JPH07176472A - Substrate heater - Google Patents

Abstract

PURPOSE:To uniformly heat the surface of a substrate by rotating the substrate conveyed to substrate support means around an axis perpendicular to the surface of the substrate. CONSTITUTION:A conveyer arm 50 for horizontally supporting a substrate W is introduced from an opening 40a of an outer wall 40 at a predetermined speed, so moved as to bring a center of the substrate W into coincidence with the center of a heat transfer plate 4, and introduced into a heat-treating atmosphere in the wall 40 previously from its rear end. A lift pin 11 is moved down, and the substrate W is supported by a ball 6 provided at the plate 4 by a point contact. Thereafter, a motor 22 is driven at a suitable speed while heat-treating it for a predetermined time, and a treating plate 5, etc., is rapidly turned integrally with the substrate W at about 180 degrees. Thus, the surface of the substrate can be uniformly heat-treated in a substrate heater for conveying and delivering the substrate from one direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate heating apparatus for heat-treating a substrate such as a semiconductor wafer or a glass substrate for a liquid crystal display, and more particularly to a substrate heating apparatus for loading and unloading a substrate from one direction.

[0002]

2. Description of the Related Art As a conventional apparatus of this type, for example, there is a hot plate type substrate heating apparatus. This apparatus, for example, a substrate coated with a specific photoresist is placed on a hot plate heated to a predetermined temperature, and the solvent contained in the photoresist is volatilized by heating for a predetermined time, The photoresist applied to the substrate is cured. This substrate heating device is provided as one unit in a processing device or the like that performs processing such as coating and developing a photoresist solution.

In recent semiconductor manufacturing processes, for example, the requirements for the contents of the processes to be performed on the semiconductor substrate, the order of the processes, and the like are variously changed depending on the element to be manufactured or other conditions. To do. For this reason, recent processing equipment facilitates flow control of substrates that are sequentially processed through a series of units in the equipment, and various processes such as a multi-layer resist process for forming photoresist in multiple layers. In order to cope with the above, a plurality of units such as a coating device and a substrate heating device are arranged on the left and right along one substrate transfer path, and the substrate is transferred by a so-called transfer robot, which is a substrate transfer unit that moves along the transfer path. With this configuration, the order in which one board passes through each unit can be easily changed. Further, in such a processing apparatus, the substrate heating apparatus is configured to carry in and carry out the substrate only from one direction corresponding to the transport path side because the substrate heating apparatus faces the substrate transport path.

[0004]

However, the conventional example having such a structure has the following problems.

That is, the conventional apparatus has a structure for loading and unloading the substrate from only one predetermined direction. In this case, the substrate is horizontally supported by the arm of the transfer robot in the transfer path, moved horizontally, carried into the outer wall of the substrate heating apparatus, and positioned above the heating surface of the hot plate. Then, at that position, it is transferred from the arm to the substrate support pin on the substrate heating device side, and after the arm is retracted, it is brought down to a position where it is in contact with or close to the upper surface of the hot plate. However, in this case, when the substrate is loaded, the front end portion (front end in the loading direction) of the substrate enters the rear end portion (rear end in the loading direction) in the processing temperature atmosphere inside the outer wall body, and reversely when unloading. The rear end portion of the substrate comes out before the front end portion outside the processing temperature atmosphere. Therefore, the front end portion (front end portion in the carrying-in direction) of the substrate stays in the heat treatment atmosphere for a longer time than the rear end portion (rear end portion in the carrying-in direction), and the heat treatment in the surface of the substrate is unevenly performed. The phenomenon occurs. Further, this phenomenon becomes remarkable as the size of the substrate increases.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a substrate heating apparatus capable of uniformly performing a heat treatment on a substrate surface.

[0007]

The present invention has the following constitution in order to achieve such an object. That is, the substrate heating apparatus according to the present invention includes substrate supporting means for supporting the substrate to be processed, and heating means for heating the substrate supported by the substrate supporting means to a predetermined temperature. In a substrate heating device for carrying in and unloading a substrate from a substrate supporting means from one direction along the substrate surface, the substrate carried into the substrate supporting means is rotated about 180 degrees around an axis perpendicular to the substrate surface. It is characterized in that it is provided with a substrate rotating means for rotating.

