JPH08222618A - Method and apparatus for conveying - Google Patents

Abstract

PURPOSE: To prevent the adherence of treated liquid to a conveyor by suppressing the vibration of the conveyor to convey a substrate to be treated, and further selecting an optimum holding method at that time in response to the state of the substrate to be treated. CONSTITUTION: In order to convey a semiconductor wafer which cannot be held at its peripheral edge due to the residue of pretreated liquid at the edge, it is conveyed by using tweezers 41 for holding only the lower surface of the wafer in contact. The upper surface of the tweezers 41 has higher frictional coefficient than other tweezers 42, 43. The conveying speed of the tweezers 41 in the case of conveying by the tweezers 41 is lower than that of the other tweezers 42, 43.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carrying method and a carrying device.

[0002]

2. Description of the Related Art For example, in a photolithography process in a semiconductor device manufacturing process, a resist coating process for forming a resist film on the surface of a semiconductor wafer (hereinafter referred to as "wafer") and a wafer after the resist film is formed. After the exposure process, a development process of developing the wafer is performed. Conventionally, the resist coating process and the development process are described in Japanese Patent Publication No. 2-3, for example.
As is known from Japanese Patent Laid-Open No. 0194, the processing is performed in accordance with a predetermined sequence in a complex processing system in which corresponding various processing devices are installed in one system.

Wafers are transferred between processing apparatuses in such a composite processing system by a transfer apparatus having a holding unit for holding a wafer which is a substrate to be processed. This will be described based on, for example, the resist coating / developing processing system 101 shown in FIG. 16. In the resist coating / developing processing system 101, the cassette station 10 for loading / unloading the wafer W into / from the cassette.
2. Brush cleaning unit 10 for cleaning the wafer W with a brush
3, a jet water cleaning device 104 for cleaning the wafer W with high-pressure jet water, the wafer W for enhancing the adhesiveness of the resist
An adhesion device 105 for treating the surface of the wafer W with water, a cooling device 106 for cooling the wafer W to a predetermined temperature, a resist coating device 107 for coating the surface of the wafer W with a resist solution,
The wafer W is transferred between a heating device 108 that heats the wafer W before and after applying the resist solution, a peripheral exposure device 109 that removes the resist on the peripheral portion of the wafer W, and an adjacent exposure processing device (not shown). A wafer delivery table 110 for the purpose, a developing device 111 for exposing the exposed wafer W to a developing solution, and selectively dissolving the exposed portion or the non-exposed portion of the resist in the developing solution are collectively incorporated.

The resist coating and developing system 101
A corrugated wafer transfer path 112 is provided in the center of the wafer transfer path 112 in the longitudinal direction (Y direction), and each processing apparatus directs its front surface (the surface having the wafer loading / unloading port) toward the wafer transfer path 112. The wafer W, which is a substrate to be processed, is held at its lower edge by the holding member 114 of the wafer transfer device 113 that is movable in the wafer transfer path 112. It is designed to be transferred and transported by. The acceleration when the wafer transfer apparatus 113 is activated and the deceleration when the wafer transfer apparatus 113 is stopped are all set to the same acceleration and deceleration regardless of the distance between the processing apparatuses to be transferred. Also, the transfer speed of the wafer transfer device 113 was the same among the processing devices regardless of the type of pre-processing.

[0005]

By the way, during the above processing,
In the process of applying the resist solution, if the resist processing solution used has a high viscosity such as polyimide, for example, a side rinse process of dissolving and removing the resist on the peripheral portion of the wafer W may be performed by the resist applying apparatus. It is difficult to remove the polyimide around the wafer. When the processing liquid residue adheres to the contact portion of the holding member 114 of the wafer transfer device 113 with the wafer W, the wafer W becomes difficult to separate from the holding member 114, and the wafer W cannot be transferred smoothly. Therefore, it is necessary to minimize the contact between the peripheral portion of the wafer W and the holding member 114.

Further, according to the above-described conventional transfer method, the transfer devices are moved under the same acceleration and deceleration regardless of the distance between the processing devices to be transferred, and all are moved at the same transfer speed. Therefore, if the travel distance is short,
There is a possibility that the wafer transfer device 113 itself may vibrate due to a momentary excessive torque fluctuation of a motor, which is a drive source, such as a servo motor. Then, the contact state between the holding member 114 and the peripheral portion of the wafer W changes due to this vibration, and the residue easily adheres to the holding member 114.

Further, there is a case where the side rinse treatment cannot be performed even in the treatment of the resist liquid having a low viscosity of the treatment liquid. In such a case, when the wafer W is transferred inside the treatment device in the state of being coated, the above-mentioned vibration occurs. As a result, the resist solution adheres to the wafer transfer device 113, and the dried resist solution is peeled off to easily generate particles.

The present invention has been made in view of the above points, and in carrying out a substrate to be processed such as a wafer, for example, it is a first object to solve the above problem by suppressing the vibration of the carrying device. To aim. Further, according to the present invention, according to the state of the substrate to be processed, the optimum transfer method at that time is selected to fundamentally prevent the adhesion of the processing liquid and the like. A second object of the present invention is to provide a carrier device suitable for the above.

[0009]

In order to achieve the above object, the invention of claim 1 holds a substrate to be processed by a transfer means in a processing system including a processing device for processing a substrate to be processed. In this method, the acceleration and / or the deceleration during the transportation by the transportation means or both of them are changed according to the moving distance of the transportation means.

According to a second aspect of the present invention, in a processing system including a plurality of processing apparatuses for processing a substrate to be processed,
A method of holding a substrate to be processed, which has been processed by one processing apparatus, by a transfer means, and transferring the processed substrate to another processing apparatus which performs the next processing of the processing, depending on a type of the processing by the one processing apparatus. Then, the method of holding the substrate to be processed in the transfer means is changed, and the transfer speed at the time of transfer to the other processing apparatus is also changed. In addition, for the transfer between one processing apparatus and another processing apparatus here,
It also includes movement within each processing apparatus, for example, movement when mounting on a mounting table or a support pin, and movement from inside the processing apparatus to outside the processing apparatus.

