72 is controlled via the robot hand control system 152, and the hand unit 80 is pulled out of the holder storage unit 104.
The process returns to step 406 of the main routine of No. 1.

In step 406, the robot hand 72 is moved to the front of the transfer table 94 via the robot hand control system 152, and then the process proceeds to step 408 where the hand unit 80 is turned upside down via the robot hand control system 152. As a result, the holder 44 sucked and held by the hand portion 80 is turned upside down and returned to the normal orientation.

At the next step 410, the robot hand 72 is controlled via the robot hand control system 152 to move the hand portion 80 above the transfer table 94. At this time, in the hand portion 80, the portion holding the holder 44 at the tip thereof moves up and down on the transfer table 94.
The holder holding member 98 is moved to a position corresponding to the notch 96.

At the next step 412, the suction of the holder 44 by the hand portion 80 is released via the robot hand control system 152, and at step 414, the holder vertical movement / rotation mechanism 100 is driven upward by a predetermined amount. Thereby, the holding member 9
8 rises and the holder 44 is held from below.

In the next step 416, the robot hand 72 is controlled via the robot hand control system 152 to retract the hand portion 80, and then the process proceeds to step 418, in which the holder vertical movement / rotation mechanism 100 is moved in the opposite direction to the front. Rotate 90 degrees. As a result, the holding member 98 rotates while holding the holder 44, and the notch 96 faces the transport arm 92 at the standby position.

At the next step 420, the first control unit 130 is notified that the preparation for the delivery of the holder 44 is completed,
The process proceeds to step 422 and waits for notification from the first control unit 130 that the insertion of the transfer arm is completed.

Now, the operation of the first controller 130 will be described again. In the first controller 130, as described above, step 22
In step 4, the second control unit 132 waits for the notification that the preparation for the delivery of the holder 44 is completed. However, the notification in step 224 makes the determination affirmative and advances to step 226. Transport arm drive system 14
After inserting the front end of the transfer arm 92 into the notch 96 via 8, the second control unit 132 is notified in step 228 that the insertion of the transfer arm 92 into the notch 96 has been completed. Then, in step 230, the second control unit 132 waits for a notification that the holder vertical movement / rotation mechanism 100 has been driven downward.

Here, the operation of the second controller 132 will be temporarily returned to. As described above, the second control unit 132 waits for the notification that the insertion of the transfer arm 92 is completed in step 422, but the notification in step 422 is affirmed because of the notification. After proceeding to step 424 to drive the holder vertical movement / rotation mechanism 100 downward and notify the first control unit 130 to that effect, a series of processing of this routine is ended.

Now, the operation of the first controller 130 will be described again. In the first control unit 130, as described above, step 23
0 from the second controller 132 to the holder vertical movement / rotation mechanism 10
Although waiting for the notification that the downward drive of 0 has been performed, the notification in step 230 is affirmed by this notification, and the process proceeds to step 232 and the transfer arm 92 is transferred via the vacuum suction means 142. The suction of the holder 44 is started. This causes the holder 44 to move to the transfer arm 92.
Is adsorbed on and retained by.

At the next step 234, the transfer arm 92 is moved to the front of the X stage 42 via the transfer arm drive system 148, and the process proceeds to step 236 to move the transfer arm 92 to the X stage 42 via the transfer arm drive system 148. Move up. Here, the transfer arm 92 is at a position where the holder 44 held by the transfer arm 92 is just fitted into the round hole 46 on the X stage 42, and the support member 50 of the holder vertical movement mechanism 144.
It is moved to a position corresponding to the notch 52 of the.

In the next step 238, the holder vertical moving mechanism 144 is driven upward, and the suction of the holder 44 by the transfer arm 92 is released. As a result, the support member 50 rises to hold the holder 44 from below, and the support member 5
The leading end of the transfer arm 92 is fitted into the notch 52 of 0.

At the next step 240, the transport arm drive system 1
After retracting the transfer arm 92 via 48, the process proceeds to step 242, and the holder vertical movement mechanism 144 is driven to descend. Thereby, the holder 44 held by the support member 50
Moves down and fits into the round hole 46 of the X stage 42.

In the next step 244, after the suction of the holder 44 by the X stage is started via the vacuum chuck 140, the series of processes of this routine is ended. After the end, the normal exposure process is restarted.

