An extreme ultraviolet high-temperature resistant thin film filter and its preparation method and application

Abstract

The present invention provides an extreme ultraviolet high-temperature resistant thin film filter, belonging to the technical field of thin film preparation. The extreme ultraviolet high-temperature resistant thin film filter includes a first Mo layer, a repeat unit layer, and a MoSi2 layer which are sequentially stacked; the repeat unit layer includes a second Mo layer and a ZrSi2 layer disposed on the surface of the second Mo layer; the thickness of the first Mo layer is 2 nm; the thickness of the second Mo layer in any unit layer of the repeat unit layer is 2.5 nm, and the thickness of the ZrSi2 layer is 1.5 nm; the thickness of the MoSi2 layer is 3 nm; the number of periodic layers of the repeat unit layer is 10 to 25. The filter prepared by the present invention has good self-supporting performance, the transmittance at different positions of the filter is quite the same, and the transmittance uniformity is good; moreover, it has high thermal stability, will not generate sand holes or cracks at high temperatures, and the filtering effect will not decrease significantly.

Description

Technical Field

[0001] The present invention belongs to the technical field of thin film preparation, and particularly relates to an extreme ultraviolet high-temperature resistant thin film filter and its preparation method and application. Background Art

[0002] Extreme ultraviolet lithography (EUVL) technology is a micro-nano processing technology that uses the EUV band, mainly the 13.5 nm band, for lithography. The most important part in extreme ultraviolet lithography is the light source. An advanced light source can generate a large amount of intense ultraviolet and extreme ultraviolet light. During this process, in addition to the required specific wavelength light, the radiated light waves also contain a large number of non-required radiation components.

[0003] During operation, various different filters will be used to filter out the light waves of non-required components. Among them, the most common filters are thin film filters and metal filters. Metal filters are optical materials obtained by depositing metals, which have high optical performance and stability, but the manufacturing cost is relatively high. Thin film filters are made by depositing thin films on soluble materials and obtaining transmissive materials after dissolving the soluble substances. The manufacturing process is simple and the price is low. Patent CN119001942A discloses a filter suitable for the 16.5 - 18.0 nm extreme ultraviolet band, but at the 13.5 nm band, the filtering effect drops significantly; Patent CN112853289A discloses a filter with excellent mechanical properties, but it only has a high transmittance in the 17.1 - 30.0 nm extreme ultraviolet band; Patent CN119471883A discloses a filtering film with high-temperature resistance performance, but it only has a high transmittance at long wavelengths above 400 nm.

[0004] Therefore, there is an urgent need to design a filter for a working wavelength of 13.5 nm, which is a thin film filter with excellent self-supporting ability and thermal stability. Summary of the Invention

[0005] The purpose of the present invention is to provide an extreme ultraviolet high-temperature resistant thin film filter and its preparation method and application. The thin film filter provided by the present invention has a high transmittance at a working wavelength of 13.5 nm, good transmittance uniformity, and at the same time has excellent self-supporting performance and thermal stability, and will not produce sand holes or cracks at high temperatures, and the filtering effect will not drop significantly.

[0006] In order to achieve the above-mentioned invention purpose, the present invention provides the following technical solutions:

[0007] An extreme ultraviolet high-temperature resistant thin film filter includes a first Mo layer, a repeat unit layer, and a MoSi2 layer that are sequentially stacked.

[0008] The repeatable unit layer includes a second Mo layer and a ZrSi2 layer disposed on the surface of the second Mo layer;

[0009] The thickness of the first Mo layer is 2 nm;

[0010] In any unit layer of the repeatable unit layer, the thickness of the second Mo layer is 2.5 nm, and the thickness of the ZrSi2 layer is 1.5 nm;

[0011] The thickness of the MoSi2 layer is 3 nm;

[0012] The periodic number of layers of the repeatable unit layer is 10 - 25.

[0013] Preferably, the total thickness of the extreme ultraviolet high-temperature resistant thin film filter is 45 nm - 105 nm.

[0014] Preferably, the diameter of the extreme ultraviolet high-temperature resistant thin film filter is more than 5 mm.

[0015] The present invention also provides a method for preparing the above extreme ultraviolet high-temperature resistant thin film filter, comprising the following steps:

[0016] Depositing a first Mo layer, a repeatable unit layer, and a MoSi2 layer on the surface of a substrate in sequence by magnetron sputtering to obtain the extreme ultraviolet high-temperature resistant thin film filter;

[0017] The repeatable unit layer includes a second Mo layer and a ZrSi2 layer disposed on the surface of the second Mo layer.