[0008]

The operation of the present invention is as follows. That is,
The substrate carried in from the predetermined direction enters the heat treatment atmosphere in the apparatus at the front end (the leading end in the carrying-in direction) before the rear end (the rear end in the carrying-in direction). Then, at any time before the substrate is heat-treated and carried out, the substrate is rotated by about 180 degrees about the axis perpendicular to the substrate surface by the rotating means. As a result, the substrate rotationally displaced by 180 degrees from the loading position is carried out of the apparatus (outside the heat treatment atmosphere). Therefore, at the time of carry-in, the front part of the substrate that was heated first (the leading end in the carrying-in direction) is carried out of the device first at the time of carrying-out, and at the time of carrying-in, the rear end part of the substrate that has been heated later (the rear-direction part in the carrying-in direction) Since it will be carried out of the device later when carrying it out,
The time for which the leading portion (carrying-in front end portion) and the rear end portion (carrying-in rear end portion) of the substrate stay in the heating atmosphere of the apparatus is almost the same.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 3 is an overall perspective view showing a processing apparatus using the substrate heating apparatus according to the present invention. The present processing apparatus is an apparatus for applying a photoresist solution to a semiconductor wafer W (hereinafter referred to as a substrate), and is roughly classified into an indexer section 61 for storing an unprocessed substrate and a processed substrate,
A substrate processing unit 62 that processes the substrate W.

The indexer section 61 is provided with four cassettes C which are placed in a line on the horizontal upper surface of the base 63, and is moved along the line of the cassettes C to take a substrate W into and out of the cassette C. The indexer transport means 64. The substrate W is transferred between the indexer unit 61 and the substrate processing unit 62 at a predetermined substrate transfer position P between the indexer transfer unit 64 and the substrate transfer unit 70 (described later) of the substrate processing unit 62. Be seen. Indexer transport means 64
Takes the substrate W to be transferred to the substrate processing unit 62 from the cassette C and transfers it to the substrate delivery position P, and also transfers the substrate W received from the substrate transfer means 70 at the substrate delivery position P and stores it in the cassette C. . Each cassette C
Are configured so that the substrates W can be stored in a horizontal posture in multiple stages in the vertical direction.

The substrate processing section 62 includes an indexer conveying means 6
4, a substrate transfer path 59 formed in a T shape with respect to the transfer path 58, a substrate transfer means 70 moving in the substrate transfer path 59, and a coating device provided on one side of the substrate transfer path 59. 67, and substrate heating devices 66 and 69 and substrate cooling devices 65 and 68 provided on the other side of the substrate transport path 59. The substrate transfer means 70 is composed of a movable base 71 that can move in the horizontal and vertical directions, and two transfer arms 50 that can support the substrate W. The transfer arm 50 includes a movable table 7
1 is provided so as to be capable of advancing and retreating in the horizontal direction, and the advancing and retreating direction thereof can be turned by the movable base 71 turning in a horizontal plane.

The substrate W in the cassette C is taken out by the indexer transfer means 64, transferred to the substrate transfer position P, and transferred to the transfer arm 50 of the substrate transfer means 70. When the substrate is transferred to the transfer arm 50, the substrate transfer means 70 moves in the substrate transfer path 59 and rotates the transfer arm 50 to direct the transfer arm 50 toward the coating device 67, and the transfer arm 50 moves forward and backward and up and down. The substrate W is moved and carried into the substrate heating device 66. The substrate W, which has been heated by the substrate heating device 66 to remove the water content, is taken out by the transfer arm 50, is similarly carried into the substrate cooling device 65, and is returned to room temperature. Next, the substrate W is carried into the coating device 67, and the photoresist liquid is coated on the surface thereof. After that, the substrate W is carried into the substrate heating device 69 to volatilize and remove the solvent component of the photoresist liquid, and then is carried into the substrate cooling device 68 to be returned to room temperature and returned to the cassette C via the indexer conveying means 64. It is stored.

In the above structure, the substrate heating device 66,
67 is a hot plate type substrate heating apparatus by proximity heating, and FIG. 1 is a longitudinal sectional view thereof.