Further, according to a third aspect of the present invention, there is provided an apparatus for carrying and carrying a substrate to be processed as a carrying apparatus for carrying out the carrying method of the second aspect, wherein a peripheral portion of the substrate to be processed is held. In a transfer device having a first arm and a second arm having a holding part for holding, a third arm having a holding part for holding only the lower surface of the substrate to be processed is held. Is provided.

[0012]

According to the carrying method of claim 1, when the moving distance of the carrying means is relatively short, for example, relative acceleration,
Decrease the deceleration, and on the contrary, if the moving distance is relatively long,
Acceleration and deceleration are relatively increased to carry the paper. As a result, when the moving distance is short, the width of torque fluctuation during acceleration and deceleration is reduced, and the occurrence of vibration can be suppressed.

According to the second aspect of the present invention, for example, when the processing liquid or the like, which may be attached when contacted, remains on the peripheral edge portion of the substrate to be processed when held by the transfer means, the peripheral edge portion is removed. Avoiding this, the substrate to be processed is conveyed while being held only by the lower surface portion. In this case, depending on how to hold,
When the transport speed is high, the substrate to be processed may be displaced during transport, and in such a case, the substrate is transported at a reduced speed. On the contrary, if there is no risk of the treatment liquid adhering to the peripheral edge of the substrate to be processed and held, the peripheral edge may be held as it is and conveyed at high speed. That is, by changing the holding position of the target substrate to be transferred and changing the transfer speed accordingly, it is possible to realize optimum transfer according to the state of the target substrate.

According to the transfer device of the third aspect, the first arm and the second arm are used when there is no risk of adhesion of the processing liquid or the like even if the substrate is brought into contact with and held by the peripheral portion of the substrate. It can be held and transported, and if it comes into contact there is a possibility that the treatment liquid will adhere.If the treatment liquid remains on the peripheral edge of the substrate to be treated,
The lower surface of the substrate to be processed is held (supported) by the third arm
Can be transported.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 to 3 show coating and development of a semiconductor wafer (hereinafter referred to as “wafer”) to which the embodiments of the present invention are applied. 1 is a plan view, FIG. 2 is a front view, and FIG. 3 is a back view.

In the coating / developing processing system 1, a plurality of wafers W as substrates to be processed are transferred into or out of the system from the outside in units of a plurality of wafer cassettes CR, for example, 25 wafers. Loading / unloading section 1 for loading / unloading the wafer W
0, a processing unit 11 in which various single-wafer processing units that perform predetermined processing on the wafer W one by one in the coating and developing process are arranged in multiple stages at predetermined positions, and are provided adjacent to the processing unit 11. It has a configuration in which an interface section 12 for transferring the wafer W to and from an exposure apparatus (not shown) to be connected is integrally connected.

In the carry-in / carry-out section 10, as shown in FIG. 1, a plurality of wafer cassettes CR, for example, up to four wafer cassettes CR are provided at the position of the positioning protrusion 20a on the cassette mounting table 20.
The respective wafer entrances / outlets can be placed in a line in the X direction (vertical direction in FIG. 1) toward the processing unit 11 side, and the cassettes can be arranged in the cassette arrangement direction (X direction) and the wafers stored in the wafer cassette CR can be arranged. The wafer transfer body 21 movable in the wafer arrangement direction (Z direction; vertical direction) is attached to each wafer cassette CR.
You can access it selectively.

Further, the wafer carrier 21 is configured to be rotatable in the θ direction in the horizontal direction, and as will be described later, an alignment unit belonging to the multi-stage unit section of the third processing unit group G ₃ on the processing section 11 side. (ALI
M) and extension unit (EXT) are also accessible.

In the processing section 11, as shown in FIG.
A vertical transfer type main wafer transfer mechanism 22 provided with the wafer transfer device according to the present embodiment is provided at the center thereof, and all processing units are arranged in multiple stages around the main wafer transfer mechanism 22. In this example, the first processing unit group G ₁
The fifth processing unit group G ₅ can be arranged, and the multi-stage units of the first and second processing unit groups G ₁ and G ₂ are arranged on the front side (front side in FIG. 1) of the system, The multi-stage unit of the third processing unit group G ₃ is arranged adjacent to the loading / unloading unit 10, and the fourth processing unit group G 3
The multi-stage unit of ₄ can be arranged adjacent to the interface unit 12, and the multi-stage unit of the fifth processing unit group G ₅ can be arranged on the back side.

As shown in FIG. 2, in the first processing unit group G ₁ , two spinner type processing units, such as a resist coating unit (for example, a resist coating unit The COT) and the developing unit (DEV) are stacked in two stages in order from the bottom.
Also in the second processing unit group G ₂ , two spinner type processing units, for example, a resist coating unit (COT) and a developing unit (DEV) are stacked in two stages in order from the bottom. These resist coating units (COT) are preferably arranged in the lower stage in this way, because draining the resist liquid is troublesome both mechanically and in terms of maintenance. However, it is, of course, possible to arrange them in the upper stage as needed.

As shown in FIG. 3, in the third processing unit group G ₃ , an oven type processing unit for carrying out a predetermined processing by placing the wafer W on the mounting table SP, for example, a cooling unit (COL) for carrying out cooling processing. , An adhesion unit (AD) that performs a so-called hydrophobic treatment for enhancing the adhesiveness of the resist, and an alignment unit (ALI that performs predetermined alignment such as orientation flat alignment and centering).
M), extension unit (EXT), pre-baking unit (PREB) that performs heat treatment before exposure treatment
AKE) and a post-baking unit (POBAKE) for performing a heat treatment after the exposure treatment are stacked, for example, in eight stages from the bottom.

Also in the fourth processing unit group G ₄ , an oven type processing unit such as a cooling unit (CO
L), extension cooling unit (EXT
COL), extension unit (EXT), cooling unit (COL), pre-baking unit (PREBAKE) and post-baking unit (P).
OBAKE) are stacked in order from the bottom, for example, in eight stages.