[0018] Preferably, the magnetron sputtering is carried out in an Ar gas atmosphere.

[0019] Preferably, the working pressure of the magnetron sputtering is 0.20 Pa - 0.28 Pa.

[0020] Preferably, the power for magnetron sputtering to deposit the first Mo layer and the second Mo layer in the repeatable unit layer is 60 W - 100 W.

[0021] Preferably, the power for magnetron sputtering to deposit the ZrSi2 layer in the repeatable unit layer is 80 W - 120 W.

[0022] Preferably, the power for magnetron sputtering to deposit the MoSi2 layer is 80 W - 120 W.

[0023] The present invention also provides an application of the extreme ultraviolet high-temperature resistant thin film filter described in the above technical solution or the extreme ultraviolet high-temperature resistant thin film filter prepared by the preparation method described in the above technical solution in extreme ultraviolet lithography.

[0024] Advantageous effects:

[0025] The present invention provides an extreme ultraviolet high-temperature resistant thin film filter, which includes a first Mo layer, a repeat unit layer, and a MoSi2 layer that are stacked in sequence; the repeat unit layer includes a second Mo layer and a ZrSi2 layer disposed on the surface of the second Mo layer; the thickness of the first Mo layer is 2 nm; the thickness of the second Mo layer in any unit layer of the repeat unit layer is 2.5 nm, and the thickness of the ZrSi2 layer is 1.5 nm; the thickness of the MoSi2 layer is 3 nm; the number of periodic layers of the repeat unit layer is 10 - 25. The thin film filter provided by the present invention uses ZrSi2 with a non-crystalline structure as a raw material, which improves the self-supporting ability of the entire filter. When the diameter is 20 mm, the transmittance at different positions at 13.5 nm is quite the same, and the transmittance uniformity is good; at the same time, MoSi2 material similar to the material of the repeat unit layer is used as a protective layer, and the thermal expansion behavior of the materials is consistent, avoiding film cracking or deformation caused by interlayer stress at high temperatures. Moreover, the MoSi2 material has excellent high-temperature stability and oxidation resistance. Therefore, the prepared thin film filter will not produce sand holes or cracks at high temperatures, and the filtering effect will not decrease significantly, and it has high thermal stability. The results of the examples show that the highest peak transmittance of the thin film filter of the present invention at 13.5 nm can reach 66.9%, and the transmittance efficiency is high; the bandwidth at the transmission main peak of the filter is about 0.28 nm, with strong light selectivity and high precision; at high temperatures, the filter does not produce sand holes or cracks, and the maximum decrease in the filtering effect is within 10%, with good thermal stability; under the condition of no support mesh, the diameter of the prepared filter can reach 20 mm, and the transmittance uniformity is good, with excellent self-supporting ability. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments.

[0027] Figure 1 It is a schematic structural diagram of an extreme ultraviolet high-temperature resistant thin film filter;

[0028] Figure 2 It is a calculation diagram of the transmission efficiency at different positions of the extreme ultraviolet high-temperature resistant thin film filter prepared in Example 6. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The present invention provides an extreme ultraviolet high-temperature resistant thin film filter, which includes a first Mo layer, a repeat unit layer, and a MoSi2 layer that are stacked in sequence;

[0030] The repeat unit layer includes a second Mo layer and a ZrSi2 layer disposed on the surface of the second Mo layer;

[0031] The thickness of the first Mo layer is 2 nm;

[0032] In any unit layer of the repeatable unit layer, the thickness of the second Mo layer is 2.5 nm, and the thickness of the ZrSi2 layer is 1.5 nm;

[0033] The thickness of the MoSi2 layer is 3 nm;

[0034] The number of periodic layers of the repeatable unit layer is 10 - 25 layers.

[0035] In the present invention, the thickness accuracy of the first Mo layer, the second Mo layer, the ZrSi2 layer, and the MoSi2 layer can reach ±0.1 nm.

[0036] In the present invention, the total thickness of the extreme ultraviolet high-temperature resistant thin film filter is preferably 45 nm - 105 nm, and specifically can be 49 nm or 85 nm.

[0037] In the present invention, the diameter of the extreme ultraviolet high-temperature resistant thin film filter is preferably 5 mm or more, and specifically can be 8 mm, 9 mm, or 10 mm.

