JPH07114232B2 - Semiconductor wafer processing apparatus and processing method thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor wafer processing apparatus for irradiating a semiconductor wafer (hereinafter simply referred to as "wafer") with ultraviolet rays to cure a photoresist, erase EPROM from ultraviolet rays, improve semiconductor circuit elements, and the like. Regarding processing method.

[0002]

2. Description of the Related Art Conventionally, a semiconductor wafer processing apparatus of this type has a single wafer processing apparatus for processing wafers one by one by sending wafers to an ultraviolet processing section in an in-line state and a batch processing apparatus for simultaneously processing a plurality of wafers. There is a device. However, in recent years, since a batch method having a device space of which width and length are substantially equal to each other is more advantageous than a single-wafer apparatus having a horizontally long conveyance section in terms of effective utilization of floor area, a batch method apparatus is used. It came to be adopted.

5 (a) and 5 (b) are a plan view and a C-C sectional view showing an example of a conventional semiconductor wafer processing apparatus. As an example of the batch method described above, for example, Japanese Patent Laid-Open No.
There is an ultraviolet irradiation device which is a semiconductor wafer processing device disclosed in 3-93112. As shown in FIG. 5, this apparatus is arranged such that a plurality of wafers are arranged side by side to irradiate ultraviolet rays, and an ultraviolet irradiation section 33 is arranged so as to sandwich the ultraviolet irradiation section 33, and the wafer is carried into the ultraviolet irradiation section 33. A wafer supply / transport unit 32 and a storage / transport unit 31 for unloading wafers are provided. Further, the wafer carry-in / out ports of the supply / conveyance unit 32 and the storage / conveyance unit 31 are on the same side, and at each of the carry-in / out ports, a carrier conveyer 36 for taking out or accommodating the wafers from the cassette 12 and a cassette 12 are mounted. The mechanism conveys conveyor 36
A supply loader 37 and a storage loader 41 for transferring wafers are provided.

The ultraviolet irradiator 33 is a light receiving area 3 which constitutes a plurality of wafer pedestals 34 in which wafers are arranged vertically and horizontally.
9, which is a closed space portion in which a plurality of ultraviolet lamps 38 are arranged side by side. Then, the wafers positioned by the stoppers 35 of the supply / transport unit 32 are transported in parallel by the shuttle mechanism 12, and the wafer pedestal 34
When the wafer is placed on all of the
Lights up and all wafers are processed.

Further, in the operation of loading / unloading wafers and irradiating ultraviolet rays, first, the cassette 12 containing a plurality of wafers is stored.
Is set in the supply loader 37. Next, the conveyor 3
Wafers are drawn from the cassette 12 one by one from the cassette 7 and transferred to the supply / conveyance unit 32. The transferred wafer is sent to the upper side of the paper surface and is stopped and positioned by a stopper 35 that sequentially projects from the supply / conveyance unit 32. The wafers positioned side by side on the supply / transport unit 32 perform the operation indicated by the arrow of the shuttle mechanism 34a, and are intermittently transported and sequentially transferred to the wafer pedestal 34. After all the wafers have filled the wafer pedestal 34, the ultraviolet lamp 38 is turned on to complete the processing of the wafers.

The processed wafer has a shuttle mechanism 34a.
By the above-mentioned operation, the sheets are sent to the storage / conveyance unit 31 and transferred in parallel. The wafers placed side by side in the storage / transportation unit 31 are sent to the lower side of the paper surface, transferred to the transport conveyor 36, and stored in the cassette 12 by the storage loader 41.

By thus disposing a relatively wide ultraviolet processing section in the center and providing narrow wafer transfer sections, which are wafer loading / unloading sections, on both sides of the ultraviolet processing section, the number of wafers to be processed can be compared. It had the advantage of requiring less space.