As described above, the cooling unit (COL) having a low processing temperature and the extension cooling unit (EXTCOL) are arranged in the lower stage, and the baking unit (PREBAKE), the post-baking unit (POBAKE) and the adhesion having a high processing temperature are arranged. By arranging the units (AD) on the upper stage, thermal mutual interference between the units can be reduced. Of course, a random multi-stage arrangement may be used.

The interface section 12 has the same size as the processing section 11 in the depth direction (X direction), but is set to have a smaller size in the width direction. A portable pickup cassette CR and a stationary buffer cassette BR are arranged in two stages on the front surface of the interface unit 12, while a peripheral exposure device 23 is arranged on the rear surface. Furthermore, a wafer carrier 24 is provided at the center of the interface section 12. The interface unit 12
Alternatively, only the stationary buffer cassette BR may be arranged, and the pickup cassette CR may be arranged in the carry-in / carry-out section 10. Further, the peripheral exposure device 23 includes the interface unit 12
You may arrange | position at the front part and the back part.

The wafer carrier 24 moves in the X and Z directions to move both cassettes CR, BR and the peripheral exposure device 23.
To access. Wafer carrier 2
4 is configured to be rotatable also in the θ direction, and is an extension unit (EX) belonging to the multi-stage unit of the fourth processing unit group G ₄ on the processing unit 11 side.
T) and also a wafer transfer table (not shown) on the side of an adjacent exposure apparatus (not shown) can be accessed.

In the coating and developing treatment system 1, as described above, the broken line is shown on the back side of the main wafer transfer mechanism 22.
Although the fifth processing unit group G ₅ of the multi-stage unit is adapted to be placed, the multi-stage units of the fifth processing unit group G ₅ is viewed from the main wafer transfer mechanism 22 along the guide rail 25, side It is configured so that it can be shifted toward. Therefore, even when the multi-stage unit of the fifth processing unit group G ₅ is provided as shown in the drawing, the space is secured by sliding along the guide rail 25, so that the main wafer transfer mechanism 22 can be secured. The maintenance work can be easily done from behind.

The multi-stage unit of the _fifth processing unit group G ₅ is not limited to the linear slide shift along the guide rail 25 as described above, but is indicated by the reciprocating rotary arrow indicated by the alternate long and short dash line in FIG. In addition, even if it is configured to be rotationally shifted to the outside of the system, it becomes easy to secure a space for maintenance work for the main wafer transfer mechanism 22.

Next, the details of the main wafer transfer mechanism 22 constituting a part of the transfer means will be described. FIG. 4 is a perspective view showing the structure of the main part of the main wafer transfer mechanism 22, and FIG. The main wafer transfer mechanism 22 is shown in FIG.
A wafer transfer device 34, which constitutes a part of the transfer means, is placed in a vertical direction (Z direction) inside a cylindrical support 33 composed of a pair of vertical walls 31 and 32 which are connected to each other at their upper and lower ends and face each other.
It is equipped so that it can be moved up and down. The cylindrical support 33
Is connected to the rotary shaft of the motor 35, and the motor 3
The rotation driving force of 5 causes the wafer transfer device 34 to rotate integrally with the wafer about the rotation axis, whereby the wafer transfer device 34 is rotatable in the θ direction. The cylindrical support 33 may be connected to another rotation shaft (not shown) rotated by the motor 35.

The wafer transfer device 34 includes a transfer base 40.
In the front-back direction of the transfer base 40, for example, X in FIG.
A plurality of holding members that are movable in any direction, that is, three tweezers 4 that constitute an arm in the present invention.
1, 42, 43 are provided. Also, each tweezers 41,
42 and 43 are both vertical wall portions 3 of the tubular support 33.
It has a shape and a size that allow it to pass through the side opening 36 between the first and the second. Each of these tweezers 41, 42, 4
3, the movement in the front-back direction is realized by a drive motor (not shown) and a belt (not shown) built in the transport base 40.

As shown in FIGS. 4 and 6, the tweezers 41 has a holding portion 41a having a substantially C-shaped plane and a supporting portion 41b for supporting the holding portion 41a.
As shown in FIG. 5, when the wafer W, which is the substrate to be processed, is held and transported by the tweezers 41, only the lower surface of the wafer W is in contact with and supported by the holding portion 41a. That is, the holding portion 41a of the tweezers 41
Has an outer diameter smaller than that of the wafer W to be transferred.

The inner diameter of the holding portion 41a of the tweezers 41 has a so-called spinner type processing unit such as a resist coating unit (COT) and a developing unit (DEV) among the processing units described above, that is, the wafer W serves as a spin chuck. The unit has a diameter larger than the outer diameter of the portion of the spin chuck that contacts the wafer in the processing unit. Further, the width of the opening cutout portion at the front end of the holding portion 41a is set to be larger than the outer diameter of the spin chuck. As a result, the holding portion 41a of the tweezers 41 comes into contact with the lower surface of the wafer W at the shaded portion in FIG. 6 to mount the wafer W, and when the wafer W is moved back and forth into the processing unit, the spin chuck It does not come into contact with a support pin, which will be described later, in another processing device.

At least the upper surface of the holding portion 41a of the tweezers 41 is made of a material having a high friction coefficient, for example, a rubber material. With such a configuration, the frictional force between the wafer W and the lower surface thereof is increased, and positional deviation during transportation is prevented. Note that the holding portion 41
The material of the front surface of a, that is, the contact portion with the back surface of the wafer W, in addition to having such a high coefficient of friction, is excellent in high temperature resistance (for example, 100 ° C. or higher) and has few particles generated. preferable. Further, in this embodiment, the holding portion 41a
The upper surface of the wafer W is in contact with the lower surface of the wafer W over the entire surface. However, for example, a plurality of appropriate protrusions may be provided on the upper surface of the holding portion 41a and the lower surface of the wafer W may be supported by the protrusion portions. Good. The holding portion 41a of the tweezers 41
The material itself may be, for example, ceramic.

