JP3123034B2 - Transmission multilayer film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission type multilayer film for light in a vacuum ultraviolet to soft X-ray region having a wavelength of 200 nm or less.

[0002]

2. Description of the Related Art Vacuum ultraviolet light having a wavelength of 200 nm or less is soft X
The light in the line region has a refractive index very close to a vacuum value of 1 for most substances, and has a large absorption, so that there is no transparent substance. Therefore, in the case of manufacturing a transmission type optical element used for visible light, it is necessary to use a structure in which a support or a substrate is not provided in a light transmitting region because a transparent substrate cannot be used. is there. Hereinafter, such a structure is referred to as free standing. 12A to 12D are known as structures of the transmission type multilayer film. The transmission-type multilayer film shown in FIG. 12A is a transmission-type multilayer film having a structure in which a silicon nitride film 112 is provided on a silicon substrate 111 having a transmission window, and a multilayer film 113 is provided thereon. 112 has no light transmission window and is not free standing. FIG.
The transmission type multi-layer film shown in (b) has a structure in which a silicon nitride film 115 having a light transmission window is provided on a silicon substrate 114 having a transmission window, and a multi-layer film 116 is provided thereon. Yes, it is a free standing transmission type multilayer film. The transmission type multilayer film shown in FIG.
In the modification of (a), the transmission type multilayer film has a structure in which a silicon nitride film membrane 118 is provided on a silicon substrate 117 having a transmission window, and a multilayer film 119 is provided on the lower surface of the membrane in the transmission window portion of the silicon substrate. The membrane has no light-transmitting windows and is not free standing. FIG.
The transmission type multilayer film of (d) has a structure in which a silicon oxide film and a two-layer membrane 121 of SiC are provided on a silicon substrate 120 having a transmission window, and a multilayer film 122 is provided thereon. The membrane 121 has no light transmission window and is not free standing. In such a conventional transmission type multilayer film, a silicide such as SiN, a boride such as BN, and diamond are usually used as a membrane. Further, Mo is usually used as the heavy element layer of the multilayer film, and Si is usually used as the light element layer.

A method shown in FIG. 13 is known as one of the methods for producing such a transmission type multilayer film. In this method, after a multilayer film is formed on an organic thin film, the underlying organic thin film is dissolved by an organic solvent (a), and the multilayer film is scooped by a support (b) to make the multilayer film free-standing. Method (H. Nomura et al., Proc. SPIEVo
l. 1720 (1992) p395). Hereinafter, it is abbreviated as a scooping method. In the scooping method, wrinkles are more easily formed on the reflection surface. Therefore, as shown in FIG.

[0004] As another method of manufacturing a transmission type multilayer film,
The method shown in FIG. 14 is known. In this method, a multilayer film is formed on a membrane used as a mask for X-ray exposure (Andrew M. Hawryluk et al., J. Vac. Sc.
i. Technol. B, Vol.6 (1988) p2153). A nitride film is formed on both surfaces of a silicon substrate (a), and a portion of the back surface through which light is transmitted is removed (b). Then, after removing silicon by wet etching with KOH or the like (c), a multilayer film is formed by forming a multilayer film on the nitride film on the surface. At this time, a method of forming a multilayer film before removing the nitride film on the back surface is also known. According to this method, an element having a large opening can be manufactured, and the allowance for the internal stress of the multilayer film is large as compared with the scooping method using a mesh. Hereinafter, it is abbreviated as an etch back method.

[0005]