[0008]

In the above-mentioned conventional semiconductor wafer processing apparatus, although a relatively large ultraviolet processing section is arranged to process many wafers at one time,
There is a limit to the processing capacity of the device because the wasted time of transferring the wafer to the ultraviolet processing unit and transferring it or transferring the wafer after processing from the ultraviolet processing unit is added as processing time. There are drawbacks. In addition, there is only one place where the cassette is placed on the storage loader and the supply loader, and it is possible to wait for a cassette that stores unprocessed wafers that are sequentially sent from the cassette transfer line or a cassette that stores processed wafers. Absent. For this reason, the order of cassettes must be managed manually,
In some cases, the cassettes may be out of order and may cause serious defects in quality. In other words, this type of device is difficult to apply to a cassette-to-cassette automation line.

FIGS. 6A and 6B are graphs showing the characteristics of the low pressure mercury lamp. Usually, a low-pressure mercury lamp is used as the above-mentioned ultraviolet lamp. However, in this low-pressure mercury lamp, the radiant intensity changes at the position of the tube as shown in FIG. 6 (a), and as shown in FIG. 6 (b), the temperature rises and the radiant intensity changes depending on the lighting time. There's a problem. Simply arranging such unstable UV lamps side by side cannot be expected to uniformly and stably process the wafer. Further, even if an unnecessary number of ultraviolet lamps are provided or the irradiation time is lengthened in order to make them uniform, irradiation is performed to unnecessary places, resulting in waste of energy and reduction in processing capacity.

Therefore, it is an object of the present invention to reduce the wasted time added as the processing time to improve the processing capacity, and to uniformly and stably process the wafers, thereby improving the cassette-to-cassette automation. It is an object of the present invention to provide a semiconductor wafer processing apparatus and a method of processing the same, which is suitable for the above and consumes less energy.

[0011]

A feature of the present invention is that a semiconductor wafer is carried in at one end and at the other end at the semiconductor wafer.
A long irradiation table having a plurality of mounting portions for carrying the semiconductor wafer at predetermined intervals and a semiconductor wafer and the semiconductor wafer are sequentially fed in one direction between the mounting portions. A first transport section having a feeding mechanism, and a first transport section of the first transport section.
An inlet for the semiconductor wafer facing the outlet
The other end is arranged so as to be perpendicular to the first transport section.
The semiconductor wafer carry-out port and
At least one mounting part for mounting the conductor wafer
Between the irradiation table and the semiconductor wafer
A direction-changing conveyance unit having a feeding mechanism for feeding in a predetermined direction;
Of the semiconductor wafer facing the unloading port
It has a hauling-in port and is arranged in parallel with the first transfer section.
The semiconductor wafer is oriented in the same direction as the carry-in port of the first transport section.
It has a haul-out port at the other end and
A long irradiation table and a feeding mechanism of the first transport unit are provided.
A second transport unit, a plurality of independently provided ultraviolet irradiation units corresponding to the first and second transport units, and the placement unit of the direction-changing transport unit, and loading of the first transport unit. Mouth
Ri said from the direction changing conveyance unit from said semiconductor wafer starts to ultraviolet projection of the ultraviolet irradiation unit in order of closeness to the prior SL first conveying portion of the entrance is carried the first conveyor section to the direction changing transport unit Sequentially sent to the 2nd transport section
The semiconductor wafer is irradiated with ultraviolet light
When the calculated time reaches a predetermined time, the UV irradiation after that
It is a semiconductor wafer processing apparatus provided with a means for stopping the irradiation of ultraviolet rays from the projecting portion .

Another feature is that one wafer that is intermittently transported is irradiated with a certain amount of ultraviolet rays during each intermittent feed, and the irradiation amount is integrated for each intermittent feed, and the wafer is transported. This is a semiconductor wafer processing method in which the irradiation of the ultraviolet rays is stopped in the intermittent feeding after the integrated irradiation amount of the wafer reaches a desired irradiation amount.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