In the figure, reference numeral 1 is a plate heater as a heating means. The plate heater 1 is closely attached to a hot plate 3 made of aluminum, ceramics or the like by a pressing plate 2. The heat transfer plate 4 is provided on the upper surface of the heat plate 3.
Is provided, and these constitute the processing plate 5. Three through holes (not shown) are formed in the heat transfer plate 4 in a positional relationship of the vertices of an equilateral triangle in a plan view, and balls 6 as substrate supporting means are fitted and adhered to the through holes, respectively. ing. Each of the balls 6 has a diameter larger than the thickness of the heat transfer plate 4, and the upper end thereof slightly projects from the heat transfer plate 4. The balls 6 are made of a low heat transfer material such as alumina or matatite. Also, each of the through holes,
A narrow opening having an opening diameter slightly smaller than the diameter of the ball 6 is formed at the upper end of the ball 6 to prevent the ball 6 from moving upward when the heat transfer plate 4 is placed on the upper surface of the heat plate 3. However, the ball 6 is configured so as not to come out. Further, a resistance temperature detector 7 for measuring the temperature in the vicinity of the plate-shaped heater 1 for controlling the temperature is inserted over the heating plate 3, the plate-shaped heater 1 and the pressing plate 2.

In the vicinity of the through holes for the balls 6 of the heat transfer plate 4, three through holes 10 are formed in a portion not overlapping with the through holes in a positional relationship of the vertices of an equilateral triangle in plan view. A lift pin 11 for delivering a substrate is inserted through each through hole 10. An annular flange 11a is formed so as to project from the middle of each lift pin 11. This lift pin 11
The lift pin 11 is supported so as to be able to move up and down by being inserted from above into a bearing 12 provided on the lower surface of the pressing plate 2. These lift pins 11 are connected to each other by screwing the lower ends to the annular connecting member 13. As a result, each lift pin 11 rotates without changing its positional relationship as the processing plate 5 rotates.

At the center of the lower surface of the pressing plate 2, a rotary shaft 20 is provided.
The upper ends of are connected. The lower end of the rotary shaft 20 is connected to the output shaft of the motor 22 via a joint 21. The rotating shaft 20 is supported by a bearing 23,
The bearing 23 and the motor 22 are fixed to the inside of the outer wall body 40 by the support member 24. The motor 22
Corresponds to the substrate rotating means in the present invention.

The outer wall 40 surrounds the plate heater 1 and the processing plate 5 described above, and holds the heat treatment atmosphere inside. An opening 40a for loading and unloading the substrate W is formed on a side wall of the outer wall body 40 on the substrate transport path 59 side, and a shutter 30 for opening and closing the opening 40a can be moved up and down inside the opening 40a. It is arranged. The shutter 30 has an opening 30a for transporting the substrate, and a lower end portion thereof is bent in the horizontal direction and connected to the rod of the air cylinder 31. At the lower end portion of the shutter 30 connected to the air cylinder 31, a push-up member 32 for pushing up the bottom portion of the annular connecting member 13 continuously provided to the lift pin 11 is arranged.

In addition, an exhaust hole 40 for purging the solvent volatilized from the photoresist film on the substrate with an inert gas such as nitrogen is provided on the side wall opposite to the opening 40a.
b is provided.

A substrate transfer path 59 is provided near the outside of the opening 40a of the outer wall body 40, and the moving base 71 of the substrate transfer means 70 moves together with the transfer arm 50. The transfer arm 50 includes a U-shaped substrate support portion 51 having an open front end configured to support the lower surface of the substrate W at three points. In addition, in the substrate transfer path 59, a moving table 71 is provided.
A drive mechanism such as a motor and a ball screw for moving and rotating the carriage is provided.
Although a similar drive mechanism that supports 0 on the moving base 71 and moves it back and forth in the horizontal direction is provided, these are not shown. The second transfer arm 50 included in the moving table 71 is also omitted in FIG. 1.

Next, the operation of the substrate heating apparatus having the above structure will be described with reference to FIG. Figure 2 (a) shows
2B shows a state when the substrate W is loaded by the transfer arm 50, FIG. 2B shows a state at the time of heat treatment, and FIG.
The state at the time of carrying out is shown.

First, while applying appropriate electric power to the plate heater 1 so that the heat transfer plate 4 has a desired processing temperature,
The resistance temperature detector 7 is monitored to control the temperature. The inside of the outer wall body 40 is supplied with an inert gas such as nitrogen in order to purge the solvent evaporated from the photoresist film deposited on the substrate W from the exhaust hole 40b. Now, in the coating device 67, the substrate W whose surface is coated with the photoresist liquid is supported by the transfer arm 50, and the outer wall body 40 is supported.
It is assumed that the paper has been transported to the vicinity of the outside of the opening 40a. The support state of the substrate W of the transfer arm 50 is not particularly limited as long as it is in a horizontal posture, but here, the substrate W is supported.
It is assumed that the orientation flat (hereinafter referred to as OF) of 1 is oriented toward the substrate heating device side.