The stay 41c provided on the supporting portion 41b is slid by a drive motor (not shown) so that the entire tweezers 41 moves in the front-back direction of the transport base 40. . The supporting portion 4
The 1b is formed with a substantially rectangular long hole 41d that forms an opening along the longitudinal direction thereof, that is, the moving direction of the tweezers 41. Further, light emitting portions 52a and 52b of the sensor, which will be described later, are positioned on the extension line in the longitudinal direction of the long hole 41d.

The tweezers 42 and 43 have basically the same structure, for example, the tweezers 4 located in the middle stage.
If the structure is explained based on 2, the tweezers 4
As shown in FIGS. 4, 6, and 7, 2 is a substantially 3/4 for directly supporting the peripheral portion of the rear surface of the wafer W, which is the substrate to be processed, with the claw-shaped supporting member 42a and holding it. An annular holding portion 42b and a support portion 42c that is integrally formed with the central portion of the holding portion 42b and supports the holding portion 42b. The stay 4 is provided on the support portion 42c.
2d is slid by a drive motor (not shown), so that the entire tweezers 42 moves in the front-back direction of the transport base 40. The supporting portion 42c
Also, similarly to the case of the above-mentioned tweezers 41, a substantially rectangular long hole (not shown) forming an opening is formed along the longitudinal direction thereof.

The forward and backward movements of the tweezers 41, 42 and 43 are controlled by a control device (not shown) composed of a computer or the like. While the tweezers are retracted, the other tweezers are moved forward. Or
Alternatively, also in such a forward movement, the initial movement can be advanced to a wafer detection position described later, and then further advanced according to the detection result, or stopped as it is.

As shown in FIGS. 4 and 7, the intervals between the tweezers 41, 42 and 43 are the same as the intervals between the upper tweezers 41 and the middle tweezers 42. It is set larger than the distance between the lower tweezers 43. This is to prevent the wafers W held by the upper tweezers 41 and the middle tweezers 42 from thermally interfering with each other.
Therefore, for example, the upper tweezers 41 is used when carrying out the cooling step to the resist coating step, and when carrying the resist solution after the resist solution coating, as described later. In the case of other transports, the middle tweezers 42 and the lower tweezers 43 are used.
In order to further enhance the effect of preventing thermal interference, for example, a heat insulating plate may be appropriately arranged between the upper tweezers 41 and the middle tweezers 42.

The transport base 40 has a structure as shown in FIGS.
As shown in FIG. 3, the sensor stand 51 is provided, and whether the tweezers 41, 42, 43 hold the wafer W as the substrate to be processed by the sensor provided at the substantially tip portion of the sensor stand 51. Also, it is possible to detect whether or not it is held in the correct position.
This sensor includes a light emitting portion 52a of a first sensor for detecting the presence or absence of the wafer W in each of the holding portions 41a, 42b, 43b of the tweezers 41, 42, 43, and the light emitting portion 52.
The wafer W is arranged further outward from a and holds the wafer W.
It has a light emitting portion 52b of a second sensor that detects whether or not it is held at a predetermined position of 1a, 42b, 43b (whether it is protruding from the predetermined position).

The light emitting portions 52 and 52b face the light receiving portion 53a of the first sensor and the light receiving portion 53b of the second sensor, which are provided in the vicinity of the front edge of the transport base 40, respectively. The presence or absence of the wafer W and the presence or absence of the above-described wafer W are determined by whether or not the detection light emitted from each of the light emitting units 52a and 52b, for example, laser light is received by the light receiving units 53a and 53b. .

In this embodiment, the tweezers 41, 42 and 43 are set at predetermined detection positions, that is, the wafer W, at the time of detection.
Between the optical axis a connecting the light emitting portion 52a and the light receiving portion 53a and the optical axis b connecting the light emitting portion 53a and the light receiving portion 53b (the position indicated by the broken line M in FIGS. 6 and 7). Detection light is emitted from the light emitting units 52a and 52b when the optical axis a is blocked by the wafer W, it is confirmed that the wafer W is held, When the axis b is not blocked, the wafer W
Is confirmed to be held correctly.

Tweezers 4 having the above structure
The vertical movement (Z direction) of the wafer transfer device 34 including the units 1, 42, and 43 is based on the following configuration. That is, the driven pulley 61 is provided near the upper end inside the one vertical wall 31, and the drive pulley 6 is provided near the lower end.
2 are provided, and the driven pulley 61 and the drive pulley 62 are provided.
An endless belt 63 for vertical drive is stretched between the endless belts 63, and the transfer base 40 of the wafer W transfer device 34 is connected to the endless belt 63 via a belt clamp 64. The rotational force of the rotary shaft 65a of the drive motor 65 fixedly arranged on the bottom surface of the cylindrical support 33 is transmitted to the drive pulley 62. With this configuration, the vertical belt drive mechanism is realized.

On the other hand, a pair of guide rails 66, 67 are vertically arranged at the left and right ends inside the vertical wall portion 31, and a pair of horizontal support members 68 projecting from the side surface of the transport base 40. Sliders 70 provided at the tips of
71 is slidably engaged with the guide rails 66, 67. With this configuration, the vertical slide mechanism is realized. By adopting the above-described vertical belt drive mechanism and vertical slide mechanism, the wafer transfer device 34 is driven in the vertical direction (Z
Direction).

Further, as shown in FIGS. 8 and 9, a rodless cylinder 72 is erected vertically between the central portion inside the vertical wall portion 31 and one guide rail 66. A substantially cylindrical movable portion 72 a, which is slidably fitted outside the rodless cylinder 72, has a transfer base 40 of the wafer transfer device 34 via the horizontal support member 68.
It is connected to the. The movable portion 72a is magnetically coupled to a piston (not shown) movably inserted in the rodless cylinder 72, and the movable portion 72a is movable.
The wafer transfer device 34 and the piston are operatively connected to each other via a so as to be simultaneously movable. Further, in the port 72b at the lower end of the rodless cylinder 72, compressed air is supplied from the regulator 73 to the pipe 7 under a pressure such that a force substantially equal to the weight of the wafer transfer device 34 is generated in the piston.
4 via. The port 72c at the upper end of the rodless cylinder 72 is open to the atmosphere.

