JPH01304400A - Production of reflecting mirror consisting of multilayered film for x-ray and vacuum ultraviolet ray - Google Patents

Abstract

PURPOSE:To produce the reflecting mirror having high reflectivity to X-rays and vacuum UV rays by setting the rate of forming multilayered film at about from 0.1Angstrom /S to 5Angstrom /S. CONSTITUTION:A silicon substrate (2''phi, 10mmt) worked to surface accuracy lambda/20 (lambda=6,328Angstrom ) is polished by diamond paste. The material 1 of the same lot as the material 1 with which the surface roughness is measured is then mounted to an ion beam sputtering device which can make evacuation to 8X10<-7>Torr ultimate vacuum degree by using a substrate holder in which 18 deg.C cooling water passes on the rear surface of the substrate 1. The alternate layers of Mo and Si are formed to 41 layers at 0.2Angstrom /S vapor deposition rate under the conditions of 1kV acceleration voltage of an ion beam, 20mA ion current and 2X10<-4>Torr gaseous argon pressure. The layer right above the substrate 1 and the extreme surface layer are formed of the Mo and the respective film thicknesses are specified to 27Angstrom of the Mo and 36Angstrom of the Si to obtain the reflecting mirror. The reflecting mirror having the high reflectivity is produced in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention is directed to optical devices, particularly to light from X-rays to vacuum ultraviolet light with a wavelength of 200 nm or less, and whose incident angle is normal incidence close to perpendicular to a mirror surface. The present invention relates to a method for manufacturing a reflecting mirror.

[Conventional technology]

Conventionally, there has been no reflector that has a high reflectance for light with a wavelength shorter than the vacuum ultraviolet region when it is incident at or near normal incidence to the surface; However, the reflectance was only 1% or less.

On the other hand, even with a grazing incidence reflector having a relatively high reflectance, it is necessary to adjust the incident angle to 1° or less or within a range of 2 to 3° from the mirror surface. Even with this, a very large reflecting surface is required even for a narrow beam in order to make the beam incident on the surface at a small angle, making the use of this device difficult and limited.

In addition, in the case of an oblique incidence mirror, there is little freedom in the configuration of the optical system, and when manufacturing a reflecting mirror, highly accurate flatness is required over a large area, which has many limitations in actual use. In addition,
In the visible to 2000 wavelength range, a multilayer reflector that utilizes the interference of multilayer thin films has been proposed. For example, as shown in Figure 2, the reflectance characteristics are approximately 80-100% reflectance in the visible range of 2000 Å or more by forming a multilayer alternating layer of a combination of two dielectric materials such as MgF2 and ZnS. is obtained at normal incidence.

However, in the case of alternating dielectric layers, absorption increases rapidly in a wavelength range of 2000 Å or less, and there are almost no combinations of materials that can be used as a reflecting mirror in wavelengths of 1000 Å or less. Also, even metal single layer films such as AA, Au, Pt etc.
At wavelengths shorter than a person's wavelength, the reflectance decreases rapidly in proportion to λ4, and at wavelengths shorter than 500 people and even shorter than 200 people, only a reflectance of 1% or less can be obtained at normal incidence.

On the other hand, attempts have been made to create a metal multilayer reflector in which two metal materials with different complex refractive indexes are alternately laminated, but in the X-ray and vacuum ultraviolet light regions, most materials have an absorption coefficient. It is expressed as a complex refractive index (n + i k, hereinafter referred to as refractive index) with an imaginary part K representing
I O-' ~ l 0-3), so the Fresnel reflectance at the boundary between the vacuum and the material thin film is very small and 0.
It is on the order of 1% or less. Further, even at the boundary between laminated thin films of different materials, the reflectance does not exceed several percent per single boundary surface.

However, by creating a multilayered structure in which different materials are alternately stacked, and by adopting a film thickness configuration that maximizes the reflectance of the multilayer film as a whole by reinforcing the reflected light from each layer boundary through interference, a high reflectance can be achieved. It becomes possible to obtain. Furthermore, it is known that by selecting a combination of different materials that increases the difference in refractive index between adjacent glabellar areas, and by combining this with the above-mentioned film thickness configuration, it is possible to realize a reflecting mirror with a high reflectance.