On the other hand, in the second controller 132, after a normal exposure process is started and a predetermined time has elapsed, the holder 44 being washed in the water tank 118 is pulled out to the outside of the water tank 118 via the support member drive system 156 and dried. Let After drying, the robot hand 72 and the holder support member 12 are respectively passed through the robot hand control system 152 and the support member drive system 156.
2A and 122B are controlled to carry out the dried holder 44 from the cleaning unit 106 by the robot hand 72. In addition,
At the time of drying the holder 44, warm air may be applied to accelerate the drying. Alternatively, the holder 44 may be dried in the storage unit 104 described above.

Next, the second controller 132 controls the robot hand 72 via the robot hand control system 152, holds the carried-out holder 44 by the hand unit 80, and carries it into the holder storage unit 104. . The second before this delivery
The control unit 132 vertically inverts the hand unit 80 holding the holder 44 via the robot hand control system 152, and then adjusts the height of the storage unit 104 via the drive mechanism 156. This height adjustment is adjusted to a height suitable for carrying the holder 44 into the holder support shelf 110 of the stage corresponding to the count value of the counter described above.

As is clear from the above description, in this embodiment, the X guide 70, the robot hand 72, the Y guide 90, the transfer arm 92, and the holder vertical movement / rotation mechanism 1 are used.
00 constitutes a holder transport system.

As described above, according to this embodiment,
Every time a predetermined number of exposures are completed, the dirt of the holder 44 is measured, and when the holder 44 is dirty, the dirty holder 44 is automatically replaced with the clean holder 44 stored in the storage unit 104. Since it is possible to restart the exposure immediately after the replacement, it is not necessary to stop the apparatus for a long time for cleaning the holder 44. Therefore, it is possible to significantly improve the throughput, and it is possible to always perform the baking with the clean holder 44, and it is possible to maintain the good overlay accuracy, and thus the yield of the semiconductor does not decrease. .

Further, according to the present embodiment, since the cleaning work is automated, it is possible to eliminate individual differences due to conventional human work and secondary contamination caused by human work. The downtime of the device per day for cleaning the holder 44 can be greatly reduced.

Furthermore, since the cleaning operation can be performed by the holder cleaning unit 106 in the other chamber 14 while the wafer 34 is being exposed in one chamber 12, the cleaning time can be reduced. The holder 44 can be sufficiently washed without any limitation.

Further, since the cleaned holder 44 is stored in the holder storage unit 104, if at least two holders 44 are prepared, the contact surface of the holder 44 with the wafer 34 is always kept clean. It becomes possible.

In the above embodiment, the wafer transfer arm and the robot hand 72 are used for both the transfer of the dirty holder 44 and the transfer of the clean holder 44 in order to avoid complication of the description. However, the present invention is not limited to this.
It is desirable to provide a dirty holder only and a clean holder only for both or one of the robot 2 and the robot hand 72. In such a case, for example, a clean carrier arm 92 dedicated to the holder is held near the X stage 42 while holding the holder 44, and when the dirt of the holder 44 is measured, the holder is quickly soiled. X can be moved by a holder vertical movement mechanism using a dedicated transfer arm 92.
The holder 44 separated from the stage 42 is received, and at the same time as this, the holder 44 held by the clean carrier arm 92 dedicated to the holder is transferred to the holder vertical movement mechanism 144, and X
It can be mounted on the stage 42. In this case, the dirty holder 44 to the transfer arm 9 is removed.
2 or a clean holder 4 via the robot hand 72
There is also no risk of foreign matter adhering to 4.

Further, in the above embodiment, the holder storage unit 10
Although the holder cleaning unit 106 is provided together with No. 4, the holder can always be kept clean by providing only one of them. For example, when only the holder storage unit 104 is provided, a large number of clean holders 44 are stored in advance in the storage unit 104, and the dirty holder 44 is carried out to the outside for cleaning work. If only the holder cleaning unit 106 is provided, it is necessary to stop the exposure work during the cleaning of the holder 44, but the exposure work interruption time is longer than that in the conventional manual work. Since the holder 44 is short and the holder 44 is reliably washed, various problems existing in the case of manual work can be solved.

