JPH03260649A - Multistage pellicle - Google Patents

Abstract

PURPOSE:To enlarge the stand-off quantity of a pellicle film from a reticle or mask, and also, to execute various inspections of the surface of the reticle or mask by a microscope by providing peticles at multistage. CONSTITUTION:A frame 14 is stuck and fixed onto a reticle or mask 10, a pellicle film 15 is extended and provided on the frame 14 and a pellicle 12 of a first state is installed. At this time point, a pattern 10a of the reticle or mask 10 is inspected by a microscope through the film 15. Subsequently, a pellicle 13 of a second stage is installed on the pellicle 12. According to such a constitution, only the installing process necessitates cleanliness, and in the regular use environment, the stand-off quantity is taken large, therefore, the reticle or the mask can be used without enhancing the cleanliness especially. Also, a multistage pellicle can be installed on both faces of the reticle or the mask.

Description

[Detailed Description of the Invention] [Summary] Regarding the pellicle provided on the reticle or mask used during exposure in the photolithography process when manufacturing semiconductor devices, the amount of standoff of the pellicle film from the reticle or mask is determined. In order to prevent the transfer of dust that adheres to the reticle or mask, a frame of a desired height is placed on the reticle or mask surface. In the pellicle, the pellicle is formed by stretching a pellicle film over an iron frame, and the pellicle is provided in multiple stages on a reticle or a mask.

[Industrial application field]

The present invention relates to a pellicle provided on a reticle or mask used during exposure in a photolithography process when manufacturing a semiconductor device.

In recent years, with the demand for higher integration of semiconductor devices, the performance and resolution of transfer devices used in photolithography processes have improved. For this reason, even a small amount of dust on a reticle or mask is transferred to an object, so the allowable size of dust is gradually becoming smaller. The same applies to the pellicle.

[Conventional technology]

FIG. 3 is a diagram showing a conventional pellicle. This consists of a frame 2 bonded onto a reticle or mask 1 having a pattern 1a, and a pellicle film (for example, a thin film of nitrocellulose) 3 stretched over the iron frame 2. Dust attempting to adhere to the reticle or mask 1 is blocked by the pellicle film 3 and adheres to the pellicle film 3. During transfer, this dust is separated from the pattern surface of the reticle or mask by the height of the frame 2 (standoff amount), so that it is located out of focus of the lens of the transfer device.

As a result, the allowable size of dust becomes larger than in the case without veritars.

[Problem to be solved by the invention]

In the conventional pellicle mentioned above, in order to further improve the transfer of dust, it is necessary to reduce the amount of dust that adheres to the pellicle film by simply improving the cleanliness at various points in the process, or by reducing the amount of dust that adheres to the pellicle film. By increasing the amount of standoff from the reticle, the size of dust allowed to be transferred was increased. However, if the standoff amount of the latter pellicle film is increased, a problem arises in that during inspection when the pellicle is attached, the reticle surface is located outside the focus of the microscope of the inspection device, making it impossible to perform inspection.

In view of the above conventional problems, it is an object of the present invention to provide a pellicle that increases the amount of standoff of the pellicle film from the reticle or mask and allows various inspections of the reticle or mask surface using a microscope.

[Means to solve the problem]

In order to achieve the above object, the multi-stage pellicle of the present invention has a frame 14 of a desired height on the surface of the reticle or mask 10 in order to prevent the transfer of dust adhering to the reticle or mask 10. A perital in which a pellicle film 15 is stretched over the reticle or mask 10 is characterized in that the pellicle is provided in multiple stages on the reticle or mask 10.

[For production]

In the multi-stage pellicle of the present invention, the first stage pellicle 12 is first placed on the reticle or mask 10, the surface of the reticle or mask 10 is inspected under a microscope, and then the second stage pellicle 13 is placed on the first stage pellicle 12. By overlapping the second pellicle 12 with the second pellicle 12, the standoff amount of the pellicle membrane 15 of the second pellicle 13 can be increased.
In addition, the reticle or mask can be inspected with a microscope before the second stage pellicle 13 is installed.

〔Example〕

FIG. 1 is a diagram showing an embodiment of the present invention.

In the figure, 10 is a reticle or mask, on the surface of which a pattern 10a of a semiconductor device is drawn. 11 is the multistage pellicle of this embodiment installed on the reticle or mask. This multi-stage pellicle consists of a first-stage pellicle 12 and a second-stage pellicle 13 installed above it. Each pellicle 12, 13 consists of a frame 14 and a pellicle membrane 15 stretched over the frame.

In this embodiment configured as described above, first, the frame 14 (for example, 4 mm in height) of the first stage pellicle 12 is adhesively fixed on the reticle or mask 10, and then the pellicle film 15 is stretched on the iron frame 14 in a clean room. Set up At this point, the pattern 10a of the reticle or mask 10 is inspected with a microscope through the pellicle film 15 to ensure the pattern. In this case, the focal length of the objective lens of the microscope needs to be longer than the standoff amount of the vertal film. Next, the second stage pellicle 13 (for example, standoff 13 mm)
) is mounted on top of the first stage pellicle 12. As a result, cleanliness is required only during the process of attaching the beretall, and in normal use environments, the standoff amount is large, so the reticle or mask can be used without particularly improving cleanliness. can.

FIG. 2 is a diagram showing another embodiment of the present invention.

In this figure, the same parts as in FIG. 1 are designated by the same reference numerals.

This embodiment differs from the previous embodiment in that the multi-stage pellicle 11 was attached to one side of the reticle or mask 10 in the previous embodiment, whereas in this embodiment the multi-stage pellicle 11 was attached to both sides. This is similar to the embodiment, and furthermore, it has the effect of preventing transfer of dust adhering to the back surface of the reticle or mask.

〔Effect of the invention〕

As explained above, according to the present invention, the size of dust transfer can be reduced without particularly improving the cleanliness in the environment where the reticle is actually used, and the pattern can be guaranteed by microscopic inspection. This makes it possible to greatly contribute to improving the quality of semiconductor devices.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing another embodiment of the present invention, and FIG. 3 is a diagram showing a conventional pellicle. In the figure, 10 is a reticle or mask, 10a is a pattern, 11 is a multi-stage pellicle, 12 is a first-stage pellicle 13, a second-stage pellicle 14 is a frame, and 15 is a pellicle film.

Claims (1)

[Claims] 1. In order to prevent the transfer of dust adhering to the reticle or mask (10), a frame (14) of a desired height is provided on the surface of the reticle or mask (10), and the frame is Pellicle membrane (
15) A multi-stage pellicle, characterized in that the pellicle is provided in multiple stages on a reticle or mask (10).