Thus, the weight of the wafer transfer device 34 is
Since it is canceled by the lift force of the rodless cylinder 72, the wafer transfer device 34 can move upward at a high speed without being affected by gravity. Further, even if the endless belt 63 for driving is cut, the wafer transfer device 34 is held at that position by the lift force received from the rodless cylinder 72, and there is no risk of falling by its own weight. Therefore, the wafer transfer device 3
There is no risk of damaging 4 itself or the cylindrical support 33.

Under the control of a controller (not shown), the acceleration and deceleration in the Z direction of the wafer transfer device 34, the deceleration, and the moving speed are variable, and the main wafer transfer mechanism 22 moves in the θ direction. The acceleration and deceleration when rotating and stopping, and the speed during rotational movement are also variable. Furthermore, the tweezers 41, 42, 43 of the wafer transfer device 34 are configured so that the acceleration, deceleration, and speed at the time of advancing and retreating are also variable.

The coating / development processing system 1 employing the wafer transfer device 34 according to the present embodiment is configured as described above. Next, the transfer operation of the wafer W in this coating / development processing system 1 will be described. Carry-out section 1
At 0, the wafer transfer body 21 accesses the cassette CR that contains the unprocessed wafer on the cassette mounting table 20, and takes out one wafer W from the cassette CR. After that, the wafer carrier 21 first moves to the alignment unit (ALIM) arranged in the multi-stage unit of the third processing unit group G ₃ on the processing station 11 side, and the wafer W is placed in the alignment unit (ALIM). Is reprinted.

Then, the alignment unit (ALI
When the orientation flat alignment and centering of the wafer W are completed in M), the wafer transfer device 34 of the main wafer transfer mechanism 22 receives the wafer W for which alignment has been completed, and the alignment unit (ALIM) in the third processing unit group G ₃ is received. The wafer W is carried into the unit by moving to the front of the adhesion unit (AD) located in the lower stage. Then, the third processing unit group G
_It is carried into the cooling unit (COL) belonging to the multi-stage unit of the _third or fourth processing unit group G ₄ . In this cooling unit (COL), the wafer W is cooled to a set temperature before the resist coating process, for example, 23 ° C.

When the cooling process is completed, the main wafer transfer mechanism 22 carries the wafer W out of the cooling unit (COL) by the tweezers 41, replaces it with the next wafer W held by the tweezers 42, and cools the wafer W. Next, the first processing unit group G ₁ or the second processing unit group G ₂
Resist coating unit (CO
Bring to T). This resist coating unit (COT)
The wafer W is coated with a resist solution in a uniform film thickness on the wafer surface by a spin coating method.

When the resist coating process is completed, the main wafer transfer mechanism 22 applies the wafer W to the resist coating unit (C
OT), then the pre-baking unit (PREB
AKE). Pre-bake unit (PREB
In AKE), the wafer W is heated at a predetermined temperature, for example, 100 ° C. for a predetermined time, and the residual solvent is evaporated and removed from the coating film on the wafer W.

When the pre-baking is completed, the main wafer transfer mechanism 22 transfers the wafer W to the pre-baking unit (PREBA).
KE) and then to an extension cooling unit (EXTCOL) belonging to the multi-stage unit of the _fourth processing unit group G ₄ . Wafer W in this extension cooling unit (EXTCOL)
Is cooled to a temperature suitable for the next step, that is, the peripheral exposure processing in the peripheral exposure apparatus 23, for example, 24 ° C. After this cooling, the main wafer transfer mechanism 22 transfers the wafer W to the extension unit (EXT) immediately above and places the wafer W on a predetermined mounting table (not shown) in this extension unit (EXT). To do.

This extension unit (EXT)
When the wafer W is mounted on the mounting table of (1), the wafer carrier 24 of the interface unit 12 is accessed from the opposite side to receive the wafer W. Then, the wafer carrier 24 carries the wafer W into the peripheral exposure device 23 in the interface section 12. Here, the wafer W is subjected to an exposure process on its peripheral portion.

When the above-mentioned peripheral exposure processing is completed, the wafer carrier 24 carries the wafer W out of the peripheral exposure apparatus 23, and a wafer receiving table (not shown) on the adjacent exposure apparatus side.
Transfer to. In this case, the wafer W may be temporarily stored in the buffer cassette BR before being transferred to the exposure apparatus.

When the entire surface exposure process in the exposure apparatus is completed and the wafer W is returned to the wafer receiving table on the exposure apparatus side, the wafer carrier 24 of the interface section 12 accesses the wafer receiving table and performs the exposure processing. An extension unit (EX) which receives the wafer W and belongs to the multi-stage unit of the fourth processing unit group G ₄ on the processing unit 11 side.
Then, the wafer is loaded into T) and placed on a predetermined wafer receiving table. In this case, the wafer W may be temporarily stored in the buffer cassette BR in the interface unit 12 before being transferred to the processing unit 11 side.

Extension unit (EXT)
When the wafer W is loaded into the developing unit, the main wafer transfer mechanism 22 accesses the wafer W from the opposite side to receive the wafer W, and the developing unit belonging to the multi-stage unit of the first processing unit group G ₁ or the second processing unit group G _2. Carry in to (DEV). In the developing unit (DEV), the wafer W is placed on the spin chuck, and the developing solution is uniformly applied to the resist on the wafer surface by, for example, a spray method. Then, when the development is completed, a rinse liquid is applied to the wafer surface,
The developer is washed off.