FIG. 12 (a) and FIG. 12 (c)
In the structure of FIG. 12 (d), the film thickness of the membrane is usually required to be about several tens to several hundreds of nm, so that the intensity of transmitted light is significantly reduced due to absorption by the membrane, and sufficient transmittance is obtained. There is a problem that can not be. FIG.
When the membrane is simply removed as in the structure shown in FIG. 2 (b), there is a problem that the stress of the multilayer film is not balanced after the removal, resulting in wrinkles or cracks. Also,
Since the multilayer film is made of a material having low dry etching resistance, such as Mo / Si, there is a problem that the multilayer film is damaged when the membrane is removed by dry etching, and the reflectance is reduced. Furthermore, in order to maintain the flatness of the transmission type multilayer film, it is necessary to control the internal stress of the multilayer film itself to zero or a weak tensile stress. However, controlling the stress causes a decrease in reflectance and the like. In such a case, the internal stress of the multilayer film itself cannot be controlled and becomes a compressive stress, and the flatness of the transmission type multilayer film is impaired due to wrinkles due to residual stress. When the internal stress is a strong tensile stress, there is a problem that the flatness is maintained but the transmission type multilayer film is damaged by cracks or the like. "Scraping method"
In the transmission type multilayer film manufactured in the above, there is a problem that the peeled multilayer film is wrinkled or cracked due to the internal stress of the multilayer film when the multilayer film is peeled from the underlying layer. Furthermore, when a mesh is used for the support, there are problems such as a decrease in transmittance due to the mesh and disturbance of the reflection surface due to wrinkles, and when a ring opening is used for the support, there are problems such as limitations on the opening area. is there. The present invention has been made in view of the above-described conventional problems.
An object of the present invention is to provide a transmissive multilayer film having a high reflectance and a high transmittance that has solved the reduction in the reflectance due to the reduction in flatness and the reduction in the transmittance due to the membrane.

[0006]

According to a first aspect of the present invention, there is provided a transmission type multilayer film having a support and a multilayer film, wherein the transmission type multilayer film is in contact with the support of the multilayer film. The layer is made of a white metal element, and the light transmitting portion is made of only a multilayer film. Further, in the transmission type multilayer film according to the second invention, in the transmission type multilayer film having a support and the multilayer film, a layer of the multilayer film which is in contact with the support is made of a white metal element, and a light transmitting portion is a multilayer film. Further, a film having a window for light transmission, and having a residual stress of the same property as the multilayer film, is opposite to the surface of the support and the support opposite to the multilayer film. On the other side of the surface of the multilayer film. Further, in the transmission type multilayer film according to the third invention, in the transmission type multilayer film having a support and a multilayer film, a layer of the multilayer film in contact with the support is made of a white metal element, and a light transmitting portion is a multilayer film. And a film having a window for light transmission and having a residual stress having a property opposite to that of the multilayer film is provided between the multilayer film and the support.

[0007]

In the first aspect of the present invention, since the layer of the multilayer film in contact with the support is made of a white metal element having high dry etching resistance, the membrane can be removed without damaging the multilayer film. As a result, a free standing transmission multilayer film having high reflectance without scattering of reflected light can be realized. In addition to this, in the second invention, the stress relaxation film having the same residual stress as the multilayer film is provided on the surface of the support opposite to the multilayer film or the surface of the multilayer film opposite to the support. According to the third aspect, by providing a stress relaxation film having a residual stress having a property opposite to that of the multilayer film between the multilayer film and the support,
The residual stress of the multilayer film can be reduced. As a result, a free standing transmission multilayer film having both high reflectance and transmittance can be realized. Thus, in the second invention, in order to reduce the influence of the internal stress of the multilayer film,
A stress relaxation film is provided to control the stress of the multilayer film, to prevent wrinkles and cracks in the multilayer film after removing the membrane, and to maintain excellent flatness. The second invention is different from the prior art in that the stress relaxation film is not formed as a membrane, but the transmission portion is formed as a free standing multi-layer film to achieve high transmittance and high reflectance simultaneously.

[0008]

FIG. 1 is a diagram for explaining a first embodiment of the present invention. The transmission type multilayer film includes a multilayer film 6, a membrane 3 made of SiN, and a silicon substrate 4. Among them, the multilayer film 6 is composed of 1 Ru and 2 Si, and Ru /
Ru is provided on both sides of the multilayer film 6, such as Si /.../ Si / Ru. With this configuration, Ru has high dry etching resistance to CF ₄ , CF ₄ + H ₂ , or CF ₄ + H ₂ + N ₂ , which is an etching gas for the nitride film, so that the multilayer film is not easily damaged when etching the membrane. Become. At this time, if both layers are made of Ru, a Mo / Si multilayer film may be used. In this case, it can be manufactured at lower cost than a multilayer film made entirely of Ru. The constituent material of the membrane 3 is SiN in this example.
However, another silicon compound such as SiC may be used.
As described above, Ru / Si /.. ./Si is used by using Ru having high dry etching resistance as one of the constituent materials of the multilayer film.
Since Ru is provided on both sides as in / Ru, the membrane can be removed by dry etching without damaging the multilayer film. As a result, a transmission type multilayer film having high reflectance without scattering of reflected light is obtained.