<During Loading of Semiconductor Wafer> (See FIG. 2A) The air cylinder 31 is driven to extend, and the shutter 30 is lifted to a position where the opening 30a of the shutter 30 coincides with the opening 40a of the outer wall 40. . Along with this, the push-up member 32 is lifted upward and pushes up the annular connecting member 13.
By the annular push-up member 13 being pushed up,
The lift pin 11 connected to this is pushed upward and stands by to support the substrate W at this position. The amount by which the lift pins 11 project from the heat transfer plate 4 needs to be at least the thickness of the transfer arm 50.

The transfer arm 50 that horizontally supports the substrate W is
It enters at a constant speed from the opening 40a of the outer wall body 40, moves so as to substantially align the center of the substrate W with the center of the heat transfer plate 4, and stops. Therefore, the OF portion of the substrate W enters the heat treatment atmosphere in the outer wall body 40 before the rear end portion.

The carrier arm 50, which is stopped while supporting the substrate W, descends by a predetermined amount, and the substrate W is attached to the lift pins 11.
Is reprinted. Then, the transfer arm 50 retracts to the outside of the outer wall body 40.

<At the time of heat treatment> (see FIG. 2B) After the transfer arm 50 is retracted to the outside of the outer wall body 40, the air cylinder 31 is driven to contract, and the shutter 30 opens the opening portion of the outer wall body 40. 40a is closed. At the same time, the lift pins 11 are lowered and the substrate W is supported by the balls 6 provided on the heat transfer plate 4 in point contact. Further, since the amount of protrusion of the balls 6 from the heat transfer plate 4 is minute, the substrate W approaches the heat transfer plate 4 and is uniformly heated by radiant heat.

From the state where the substrate W is placed on the upper surface of the heat transfer plate 4 as described above, the heat treatment time is counted, and the heat treatment is performed for a predetermined time, for example, 60 to 90 seconds.

When the substrate W is supported by the balls 6, the motor 22 is rotationally driven at an appropriate speed, and the processing plate 5 and the substrate W are integrated with each other rapidly (for example, within 5 seconds) to almost 1 second.
It is rotated and displaced by 80 degrees. As a result, the OF of the substrate W is in a state of being directed toward the opening 40a side of the outer wall body 40. Depending on the rotation speed of the motor 22 at this time, since the substrate W is supported by point contact, the position may shift. In order to prevent this, a guide for guiding the substrate W may be provided on the heat transfer plate 4. In FIG. 2B, the substrate W is placed on the heat transfer plate 4 and then is shown as standing by outside the outer wall body 40 as it is. While the W is being heated, the substrate transfer device 70 moves to another place to transfer another substrate from another device to another device. Immediately before the heating of the substrate W in the substrate heating device is completed, the substrate W is moved to the position at which the substrate was loaded.

<During Unloading of Semiconductor Wafer> (See FIG. 2C) After the elapse of a predetermined heat treatment time, the shutter 30 is driven upward by the air cylinder 31, and the lift pins 11 are raised to lift the substrate W. To support. Then, the transfer arm 50 enters through the opening 40a, and the lift pin 1
The lower side of the substrate W supported by 1 is entered. Next, the transfer arm 50 moves up by a predetermined amount to receive and support the substrate W. At this time, the orientation of the OF of the substrate W is in a state in which the orientation is changed by about 180 degrees from that at the time of loading.

The transfer arm 50 supporting the substrate W moves backward from the opening 40a of the outer wall body 40 at a constant speed. Therefore, the OF portion of the substrate W is released from the heat treatment atmosphere before the rear end portion. At the time of loading, since the OF portion is already in the heat treatment atmosphere, considering both the loading and unloading of the substrate, the time during which the rear end portion of the substrate W and the OF portion are exposed to the heat treatment atmosphere is The heat treatment in the substrate W is made substantially equal, and the heat treatment is uniformly performed in the surface.