When the developing process is completed, the main wafer transfer mechanism 22 carries the wafer W out of the developing unit (DEV), and then the third processing unit group G ₃ or the fourth processing unit group G ₄ is processed. Carry it into the post baking unit (POBAKE) belonging to the multi-stage unit. In this post-baking unit (POBAKE), the wafer W is heated, for example, at 100 ° C. for a predetermined time. As a result, the resist swollen by development is cured and chemical resistance is improved.

When the post-baking is completed, the main wafer transfer mechanism 22 carries the wafer W out of the post-baking unit (POBAKE) and then into the cooling unit (COL). After the temperature of the wafer W is returned to room temperature, the main wafer transfer mechanism 22 transfers the wafer W to the extension unit (EXT) belonging to the third processing unit group G ₃ .

This extension unit (EXT)
When the wafer W is mounted on the mounting table (not shown) in the inside,
The wafer transfer body 21 on the loading / unloading section 10 side accesses from the opposite side to receive the wafer W. And wafer carrier 2
First, the received wafer W is put into a predetermined wafer accommodating groove of the cassette CR for accommodating processed wafers on the cassette mounting table 20.

In the above series of processing procedures, the transfer between the processing units is all performed by the main wafer W transfer mechanism 22, and the wafer W to be processed is either tweezers 41, 42 or 43 of the transfer device 34. It is held and conveyed by the tweezers, but in the present embodiment,
First, according to the distance between the processing units, the wafer transfer device 34 is moved up and down in the Z direction, and the main wafer transfer mechanism 22 is rotated by θ.
The acceleration as well as the deceleration of each rotation in the direction can be varied.

[0058] As shown in FIG. 1, for example, than when conveyed from the first processing unit group G ₁ to the third processing unit group G _3, the third processing unit group G ₃ second processing The moving distance of the transport device 34 is longer when the rotational movement is made to the unit group G ₂ . In such a case, the acceleration of the first processing unit group G ₁ → the acceleration of the _third processing unit group G ₃ ,
By lowering the deceleration than the acceleration and deceleration of the third processing unit group G ₃ → the second processing unit group G ₂ ,
It is possible to suppress the momentary excessive torque fluctuation of the motor 35 that drives the rotational movement and suppress the occurrence of vibration. In addition, it becomes possible to avoid a moving state in which a sudden stop immediately after a sudden start. Therefore, tweezers 4
It is possible to suppress the vibration of the wafer W held by 1, 42, 43 and realize a good holding state. In this case, the numerical values of the acceleration and deceleration are calculated in advance according to the transport distance between the processing units, and automatically changed by the control device such as a computer according to the moving distance accompanying the actual processing. I will let you.

By the way, a resist coating unit (COT)
After the resist solution is applied to the wafer W by the method described above, when the wafer W is transferred to a pre-bake unit (PREBAKE) that performs a heat treatment as a next step, the applied resist solution is a highly viscous resist solution, for example, a polyimide-based resist solution. In this case, as described above, the resist coating unit (COT)
Therefore, even if the side rinse process is performed, the polyimide on the peripheral edge of the wafer is hard to be removed. Therefore, when transferring from the resist coating unit (COT) to the pre-bake unit (PREBAKE), the wafer W
Need not be attached to the holding member that directly holds.

In this respect, since the wafer transfer device 34 in this embodiment is equipped with the tweezers 41 serving as the third arm for supporting only the center side of the lower surface of the wafer W from the peripheral portion, the resist coating unit ( When the wafer W coated with the resist solution is taken out from the COT) and conveyed to the pre-bake unit (PREBAKE), if the wafer W is held by the holding portion 41a of the tweezers 41, the resist solution or the like on the peripheral portion can be removed. There is no possibility that the processing liquid will adhere to the tweezers 41.

When the wafer W is transferred using the tweezers 41, the wafer W is transferred while being placed on the holding section 41a and held by the frictional force. Is carried out from the resist coating unit (COT), the pre-baking unit (P
It is desirable to lower the speed of carrying in the REBAKE), moving in the Z direction, and rotating in the θ direction as compared with the case of other carrying. That is, since the upper surface of the holding portion 41a of the tweezers 41 is processed to have a high friction coefficient, the mounted wafer W is not likely to be displaced even if it is moved at a normal transfer speed. By lowering the speed itself, the wafer W can be transported more safely and without positional deviation. Regarding the transport speed in this case, an appropriate speed is previously obtained by an experiment depending on the material of the contact portion of the holding portion 41a with the wafer W.

Regarding this point, it is conceivable to employ, for example, a vacuum suction type tweezers, but this makes the structure complicated, and the temperature of the portion of the wafer W that is vacuum-sucked is different. In view of the possibility that the height may be lower than that of the portion, which results in non-uniform processing, the means for transporting with tweezers 41 as in this embodiment has a simpler structure, and the processing can be performed more easily. There is an advantage that the homogenization is not hindered.

Further, in this embodiment, the holding member of the type for mounting and holding the wafer W was provided with only one of the tweezers 41 described above, but of course, two or more thereof may be provided. For example, by providing two, it is possible to deal with the case where a so-called multi-step heat treatment needs to be performed after the application of the resist solution. That is, if the resist is not completely cured by one-time (primary) heat treatment and the heat treatment (secondary) is continuously performed again at a higher temperature, the wafer W is still left after the first heat treatment is completed. When it is not preferable to directly hold the lower edge of the peripheral edge portion of the wafer, a holding member (tweezers) of a type for mounting and holding the wafer W is insufficient when the wafer W is exchanged in the primary heat treatment unit. It will be. Therefore, by providing tweezers having the same structure as the tweezers 41 as a so-called fourth arm, it is possible to cope with such multi-step heat treatment.

The above description is for the wafer W between the processing units.
Acceleration, deceleration control, conveyance speed control,
Further, although it was related to the selection of the transfer means, the yield can be improved by controlling the speed of the transfer of the wafer in each processing unit and the vertical movement of the transfer device 34 at the time of receiving the wafer. it can.