1 (a) and 1 (b) are a plan view and an AA sectional view showing an embodiment of a semiconductor wafer processing apparatus of the present invention. As shown in FIG. 1, this semiconductor wafer processing apparatus includes an irradiation table 1b having a loading section 3b on which a wafer loading port is arranged at one end and a plurality of wafers are placed side by side in a row; A mounting portion 3b for arranging a plurality of wafers side by side in a row with the wafer carry-out port arranged on the same side.
A storage unit 2c having an irradiation table 1c having a plurality of wafers, and a wafer which is connected to the wafer outlet of the supply unit 2b and the transfer port of the storage unit 2c and is sent from the supply unit 2b to the storage unit 2c. Irradiation table 1 with a mounting part 3b
a direction changing unit 2a provided with a and a plurality of ultraviolet irradiations having an ultraviolet lamp 8, a reflecting plate 9 and a cooling fan 11, which are independently arranged corresponding to the irradiation units 1b, 1a and the mounting unit 3b of 1c. The unit 13 is provided.

Further, a transfer arm 3 is arranged below the irradiation tables 1a, 1b and 1c, and the transfer arm 3 intermittently sends the wafer by the movement of the drive arm 7 shown by the arrow of CDEF, so that the wafer receiving portion 3a and An intermittent feed mechanism is provided which cooperates to transfer the wafer from one mounting portion 3b to the next mounting portion 3b.

Further, a plurality of wafers are stored in front of the wafer loading / unloading ports of the supply section 2b and the storage section 2c.
A supply loader 5 and a storage loader 6 on which one cassette 12 is placed are arranged. And one of the two cassettes 12 coincides with the transfer line.
Then, the wafer is pulled out by the supply loader 5 and transferred to the positioning unit 15 in front of the wafer loading port, or stored in the positioning unit 17 in front of the loading port. On the other hand, the other cassette 12
The cassettes 12 are sequentially sent by the cassette-to-cassette automatic method and do not coincide with the transfer line. That is, this location is the buffer station of the cassette. Therefore, when the wafers in the cassette 12 that match the line are exhausted or full, the supply loader 5
Also, the storage loader operates to move the other cassette 12 so as to fit the transport line, and the empty or full cassette 1
2 is removed from the transfer line.

The ultraviolet irradiating section 13 is independently attached to each of the irradiation sections 1b, 1a and 1c of the supply section 2b, the direction changing section 2a and the storage section 2c in correspondence with the wafer mounting section 3b, and is controlled separately. There is. Therefore, the ultraviolet lamps of the individual ultraviolet irradiation units can be turned on or off arbitrarily even while the wafer is being transported or stopped. This means that the wafer can be irradiated with ultraviolet rays at the same time as it enters the carry-in port, and while the wafers are sequentially transferred to the mounting portion 3a, they are irradiated with ultraviolet rays for a fixed time for each feeding step and the irradiation time is integrated,
When the accumulated ultraviolet irradiation time reaches a predetermined time, the ultraviolet irradiation time can be included in the transfer time by sending the wafer intermittently without turning on the ultraviolet lamp 8 of the ultraviolet irradiation unit 13 after that. I can. For this reason, the length of the transfer line is designed such that the transfer time of the wafer in the supply unit 2b including the direction changing unit 2a and the storage unit 1c is longer than the maximum irradiation time in each process.

FIG. 2 is an enlarged top view showing an ultraviolet ray irradiation portion of FIG. This independently controllable UV irradiation unit
As shown in FIG. 2, the lamp holder 10 attached to the cover 13 a and the U inserted into the lamp Honda 10
Three ultraviolet lamps 8 which are letter-shaped low-pressure mercury lamps,
It is composed of a reflector 9 arranged on the back surface of the ultraviolet lamp and a cooling fan (not shown). Further, in this ultraviolet irradiation unit, the size of the ultraviolet lamp 8 is sufficiently larger than that of the wafer 4, and by providing the reflecting plate 9 thereat, the irradiation intensity distribution becomes uniform and the irradiation intensity itself. As a result, the irradiation time was shortened. By the way, when the light illuminance distribution on the wafer surface was measured, the in-plane illuminance distribution was obtained within 10%. By improving this distribution and improving the irradiation intensity, it was expected that the irradiation time could be shortened by 30%.

