JPS6184017A - Mask conveying device - Google Patents

Abstract

PURPOSE:To prevent the erroneous setting of a mask by a method wherein, in a mask conveying device, a means with which the obverse and reverse of the mask is automatically detected in the state before it is baked, is provided in a mask conveying device. CONSTITUTION:A metal film 7 is coated on the lower surface (obverse) of a mask 1, and the light sent from a light-emitting element 6a is reflected by the metal film 7 and returns to a light-receiving element 6b when the obverse and the reverse of the mask are normally positioned, but when the obverse and the reverse are inversely positioned, the light does not return to the light- receiving element 6b. Accordingly, the fact that the obverse and the reverse are inversely positioned is confirmed, and the mask is not baked in the state where it is erroneously set.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to a mask transport device used in a semiconductor exposure apparatus, and in particular detects the front and back sides of a mask within a mask cassette, in the middle of a mask transport path, or at a mask loading position. The present invention relates to a mask conveying device that prevents mask missetting by providing means.

(Blue slip of the invention) In conventional semiconductor exposure VT systems, the mask was attached manually because the mask was small enough to be held in the hand and because changing the mask was not complicated.

However, in recent years, the integration and density of integrated circuits have rapidly increased, and there has been a strong desire to improve yields in order to further reduce the cost per chip. The above requirements are often not met due to dust, dirt, etc. that adhere during installation.

Wafer diameters are becoming larger in order to improve yields, and masks are also becoming larger, making it difficult to hold them in the hand.

Recently, several devices have been proposed that can automatically transport masks. For example, there is a known device that can load a plurality of mask cullets containing masks, and has a linear surface that takes out the mask from this mask cassette and automatically feeds it to a mask chuck provided on a mask stage. ing.

However, even with this device, the work of storing the mask in the mask cassette is done manually, so if the worker accidentally inserts the mask inside out, the mask will be placed inside out in the mask chuck. There was a drawback that printing was performed as it was sent.

(Objective and Summary of the Invention) In order to eliminate the drawbacks of the prior art described above, the present invention provides a means for automatically detecting the front and back sides of the mask in the mask 110 feeding device at a stage before printing is performed. The purpose is to prevent missetting of masks based on the concept of "Pull".

(Explanation of Examples) Hereinafter, the present invention will be described in detail with reference to the drawings.

Fig. 1 (a) is a perspective view of the mask hand section of the mask transport device, and Fig. 1 (b) is a vertical cross-sectional view of the same figure (a). cassette bottom cover,
Reference numeral 3 designates an arm (A) for transporting the mask cassette once, 4 an arm with a front/back detection sensor, 5 a mask hand for transporting the mask 1, and 6 a front/back detection sensor I.

In FIG. 3A, the mask 1 is conveyed under the mask hand 5 by the fork 3 while being stored in the lower lid 2 of the mask cassette. Here, the mask 1 is automatically positioned by a mask positioning mechanism provided in the mask hand 5. At this time, as shown in the same figure (b), the mask 1
A front and back detection sensor 6 is arranged on the lower surface by an arm 4 to determine whether the front and back sides of the mask 1 are normal or not, and if not normal, an alarm is issued.

Next, details of the front/back detection mechanism of the present invention will be explained.

FIGS. 2(a) and 2(b) are diagrams for explaining the front/back detection mechanism when an optical sensor is used as the front/back detection sensor.

In the same figure, the lower surface (surface) of the mask 1 has metal +1
! If J7 is coated and the front and back sides are normal, the light emitted from the light emitting element 6a is reflected by the metal film 7 and returns to the light receiving element 6b as shown in the figure (a>). However, as shown in Figure (b), if the front and back sides of the mask are reversed, the light emitted from the light emitting element 6a will return to the light receiving element 6b, so the front and back sides will not be reversed. Recognized.

Similarly, an arrangement as shown in FIG. 3 can be used as an example of using an optical sensor as the front/back detection sensor.

In other words, as shown in Figure (a), when the front and back sides are single, the light emitted from the light emitting element 6a is reflected by the metal film 7 and does not reach the light receiving element 6b, but as shown in Figure (b). If the front and back of the mask are reversed as shown in FIG. b) is a diagram illustrating a front/back detection mechanism when an electric sensor is used as the front/back detection sensor.

In the figure, when the capacitance sensor 8 is disposed on the lower surface of the mask 1, the difference in the distance between the capacitance sensor 8 and the metal film 7 causes a difference in static absorption, making it possible to determine whether the capacitance sensor 8 is covered or not. Furthermore, a method of testing whether there is continuity by bringing an electrode into contact with the metal film portion 7 can also be applied.

In the above-mentioned embodiment, the front/back detection sensor is arranged in the middle of the mask conveyance path, but the front/back detection means for the mask can be installed inside the mask cassette or in the mask loading device before printing is performed. It may be provided in either.

(Effects of the Invention) As explained above, according to the present invention, since it is possible to detect the front and back sides of the mask at the stage of printing, it is possible to prevent missetting of the front and back sides of the mask and prevent the mask from turning over. This prevents the printer from being burned while the printer is still set.

[Brief explanation of drawings]

Figure 1(a) is a perspective view of the mask hand section of the mask transport device, Figure <b'> is a vertical sectional view of Figure 1(a), and Figures 2 and 3 are the front and back detection sensors. using a sensor
FIG. 4 is a diagram illustrating the front/back detection mechanism in the case where an electric sensor is used as the front/back detection λ0 sensor. 1... Mask, 2... Lower lid of mask cassette, 3.
...Fork, 4... Arm, 5... Mask hand, 6... Tableware i-sensor, 6a... Light emitting element, 6
b... Light-receiving cable, 7... Metal film, 8... Capacitance sensor.

Claims (1)

[Claims] 1. A plurality of mask cassettes each containing a mask;
A device that automatically takes out a mask from this mask cassette and transports it to a mask chuck provided on a mask stage, and means for detecting the front and back sides of the mask either in the mask cassette, on the mask transport path, or in the mask loading device. A mask conveying device characterized by being provided with. 2. The mask conveying device according to claim 1, wherein the front/back detection means is an optical sensor. 3. The mask conveying apparatus according to claim 1, wherein an electric sensor is used as the front/back detection means.