JPS6136221B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to the structure of a mask cleaning device.

Fine element patterns for semiconductor integrated circuit devices, etc.
In the production of photomasks used to form wiring patterns, etc., the adhesion of dust on the dry plate or blank plate coated with photoresist (hereinafter referred to as the blank plate) on which the mask pattern is to be formed is a problem in the production of the photomask. This causes a decrease in yield and manufacturing quality.

Conventionally, in the production of photomasks, the method of removing dust adhering to the dry plate or blank plate is to remove the dust from the dry plate or blank plate using a jet of nitrogen gas containing ozone, which is injected from an air gun equipped with an ionizer. It was a method of blowing away one by one from the beginning.

However, in this conventional method, there is a phenomenon in which the nitrogen gas jet stirs up dust around the dry plate or blank plate during blowing away, and this dust is deposited again on the surface where it has been blown away. It was difficult to completely clean it.

In view of the above-mentioned problems, the present invention has been developed by setting a dry plate or blank plate on which a pattern is to be formed in a mask manufacturing apparatus, and blowing away dust while evacuating the area around the dry plate or blank plate. Alternatively, an apparatus for completely cleaning the blank board surface is provided.

That is, the mask cleaning device of the present invention includes a gasket around the lower opening, and has a lid-like structure that can be airtightly placed on the dry plate holder of the mask manufacturing device via the gasket. inside the body,
A nozzle assembly having a plurality of nozzles equipped with an ionizer and capable of rotating horizontally with respect to the opening surface is provided, and a plurality of exhaust ports are provided on the inner wall of the lid-like structure around the nozzle assembly. It is characterized by being arranged with.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the structure of an apparatus according to the present invention and a method of manufacturing a mask using the apparatus of the present invention will be described in detail below with reference to illustrated cross-sectional views.

The figure shows a state in which a dry plate 1 on which a pattern is to be formed in the production of a photomask is fixed on a dry plate holder 2, and a mask cleaning device having a lid-like structure according to the present invention is placed over the dry plate holder 2. be.

As shown in the figure, the mask cleaning device of the present invention has a gasket 4 disposed around the periphery of an opening 3 on the lower surface of the device, and a nozzle disposed in the center of a lid-like structure 6 having a handle 5 on the top. At the tip of the tubular rotating shaft 7 that allows air and intake, there is a plastic material such as hard vinyl chloride that is horizontal to the opening surface of the lid-like structure 6, or in other words, to the top surface of the dry plate holder 2 of the mask manufacturing device, and that is sealed at both ends. A nozzle assembly 8 is provided, in which nozzles 10 having a plurality of ionizers 9 each having a ventilation axis formed in a direction perpendicular to the opening surface are arranged. A plurality of exhaust ports 11 are provided on the inner wall of the lid-like structure 6 around the aggregate 8.

However, in order to clean a dry plate on which a pattern is to be formed, for example, using the apparatus of the present invention when manufacturing a photomask, first place the photosensitive surface on the dry plate holder 2 of the mask manufacturing apparatus as shown in the figure. The dry plate 1 is fixed under vacuum, and the mask cleaning device is placed on the dry plate holder 2 with the opening 3 facing down so as to cover the dry plate 1, and the mask cleaning device is brought into close contact with the dry plate holder 2 by the gasket 4 of the cleaning device. .

During the comparison, the distance between the tip of the nozzle 10 of the mask cleaning device and the top surface of the dry plate 1 is set in the range of 1 to 5 mm.

Next, the space formed by the dry plate holder 2 and the inner wall surface of the lid-like structure 6 of the mask cleaning device is evacuated under reduced pressure through a plurality of exhaust ports 11 provided on the inner wall of the lid-like structure 6.

Next, while the depressurized exhaust is being performed, ozone is mixed in from the nozzle 10 by the ionizer 9 while rotating the nozzle assembly 8 inside the lid-like structure 6 in a constant direction at a gentle speed of 3 to 10 rpm. Nitrogen gas is blown at right angles onto the dry plate 1 at a pressure of 1.4 to 5 kg/cm ² to blow off the dust adhering to the dry plate 1, and the exhaust port 11 on the inner wall of the lid-like structure 6 is
from the outside of the device.

Next, while continuing to rotate the nozzle assembly 8, the inside of the nozzle assembly 8 is evacuated through the rotation shaft 7, and air is sucked in from the nozzle 10 to lift the dust stuck on the dry plate 1.

Alternately blow and inhale nitrogen as described above.
The dry plate 1 is cleaned several times for about 10 seconds each, and at this time, adjusting the amount of exhaust air from the exhaust port 11 on the inner wall of the lid-like structure 6 is an important point for complete cleaning.

When the above operations are completed, the supply and exhaust of nitrogen gas to the mask cleaning device is stopped, and the device is removed from the dry plate holder and the dry plate is immediately exposed.

In the above embodiment, the case where the device of the present invention is used to clean the surface of a dry plate for a mask has been explained, but the device of the present invention can be used not only for cleaning a dry plate but also for cleaning a blank plate coated with resist and a master photomask. Of course, the present invention can also be used with any projection-type or contact-type mask manufacturing apparatus.

In addition, in the above embodiment, the case where the ventilation axis of the nozzle is perpendicular to the opening surface of the lid-like structure has been described, but the angle of the ventilation axis may vary depending on the shape and size of the dust. It is preferable to set it to .

As explained above, the apparatus of the present invention removes dust attached to the dry plate or blank plate on which a pattern is to be formed while the dry plate or blank plate is isolated from the outside world, so that cleaning can be completed completely. This has the effect of greatly improving the manufacturing yield and manufacturing quality of photomasks.

[Brief explanation of the drawing]

The figure is a sectional view of an example of a mask cleaning device according to the present invention. In the figure, 1 is a dry plate, 2 is a dry plate holder, and 3 is a dry plate.
1 is an opening, 4 is a gasket, 5 is a handle, 6 is a lid-like structure, 7 is a rotating shaft, 8 is a nozzle assembly, 9 is an ionizer, 10 is a nozzle, and 11 is an exhaust port.

Claims (1)

[Claims] 1. A lid-like structure is provided with a gasket on the periphery of the lower opening, and can be airtightly placed on the dry plate holder of the mask manufacturing device via the gasket;
A nozzle assembly having a plurality of nozzles equipped with an ionizer and having a structure capable of rotating in a horizontal direction with respect to the opening surface is provided inside the structure,
A mask cleaning device characterized in that a plurality of exhaust ports are arranged on the inner wall of the lid-like structure around the nozzle assembly.