[0038] The present invention also provides a method for preparing the above-mentioned extreme ultraviolet high-temperature resistant thin film filter, including the following steps:

[0039] Using magnetron sputtering method, the first Mo layer, the repeatable unit layer, and the MoSi2 layer are sequentially deposited on the surface of the substrate to obtain the extreme ultraviolet high-temperature resistant thin film filter;

[0040] The repeatable unit layer includes a second Mo layer and a ZrSi2 layer disposed on the surface of the second Mo layer.

[0041] In the present invention, the substrate is preferably a soluble substrate or an insoluble substrate; the soluble substrate preferably includes a sodium chloride substrate; the insoluble substrate preferably includes a copper grid.

[0042] In the present invention, after depositing a thin film on the surface of the sodium chloride substrate, it is preferably demolded in an aqueous solution.

[0043] In the present invention, the magnetron sputtering is preferably carried out in an Ar gas atmosphere.

[0044] In the present invention, the working pressure of the magnetron sputtering is preferably 0.20 Pa - 0.28 Pa, and specifically can be 0.22 Pa, 0.24 Pa, or 0.25 Pa.

[0045] In the present invention, the power of magnetron sputtering for depositing the first Mo layer and the second Mo layer in the repeatable unit layer is preferably 60 W - 100 W, and specifically can be 70 W, 80 W, or 90 W, and the target used is a Mo target.

[0046] In the present invention, the power for magnetron sputtering to deposit the ZrSi2 layer in the repeatable unit layer is preferably 80 W to 120 W, specifically it can be 90 W, 100 W or 110 W, and the target used is a ZrSi2 target.

[0047] In the present invention, the power for magnetron sputtering to deposit the MoSi2 layer is preferably 80 W to 120 W, specifically it can be 90 W, 100 W or 110 W, and the target used is a MoSi2 target. In the present invention, the MoSi2 layer serves as a protective layer and can maintain a stable structure at high temperatures.

[0048] The present invention also provides the application of the extreme ultraviolet high-temperature resistant thin film filter described in the above technical solution or the extreme ultraviolet high-temperature resistant thin film filter prepared by the preparation method described in the above technical solution in extreme ultraviolet lithography.

[0049] In the present invention, the working wavelength of the extreme ultraviolet high-temperature resistant thin film filter is preferably 13.5 nm. In the present invention, when electromagnetic waves of 13.5 nm are incident, it is preferably normal incidence, and the incident angle is 0.

[0050] In the present invention, unless otherwise specified, all raw material components are commercially available products well-known to those skilled in the art or are prepared by methods well-known to those skilled in the art.

[0051] To further illustrate the present invention, the extreme ultraviolet high-temperature resistant thin film filter provided by the present invention will be described in detail below with reference to the accompanying drawings and embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0052] Example 1

[0053] Place a soluble substrate (sodium chloride substrate) in a vacuum chamber, introduce Ar gas, use Mo target, ZrSi2 target and MoSi2 target, and perform magnetron sputtering in an Ar gas atmosphere. The working pressure is 0.25 Pa, and deposit a first Mo layer, a repeatable unit layer (including a Mo layer and a ZrSi2 layer provided on the surface of the Mo layer), and a MoSi2 layer on the surface of the substrate in sequence;

[0054] The thickness of the first Mo layer is 2 nm, the thickness of the Mo layer in the repeatable unit layer is 2.5 nm, the thickness of the ZrSi2 layer is 1.5 nm, the thickness of the MoSi2 layer is 3 nm, and the number of periodic layers of the repeatable unit layer is 10;

[0055] The magnetron sputtering power of the first Mo layer and the second Mo layer in the repeatable unit layer is 80 W;

[0056] The magnetron sputtering power of the ZrSi2 layer in the repeatable unit layer is 100 W;

[0057] The magnetron sputtering power of the MoSi2 layer is 100 W;

[0058] The coated film material is placed in a coating fixture, and the substrate is removed by demoulding in water to obtain an extreme ultraviolet high-temperature resistant thin film filter with a total thickness of 45 nm and a diameter of 5 mm.

[0059] Example 2

[0060] The difference from Example 1 is only that: the diameter of the prepared filter is 8 mm and the total thickness remains unchanged.

[0061] Example 3

[0062] The difference from Example 1 is only that: the diameter of the prepared filter is 10 mm and the total thickness remains unchanged.

[0063] Example 4

[0064] The difference from Example 1 is only that: the diameter of the prepared filter is 15 mm and the total thickness remains unchanged.

[0065] Example 5

[0066] The difference from Example 1 is only that: the diameter of the prepared filter is 20 mm and the total thickness remains unchanged.

[0067] Example 6

[0068] The difference from Example 1 is only that: the diameter of the prepared filter is 20 mm, the number of periodic layers of the repeat unit layer is 25, and the total thickness is 105 nm.