Although not shown in the drawing, for example, if a light quantity measuring device is arranged near the wafer 4 corresponding to the end of the ultraviolet lamp 8 and the change of the projected light quantity is constantly monitored. , Quality due to irradiation intensity deterioration can be prevented in advance. In addition, it is possible to find the time when the ultraviolet lamp 8 starts to deteriorate and needs to be replaced. Further, when replacing the ultraviolet lamp, it is sufficient to simply remove the lamp holder 10 from the cover 13a, remove the lamp holder 10 from the cover 13a, and replace the ultraviolet lamp 8 without removing the large-sized cover 13a as in the conventional example. It has a structure that is easy to maintain.

3 (a) to 3 (c) are enlarged plan views and sectional views taken along line BB of the irradiation table of FIG. 1, and FIG. 4 is an enlarged view of the wafer supply loader and storage loader of FIG. FIG. Next, the operation of this semiconductor wafer processing apparatus will be described with reference to FIGS. 1, 3 and 4.

First, as shown in FIGS. 1 and 4, the cassette 12 placed on the feed loader 5 on the transfer line is lowered from the feed screw 22 by one groove pitch of the cassette 12. As a result, the wafer 4 stored at the bottom of the cassette 12 comes into contact with the transfer belt (not shown). Then, the wafer 4 is transferred to the cassette 12 by shifting to the transfer belt.
It is pulled out and transferred to the positioning unit 15. Next, the wafer 4 is attracted by the chuck of the supply arm 16 waiting in the positioning unit 15 and transferred to the first mounting unit 3b of the irradiation table 1b. At the same time, the ultraviolet lamp 8 of the ultraviolet irradiation unit 13 on the first mounting unit 3b is turned on.

At the same time when the wafer 4 is transferred to the first mounting portion 3b, the next wafer is pulled out from the supply loader 5 and transferred to the positioning portion 15 as described above. Next, as shown in FIG. 3, the wafer 4 mounted on the first mounting portion 3b is moved by the CDEF operation of the drive arm 7 of FIG.
The wafer 4 of the wafer receiving portion 3a is pushed up by pushing up the wafer 4 with a
Are transferred to the second mounting portion 3b. At the same time, the ultraviolet lamp 8 of the ultraviolet irradiation unit 13 of the second mounting unit is turned on. At this time, the first ultraviolet lamp remains on. On the other hand, the wafer 4 placed on the positioning unit 15
Is transferred by the supply arm 16 to the first mounting portion 3b that has been emptied and is irradiated with ultraviolet rays by the ultraviolet lamp 8 which is still lit.

In this way, the wafers 4 are sequentially transported in the order of No. 3 and No. 4, and the ultraviolet lamp 8 of the ultraviolet irradiating unit 13 in the moving area is turned on to expose the wafer 4 to ultraviolet rays. Then, the wafers are supplied from the cassette 12 one after another to the first mounting portion 3b which is vacant with the movement of the wafers. When the first wafer is sent to the No. 4 mounting unit 3b, the No. 5, No. 6, No. 7, and so on are sequentially sent by the transfer arm 3 in the direction changing unit 2a. Of course, ultraviolet rays are emitted by the ultraviolet ray irradiation section 13 corresponding to each number. And the last mounting part 3
In step b, the integrated ultraviolet irradiation time reaches the desired irradiation time, and the processed wafer is unloaded from the unloading port.

However, the irradiation time may be set short depending on the processing conditions. , For example, No. 7 mounting portion 3b
When the total irradiation time up to is reached to the desired irradiation time, in this case, the ultraviolet lamp of the ultraviolet irradiation unit 13 corresponding to the No. 8 mounting unit 3b in the storage unit 2c is not turned on and the wafer No. 8 to No. The wafer is unloaded from the storage unit 2c by simply carrying the wafer.