The combinations of materials known to date for the composition of multilayer films include transition metals as low refractive index materials, and most of the high refractive index materials use semiconductor elements such as carbon and silicon. there were. Typical examples include the combination of tungsten (W) and carbon (C), and the combination of tungsten (W) and carbon (C).
There are combinations of M o ) and silicon (Sl), etc.

In order to obtain a high reflectance in this type of multilayer reflector, it is necessary to have roughness on the substrate surface, the interface between each layer of the multilayer reflector and its adjacent layer, and the surface roughness of the multilayer reflector. It is important to reduce the

Generally, the reflectance when there is roughness at the boundary between each layer of a multilayer film and its adjacent layer is given by the following equation relative to the reflectance when the interface is ideal.

IS/I7 = eXp [-(2yr m σ/d)2
]Here ■8・Reflectance when the interface is rough, IT Reflectance when the interface is not rough, m3 Reflection order, σ Roughness of the interface (y m s value), d: Periodic film thickness.

FIG. 2 shows IS/I0 versus σ/d. According to this, when m = 1, a/d is 0. ], ■8 becomes ■1
At 0.2, it decreases to just under 70%, and to 20% at 0.2.

Therefore, it is necessary to minimize the roughness (expressed as roughness) of the interface σ.

As a means of measuring and evaluating surface roughness, for example, a multilayer film reflecting mirror fabricated on a substrate with surface roughness #1 of a method that averages roughness over a wide area (several μm) such as a heterodyne interferometric surface roughness meter is used. A method is used to indirectly determine the roughness of the interface by measuring the surface roughness of the surface. This method not only provides information averaged over a wide area, but also
It is impossible to directly know the surface roughness of the interface between each layer of the multilayer reflector and the eyebrows adjacent to it. In particular, unevenness with a size of several amps or more and several thousand angstroms or less in the interface between each layer and the adjacent layer and in the direction parallel to the surface plane causes a phase shift of diffracted X-rays and vacuum ultraviolet rays, and interferes with the reflectance. However, with the surface roughness measurement method described in Section 1, it was not possible to obtain this information indirectly. No consideration was given to irregularities with a size of less than 2,000 angstroms, which could be caused by several people parallel to each other, and therefore no efforts were made to investigate the causes of such irregularities or to suppress them.

[Problem to be solved by the invention] In recent years, cross-sectional observation using a transmission electron microscope has become an effective means of analyzing thin films. In the sample with a low anti-n=1 ratio, it was observed that the unevenness at the interface propagated from the lower layer to the upper layer, forming a columnar structure. This is thought to be because the deposited particles aggregate to form an island-like structure after adhering to the substrate, and when the next layer is deposited, they grow to form islands on top of the next layer. As a result, not only does a roughness occur at the interface, but the roughness is also expanded toward the layer.Furthermore, in samples where this phenomenon occurs, when the crystallinity is evaluated by electron beam diffraction, the roughness is In many cases, the layer with a similar structure was crystallized.In other words, the layer had a similar structure to the base.
When a substance having a larger BL concentration energy than the deposition energy is deposited, the deposited particles aggregate on the substrate to form horizontal islands, and crystallization occurs at this time. Further, when crystallization occurs even without the formation of an island structure, grain boundaries are always formed, but irregularities occur at the boundaries of the grain boundaries.

Therefore, in order to produce a reflecting mirror with high reflectance, it is necessary to suppress aggregation of deposited particles and reduce irregularities at the interface between each layer and its adjacent layer due to island structures and crystal grain boundaries. In particular, the surfaces of the laminated thin film layers and their interfaces are known from the patent applications already filed by the present applicant (Japanese Patent Application No. 62-249696 and Japanese Patent Application No. 62-249697).
), it is necessary that the r m s value of the surface roughness be 1/8 or less of the wavelength used in order to suppress the phase disturbance of the reflected light.

Conventionally, no special consideration has been given to the formation of such a smooth thin film surface, and the method for forming it has never been examined in detail.

In the present invention, we propose a method to reduce these unevenness, and
The purpose of this invention is to provide a method for manufacturing a multilayer reflector that has high reflectance for line and vacuum ultraviolet rays.

