JPS6156611B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dust-free baking method, and more particularly to a dust-free baking method using a hot plate.

For example, when baking a photo mask coated with photoresist, conventionally the sixth
A photo mask 33 is placed inside the jig 32 as shown in the figure.
was placed in a hot air circulation furnace 31 shown in FIG. 7 for baking. However, in such a conventional method, when the hot air is circulated, dust inside the furnace 31 also circulates like the hot air and adheres to the semi-dry surface of the photo mask 33, and the dust on the mask 33 to the jig 32 also circulates.
Dust was also generated when the photo mask 33 was put in and taken out, deteriorating the quality of the photo mask 33.

The present invention is intended to overcome the drawbacks of the conventional baking equipment, and its purpose is to provide a method that allows baking to be performed in a dust-free manner.

According to the baking method of the present invention to achieve such an object, the hot plate is heated so that a plurality of objects to be processed can be arranged in a line on the surface of the hot plate from one end of the hot plate to the other end. defining the size of the plate, and simultaneously moving each of a plurality of objects to be processed arranged in a line on the surface of the hot plate in a first period while floating them from the surface of the hot plate;
In a second period after the movement, the plurality of objects to be processed are simultaneously brought into contact with the surface of the hot plate and heated, and the operations of the first period and the second period are alternately repeated. The method is characterized in that a plurality of objects to be processed are sequentially and intermittently transferred from one end of the plate toward the other end, and the objects to be processed are baked during this transfer period.

According to the present invention, baking is performed during the period in which the objects to be processed are sequentially and intermittently transferred from one end of the hot plate to the other end, and is therefore particularly effective when baking a large number of objects to be processed continuously.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a partially omitted plan view of an apparatus used in carrying out the baking method of the present invention,
A straight and elongated hot plate 2 is arranged in a heat-insulating furnace body 1, and a width slightly larger than that corresponding to the object to be processed, that is, a photo mask 3 (hereinafter referred to as photo mask) is placed on the upper surface of this plate 2. A larger guide groove 4 is formed, and this guide groove 4
The tip of the feed pin 5 is positioned at an intermediate position in the width direction of
It is opened wider than the width of the pin 5 and connected integrally with the connecting rod 6, and the connecting rod 6 is connected via the arm rod 7.
is slidably attached to the fixed shaft 8, and the end of the connecting rod 6 is connected to the cam 1 through a link 9 so as to be able to perform intermittent reciprocating motion along the direction in which the guide groove 4 is formed.
It is connected to 0. In addition, as shown in FIG.
A roller 13 attached to one end of the link 12 is brought into contact with the link 12, and a cam follower 14 is attached to the other end of the link 12 and brought into contact with a cam 15, thereby enabling the connecting rod 6 to rotate about the fixed shaft 8 as a fulcrum. The tip of the feed pin 5 extending from the connecting rod 6 is bent downward so that it does not come into contact with the plane of the guide groove 4.

FIG. 3 is an enlarged cross-sectional view of the hot plate 2 shown in FIG.
Small holes 16 and 17 for air injection are formed in the plane and side surfaces forming the guide groove 4, respectively, and these small holes 16 and 17 are provided in pairs near the corners of both widthwise ends of the guide groove 4. , are formed repeatedly in the extending direction of the guide groove 4 in this state so that the interval between the small holes 16 and 17 is sufficiently narrowed. The ends of each of the small holes 16 and 17 are connected to a common pipe 18, and connected to an air supply source (not shown) via a heat exchanger 19, an air filter 20, and a heater 21.

FIG. 4 is a partially omitted cross-sectional view of FIG. 1 showing the arrangement of the hot plate and this heating means, viewed from the connecting rod side, and shows a lower part of the hot plate 2 at a certain distance from the back surface of the hot plate 2. A reflective shade 22 with an arcuate cross section is placed at a position facing the inner surface plate 2, and a heater 23 is provided between them, so that the heat of the heater 23 is reflected directly or indirectly on the inner surface of the reflective shade 22 and is heated to the hot plate. 2 can be heated.

Next, the relationship between the vertical movement and the transverse movement of the feed pin 5 will be explained using a diagram in FIG. 5. The horizontal axis of the diagram shows time (S), and the vertical axis shows height (mm).
and travel distance (mm). Therefore, the feed pin 5 does not move horizontally from the point when the feed pin 5 is fully raised to the upper limit until it reaches the lower limit at point 24, and when it reaches point 24, the horizontal movement starts and continues until it reaches point 25. , at this point 25, the pin 5 is raised, and during this time the traverse of the pin 5 has stopped, and when it reaches the point 26, it returns to the traverse, and in this case, the pin 5 remains in the raised state and returns to the initial position. Return to position.

By repeating this as one cycle after a certain period of time (bake time), the photo mask 3 is sequentially and intermittently fed.

Furthermore, the air blown from the small holes 16 and 17 of the hot plate 2 shown in FIG.
At step 9, the heater 23 is preheated and the air is further warmed to an appropriate temperature, and a certain amount of air is blown out from each of the small holes 16 and 17 via the piping 18, so that the photo mask 3 can be floated. . This air can be freely blown and stopped by a switching device (not shown).