Next, the wafer No. 10 which has undergone the ultraviolet ray treatment is transferred to the positioning section 17 by the storage arm 14 and stored in the uppermost groove of the cassette 12 by the conveyor belt (not shown). The processed wafers thus transferred to the No. 10 mounting unit 3b are sequentially transferred to the cassette 1
It is stored in 2. When the cassette 12 is filled with the wafers 4, as shown in FIG. 4, the air cylinder 28 is actuated, the base 24 moves on the slide base 25, the base 24 is positioned by the stopper 26a, and the cassette full of wafers is loaded. 12 corresponds to the cassette carrying line and is carried to the next process. The empty cassette 12 is then aligned with the transport line of this device. Of course, the cassette 12 in the supply unit 2b
If it is also empty, the operation of the supply loader 5 causes an empty cassette 12
Is removed from the equipment line, transferred to the cassette return conveyor line, and returned to the previous process. Then, the cassette 12 full of unprocessed wafers is automatically aligned with the transfer line of this apparatus.

By continuously irradiating the wafers and irradiating them with ultraviolet rays while conveying them as described above, the ultraviolet ray irradiation time can be included during the conveyance, and the irradiation time alone can be calculated as the wafer processing time. Therefore, a large amount of wafers in the transfer line can be processed within the irradiation time. By the way, when a wafer which requires an irradiation time of about 10 minutes was tried, it was found that the throughput was improved by 30% or more with respect to the conventional throughput. Further, even if the irradiation time is short, if the desired irradiation processing time is reached, it is not necessary to turn on the ultraviolet lamp thereafter, and further reduction of power consumption can be expected in consideration of the above-mentioned improvement of irradiation intensity.

The embodiment of the present invention has been described above with reference to the drawings. Although the supply section 2b, the direction changing section 2a and the storage section 2c shown in FIG. 1 are shown with the same length, the irradiation time is long. When applied to the processing device, the storage unit 2c and the supply unit 2b have the same length, and the irradiation unit is not provided in the direction changing unit, and the direction changing function is simply provided to shorten the length. It is desirable to provide a plurality of rows of intermediate conveying units between them and connect them by a direction changing unit to lengthen the conveying path so that the conveying time and the irradiation time coincide with each other. Even in this case, it is essential to lay out the entire device so that it fits in a square and effectively use the floor area. It is desirable that the wafer loading / unloading ports are arranged on the same side, and a loading / unloading port is provided with a loader capable of alternately exchanging two cassettes so as to be compatible with a cassette-to-cassette type automation line.

[0028]

As described above, according to the present invention, a plurality of transfer lines for intermittently transferring wafers are arranged or crossed and connected to each other so as to efficiently arrange the floor area, and the wafer transfer path is lengthened. A plurality of ultraviolet irradiation units are independently provided on the connected transfer lines, and while controlling the ultraviolet irradiation units to transfer the wafer, the ultraviolet irradiation is performed for each ultraviolet irradiation unit and the irradiation time is integrated, and the transfer line is transferred. Since the UV irradiation time can be included in the transfer time by completing the processing of all the wafers on the transfer line before the wafer is unloaded from the wafer unloading port, the processing can be performed without adding the transfer time. The number of processed wafers can be calculated by the number of wafers in the transfer line only by the time.
As a result, the processing capacity is further improved.

Further, by providing a reflector for reflecting the ultraviolet light of the ultraviolet lamp and directly superimposing it on the ultraviolet irradiation part and a cooler for suppressing the temperature rise in the ultraviolet irradiation part, the distribution of the projected light is made uniform, and There is an effect that the quality can be stably maintained and the irradiation intensity of the ultraviolet light can be secured with a small amount of electric power.

Furthermore, by placing two cassettes at the wafer loading / unloading port of the transfer line and providing a loader for alternately changing the positions of the transfer line and the cassette transfer line outside the apparatus, it is difficult to apply the batch method. The effect is that it can be applied to a difficult single-wafer cassette-to-cassette automation line.

[Brief description of drawings]

FIG. 1 is a plan view and an AA sectional view showing an embodiment of a semiconductor wafer processing apparatus of the present invention.

FIG. 2 is an enlarged top view showing an ultraviolet irradiation portion of FIG.

3A and 3B are a plan view and a BB cross-sectional view showing an enlarged part of the irradiation table in FIG.

FIG. 4 is an enlarged front view showing the wafer supply loader and the storage loader of FIG.

5A and 5B are a plan view and a C-C sectional view showing an example of a conventional semiconductor wafer processing apparatus.

