HK1166376B - Dustproof film assembly - Google Patents

Description

Dustproof film assembly

Technical Field

The present invention relates to a method for manufacturing a pellicle for lithography used as a dust remover of a mask for lithography in the manufacture of semiconductor devices, printed wiring boards, liquid crystal displays, and the like, and more particularly to an adhesive for a pellicle frame.

Background

In the manufacture of LSI (large scale integration), ultra LSI (very large scale integration), or liquid crystal displays, patterns are formed by irradiating a semiconductor wafer or a liquid crystal master with light. When foreign matter adheres to a photomask or a reticle (collectively referred to as a photomask in this specification) used in this case, the pattern transferred to the semiconductor wafer or the liquid crystal mother panel is not only indistinct in the edge portion but also smeared in the background and impaired in size, quality and appearance.

Thus, exposure of the semiconductor wafer or the liquid crystal master is performed in a clean room. However, even so, it is difficult to completely prevent foreign matter from adhering to the photomask surface. Therefore, a dust cover called a pellicle having a high transmittance to exposure light is usually attached to the surface of the photomask, and the photomask is exposed to a semiconductor wafer or a liquid crystal master. In this case, the foreign matter is not directly attached to the photomask but is attached to the pellicle, and thus, when photolithography is performed, the foreign matter on the pellicle is irrelevant to transfer by merely aligning the focus with the pattern on the photomask.

In general, a pellicle is produced by attaching a pellicle to an upper end surface of a pellicle frame, forming an adhesive layer on a lower end surface of the pellicle frame to be adhered to a photomask, and providing a separation layer (separation portion) for protecting the adhesive layer on the adhesive layer. The dustproof film is made of cellulose resin such as nitrocellulose and cellulose acetate, fluororesin and the like having high transmittance to exposure light. The pellicle assembly frame is formed of aluminum, stainless steel, polyethylene, or the like. The method for pasting the dustproof film on the dustproof film component frame comprises the following steps: a dust-proof pellicle frame is formed by applying a readily soluble solvent for a dust-proof pellicle film material to the upper end surface of the frame, air-drying the dust-proof pellicle film, and then attaching the dust-proof pellicle film (see patent document 1), or attaching the dust-proof pellicle film to the frame with an adhesive such as an acrylic resin, an epoxy resin, or a fluororesin (see patent documents 2 and 3). The adhesive layer is composed of polybutylene resin, polyvinyl acetate resin, acrylic resin, silicone resin, and the like.

When the pellicle is used, the separation layer is peeled off, and pressure is applied to the adhesive layer against the photomask until the pressure is applied, whereby the pellicle is attached to the photomask. The step of forming a pattern by irradiating light is performed by punching down the pellicle, and the mechanism thus formed can be used for several years at the longest.

However, in order to inspect foreign matter after the pellicle is attached to the photomask, if the adhesive for attaching the pellicle to the photomask is transparent, the foreign matter may be erroneously inspected, particularly in the vicinity of the pellicle. This is because the light emitted from the light source for inspecting foreign matter is reflected and refracted inside and on the surface of the adhesive to be stray light and enters the detector, and the detector erroneously recognizes the stray light as foreign matter, and as a result, erroneously detects the presence of foreign matter.

In this way, although there is no foreign matter on the pellicle assembly and on the photomask, the inspection machine determines that there is a foreign matter, and determines that the product is defective.

Patent document 1: japanese laid-open patent publication No. 58-219023

Patent document 2: specification of U.S. Pat. No. 4861402

Patent document 3: japanese examined patent publication No. 63-27707

The present invention has been made in view of the above circumstances, and an object of the present invention is to select an adhesive that does not cause a problem that light is reflected and refracted in the adhesive to generate stray light and cause erroneous detection when detecting a foreign object in a dust-proof film assembly.

Disclosure of Invention

The invention comprises the following contents:

1. an adhesive for a pellicle, the pellicle comprising at least a pellicle frame and a pellicle, wherein the pellicle is attached to one end face of the pellicle frame, an adhesive for attaching the pellicle to a glass substrate is provided on the other end face of the pellicle frame, and a peelable sheet is provided on the upper surface of the adhesive, the adhesive being characterized in that: the total light transmittance is not more than 70%.