[0069] Test Example

[0070] Under the conditions that the working wavelength is 13.5 nm, the electromagnetic wave is incident at normal incidence, and the incident angle is 0, the transmittance of the filters prepared in Examples 1 to 6 is tested, and the test results are shown in Table 1 below.

[0071] Table 1 Transmittance of Filters Prepared in Examples 1 to 6

[0072]

[0073] Figure 1 is a schematic structural diagram of an extreme ultraviolet high-temperature resistant thin film filter; according to Figure 1 It can be seen that the filter includes a repeat unit layer; the repeat unit layer includes a Mo layer and a ZrSi2 layer disposed on the surface of the Mo layer.

[0074] Figure 2 is a calculation diagram of the transmission efficiency at different positions of the extreme ultraviolet high-temperature resistant thin film filter prepared in Example 6; from Figure 2It can be seen that except for the edge position of the filter where the transmittance cannot be measured due to fixed gluing, the transmittances at other different positions are quite the same, indicating good transmittance uniformity of the filter.

[0075] After irradiating the filters prepared in Examples 1 to 6 at a high temperature of 500 °C to 800 °C for 30 minutes respectively, it was observed that the film layers of the filters were intact without sand holes or cracks. Under the conditions that the working wavelength was 13.5 nm, the electromagnetic wave was incident at normal incidence, and the incident angle was 0, the transmittance of the filters after high-temperature irradiation was measured. The results showed that the maximum decrease in the filtering effect was within 10%.

[0076] Although the above embodiments have described the present invention in detail, they are only a part of the embodiments of the present invention, not all of them. People can also obtain other embodiments based on these embodiments without creative efforts, and these embodiments all fall within the protection scope of the present invention.

Claims

1. An extreme ultraviolet high temperature resistant thin film filter, characterized in that: It includes a first Mo layer, a repeatable unit layer and a MoSi2 layer which are stacked in sequence; The repeatable unit layer includes a second Mo layer and a ZrSi2 layer disposed on the surface of the second Mo layer; The thickness of the first Mo layer is 2 nm; The thickness of the second Mo layer in any unit layer of the repeatable unit layer is 2.5 nm, and the thickness of the ZrSi2 layer is 1.5 nm; The thickness of the MoSi2 layer is 3 nm; The number of periodic layers of the repeatable unit layer is 10-25.

2. The extreme ultraviolet high temperature resistant thin film filter according to claim 1, characterized in that: The total thickness of the extreme ultraviolet high temperature resistant thin film filter is 45nm~105nm.

3. The extreme ultraviolet high temperature resistant thin film filter according to claim 1, characterized in that: The diameter of the extreme ultraviolet high temperature resistant thin film filter is greater than 5 mm.

4. The method for preparing the extreme ultraviolet high temperature resistant thin film filter according to any one of claims 1 to 3, characterized in that: The following steps are involved: The first Mo layer, the repeatable unit layer and the MoSi2 layer are sequentially plated on the surface of the substrate by a magnetron sputtering method to obtain the extreme ultraviolet high temperature resistant thin film filter; The repeatable unit layer includes a second Mo layer and a ZrSi2 layer arranged on the surface of the second Mo layer.

5. The method for preparing the extreme ultraviolet high temperature resistant thin film filter according to claim 4, characterized in that: The magnetron sputtering was performed in an Ar gas atmosphere.

6. The method for preparing the extreme ultraviolet high temperature resistant thin film filter according to claim 4, characterized in that: The working gas pressure of the magnetron sputtering is 0.20Pa~0.28Pa.

7. The method for preparing the extreme ultraviolet high temperature resistant thin film filter according to claim 4, characterized in that: The power of the magnetron sputtering coating of the first Mo layer and the second Mo layer in the repeatable unit layer is 60W-100W.

8. The method for preparing the extreme ultraviolet high temperature resistant thin film filter according to claim 4, characterized in that: The power of the magnetron sputtering coating of the ZrSi2 layer in the repeatable unit layer is 80W~120W.

9. The method for preparing the extreme ultraviolet high temperature resistant thin film filter according to claim 4, characterized in that: The power of the magnetron sputtering coating MoSi2 layer is 80W~120W.

10. Use of the extreme ultraviolet high temperature resistant thin film filter described in any one of claims 1 to 3 or the extreme ultraviolet high temperature resistant thin film filter prepared by the preparation method described in any one of claims 4 to 9 in extreme ultraviolet lithography.

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