Next, a method for producing such a transmission type multilayer film will be described in detail with reference to FIG. CVD on both sides of Si substrate 4
Method (CVD: Chemical Vapor Deposition) or EC
R-CVD method (ECR: Electron Cyclotron Resonanc
According to e), a silicon compound 3 such as SiN or SiC is deposited (b). Next, a resist 5 is applied to the back surface (c),
The portion corresponding to the light transmission window is exposed and developed to form a resist pattern (d). For the exposure, light exposure or EB exposure or the like usually used in an LSI manufacturing process is used. After that, using the resist pattern 5 as a mask, CF ₄ , CF ₄
+ H _2, or CF ₄ + H ₂ + by dry etching a halogen gas as a main etching gas such as N _2, a silicon compound 3 is removed by etching (e). Furthermore, S
The i-substrate 4 is removed by wet etching to form a membrane substrate (f). Here, the wet etching is performed using an etching solution such as KOH or amine. Next, Ru1 and Si2 are alternately deposited on the membrane substrate to form a multilayer film 6 (g). Finally, the membrane 7 is removed by dry etching to form the transmission window 8 (h). The etching gas at this time is CF ₄ ,
CF ₄ + H _2, or CF ₄ + H ₂ + a halogen gas such as N ₂ is used mainly as the etching gas.

FIG. 3 is a view showing another method of manufacturing a transmission type multilayer film. Steps (a) to (e) are the same as (a) to (e) in FIG. As described above, the multilayer film 6 is laminated before back-etching the window-opened substrate 4 (f), and thereafter the substrate 4 is removed by wet etching using KOH or an amine-based etchant (g). Membrane 7
(H) may be a process of forming the transmission window 8 by dry etching. In this case, since the back-etching step of the Si substrate is performed prior to the formation of the multilayer film, damage to the multilayer film due to the etchant of the back-etch can be prevented, and the margin for the stress control range of the membrane alone is large. There is. In other words, there is no process for free standing with the membrane alone,
It can be applied even when the membrane has a compressive stress. The internal stress of the multilayer film is several M in the conventional magnetron sputtering.
Although it was a relatively strong compressive stress of about Pa to 1 GPa,
In the present invention, the pressure is reduced to several tens MPa or less by optimizing the manufacturing conditions of the multilayer film such as the gas pressure, the substrate temperature, and the film forming rate. Therefore, even if the membrane is completely removed by etching, wrinkles may occur due to the internal stress of the multilayer film,
Free standing is possible because there is no crack. The above manufacturing process can be easily manufactured at low cost because there is no special process, and the semiconductor manufacturing process can be used as it is, which is suitable for mass production.

FIG. 4 shows a second embodiment of the present invention. 1, 2, 3, and 4 are the same as the materials described in FIG. 1, and are transmission type multilayer films having a structure in which a stress relaxation film 7 is provided on the back surface of the substrate. In this embodiment, the residual stress of the multilayer film 6 is a compressive stress, and the compressive stress of the multilayer film 6 is canceled by the compressive stress of the stress relieving film 7 to relieve the stress and to reduce the flatness of the transmission type multilayer film. Hold. Thereby, the transmission type multilayer film has both high reflectance and transmittance without impairing the reflectance and transmittance. SiC, SiO ₂ ,
A silicon compound such as SiN is used.