2. The adhesive for pellicle assembly as described in 1 above is preferably black.

According to the present invention, since the adhesive for attaching the pellicle to the photomask has a total light transmittance of 70% or less, and particularly in the vicinity of the pellicle frame, when the photomask is inspected, since no light for inspecting foreign matters is reflected or refracted by the adhesive and enters the foreign matter inspector as stray light, erroneous detection of foreign matters can be suppressed, and a decrease in yield can be prevented. In addition, the black adhesive can inhibit the reflection of the light for foreign matter inspection on the surface of the adhesive, thereby preventing the reduction of the yield.

Drawings

The FIGURE is a schematic view of one embodiment of a pellicle assembly of the present invention.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings, but the present invention is not limited thereto.

The FIGURE is a schematic view of one embodiment of a pellicle assembly of the present invention.

In the pellicle 10 of the present invention, an adhesive 13 for adhering a pellicle to a substrate is formed on the lower end face of a pellicle frame so that a pellicle film 11 is tightly adhered to the upper end face of the pellicle frame in a regular rectangular frame shape (rectangular frame shape or square frame shape) corresponding to the shape of the substrate (photomask or glass substrate portion thereof) to which the pellicle 10 is to be adhered. Further, a releasable separation film (separation layer) 14 for protecting the adhesive 13 is attached to the lower end surface of the adhesive 13.

In the present invention, the material of the dust-proof film is not particularly limited, and a known material having good light transmittance such as nitrocellulose, cellulose acetate, or fluororesin may be used.

In the present invention, the material of the pellicle frame is not particularly limited, and known metals such as aluminum and stainless steel, and synthetic resins such as polyethylene can be used.

In the present invention, the adhesive layer is provided at a predetermined width (usually, equal to or less than the width of the dustproof pellicle frame) on the lower end face of the dustproof pellicle frame, and the entire periphery of the dustproof pellicle frame is attached to the substrate.

As the adhesive, known ones can be used, and for example, a polybutene-based adhesive, a polyvinyl acetate-based adhesive, a silicon-based adhesive, an acrylic adhesive, and the like can be used.

The total light transmittance of the adhesive is preferably 70% or less. The total light transmittance was measured by using a haze meter (ヘ - ズメ - タ) HGM-2 (trade name, manufactured by gas laboratory Co., Ltd.) as a pressure-sensitive adhesive. If the total light transmittance is greater than 70%, the light emitted from the foreign substance inspection machine is reflected and refracted inside the adhesive to become stray light, and the stray light enters the inspection device, and the presence of a foreign substance is erroneously detected. Further, in order to suppress reflected light generated on the surface of the adhesive, the adhesive is preferably black.

The total light transmittance of the adhesive is suppressed to 70% or less by adding fumed silica, crystalline silica, precipitated silica, hollow filler, titanium dioxide, magnesium oxide, zinc oxide, aluminum hydroxide, magnesium carbonate, calcium carbonate, zinc carbonate, layered mica, diatomaceous earth, glass fiber, or the like. The blackening can be carried out by adding a blackening agent such as carbon black or a black pigment such as iron oxide or a dye. The fillers and the blackening agent are added in amounts such that the performance of the adhesive is not lowered.

The adhesive layer is formed by applying the adhesive to the pellicle frame, diluting the adhesive with a solvent as necessary, applying the diluted adhesive to the lower end of the pellicle frame, and then heating, drying and curing the diluted adhesive. In this case, the method of applying the adhesive includes brush coating, spray coating, automatic quantitative coating, and the like.

The release sheet (release sheet) is provided for protecting the adhesive. Since the pellicle is peeled off when it is used, a release film (separation film) is provided when it is necessary to protect the adhesive before the pellicle is used. Dustproof film module products are generally circulated in a form of attaching a release film (separation film).

The material of the release sheet (separator) is not particularly limited, and a known material can be used. In addition, as a method for attaching the release film (separation film) to the adhesive, a known method may be used as long as the release film (separation film) can be attached to the adhesive.

Examples

The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples.

Example 1

First, a dustproof thin film module frame was produced, and by chamfering (R-machining) both inner and outer peripheral edges of both end faces of the frame having an outer dimension of 782 × 474mm, an inner dimension of 768 × 456mm, and a height of 5.0mm, an aluminum alloy dustproof thin film module frame having a flat face width of both end faces of the frame of 4.0mm, an inner radius of a corner of 2.0mm, and an outer radius of 6.0mm was produced, and the surface thereof was subjected to black aluminum oxide film treatment.

The pellicle frame was carried into a clean room, washed thoroughly with a neutral detergent and pure water, and dried.

