JPS63131144A - Plate storage cassette - Google Patents

Abstract

PURPOSE:To prevent dust from being produced owing to the swinging of a plate during conveyance by providing a cassette with a duct which sucks and fixes the plate suctionally. CONSTITUTION:A mask 2 is stored in a mask cassette consisting of a lower cassette disk 1 provided with the duct 3 for air suction and an upper cassette dish 5; and one end of the duct 3 is open in a mask support surface and the other end is open in the outside flank of the lower disk 1. When the mask 2 is taken out, the lower disk 1 is supported by a fork band 6 and then a suction pad 7 covers the opening part of the duct 3; and the duct 3 is evacuated to suck and fix the mask 2 to the lower disk 1. Consequently, the mask 2 does not swing during its conveyance, so the production of dust is suppressed and an easy-to-clean structure is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an original storage cassette in which an original can be fixed within the cassette via an adsorption conduit.

[Prior Art] A plurality of original plates (masks or reticles, hereinafter collectively referred to as masks) used in semiconductor exposure equipment are stored in the exposure device. During exposure, etc., a desired mask is selected and set at a predetermined position.

The plurality of masks are stored in independent storage cassettes (hereinafter referred to as mask cassettes) and protected from dust and contamination.

FIG. 3 shows an example of a conventional mask cassette.

In the figure, the mask cassette is divided into an upper tray 10 and a lower tray 11, and the mask is stored on the lower tray 11.

[Problems to be Solved by the Invention] However, in such a conventional example, there is no means for fixing the mask to the lower tray, so great care must be taken when transporting the mask. Specifically, the mask in the cassette had to be moved at a slow speed to prevent it from shaking.

Furthermore, since the mask serves as an original plate to be transferred by a semiconductor exposure device, it must be sufficiently controlled to prevent dust from adhering to it and contaminating the pattern surface. However, if the cassette is shaken during transportation, the cassette and mask may slide, and fine dust may be generated from the sliding surfaces. This is something that must be avoided at all costs when handling masks. For the above reasons, mask cassettes are required to have a structure that does not generate dust, has good airtightness, is easy to take out, and is easy to clean.

In view of the problems of the prior art described above, the present invention provides a means for fixing the original to the cassette during transportation, thereby reducing sliding without complicating the structure of the cassette case and without impairing the cleanability or sealing performance. The purpose is to eliminate this problem, prevent it from occurring, and speed up the transportation for replacing the original plate.

[Means and operations for solving the problems] In order to achieve the above object, the present invention provides an original storage cassette with a conduit that attracts and fixes the original by being sucked in air.

[Example] Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 is a sectional view of a mask cassette according to an embodiment of the present invention. This mask cassette has a lower plate added with a suction conduit for suction and fixation. In the figure, 1 is a cassette lower plate, 2 is a mask, 3 is a suction pipe, and 5 is a cassette upper plate. Conventional cassettes do not have conduit 3,
The mask 2 was simply placed on the lower plate 1.

FIG. 2 is a sectional view showing the fork hand grasping the lower plate. In the same figure, 6 is a fork hand,
7 is a suction pad fixed to the fork hand 6. The adsorption pad 7 is connected to a vacuum pump via a pipe line. 8 is a solenoid valve, and 9 is a vacuum switch that detects the degree of vacuum.

To take out the mask 2, as shown in FIG. 2, support the lower plate 1 with the fork hand 6 and pull it out in the direction of arrow A. If this withdrawal speed was high, the mask would swing because the mask was not fixed to the lower tray in the past. Therefore, in this embodiment, the lower tray 1 is provided with a suction conduit 3 whose one end opens to the mask support surface of the lower tray 1 and the other end opens to the outer surface of the lower tray 1. , is positioned so as to cover the opening to the outer surface of the conduit 3 of the lower plate 1 when the fork hand 6 reaches under the lower plate 1 and supports the lower plate 1.

Therefore, in this embodiment, the fork 6 is attached to the lower plate 1.
When the mask 2 is fixed, if the pipe line 3 is evacuated via the suction pad 7, the mask 2 is attracted to the lower plate 1 and fixed. After confirming that the mask is attracted, the fork hand 6 is pulled out. As a result, the mask 2 is transported while being suctioned and fixed to the lower tray 1, and moves eight times to a position where only the mask is taken out.

So far, we have described the time of transport only within the mask exchanger.

Currently, as mentioned earlier, multiple masks are stored in the exchanger, and only one mask is selected automatically from there. Therefore, if the relevant mask is not stored in the exchanger, a person must replace the relevant mask with an unnecessary mask in the exchanger. In such cases, each device (
Masks are transported to the automatic mask exchange machine by humans. If this transportation is mechanized and automated in the future, this luck iQ2
There is also concern about the sliding movement of the mask and cassette inside.

This case can also be dealt with by suctioning and fixing the mask as in this embodiment.

Furthermore, in this embodiment, when the lower plate is fixed and suctioned with the fork hand 6, it is also possible to detect the pressure change in the conduit using the vacuum switch 9, etc., and check the presence or absence of the mask in the cassette. .

In addition, when using this mask cassette and storing the mask in the factory, if the pipe line 4 shown in Fig. 1 is provided in addition to the adsorption pipe line 3, nitrogen gas etc. can be supplied through it. By pouring in the mask cassette, the inside of the mask cassette can be kept at a more positive pressure than the outside periphery, so even if there is a gap in the cassette, dust can be prevented from entering.

[Effects of the Invention If the means for fixing the original in the cassette is mechanical, the structure of the cassette becomes complicated and dust becomes difficult to remove even when washed. However, as explained above, according to the present invention, with a simple structure that only includes a conduit for the operator, it is possible to suction and fix the original, eliminate swinging of the original, and suppress the generation of dust. There is. Moreover, the structure is easy to clean.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of the Masufukasera according to an embodiment of the present invention, Fig. 2 is a cross-sectional view showing the fork hunt 6 grasping the lower plate, and Fig. 3 is a cross-sectional view of the upper plate and the lower plate. It is a figure which shows the conventional example of the mask cassette comprised from two parts. 1. Lower cassette tray, 2: Mask, 3. Pipe line for adsorbing and fixing the mask, 4: Pipe line for nitrogen sparging, 5: Upper tray for mask cassette, 7: Adsorption pad, 8. Vacuum condition for conduit 3 9: Vacuum switch that detects the degree of vacuum in the pipe. Patent Applicant Canon Co., Ltd. Agent Patent Attorney Tatsuo Ito Agent Patent Attorney Tetsuya Ito Figure 1 Figure 2

Claims (1)

[Scope of Claims] 1. An original storage cassette characterized by having a conduit that attracts an original when air is drawn therein. 2. The original storage cassette according to claim 1, wherein air is drawn into the conduit by an air intake means having an intake port in the transport device when at least the original is transported together with the storage cassette.