FIG. 6 is a graph showing characteristics of a low pressure mercury lamp.

[Explanation of symbols]

 1a, 1b, 1c Irradiation table 2a Direction conversion section 2b Supply section 2c Storage section 3 Transfer arm 3a, 34 Wafer receiving stand 3b Loading section 4 Wafer 5,37 Supply loader 6,41 Storage loader 7 Drive arm 8,38 Ultraviolet lamp 9 Reflector 10 Lamp Holder 11 Cooling Fan 12 Cassette 13, 33 Ultraviolet Irradiation Unit 13a Cover 14 Storage Arm 15, 17 Positioning Unit 16 Supply Arm 18 Slit 19, 24 Base 20 Units 21 Drive Unit 22 Feed Screw 25 Sliding Base 26a, 26b, 35 Stopper 28 Air Cylinder 31 Storage Conveying Section 32 Supply Conveying Section 34a Shuttle Mechanism 36 Conveying Conveyor 39 Light-Receiving Area

Claims (4)

[Claims] 1. A loading port for loading a semiconductor wafer at one end
The semiconductor wafer has an outlet for carrying the semiconductor wafer at the other end.
A first transfer unit having a long irradiation table having a plurality of mounting units for mounting a wafer at predetermined intervals and a feeding mechanism for sequentially feeding the semiconductor wafer between the mounting units in one direction.
And the semiconductor facing the carry-out port of the first carrying section.
It has a wafer loading port and is perpendicular to the first transfer section.
Are arranged so that the semiconductor wafer carry-out port is provided at the other end.
Having the above and mounting the semiconductor wafer
Irradiation table having at least one table and the semiconductor wafer
And a feeding mechanism that sequentially feeds between the mounting portions in one direction.
The direction-changing transport unit and the outlet of this direction-changing transport unit.
The first transfer device having an inlet for the semiconductor wafer facing it.
It is arranged in parallel with the feeding section and is the same as the carry-in port of the first conveying section.
If the other end has an outlet for the semiconductor wafer in the direction
The long irradiation table of the first transfer unit and the first transfer unit
A second conveying unit that includes a part of the feeding mechanism, said first and second transport unit and a plurality of ultraviolet irradiation unit provided in correspondence independently the mounting section of said direction changing transport unit, the
The semiconductor wafer is loaded from the loading port of the first transfer section.
Is Previous Symbol the second conveying unit from a first of said direction changing transport unit the order close to the entrance of the transport unit starts UV projection of the ultraviolet irradiation unit from the first conveyor section to the direction changing transport unit Ultraviolet rays are sequentially applied to the semiconductor wafers that are sequentially sent to the storage unit.
When a line is radiated and the UV irradiation accumulated time reaches a predetermined time,
Hands to stop the subsequent UV irradiation of the UV irradiation unit
The semiconductor wafer processing apparatus, characterized in that it comprises a stage. 2. The ultraviolet irradiation unit includes an ultraviolet lamp having a radiation area larger than the semiconductor wafer surface, a reflector for reflecting the radiation of the ultraviolet lamp, a cooler for suppressing a temperature rise, and the ultraviolet lamp. The semiconductor wafer processing apparatus according to claim 1, further comprising a lamp adapter to be loaded. 3. A table on which two cassettes each having a semiconductor wafer take-in / take-in port are placed side by side facing the semiconductor wafer carry-in / out port, and the take-out / take-in port of one of the cassettes is moved by moving the table. 2. The semiconductor wafer processing apparatus according to claim 1, further comprising a loader for supplying and storing a semiconductor wafer having a mechanism that matches the loading / unloading port. 4. A semiconductor wafer that is intermittently transported is irradiated with a constant amount of ultraviolet light during each intermittent feed, and the irradiation amount is integrated for each intermittent feed, and the integrated semiconductor wafers are integrated. A method for processing a semiconductor wafer, characterized in that, when the irradiation amount reaches a desired irradiation amount, the irradiation of the ultraviolet rays is stopped in the intermittent feeding thereafter.