FIG. 5 is a view for explaining a method of manufacturing the transmission type multilayer film shown in FIG. CVD or EC on both sides of Si substrate 4
A silicon compound 3 such as SiN or SiC is deposited by the R-CVD method (b). Next, a stress relaxation film 7 having a compressive stress is formed on the silicon compound 3 formed on the back surface of the substrate 4 by a sputtering method or an evaporation method (e). The substrate 4 warps in a concave shape due to the compressive stress of the stress relaxation film 7. Then, a resist 5 is applied on the stress relaxation film 7 (d), and a portion corresponding to the light transmission window is exposed and developed to form a resist pattern (c). For the exposure, a method usually used in an LSI manufacturing process such as light exposure or EB exposure is used.
After that, using the resist pattern 5 as a mask, CF ₄ , C
By dry etching using a halogen gas such as F ₄ + H ₂ or CF ₄ + H ₂ + N ₂ as a main etching gas,
The stress relaxing film 7 is removed by etching (f), and then a part of the silicon compound 3 is removed by etching (g). Further, the Si substrate 4 is removed by wet etching,
A membrane substrate is prepared (h). Here, the wet etching is performed using an etching solution such as KOH or amine. Next, Ru1 and Si2 are alternately deposited on the membrane substrate to laminate the multilayer film 6 (i). By laminating the multilayer film, the warpage of the substrate 4 returns to its original state due to the internal stress of the multilayer film itself. Therefore, the compressive stress of the multilayer film is reduced, and a flat multilayer film is obtained. Finally, a transmission window is formed in the membrane 7 by dry etching (j). At this time, an etching gas mainly containing a halogen gas such as CF ₄ , CF ₄ + H ₂ , or CF ₄ + H ₂ + N ₂ is used. Also in this embodiment, the multilayer film laminating step (i) may be performed before the substrate back etching step (h). In this case, since the back-etching step of the Si substrate is performed prior to the formation of the multilayer film, it is possible to prevent damage to the multilayer film due to the etchant of the back-etch, and it has a large margin for the stress control range of the membrane alone. There is. That is, since there is no process of free standing the membrane alone, the present invention can be applied even when the membrane has a compressive stress.

FIG. 6 is a diagram showing a third embodiment of the present invention. 1, 2, 3, and 4 are the same as the materials described in FIG. In the present embodiment, the residual stress of the multilayer film 6 is a strong tensile stress. In the second embodiment, the stress relaxation film 7 is provided on the back surface of the substrate. In this embodiment, the structure has the stress relaxation film 7 on the multilayer film. The tensile stress of the multilayer film 6 is relaxed by the tensile stress of the stress relaxation film 7. As the stress relaxation film 7, a silicon compound such as SiC, SiO ₂ , or SiN is used.

FIG. 7 is a view for explaining a method of manufacturing the transmission type multilayer film shown in FIG. A silicon compound 3 such as SiN or SiC is deposited on both surfaces of the Si substrate 4 by a CVD method or an ECR-CVD method (b). Next, a resist 5 is applied on the silicon compound 3 formed on the back surface of the substrate 4 (c), and a portion corresponding to the light transmission window is exposed and developed to form a resist pattern (d). For the exposure, a method usually used in an LSI manufacturing process such as light exposure or EB exposure is used.
After that, using the resist pattern 5 as a mask, CF ₄ , C
By dry etching using a halogen gas such as F ₄ + H ₂ or CF ₄ + H ₂ + N ₂ as a main etching gas,
Part of the silicon compound 3 is removed (e). Next, Ru1 and Si2 are alternately deposited on the silicon compound 3 formed on the surface to form the multilayer film 6 (f). The substrate 4 warps in a concave shape due to the tensile stress of the multilayer film 6. Further, the multilayer film 6
A stress relaxation film 7 having a tensile stress is formed on the substrate by sputtering or vapor deposition (g). Then, the substrate 4 further warps in a concave shape due to the tensile stress of the stress relieving film 7, and as a result, the tensile stress of the multilayer film in the window portion is relieved. Therefore, damage due to cracks in free standing can be prevented. Thereafter, a resist 5 is applied on the stress relieving film 7, and a portion corresponding to the light transmission window is exposed and developed to form a resist pattern (h). Thereafter, the stress relaxation film 7 in the window portion is removed by dry etching using the resist pattern as a mask (i), and the Si substrate 4 is removed.
Is removed by wet etching (j). here,
Wet etching is performed with an etching solution such as KOH or amine. Finally, the silicon compound 3 in the window is removed by dry etching (k). At this time, CF ₄ , CF ₄ + H ₂ , or CF ₄ is used as an etching gas.
An etching gas mainly containing a halogen gas such as ₄ + H ₂ + N ₂ is used. Also in this embodiment, the multilayer film laminating step (i) may be performed after the substrate back etching step (j).

FIG. 8 is a diagram showing a fourth embodiment of the present invention. 1, 2, 3, and 4 indicate the same materials as those described in FIG. In this embodiment, the multilayer film 6 and the nitride film 3
And a structure having a stress relaxation film 7 between them. In this structure, when the residual stress of the multilayer film 6 is a compressive stress, the residual stress of the stress relieving film 7 is changed to a tensile stress, so that the stress can be relaxed and the flatness of the transmission type multilayer film can be maintained. On the other hand, when the residual stress of the multilayer film 6 is a strong tensile stress, the residual stress of the stress relieving film 7 is changed to a compressive stress to relieve the stress and prevent breakage of the transmission type multilayer film such as a crack. Can be. As the stress relaxation film 7, SiC,
A silicon compound such as SiO ₂ or SiN is used.