In addition, in the embodiment, the small holes 16, 17
It uses simple air blown out from the
Instead of this air, an inert gas such as nitrogen (N ₂ ) gas may be used, and the gas is heated to fill the small holes 16 and 17.
Make it blow out more, or let it blow out without heating it.

Next, to explain the dust-free baking method of the embodiment step by step, first, the photo mask 3 is placed on the furnace body 1.
When feeding the photo mask 3 into the interior, the photo mask 3 is placed in the position shown by the two-dot chain line in FIG. 1 using a coating device (not shown) so that the photo resist coated side (pattern side) 27 of the photo mask 3 faces upward. At this position, use the feed pin 5 to attach the photo mask 3.
and feed it into the furnace body 1. At this time, the photo mask 3 is sent in a slightly floating state from the inner surface of the guide groove 4 by the air blown out from the small holes 16 and 17, and when it has moved one pitch, that is, 31 photo masks, the air is cut off and the mask 3 is moved. The floating state changes to a state in which the back surface is aligned with at least the bottom surface of the inner surface of the guide groove 4, and the photoresist surface is baked by being heated by the hot plate 2. In this case, baking is performed by the intermittent feeding. This is done by the operation of the pin 5 and the air blowing operation from the small holes 16 and 17 until it reaches the outlet end of the furnace body 1, and the photo mask 3 that has been baked in this way is heated again. Due to the operation of the feed pin 5 and the blowing force of the air from the small holes 16 and 17, the air is sent out of the furnace body 1 while maintaining a non-contact state with the guide groove 4, and then the photo mask is removed by an arbitrary pick-up means (not shown). 3
be taken up and accommodated. In this way, the work of taking in the photo mask 3 from one side of the furnace body 1 and removing it from the other side is performed continuously. Furthermore, when the photo mask 3 is moved by the feed pin 5, pre-warmed air is blown even when the mask 3 is separated from the hot plate 2, thereby reducing the temperature of the photo mask 3. Send while maintaining sufficient temperature without lowering the temperature.

For reference, the baking time of the photo mask 3 in the furnace body 1 is, for example, about 10 minutes net.

As is clear from the above explanation, according to the present invention, a hot plate is placed inside the furnace body and the photo mask is heated by this plate, so unlike the conventional hot air circulation type, there is no need to heat the inside of the furnace. It does not generate dust etc.

Furthermore, since we are trying to move within the reactor body,
There is no dust generated when the photo mask is taken in and taken out of the jig and when this jig is taken in and out of the furnace body as in the past. Further, during the entire process of baking the photo mask, there is no part where dust is generated, and the baking is completed in a state where the photoresist surface of the photo mask is always kept clean.

Therefore, the quality of the pattern formed on the surface of the photo mask can be improved.

Closely adheres to the hot plate, heats evenly, and
By sending pre-warmed air, photo-
The temperature distribution within the mask becomes uniform, and the accuracy of the pattern formed on the photo mask surface can be maintained sufficiently.

Further, since the photo plate is automatically and continuously supplied and baked by blowing out air and operating the feed pin, it is possible to save labor and reduce the number of personnel.

In the above embodiments, the object to be processed is a photo film.
Although the mask 3 is shown as an example, it is also fully applicable to wafers.

[Brief explanation of the drawing]

FIG. 1 is a partially omitted plan view of the apparatus used in carrying out the baking method of the present invention, FIG. 2 is a view taken along the line A-A' shown in FIG. Figure 3 is an enlarged cross-sectional view of the hot plate in Figure 1, and Figure 4 is a partially omitted cross-section of Figure 1, showing the arrangement of the hot plate and heating means, as seen from the connecting rod side. Figures 5 and 5 are diagrams showing the relationship between the vertical and lateral movements of the feed pin, and Figures 6 and 7 are schematic diagrams of a jig and a hot air circulation furnace used in carrying out the conventional baking method. 1...Furnace body, 2...Hot plate, 3...
Photo mask, 4... Guide groove, 5... Feed pin, 6... Connecting rod, 7... Arm rod, 8... Fixed shaft,
9...Link, 10...Cam, 11...Spindle, 1
2... Link, 13... Roller, 14... Cam follower, 15... Cam, 16... Small hole, 17...
Small hole, 18... Piping, 19... Heat exchanger, 20...
...Air filter, 21...Heater, 22...
Reflective shade, 23... Heater, 24... Point, 25...
Point, 26... Point, 27... Surface coated with photoresist, 31... Hot air circulation furnace, 32... Jig, 33
...Photo mask.

Claims (1)

[Claims] 1. The size of the hot plate is defined so that a plurality of objects to be processed can be arranged in a line on the hot plate surface from one end to the other end, and the hot plate surface is A plurality of objects to be processed arranged in a line are moved simultaneously while floating from the surface of the hot plate, and a second object after the movement is moved.
By bringing the plurality of objects to be processed into contact with the surface of the hot plate at the same time and heating them, and repeating the operations of the first period and the second period alternately, the hot plate is heated from one end side to the other. A baking method characterized in that a plurality of objects to be processed are intermittently transferred one after another toward an end side, and the objects to be processed are baked during the transfer period.