That is, normally, in each processing unit, when the wafer W is transferred from the tweezers 41, 42, 43 of the transfer device 34, the entire transfer device 34 descends and moves vertically, for example, provided in the processing unit. The wafer W is placed on a free support pin. Then, the transfer device 34 descends as it is, and after the wafer W is completely carried by the support pins,
The transfer device 34 retreats and retracts to the outside of the processing unit, and then the support pins descend to place the wafer W on a predetermined mounting table for processing. In the case of a spin chuck, basically the same receiving procedure is performed. When the wafer W is transferred to the transfer device 34, the procedure is the reverse of this. First, the support pins are lifted to carry the wafer W, and then the tweezers of the transfer device advance to the lower surface of the wafer W. Then, the entire transfer device is raised to receive the wafer W with the tweezers.

In such a case, conventionally, the descending speed of the carrier is
The rate of climb was constant. Therefore, when the wafer W is transferred to the support pins, when the wafer W comes into contact with the support pins, an impact may be generated to cause abnormal noise, or in an extreme case, a positional shift may occur. When the wafer W is transferred to the tweezers of the transfer device, when the transfer device moves up and the tweezers come into contact with the lower surface of the wafer W, an impact is generated and abnormal noise is generated, or even more correctly. I could not deny that I could not hold it.

In order to deal with such a situation, the following carrying method can be realized in this embodiment. For example, as a model case, a case where the wafer W is transferred into an adhesion unit (AD) provided in the _third processing unit group G ₃ employed in the coating and developing processing system 1 will be described as an example.

FIG. 10 shows this adhesion unit (A
The cross section of the main part of D) is shown, and the processing container 81 of this adhesion unit (AD) is a cylindrical hot plate holder 83 and a hot plate holding a disk-shaped hot plate 82 as a mounting table SP. It is composed of a lid body 84 which is placed on 82 through a gap S ₁ and a space S ₂ . A gas inlet port 84 a for introducing HMDS gas into the processing container 81 from a HMDS (hexamethyldisilazane) gas supply unit (not shown) through a gas supply pipe 85 is provided in a central portion of the lid 84.
Are formed.

The lid 84 has an upper lid 84b and a lower lid 8 which are branched into two upper and lower portions so that a hollow portion S ₃ is gradually formed from the vicinity of the gas inlet 84a toward the outer side in the radial direction.
It has a double lid structure constituted by 4c, and a gap S ₄ is formed over substantially the entire circumference between the outer peripheral edge portion of the upper lid portion 84b and the inner side surface of the side wall of the lower lid portion 84c. In addition, a ventilation portion 84d is formed over substantially the entire circumference in the connecting portion between the upper lid portion 84b and the lower lid portion 84c, and the gap 84e between the upper lid portion 84b and the lower lid portion 84c is a lid body. It communicates with an exhaust port 86 provided on the outer surface of 84. As a result, the HM introduced from the gas inlet 84a
The DS gas is uniformly diffused in the space S ₂ toward the surroundings, and is uniformly exhausted through the gap S ₄ . The exhaust port 86 is connected to an exhaust pump (not shown) via an exhaust pipe 87.

The hot plate 82 is made of a metal having a high thermal conductivity, for example, aluminum, and the wafer W as a substrate to be processed is placed on the upper surface thereof. A heater for heating the wafer W, such as a resistance heating element and a temperature sensor, is built in the hot plate 82, and a temperature control mechanism for controlling the heat generation temperature of the heater is provided outside the hot plate 82. (Not shown) and the like are also provided. In addition, a plurality of locations on the hot plate 82,
For example, through holes 82a are formed at three locations, and vertically movable support pins 88 used for wafer transfer are inserted into these through holes 82a in a loosely fitted state.
When the wafer W is loaded or unloaded, the support pins 88 project (raise) above the upper surface of the hot plate 82 to carry the wafer W, and the tweezers 41 of the wafer transfer device 34 in the main wafer transfer mechanism 22 are used. The wafer W is transferred between 42 and 43.

The adhesion unit (A
A case in which the wafer W is loaded into D) and the wafer W held by, for example, the tweezers 42 is transferred onto the support pins 88 will be described with reference to FIGS. 11 to 15. It should be noted that the arrows in FIGS. 11 to 15 indicate the magnitude of the speed, and when two arrows are displayed, it indicates that the speed is higher than when there is one arrow. As shown in FIG. 11, after the tweezers 42 holding the wafer W advance to the descent start position of the tweezers 42 in the adhesion unit (AD), the transfer device is initially relatively high speed. The whole 34 is lowered.

Then, as shown in FIG. 12, the wafer W held by the holding portion 42a of the tweezers 42 ascends from the heat plate 82 of the adhesion unit (AD) and stands by for holding the support pins 88. When approaching, the descending speed is switched and this time the descending speed is relatively low. Then, as shown in FIG. 13, even when the lower surface of the wafer W comes into contact with the tops of the support pins 88, the wafer W is still lowered at the relative low speed, and as shown in FIG. The relative low speed is maintained until the holding portion 42a of the tweezers 42, which is carried on 88, is separated slightly below the top of the support pin 88. After that, the descending speed is switched to a relatively high speed, and thereafter, as shown in FIG.
The tweezers 42 are lowered at the relative high speed until the tweezers 42 are lowered to a predetermined lowering point. Then, the tweezers 42 is retracted after reaching a predetermined descending point.

By switching the lowering speed of the tweezers 42 (wafer transfer device 34) as described above, when the wafer W is carried by the support pins 88, the lower surface of the wafer W becomes the top of the support pins 88 at a relatively low speed. The impact is small because they come into contact. Therefore, no abnormal noise is generated and the wafer W is not displaced. Moreover, the transfer time as a whole does not become so long.