[Failure to solve the problem]

According to the present invention, in the method for manufacturing a multilayer reflector for X-rays and vacuum ultraviolet light, which has a reflector with a multilayer structure consisting of alternating layers of substances having different refractive indexes on a substrate, the formation of the multilayer film is performed using ion beams. This can be achieved by using a beam sputtering method and setting the film formation rate to about 01 λ/S to 5 Å/S.

In other words, in an ion beam sputtering device, a part that generates the ions necessary for sputtering, a target to be irradiated with the ion beam, and a substrate on which atoms or molecules flying from the target are placed are placed. The substrate is not directly exposed to plasma for ionization. Also,
The number of ionized particles that fly directly from the plasma region is small (there is also less heating of the substrate by thermal radiation from the plasma, and as a result, the substrate temperature is less likely to rise).Therefore, there are fewer atomic or molecular units from the sputtered target. By controlling only the amount of flying particles per hour, it is possible to suppress the agglomeration of adhered particles and form an amorphous film on the substrate.For film formation by ion beam sputtering, As mentioned above, since the temperature rise of the board is not large, it is usually sufficient to maintain it near room temperature by water cooling, etc., but in order to further eliminate the influence of heating, it is necessary to use other refrigerants or cooling devices. , it may be cooled to below room temperature.

Further, it is also possible to use an electron beam evaporation method as a film forming method. In this case, a crucible for melting the vapor deposition material is usually placed below the substrate without any obstruction, and the substrate always faces the crucible during vapor deposition. Furthermore, multilayer reflectors for X-rays and vacuum ultraviolet rays often use high-intensity light sources such as synchrotron radiation, and in order to prevent damage, high-melting point metals or compounds are used as the film material. is often used. Therefore, it is not uncommon for the temperature of the crucible to exceed 2000 degrees Celsius, and the substrate is usually significantly heated by blackbody radiation from the crucible. For example, when e-beam evaporating molybdenum, a substrate placed ~60 cm from the crucible can easily reach ~50°C. Therefore, in order to prevent local crystallization and suppress the formation of island-like structures to obtain an amorphous film, the substrate temperature must be maintained at about -200°C to -50°C by cooling the substrate. If you do, you will achieve your goal. Even in the electron beam evaporation method, as the evaporation rate increases, the probability of island-like growth increases, so it is preferable not to exceed about 5 Å/S. In particular, since the thickness of a multilayer film is 20 to 30 layers, it is difficult to control the film thickness sufficiently accurately and precisely if the film is formed at a rigid speed, and even if a desirable film quality is obtained, it is practically unusable. This may result in a thick film.

According to the above film formation method, which is used to solve the problems in the conventional method, it is possible to prevent the agglomeration of the deposited material, suppress the formation of island structures or microcrystalline boundaries, and suppress unevenness at the interface. becomes. If the vapor deposited substances do not aggregate during the formation of each layer and are uniformly laminated in an amorphous state, these unevenness will not occur and a smooth interface can be formed.

The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic cross-sectional view of a multilayer reflector for X-rays and vacuum ultraviolet rays according to the present invention. Here, layers 2, 4 . . . of first materials having mutually different refractive indexes are formed on a substrate l. ... and second material layers 3, 5 . ... alternately increase the thickness by d2. d
4. ...and d3. d5. ...They are stacked together. In the reflective mirror of the present invention, it is desirable that all the layers constituting the multilayer film be amorphous in order to minimize the roughness of the interface. However, even if one of the constituting layers is amorphous, If it is crystalline, it is possible to reduce the roughness of the interface between each layer.The roughness of the interface often occurs.
This is because the amorphous layer has the property of propagating to two layers, so the introduction of the amorphous layer prevents the propagation.

In order to make the films constituting the multilayer film amorphous, there are methods such as selection of constituent materials, selection of film formation method, high purity of vapor deposition materials, and addition of materials that promote amorphous film formation. However, particularly effective means are to use ion beam sputtering to form a film at a low deposition rate, or to use electron beam evaporation to sufficiently cool the substrate.