Furthermore, the control algorithm described in the above embodiment is an example, and can be variously modified.

[0088]

As described above, according to the present invention,
Since it is possible to maintain the substrate holder in a clean state at all times without stopping the device for a long time, it is possible to improve the soup while preventing the yield of semiconductor elements, etc. from decreasing due to contamination of the substrate holder. The effect is that you can.

In particular, according to the second aspect of the present invention, since the dirty substrate holder is automatically cleaned by the cleaning unit, the difference between individuals caused by the conventional manual work and the work caused by the human being are caused. The effect is that secondary pollution can be eliminated.

According to the third aspect of the present invention, the cleaning of the substrate holder by the cleaning unit is possible even after the replacement of the substrate holder and the start of the exposure process, and at least two substrate holders are prepared. The holder can be kept clean at all times without stopping the device for a long time.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view showing an overall configuration of an exposure apparatus according to an embodiment.

FIG. 2 is a schematic cross-sectional view showing the overall configuration of the apparatus shown in FIG.

FIG. 3 is a view showing an X stage together with a holder in a partially cutaway manner.

FIG. 4 is a schematic perspective view showing an enlarged hand portion constituting a robot hand.

FIG. 5 is a right side view in FIG. 1 showing a holder storage part partially omitted.

FIG. 6 is an operation explanatory view of an arm portion holding a holder.

FIG. 7 is a right side sectional view of the holder cleaning unit in FIG. 1.

8 is a block diagram showing a schematic configuration of a control system of the apparatus of FIG.

FIG. 9 is a flowchart showing a main control algorithm of the first controller.

FIG. 10 is a flowchart showing a subroutine of “dirt detection of holder” in FIG. 9;

FIG. 11 is a flowchart showing a main control algorithm of a second controller.

FIG. 12 is a flowchart showing a subroutine of “passing a holder to a cleaning unit” in FIG. 11.

FIG. 13: “Holding the holder out of the holder storage” in FIG.
3 is a flowchart showing the processing of the subroutine.

[Explanation of symbols]

10 Exposure Device 30 Reticle (Mask) 34 Wafer (Photosensitive Substrate) 42 X Stage (Stage) 44 Holder (Substrate Holder) 70 X Guide (Part of Holder Transfer System) 72 Robot Hand (Part of Holder Transfer System) 90 Y Guide (part of holder transfer system) 92 Transfer arm (part of holder transfer system) 100 Holder up / down movement / rotation mechanism (part of holder transfer system) 104 Holder storage part (storage part) 106 Holder cleaning part 144 Holder up / down Moving mechanism (detachment mechanism)

Claims (3)

[Claims] 1. An exposure apparatus for transferring a pattern formed on a mask onto a photosensitive substrate on a substrate holder, the stage detachably supporting the substrate holder; and the substrate holder attached to and detached from the stage. An attachment / detachment mechanism; a storage unit capable of storing the substrate holder; a transfer of the substrate holder to and from each of the attachment / detachment mechanism and the storage unit, and transfer of the substrate holder between the attachment / detachment mechanism and the storage unit. And an exposure apparatus having a holder transfer system for performing. 2. An exposure device for transferring a pattern formed on a mask onto a photosensitive substrate on a substrate holder, wherein the stage detachably supports the substrate holder; and the substrate holder is attached to and detached from the stage. An attachment / detachment mechanism; a holder cleaning unit for cleaning the substrate holder; a transfer of the substrate holder to and from each of the attachment / detachment mechanism and the holder cleaning unit, and the substrate holder between the attachment / detachment mechanism and the holder cleaning unit. And an exposure apparatus having a holder transport system for transporting. 3. An exposure apparatus for transferring a pattern formed on a mask onto a photosensitive substrate on a substrate holder, wherein the stage detachably supports the substrate holder; and the substrate holder is attached to and detached from the stage. An attachment / detachment mechanism; a storage unit capable of storing the substrate holder; a holder cleaning unit for cleaning the substrate holder; and a transfer of the substrate holder with each of the attachment / detachment mechanism, the storage unit and the holder cleaning unit, An exposure apparatus comprising: the attachment / detachment mechanism, a holder transport system that transports the substrate holder among the storage unit and the holder cleaning unit.