JP3361429B2 - Dustproof frame member for low reflection circuit transfer device excellent in light resistance and method of manufacturing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frame member for a so-called pellicle, which is a dustproof device for preventing dust from adhering to a photomask or the like and performing proper circuit transfer in the manufacture of semiconductor integrated circuit components. In particular, the present invention relates to a dust-proof frame member for a circuit transfer device, which has low reflection and hardly changes a black color tone even when used in a circuit transfer device using an excimer laser having a wavelength of ultraviolet rays or a far-ultraviolet region as a light source.

[0002]

2. Description of the Related Art A dustproof device used for transferring a semiconductor integrated circuit, a so-called pellicle, is a form in which a transparent resin film is held by a frame made of an aluminum alloy to prevent dust from adhering to a photomask or the like which is a source of a circuit. It enables high precision lithography. Usually, this aluminum alloy frame member is processed into a frame shape with high dimensional accuracy by processing such as cutting, and it is necessary to harden the surface and prevent scratches as well as light reflection. Therefore, it is dyed black and anodized.

[0003]

First, the aluminum alloy used for this purpose needs to have high strength because it needs to be machined into a frame shape with high dimensional accuracy by machining such as cutting. The dyed alumite used in the prior art is colored by permeating an organic dye into the pores in the alumite film. This dye may stay relatively close to the surface of the pore, and the dyed alumite product has a problem that when it is irradiated with ultraviolet rays, the organic dye chemically changes to cause color tone change and fading. In semiconductor circuit transfer, there is a tendency to use a light source with a shorter wavelength in order to improve the degree of circuit integration.
Not only ultraviolet rays such as i-line (wavelength 365 nm) but also excimer laser (KrF excimer laser: wavelength 248 nm, ArF excimer laser: wavelength 193 nm), which is a kind of far ultraviolet ray, is used. In this way, when high-energy light with a short wavelength is used, the problem of discoloration is more likely to occur, and unpredictable reflection occurs due to discoloration of the dust-proof frame due to aging or incorrect irradiation, increasing the risk of circuit transfer errors. . Therefore, if a low-reflection black dustproof frame that is excellent in light resistance with little discoloration against ultraviolet rays, far ultraviolet rays, and excimer lasers can be obtained, it will greatly contribute to the manufacturing stability and reliability of semiconductor integrated circuit components.

[0004]

[Means for Solving the Problems] Therefore, as a result of various investigations, an aluminum alloy having a proof stress of 350 N / mm ² was processed into a frame shape, and Ni, Co, Cu in the pores in the anodic oxide film were processed in an appropriate state. It was found that it is possible to produce a low-reflection black dustproof frame member having good light resistance to ultraviolet rays and excimer lasers by electrolytically depositing Sn, Fe, Sn or Fe, and the present invention has been completed.

That is, Zn 3.5 to 9.5 of claim 1
%, Mg 1 to 4.5%, Cu 0 to 3%, the balance impurities and Al, and a proof stress of 350 N / mm ² or more, a frame-shaped Al alloy member, and a film thickness formed on the surface of 4 to 35 μm.
Ni, Co, Cu, S in the pores of the anodic oxide film of m
One or more of n and Fe are electrolytically deposited and L value <4
A dustproof frame member for a low reflection circuit transfer device having excellent light resistance, which is characterized by a black color of 0.

The Al alloy member according to claim 2 further comprises Mn.
0.05 to 0.35%, Cr 0.05 to 0.35%, C
o0.05-0.35%, Zr0.05-0.35%,
The dustproof frame member for a low reflection circuit transfer device according to claim 1, characterized in that it contains one or more of Ni 0.05 to 0.35% and V 0.05 to 0.35%.

The surface roughness Ra according to claim 3 is 0.3 to 1.
The dust-proof frame member for a low-reflection circuit transfer device according to claim 1 or 2, wherein the dust-proof frame member is adjusted to 2 µm.