FIG. 9 is a view for explaining a method of manufacturing the transmission type multilayer film shown in FIG. CVD or E on both surfaces of Si substrate 4
A silicon compound 3 such as SiN or SiC is deposited by CR-CVD (b). Next, a stress relaxation film 7 is formed on the silicon compound 3 formed on the surface of the substrate 4 by sputtering or vapor deposition (c). Thereafter, a resist 5 is applied on the silicon compound 3 formed on the back surface of the substrate 4 (d), and a portion corresponding to the light transmission window is exposed and developed to form a resist pattern (e). For the exposure, a method usually used in an LSI manufacturing process such as light exposure or EB exposure is used. Then, using the resist pattern 5 as a mask,
A part of the silicon compound 3 is removed by dry etching using a halogen gas such as CF ₄ , CF ₄ + H ₂ or CF ₄ + H ₂ + N ₂ as a main etching gas (f). Further, the Si substrate 4 is removed by wet etching to form a membrane substrate (g). Here, the wet etching is performed using an etching solution such as KOH or amine. Next, Ru1 and Si2 are alternately deposited on the stress relaxation film 7 to form the multilayer film 6 (h). Finally, the silicon compound 3 in the window portion is removed by dry etching (i), and subsequently, the stress relaxation film 7 in the window portion is removed (j). The etching gas at this time is CF ₄ , C
An etching gas mainly containing a halogen gas such as F ₄ + H ₂ or CF ₄ + H ₂ + N ₂ is used. Also in this embodiment, the multilayer film laminating step (h) may be performed before the substrate back etching step (g).

FIG. 10 is a diagram showing a fifth embodiment of the present invention. 1, 2, 3, and 4 indicate the same materials as those described in FIG. In this embodiment, the substrate 4 and the nitride film 3
Have a stress relaxation film 7 between them. This structure has basically the same effect as the structure of the fourth embodiment. However, when a multilayer film is laminated on a nitride film having a relatively small surface roughness, it is difficult to reduce the surface roughness of the stress relaxation film. Suitable. As the stress relaxation film 7, a silicon compound such as SiC, SiO ₂ , or SiN is used.

FIG. 11 is a view for explaining a method of manufacturing the transmission type multilayer film shown in FIG. Stress relaxation film 7 on the surface of Si substrate 4
Is formed by sputtering or vapor deposition (b). Thereafter, S or S is applied to both surfaces by CVD or ECR-CVD.
A silicon compound 3 such as iN or SiC is deposited (c). Next, a resist 5 is applied on the silicon compound 3 formed on the back surface of the substrate 4 (d), and a portion corresponding to the light transmission window is exposed and developed to form a resist pattern (e). For the exposure, a method usually used in an LSI manufacturing process such as light exposure or EB exposure is used. Then, using the resist pattern as a mask, CF ₄ , CF ₄ + H ₂ , or C 4
Part of the silicon compound 3 is removed by dry etching using a halogen gas such as F ₄ + H ₂ + N ₂ as a main etching gas (f). Further, the Si substrate 4 is removed by wet etching (g). Here, the wet etching is performed using an etching solution such as KOH or amine. Further, the stress relaxation film in the window portion is removed by dry etching to form a membrane substrate (h). next,
Ru1 and Si2 are alternately deposited on the silicon compound 3 to form a multilayer film 6 (i). Finally, the silicon compound 3 in the window
Is removed by dry etching (j). At this time, an etching gas mainly containing a halogen gas such as CF ₄ , CF ₄ + H ₂ , or CF ₄ + H ₂ + N ₂ is used. Also in the present embodiment, the multilayer film laminating step (i) may be performed before the substrate back etching step (g).

