JPS6045091B2 - Plate-shaped object conveyance mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a plate-like object conveying mechanism, and particularly to a so-called air bearing that conveys a wafer whose upper surface is coated with photoresist by means of an air flow or the like.

In the assembly of semiconductor devices, etc., various types of processing are performed on thin silicon plates (wafers).
A so-called air bearing is used in which air, nitrogen, etc. are blown out from a plurality of injection holes 2 inclined in the transport direction from the bottom surface of the wafer 3, and the wafer 3 is lifted up and transported by this air flow.

In addition, there are jetties (protrusions) 4 on both sides of the upper surface of the guide table 1.
is provided to guide the wafer 3. By the way, when forming various patterns (insulating layer patterns, wiring layer patterns, etc.) on the wafer surface, a photosensitive agent such as photoresist is applied in advance to the entire upper surface of the wafer.

This photoresist is also conveyed to a drying oven after coating, and the air bearing of the above-mentioned structure is also used for this conveyance. Due to the action of surface tension, the photoresist coated on the top surface of the wafer bulges at its periphery and at the same time overhangs its periphery. As a result, when the peripheral surface of the wafer comes into contact with the jetty 4 during movement of the wafer, the protruding photoresist adheres to the inner wall surface of the jetty 4, making it difficult for the wafer to move smoothly. Further, due to repeated adhesion of photoresist, large protrusions are formed on the inner wall surface of the jetty, and the wafer may get caught and become unable to move. Further, as shown in FIG. 2, when stopping the wafer 3 in an air bearing, a stopper 5 is permanently installed or temporarily protrudes at the end or halfway of the guide table 1. is attached.

Since the wafer 3 collides with the stopper 5, the stopper 5
The photoresist that has adhered to the wafer may partially scatter and adhere to the wafer surface. If a lump of photoresist adheres to the photoresist in this way, problems such as poor adhesion with the mask and incomplete exposure and unclear patterns occur during the subsequent close-contact type exposure process. Therefore, an object of the present invention is to provide an air bearing in which the photoresist coated on the upper surface of the wafer does not adhere to the protrusion 7 or stopper provided on the guide table.

In order to achieve such an object, the present invention provides a plate-like object conveying mechanism that conveys the plate-like object along the groove by injecting gas from the bottom of the groove toward the lower surface of the plate-like object inserted into the groove. The gas injection hole at the bottom is inclined so that the gas is injected into the center of the groove, and the inner wall surfaces of the protrusions on both sides forming the groove are inclined upward so as to widen each other. The present invention will now be explained with reference to Examples.

FIG. 3 shows an embodiment of the plate-like object conveyance mechanism of the present invention. The figure shows an air bearing consisting of a guide table 7 in the form of an elongated plate and jetties (protrusions) 8 provided along both sides of the upper surface of the guide table 7. For example, nine rows of seven injection holes are bored in the upper surface of the guide table 7 of this air bearing along its longitudinal direction. These injection holes 9 communicate with guide holes 10 formed from a hollow portion within the guide table 7. This guide hole 10 is connected to a high-pressure pump system (not shown), and air and nitrogen are fed into it. The center of the injection hole array extends directly upward, but both sides thereof are inclined so that the airflow ejected from the injection holes 9 is directed toward the upper center of the guide table 7. This is the result of consideration being given so that the wafer 11 moving in a floating state on the guide table 7 always moves through the center of the guide table 7. Also,
The inner walls 12 of the jetty 8, in other words, the inner walls on both sides of the transport path (groove) 13 that guides the wafer 11 created by the pair of jetties 8 and the guide table 7 are sloped surfaces that widen upward. It is becoming. This is because when the wafer 11 comes into contact with the inner wall 12 during movement, only the bottom periphery of the wafer 11 comes into contact with the inner wall 12, and the top periphery does not. This prevents the protruding portion from contacting the inner wall 12. Furthermore, a wafer 1 is placed on the inner wall 12 of the jetty 8.
For example, two rows of injection holes 15 are provided so that the injection holes 13 do not come into contact with the inner wall surface.

These injection holes 15 communicate with a guide hole 16 in the jetty 8, and this guide hole 16, like the guide hole 10, is connected to a high-pressure pump system.
4 (According to such an air bearing, the injection hole 9 on the bottom of the guide table 7 and the injection hole 1 on the jetty 8
When the wafer 11 is transferred after applying the photoresist 14 on the upper surface by spraying air or nitrogen from the groove 1
The airflow from the injection hole 9 at the bottom of the groove 3 flows in the wafer transport direction and also flows so as to position the wafer 11 at the center of the groove 13 . Further, a gas flow is generated toward the circumferential surface of the wafer 11 from the injection holes 15 or 7 in the inner wall forming the groove 13. For these reasons, it is extremely rare for the peripheral edge of the wafer to come into contact with the inner wall 12 during movement of the wafer. Furthermore, even if the peripheral edge of the wafer were to come into contact with the inner wall 12, the inner wall 12 is inclined and only the lower peripheral edge of the wafer 11 contacts the inner wall.
The photoresist 14 coated on the upper surface of the wafer 11 and protruding from the periphery of the upper surface of the wafer 11 comes into contact with the inner wall 12 and hardly adheres to the inner wall 12. Therefore, the wafer 11 is transported smoothly. Further, as shown in FIG. 4, the guide table 7 is located at the end or in the middle (the figure shows an example of the end).

) is also tilted so that only the periphery of the lower surface of the wafer 11 comes into contact with the stopper 17 and the periphery of the upper surface does not, so that photoresist does not adhere to the stopper 17 either. As a result, even if the wafer 11 comes into contact with the stopper 17, since no photoresist is attached to the stopper, there will be no photoresist lumps attached to the photoresist surface of the wafer 11, and the subsequent contact exposure process will be clear. A photosensitive pattern is formed. Note that the present invention is not limited to the above embodiments.

Further, the object to be transported in the present invention is not limited to a wafer, and the applied object is not limited to photoresist. As described above, according to the plate-like object transport mechanism of the present invention, a plate-like object whose upper surface is coated with a coating material can be smoothly transported.

Further, the coated surface of the plate-like object coated with the coating material is not stained with the coating material.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a conventional air bearing, FIG. 2 is a partial sectional view of an air bearing also having a stop mechanism, FIG. 3 is a sectional view of an air bearing of the present invention, and FIG. 4 is a sectional view of an air bearing of the present invention. FIG. 7 is a partial cross-sectional view showing another embodiment. DESCRIPTION OF SYMBOLS 1... Guide table, 2... Injection hole, 3... Wafer, 4... Jetty (protrusion), 5... Stopper, 6...
...Photoresist, 7...Guide table, 8...
Jetty (projection ', Y), 9... Injection hole, 10... Guide hole, 11... Wafer, 12... Inner wall, 13... Conveyance path (groove), 14... Photoresist , 15... Injection hole, 16... Guide hole, 17... Stopper.

Claims (1)

[Claims] 1 A plate-shaped object transport mechanism for transporting a wafer whose main surface is coated with photoresist along the groove by injecting gas from the bottom of the groove, and the gas injection hole at the bottom injects gas into the center of the groove. What is claimed is: 1. A plate-like object conveying mechanism characterized in that the inner wall surfaces of the protrusions on both sides forming the groove are inclined so as to diverge upwardly and from each other.