The adhesive having a total light transmittance of 70% or less was prepared by adding fumed silica (fumed silica) music-120A (trade name, manufactured by shin-Etsu chemical Co., Ltd.) to 100 parts by mass of a silicon adhesive X-40-3122 (trade name, manufactured by shin-Etsu chemical Co., Ltd.) and mixing them. Thereafter, the prepared adhesive is applied to the lower end face of the dustproof pellicle assembly frame.

Then, the adhesive was air-dried until it did not flow, and the pellicle frame was further heated to 130 ℃ by a high-frequency induction heater (not shown) to cure the adhesive.

Further, a silicone adhesive KR-3700 (trade name, product of shin-Etsu chemical Co., Ltd.) was applied to the upper end surface of the frame of the pellicle, and a pellicle was attached thereto, and the excess film on the outer side was cut with a knife, thereby completing the production of a pellicle.

Example 2

A pellicle was fabricated in the same manner as in example 1, except that 0.3 part by mass of black carbon paste (カ - ボンペ - スト) K-LIMS color-02 (trade name, manufactured by shin-Etsu chemical Co., Ltd.) was added to 100 parts by mass of silicon adhesive X-40-3122 (trade name, manufactured by shin-Etsu chemical Co., Ltd.) and the mixture was mixed.

Example 3

A pellicle was prepared in the same manner as in example 1 except that 3 parts by mass of black iron oxide paste (ペ - スト) K-color-FE 035 (trade name, manufactured by shin-Etsu chemical Co., Ltd.) was added to 100 parts by mass of silicon adhesive X-40-3122 (trade name, manufactured by shin-Etsu chemical Co., Ltd.) and mixed.

Example 4

A pellicle was fabricated in the same manner as in example 1, except that 0.3 part by mass of black paste (カ - ボンペ - スト) LIMS color-02 (trade name, manufactured by shin-Etsu chemical Co., Ltd.) was added to 100 parts by mass of acrylic pressure-sensitive adhesive SK-1425 (trade name, manufactured by Hokko chemical Co., Ltd.) and mixed to prepare a mixture.

Comparative example

A pellicle was prepared in the same manner as in example 1, except that the silicon adhesive X-40-3122 (trade name, manufactured by shin-Etsu chemical Co., Ltd.) was used as it is.

The evaluation results of examples and comparative examples are shown in Table 1.

Appearance:

the apparent colors of the adhesives prepared in examples 1 to 4 and comparative example were visually observed.

Total light transmittance:

the adhesives prepared in examples 1 to 4 and comparative example were cured to prepare sheets of 50X 2mm, and the total light transmittance was measured with a haze meter (ヘ - ズメ - タ) HG M-2 (trade name, manufactured by gas laboratory Co., Ltd.).

Detecting foreign matters:

the dust-proof pellicle assemblies prepared in examples 1 to 4 and comparative example were observed for foreign matters on the dust-proof pellicle. Whether or not there was a foreign object was erroneously detected was observed by changing the irradiation angle of the light source for foreign object detection.

Watch (A)

	Example 1	Example 2	Example 3	Example 4	Comparative example 4
						Apparent color of adhesive	Milky white color	Black color	Black color	Black color	Colorless and transparent
Total light transmittance (%)	50	0	0	0	90
						Inspection of foreign matter	Without false detection	Without false detection	Without false detection	Without false detection	Has false detection
Comprehensive evaluation	Qualified	Qualified	Qualified	Qualified	Fail to be qualified

From the results of the above table, it can be confirmed that: by using the adhesive, the false detection of foreign matters is avoided, and the reduction of the product qualification rate is prevented.

Claims (3)

1. A dustproof thin film component at least comprises a dustproof thin film and a dustproof thin film component frame, wherein the dustproof thin film is attached to one end face of the dustproof thin film component frame, an adhesive layer used for attaching the dustproof thin film component to a glass substrate is arranged on the other end face of the dustproof thin film component frame, and a strippable sheet is arranged between the adhesive layer, and the dustproof thin film component is characterized in that: the adhesive layer is composed of a uniform mixture of an adhesive and a filling agent, and the total light transmittance of the adhesive layer is less than 70%.

2. The dust cover assembly of claim 1, wherein: the filler is selected from fumed silica, crystalline silica, settling silica, hollow filler, titanium dioxide, magnesium oxide, zinc oxide, aluminum hydroxide, magnesium carbonate, calcium carbonate, zinc carbonate, layered mica, diatomaceous earth and glass fiber.

3. The dust cover assembly of claim 2, wherein: the adhesive layer is black.