In the above embodiment, R is used as the heavy element in the multilayer film.
u and Ru / Si /
Ru /... / Si / Ru were used to start with Ru and end with Ru. Further, even if only the layers at both ends are made of Ru and the intermediate heavy metal layer is made of Mo, the effect of the present invention is not impaired, and the production can be performed at low cost. As described above, Ru is used as a constituent element of the multilayer film because it is experimentally known that Ru has high etching resistance with a halogen gas such as CF ₄ . Accordingly, Ru, which is also considered to have high etching resistance due to halogen gas such as CF _{4, also}
Other white metal elements (Ru, Pd, Os, Ir, Pt)
It is needless to say that the same effect can be obtained by using as a heavy metal element or a layer at both ends of the multilayer film. Also,
For forming the multilayer film, magnetron sputtering, ion beam sputtering, EB vapor deposition, CVD, ECR sputtering, or the like can be used. In addition, a silicon compound such as SiN or SiC can be formed by a sputtering method or the like in addition to CVD. In particular, the ECR-CVD method is suitable since a film having good smoothness and a very small residual stress can be formed at a low temperature without heating the substrate.

[0020]

The transmissive multilayer film of the present invention has a high transmissivity and a high reflectivity due to excellent flatness. Therefore, it can be applied as an X-ray optical element such as a beam splitter and a power filter. Furthermore, the transmission type multilayer film of the present invention is used as a polarizer, an analyzer and the like to constitute an X-ray polarization analyzer, so that it can be applied as an atomic-order analyzer. Further, if it is used as a coherent X-ray beam splitter, it can be applied to X-ray holography using an interferometer, two-beam interference, or the like. Further, the fabrication process of the present invention is an application of a semiconductor fabrication process and is suitable for mass production.

[Brief description of the drawings]

FIG. 1 is a view showing the structure of a first embodiment of a transmission type multilayer film of the present invention.

FIGS. 2A to 2H are diagrams illustrating a process of manufacturing a transmission type multilayer film according to a first embodiment, wherein FIGS.

FIGS. 3A to 3C show other manufacturing steps of the first embodiment.
(H) shows each step.

FIG. 4 is a view showing a structure of a transmission type multilayer film according to a second embodiment of the present invention.

FIGS. 5A to 5J are diagrams illustrating the steps of manufacturing the transmission type multilayer film according to the second embodiment, in which FIGS.

FIG. 6 is a view showing the structure of a third embodiment of the transmission type multilayer film of the present invention.

FIGS. 7A to 7K are diagrams illustrating the steps of manufacturing a transmission-type multilayer film according to a third embodiment, in which FIGS.

FIG. 8 is a view showing the structure of a fourth embodiment of the transmission type multilayer film of the present invention.

FIGS. 9A to 9J are diagrams illustrating the steps of manufacturing the transmission type multilayer film according to the fourth embodiment, in which FIGS.

FIG. 10 is a view showing the structure of a fifth embodiment of the transmission type multilayer film of the present invention.

FIGS. 11A to 11J are diagrams illustrating the steps of manufacturing a transmission type multilayer film according to a fifth embodiment, wherein FIGS.

FIG. 12 is a view showing a structure of a conventional transmission type multilayer film;
(A) to (d) show different structures.

FIG. 13 is a view for explaining an example of a conventional manufacturing process of a transmission-type multilayer film, wherein (a) to (c) show each process.

FIGS. 14A to 14D are diagrams showing an example of a manufacturing process of a conventional transmission type multilayer film, wherein FIGS.

[Explanation of symbols]

 1 White metal element layer such as Ru 2 Light element layer 3 Membrane 4 Silicon substrate 5 Resist 6 Multilayer film 7 Stress relaxation film 111 Silicon substrate 114 Silicon substrate 117 Silicon substrate 120 Silicon substrate 112 Membrane 115 Membrane 118 Membrane 121 Membrane 113 Multilayer film 116 Multilayer film 119 Multilayer film 122 Multilayer film

──────────────────────────────────────────────────の Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H01L 21/027 G03F 1/16 INSPEC (DIALOG)

Claims (3)

(57) [Claims] In a transmission type multilayer film having a support having a transmission window and a multilayer film provided on the support, a lower surface of the multilayer film in contact with the support and an upper surface of the multilayer film not in contact with the support are each made of white metal. A transmission type multilayer film comprising an element. 2. The method according to claim 1, wherein a stress relaxation film having a residual stress having the same property as that of the multilayer film is provided on either an upper surface of the multilayer film or a lower surface of the support not in contact with the multilayer film. The transmission type multilayer film according to claim 1. 3. The transmission type multilayer film according to claim 1, wherein a stress relaxation film having a residual stress having a property opposite to that of said multilayer film is provided between said multilayer film and said support. .