The surface of the substrate 1 on which the multilayer film is laminated may be flat or
After processing into convex, concave, or aspherical shapes and polishing with diamond paste, floating polishing, chemical polishing, long-term heating in an ultra-high vacuum at a temperature slightly lower than the melting point of the substrate material, or flash heating Repeat polishing until the surface has a sufficient roughness.

In this process, any impurities deposited on the substrate surface are also removed.

It is also effective to provide a buffer layer between the substrate surface and the multilayer film so that the roughness of the substrate surface does not affect the multilayer film.

The fouling rate exhibited by the multilayer reflector for X-rays and vacuum ultraviolet rays of the present invention is determined by the difference in refractive index of two materials with different refractive indexes forming alternating layers, the absorption rate of each layer, and the number of laminated layers. The difference in refractive index varies depending on the wavelength of the irradiated light, etc., but the difference in refractive index is practically small when the number of layers is, for example, 100 (0.
It is desirable that the number is 01 or more.

In order to provide each layer of the alternating layers with a difference in refractive index, the alternating layers are made of a material with a high refractive index and a material with a low refractive index for light in the X-ray/vacuum ultraviolet region, which is the object of the present invention. Just form it.

Average film thickness d2 of each layer. d3. ... is approximately 1/4 of the target wavelength, and is a laminated film made of the same film quality alternately, and the film thickness is set to satisfy the condition that all reflected light at the boundary between each layer interferes constructively. Satisfy or
Alternatively, it is determined by either or both of satisfying the condition that the decrease in reflectance of the multilayer film as a whole is smaller when comparing absorption loss in each layer and decrease in reflectance due to phase shift. In this case, the film thickness may be the same for all layers of the same material, or may be changed for each layer so that the thickness is not necessarily equal so as to maximize the reflectance.

For the laminated structure, it is desirable to select a material that provides a large difference in the refractive index of the final layer that is in contact with the substrate or vacuum and the refractive index of the substrate or vacuum. It is also preferable that the difference in refractive index between the substrate and the layer in contact with the substrate is large.

In addition, the reflectance increases as the number of alternating layers increases, so it is preferable that the number of layers be 5 or more, but if the number is too large, the influence of the absorbing layer will become significant, so considering the ease of fabrication, It's good up to the layer level. Further, a protective layer made of a stable material with low absorption may be provided as the final layer.

〔Example〕

Example 1 A silicon substrate (2"φ,] Om m t ) processed to an area density of S/20 (λ-6328) was polished using a diamond mode paste. The surface roughness was measured using a heterodyne interferometric surface roughness meter. When measured, the r m s value was 3.05.
It was a person.

A substrate from the same lot as the substrate whose surface roughness was measured was placed in an ion beam sputtering device capable of evacuation to an ultimate vacuum of 8 x 10' torr, using a substrate holder with cooling water at 8°C passed through the back side of the substrate. I installed the board. The accelerating voltage of the ion beam is I K V and the ion current is 20 m
A, 41 alternating layers of Mo and Si were formed at a deposition rate of 0.2 Å/S under conditions of argon gas pressure of 2×10” torr. The layer directly above the substrate and the outermost layer were Mo;
Reflector A was obtained with a film thickness of 27 for Mo and 36 for Sl.

Also, on the same substrate as in Example 1, with the same structure as the reflecting mirror A,
Vacuum achieved by F-machinetron sputtering equipment]
, X] ]0-6 torr, argon gas pressure 1×
A multilayer reflective mirror B of Mo and Si was prepared at 10-3 torr, incident power of 100 W, and reflected power of 5 W. The film formation rate at this time was 0.2 for both Mo and Si. Each cross section of these reflecting mirrors A and B was observed using a transmission electron microscope. In reflecting mirror A, both the Mo layer and the Si layer were amorphous, and the roughness of the interface was 3.2 in r m s value. On the other hand, in reflecting mirror B, the Si layer was amorphous, but the Mo
Although the layers did not form an island structure, they were crystallized.

In addition, grain boundaries were formed that were about 100 grains thick in the direction parallel to the layer plane and about 25 grains thick in the direction perpendicular to the layer plane. Therefore, the roughness of the interface was 4.5 in rms value. The crystallinity of reflecting mirrors A and B was also confirmed by X-ray diffraction and electron beam diffraction.