When the processed wafer W is received by, for example, the tweezers 42 after the adhesion process is completed, the tweezers 42 (wafer transfer device) can be operated by the reverse procedure described above, that is, the procedure of FIG. 34) should be raised. That is, tweezers 4 until the state of FIG.
2 is raised at a relatively high speed, and then tweezers 4 at a relatively low speed until the state of FIG. 12 is reached.
Raise 2. When raising from the state of FIG. 12 to the state of FIG. 11, the tweezers 42 (wafer transfer device 34) are raised again at a relatively high speed. As a result, when the holding portion 42a of the tweezers 42 receives the wafer W, the contact impact between the holding portion 42a and the lower surface of the wafer W is suppressed, and the wafer W can be reliably held at a predetermined position in the holding portion 42a. become. For each of the above-mentioned speeds, an appropriate speed is obtained in advance by experiments or the like, and tweezers 4
2 is automatically selected according to the position 2 to perform variable control of speed.

Incidentally, the control of the ascending / descending speed at the time of delivery of the wafer W of the wafer transfer device 34 is not limited to the unit having the support pins 88 described above, but another processing unit having a spin chuck, such as a resist coating unit ( It can also be applied when the wafer W is delivered to and from the COT).

The above-described embodiment is an apparatus for transporting the wafer W of the resist coating and developing treatment system used in the photolithography process in the semiconductor device manufacturing process.
Although it is an example applied to the transfer method, the present invention can be applied to a transfer apparatus and a transfer method of another processing system that has a plurality of processing units and needs to transfer the substrate to be processed between these processing units. is there. The substrate to be processed is not limited to the semiconductor wafer described above, but may be an LCD substrate, a CD substrate, a photomask, various printed substrates, or a ceramic substrate.

[0077]

According to the carrying method of the present invention, since the acceleration and deceleration during carrying are changed according to the length of the moving distance, it is possible to suppress the occurrence of vibration of the carrying means during carrying. it can.

According to the transfer method of claim 2, it is possible to realize the optimum transfer according to the state of the substrate to be processed, and to balance the prevention of contamination due to the adhesion of the processing liquid and the high speed transfer. Can be realized.

According to the transfer device of claim 3, the transfer method of claim 2 can be carried out, and the prevention of contamination due to the adhesion of the treatment liquid and the like and the high-speed transfer can be realized in a well-balanced manner. .

[Brief description of drawings]

FIG. 1 is an explanatory plan view showing an overall configuration of a coating and developing treatment system including a wafer transfer device according to an embodiment of the present invention.

FIG. 2 is a front explanatory view of the coating and developing treatment system of FIG.

FIG. 3 is a rear view of the coating and developing treatment system of FIG.

FIG. 4 is a schematic perspective view showing a configuration of a main part of a main wafer transfer mechanism having a wafer transfer device according to an embodiment of the present invention.

5 is an explanatory view of a vertical cross section of the main wafer transfer mechanism of FIG.

FIG. 6 is a plan view of the wafer transfer device according to the embodiment of the present invention.

FIG. 7 is a side view of the wafer transfer device according to the embodiment of the present invention.

8 is an explanatory view of a plane cross section of the main wafer transfer mechanism of FIG.

9 is an explanatory view of a side cross section of the main wafer transfer mechanism of FIG.

10 is an explanatory diagram of a front cross-section of an adhesion unit provided in the coating and developing treatment system of FIG.

FIG. 11 is a view showing a lifting operation of the wafer transfer device according to the embodiment of the present invention, which is a side view showing a state where the wafer transfer device starts to descend at a relatively high speed.

FIG. 12 is a diagram showing a lifting operation of the wafer transfer apparatus according to the embodiment of the present invention, showing a state at the time when the lower surface of the wafer approaches the top of the support pin and the lowering speed is switched to a relatively lower speed. FIG.

FIG. 13 is a view showing an operation of the wafer transfer device according to the embodiment of the present invention, which is a side surface explanatory view showing a state when the lower surface of the wafer comes into contact with the tops of the support pins.

FIG. 14 is a view showing the operation of the wafer transfer apparatus according to the embodiment of the present invention, in which the wafer is completely carried by the support pins and the holding portion of the tweezers is slightly separated from the support pins, and the descending speed is lowered. It is a side explanatory view showing a state of switching to a relatively high speed.

FIG. 15 is a side view illustrating the operation of the wafer transfer apparatus according to the embodiment of the present invention, showing a state in which the tweezers are lowered to a predetermined lowering point.

FIG. 16 is a perspective view of a conventional resist coating and developing treatment system.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Coating and developing system 11 Processing part 22 Main wafer transfer mechanism 33 Cylindrical support 34 Wafer transfer device 40 Transfer bases 41, 42, 43 Tweezers 41a Holding part 82 Hot plate 88 Support pin AD Adhesion unit G _{1 to} G ₅ processing unit group W wafer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location H01L 21/30 566 569D (72) Inventor Shigeaki Iida 2655 Tsukuri, Kikuyo-cho, Kikuchi-gun, Kumamoto Tokyo Electron Kumamoto Plant, Kyushu Co., Ltd. (72) Inventor Atsushi Okura 2655 Tsukyu, Kikuyo-cho, Kikuchi-gun, Kumamoto Prefecture Tokyo Electron Kumamoto Plant, Kyushu Co., Ltd.

Claims (3)

[Claims] 1. A method for holding and carrying the substrate to be processed by a carrying means in a processing system including a processing device for carrying out processing on the substrate to be processed, wherein the carrying is performed according to a moving distance of the carrying means. At least one of acceleration and deceleration at the time of transportation by means is changed. 2. In a processing system comprising a plurality of processing devices for processing a substrate to be processed, the substrate to be processed, which has been processed by one processing device, is held by a transfer means, and the next process of the process is performed. In the method of carrying to another processing apparatus to perform, depending on the type of processing in the one processing apparatus, while changing the method of holding the substrate to be processed in the carrying means, the carrying speed at the time of carrying to the other processing apparatus A method of transporting, characterized in that 3. A carrier for holding and carrying a substrate to be processed, comprising: a carrying device having a first arm and a second arm having a holding part for holding a peripheral portion of the substrate to be processed. A transfer device, comprising: a third arm having a holding portion that holds only the lower surface of the substrate to be processed and holds the substrate to be processed.