The alloy material having the above chemical composition according to claim 4 is subjected to solution treatment and artificial aging treatment so that the yield strength is 350.
N / mm ² or more, frame shape imparting processing is performed on this, and an anodized film having a film thickness of 4 to 35 μm is formed on the surface in a sulfuric acid bath, and then Ni salt, Co salt, Cu salt, Sn salt, Fe salt Of 1
A method for producing a dust-proof frame member for a low-reflection circuit transfer device, which is excellent in light resistance, characterized in that it is colored by electrolytic deposition in a bath containing one or more kinds thereof and is colored black. Is.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below.
The aluminum alloy of the present invention is 3.5 to 9.5% Zn,
1 to 4.5% Mg is contained as an essential component, but these elements are effective components for improving the strength. If the content of each element is less than the lower limit, the strength may be insufficient. -Hot workability deteriorates and manufacturing becomes difficult. Cu may be added to further improve the strength, but the upper limit of addition is 3 for the same reason as Zn and Mg.
%. When positively added, 0.5% or more is preferable, so Cu of less than 0.5% is regarded as an impurity in this specification. In addition, Mn of 0.05 to 0.35%,
The inclusion of one or more of Cr, Co, Zr, Ni and V has the effect of preventing crystal grain coarsening and suppressing unevenness in the surface color tone after alumite, and therefore may be added. If the content of each exceeds 0.35%, the rolling workability due to the coarse crystallized product increases. Mn, Cr, Co, Zr, Ni and V below 0.05% are considered as impurities in this specification. Further, usually in an aluminum alloy, Ti is singly added or added together with B to refine the cast structure. In this case, the upper limit of Ti content is 0.05% and the upper limit of B content is 0.01%. Besides this, F up to 0.5%
There is no problem in containing e, Si and trace elements mixed from the ingot as unavoidable impurities.

After casting, this alloy is hot-rolled or extruded, and if necessary, cold-worked. This alloy is mainly subjected to frame shape imparting processing by machining such as cutting. The aluminum alloy used in the present invention has a proof stress before frame shape imparting processing of 350 N / m.
It must be at least m ² . This is a condition necessary for achieving high dimensional accuracy without causing deformation during shape imparting processing by machining such as cutting, and for preventing deformation or flaw due to external force during use. Therefore, the alloy is subjected to solution treatment / quenching and artificial aging treatment. Here, strain correction may be performed after solution treatment / quenching or after artificial aging. The solution treatment / quenching and artificial aging treatment conditions are appropriately selected so as to satisfy the above-mentioned yield strength value.

After the frame shape giving process, the surface roughening process is performed. There are mechanical roughening treatments such as blasting and chemical methods of roughening by etching with an acidic or alkaline liquid, and these are used alone or in appropriate combination. The degree of this roughening is controlled so that the surface roughness of the final dustproof frame member is Ra 0.3 to 1.2 μm. This is a necessary condition for obtaining a so-called matte black color with low reflectivity. If Ra of the final dustproof frame member is less than 0.3 μm, it is unsuitable because it becomes a black color with strong reflection, and if it exceeds 1.2 μm, it becomes grayish and stains easily adhere to the surface, which is not preferable. .

After that, an anodized film of 4 to 35 μm is formed on the surface of the member by anodizing treatment with a sulfuric acid bath. (Primary electrolysis) If the thickness of the anodic oxide film is less than 4 μm, surface defects are likely to occur during handling, and a stable black color tone cannot be obtained.
If it exceeds 5 μm, there arise problems in that the anodizing treatment time is long and it is uneconomical, and the film is easily cracked. Considering the productivity and the stability of quality, the more preferable range of the thickness of the anodized film is 6 to 25 μm.

Then, this is further subjected to a secondary electrolytic deposition treatment to color the surface of the member black. The electrolytic deposition bath is N
The i salt, the Co salt, the Cu salt, the Sn salt, and the Fe salt can be appropriately selected by adding one kind or two or more kinds, but typically, a bath containing nickel sulfate and boric acid can be mentioned. as a result,
Ni, Co, and
One or more of Cu, Sn and Fe exist, but these are essential for coloring this product black.
These metals may be present as colloidal particles or oxides. Unlike the conventional so-called dyed alumite using an organic dye, the film colored by electrolytic deposition of the present invention has almost no fading upon irradiation with ultraviolet rays or excimer laser. This is because the components that contribute to coloring have the property that they do not change substantially even when they are exposed to ultraviolet rays or excimer lasers, and their precipitation penetrates deep into the pores of the anodic oxide film, making it difficult to directly receive strong irradiation. is there.

Further, in the present invention, the dustproof frame member has a black color with an L value of <40 in order to prevent unnecessary reflection, and the black color in the present invention includes dark gray. From the viewpoint of low reflection, glossiness (60 °) <10 is desirable.

After the electrolytic deposition treatment, a sealing treatment is appropriately performed by a usual method. In addition, if necessary, cleaning and removal of adhering substances are appropriately performed at each stage of manufacturing.

[0016]

EXAMPLES The present invention will be specifically described below with reference to examples.