Immediately after this, another substrate W supported by the other transfer arm 50 of the substrate transfer device 70 is carried into the outer wall body 40 and placed on the heat transfer plate 4. Then, the shutter 30 is closed, and the heat transfer plate 4 is rotationally driven in the direction opposite to the rotational driving direction in the previous processing. As described above, after the substrate W is unloaded, the next substrate W is loaded without rotating to return the heat transfer plate 4 to the original state, so that the exhaust hole 40 is opened while the shutter 30 is open.
It is prevented that the gas flowing from the opening 40a along with the gas exhausted from b cools only one side of the heat transfer plate 4 on the opening 40a side to cause nonuniform temperature distribution. .

In this example, the direction of the substrate W was changed rapidly after the substrate was loaded. This is to quickly move the heat transfer plate 4 whose temperature has been lowered by the gas flowing in from the opening 40a when the substrate W is carried in, to the inner side of the outer wall body 40 and quickly return to the processing temperature. However, in the case where this temperature drop is not a problem, the substrate W
The direction change may be performed at any timing and at any speed by the end time of the heat treatment.

Further, in order to make the amount of heat received by the substrate W uniform, the description has been given by taking the apparatus of the proximity heating system in which the substrate W is slightly floated above the heat transfer plate 4 and heated. A heating method that directly contacts the heat transfer plate 4 may be used. In this case, the heat transfer plate 4 corresponds to the substrate supporting means in the present invention.

Further, in this embodiment, the heat transfer plate 4 is rotated by the motor 22 in order to change the direction of the substrate W. However, as shown below, only the substrate W is rotated without rotating the heat transfer plate 4. May be rotated.

For example, there is provided a substrate rotating means which is disposed on the inner upper portion of the outer wall body 40, descends from the upper portion, and changes the direction by gripping and rotating the peripheral edge of the substrate W at at least three points. In addition, the lift pins 11 provided in the heat transfer plate 4 are arranged and configured so that they do not interfere with the heat transfer plate 3 or the like so that the lift pins 11 can change direction while receiving and supporting the substrate W. , Annular connecting member 13
May be driven to rotate.

Further, the present invention is not limited to the hot plate type substrate heating apparatus as in the present embodiment and can be implemented in various substrate heating apparatuses. For example, the heating means is a lamp annealing apparatus including an infrared lamp or the like arranged in the upper portion of the outer wall body, and a thermal radiation annealing apparatus using a graphite heater in which the heating means can be arranged at any position.

[0035]

As is apparent from the above description, according to the present invention, the substrate loaded into the heat treatment apparatus is rotationally displaced by about 180 degrees about the axis perpendicular to the substrate surface, and the portion previously loaded. Since the parts that have been carried in later are replaced and carried out from the heat treatment apparatus, the time of staying in these heat treatment apparatuses becomes equal. Therefore, it is possible to uniformly perform the heat treatment on the surface of the substrate in the substrate heating apparatus that loads and unloads the substrate from one direction.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a substrate heating apparatus according to an embodiment.

FIG. 2 is a diagram for explaining a process from substrate loading to substrate unloading.

FIG. 3 is a perspective view showing an entire processing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Plate-shaped heater (heating means) 2 ... Pressing plate 3 ... Heat plate 4 ... Heat transfer plate 5 ... Processing plate 6 ... Ball (substrate support means) 11 ... Lift pin 13 ... Annular coupling member 20 ... Rotating shaft 22 ... Motor ( Substrate rotating means) 30 ... Shutter 40 ... Outer wall body 50 ... Transfer arm W ... Substrate

Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location H01L 21/68 A (72) Inventor Makoto Matsushita 322 Hazushi Furukawacho, Fushimi-ku, Kyoto-shi, Kyoto Prefecture Dai Nippon Screen Manufacturing Co., Ltd. Company Rakusai Factory (72) Inventor Masami Otani 322 Hazushishi Furukawa-cho, Fushimi-ku, Kyoto-shi, Kyoto Dainippon Screen Mfg. Co., Ltd. Rakusai Factory

Claims (1)

[Claims] 1. A substrate supporting means for supporting a substrate to be processed,
A heating means for heating the substrate supported by the substrate supporting means to a predetermined temperature, and carrying in and unloading of the substrate from the substrate supporting means is performed from one direction along the substrate surface. The substrate heating apparatus is provided with a substrate rotating means for rotating the substrate carried into the substrate supporting means by about 180 degrees around an axis perpendicular to the substrate surface.