Ingots of the chemical composition shown in Table 1 (diameter of about 200
mm extruded plate (for alloy ABC-width 1)
15mm x thickness 7mm, for alloy DEF-width 115mm x
(Thickness 8 mm) was subjected to solution treatment / water quenching at 460 ° C. for 1 hour and artificial aging treatment at 120 ° C. for 25 hours. As a result, the yield strength of the material is 350 N / m as shown in Table 2.
m ² or more. This is mainly cut by an NC processing machine, and the length is 100 mm, the width is 100 mm, and the thickness is 5.5 m.
The frame shape was m with a wall thickness of 2 mm. The average diameter is about 5
After blasting with 0 μm glass beads, etching treatment with 5% sodium hydroxide solution (40 ° C.) or 15% ammonium fluoride solution (50 ° C.) was performed, and this was anodized in 15% sulfuric acid (20 ° C.). , 1 A / dm ² )
Then, anodized films with various thicknesses were formed. After that, a coloring treatment by secondary electrolytic deposition as shown in Table 3 is further performed (however, No. 20 is a dyed alumite dyed by MLW of Dye Sand Co.), and then a nickel acetate-based sealing bath (Sand Co .: Sealing Salt AS). 5 g / liter, 95
Sealing treatment was performed at 10 ° C for 10 minutes.

As a result, the material of the present invention had a low reflective black surface with L value <40 and gloss (60 °) <10 (Table 4). On the contrary, the film thickness and the surface roughness deviate from the specifications of the present invention. In Nos. 16 to 19, there was a problem in terms of color tone or film characteristics. In addition, alloys D, E, F
Is a chemical component that has the effect of refining recrystallized grains,
Since Cr, Co, Zr, Ni, and V are not substantially added, the recrystallized grains are partially coarsened during the solution treatment, and a relatively thick surface coarse recrystallized portion is generated in the material before cutting. . For this reason, since it is necessary to completely remove this, the alloys A, B, and C can be cut by 7 → 5.5 mm, while the alloys D, E, and F are 8 → 5. 5m
m had to be cut.

[0019]

[Table 1]

[0020]

[Table 2]

[0021]

[Table 3]

[0022]

[Table 4]

Among the above, Example No. 4, 7, 8,
9, 11, 13 and Comparative Example No. 20 (dyed alumite product) is irradiated with KrF excimer laser,
The change in color tone was examined. The results are shown in Table 5. The excimer laser irradiation conditions are as follows: pulsed light with an irradiation intensity of 0.5 mJ / cm ² is applied to a site of 5 × 5 mm, and the total irradiation amount is 20,000 J.
It is obtained by the / cm ² and so as.

[0024]

[Table 5]

The results are shown in Table 5. The product of the present invention hardly changes in color tone by excimer laser irradiation and can maintain a black appearance, whereas the so-called dyed alumite product using an organic dye shows a marked fading. It happens and cannot keep black.

[0026]

INDUSTRIAL APPLICABILITY The present invention relates to a dustproof frame member for semiconductor production having a low reflection black color tone which is excellent in light resistance to ultraviolet rays and excimer lasers, and a method for producing the same. Since it can be applied to excimer laser, it will greatly contribute to the high performance of semiconductor parts.

Front page continuation (58) Fields surveyed (Int.Cl. ⁷ , DB name) G03F 1/08-1/16 H01L 21/027

Claims (4)

(57) [Claims] 1. Zn 3.5 to 9.5%, Mg 1 to 4.5
%, Cu 0 to 3%, and the balance impurities and Al,
A frame-shaped Al alloy member having a proof stress of 350 N / mm ² or more, and one or two kinds of Ni, Co, Cu, Sn, and Fe in the pores of the anodized film having a film thickness of 4 to 35 μm formed on the surface. A dustproof frame member for a low reflection circuit transfer device having excellent light resistance, characterized in that the above is electrolytically deposited to become black with an L value of <40. 2. The Al alloy member further has Mn of 0.05 to
0.35%, Cr0.05-0.35%, Co0.05
~ 0.35%, Zr0.05 ~ 0.35%, Ni0.0
The dust-proof frame member for a low-reflection circuit transfer device according to claim 1, which contains one or more of 5 to 0.35% and V0.05 to 0.35%. 3. The dustproof frame member for a low-reflection circuit transfer device according to claim 1, wherein the surface roughness Ra is adjusted to 0.3 to 1.2 μm. 4. An aluminum alloy material having the chemical composition according to claim 1 or 2 is subjected to solution heat treatment and artificial aging treatment to have a proof stress of 350 N / mm ² or more, which is subjected to frame shape imparting processing, and sulfuric acid. Film thickness 4-35μm on the surface in the bath
After forming the anodic oxide film of Ni, Co salt, Cu
A dust-proof frame member for a low-reflection circuit transfer device having excellent light resistance, which is characterized by being electrolytically deposited in a bath to which one or more of salt, Sn salt, and Fe salt are added, and colored and blackened. Manufacturing method.