When soft X-rays of 124 wavelengths were incident on each multilayer reflector at an angle of 10' from the surface normal, a reflectance of 65.2% was obtained for reflector A, and a reflectance of 65.2% for reflector B. 5
A reflectance of 8.3% was obtained. This difference in reflectance was caused by the difference in interface roughness due to the difference in manufacturing method.

Example 2 A substrate with the same surface precision and roughness as Example 1 was ion-treated.
A multilayer reflector using Mo and Si was fabricated using a beam sputtering device under the same conditions except for the ion current and deposition rate. The film thicknesses of Mo and Si were 27 Å and 36 Å, respectively. Ion current is 30mA, deposition rate is 1Å
/S.

When the manufactured reflecting mirror was evaluated using an X-ray diffraction device, it was found that M
No peak indicating crystallization was observed in either the Si layer or the Si layer. When the cross section was observed using a transmission electron microscope, the unevenness of the interface was small and the roughness value (rms value) was 2.8A. This value is 1/16 of the wavelength used (design wavelength) of 124 people.
It was much smaller than. Synchrotron radiation was spectrally analyzed in the same manner as in Example 1, and soft X-rays of 24 wavelengths were incident at an angle of 1.2° from the normal to the surface, and a reflectance of 59.1% was obtained.

Example 3 A fused silica substrate (
Second, a multilayer film was formed by ion beam sputtering. Ion beam acceleration voltage I
KV, ion current 100 mA, ultimate vacuum 8X
10=torr, argon gas pressure lXl0-3
A Mo, Si multilayer film was produced under torr conditions. Mo
layer.

The Si layers were 21 layers and 20 layers, respectively, and their thicknesses were 26.9 and 36 layers, respectively. When the prepared reflecting mirror was observed with a transmission electron microscope, the roughness of the layer interface was r
The ms value was 5.3 people. When the surface roughness of the multilayer film was measured using the heterodyne interference method, the rms value was 5, which was smaller than 1/16 of the wavelength used.

Using the same ion beam sputtering device, acceleration voltage IKV, ion current 150mA, ultimate vacuum 8X1
0-'torr, argon gas pressure 3X10-3t
41 alternating layers of Mo and Si were formed at a deposition rate of 10 Å/S under the conditions of When the prepared reflecting mirror was subjected to electron beam diffraction, a pattern indicating a linear Mo orientation was observed, and when the in-plane state was observed using a transmission electron microscope, an island-like structure was observed. The size of the island is approximately 300 A.
The roughness was 20 people in terms of rms value. In order to evaluate the reflection characteristics, we analyzed the synchrotron radiation light124
When human soft X-rays were incident at an incident angle of 10° from the surface normal, the fouling rate was measured and a value of 8.8% was obtained. This value was significantly lower than the design value of 65%, and this low value was due to surface roughness.

Example 4 A silicon substrate prepared in the same manner as in Example 1 was set on the heater surface of the substrate holder of the ultra-high vacuum electron beam evaporation apparatus shown in Fig. 3, and heated to 1200°C (2 hours) prior to evaporation. . Thereafter, the substrate was left to cool to room temperature, and then the substrate was soaked in a copper claw protruding from the liquid nitrogen shroud for 5 hours. When the substrate temperature was measured with a thermocouple thermometer, it was -1800C.

In the apparatus shown in FIG. 3, two electron beam evaporation sources are arranged symmetrically with respect to the substrate, and 99.99% molybdenum (hereinafter referred to as M o ) is placed in each electron gun hearth.
and 99,999% silicon (hereinafter referred to as Si) were set in advance. After waiting until the degree of vacuum reached 3×10 −10 torr, deposition was started.

Both Mo and Si were preheated with an electron beam in advance (with the shutters on each hearth and the main shutter closed ()), and after preheating for 30 minutes to 1 hour, the evaporation rate of each was 1 person/m i n, 3 A/
A crystal oscillator type film thickness meter (not shown in the figure) installed near each hearth provided feedback so that the above-mentioned deposition rate was maintained. then 8
Vapor deposition was performed while maintaining a vacuum level of X10-10 torr. As shown in FIG. 1, the first substance is M o and the second substance is Mo.
Using Si as the material, a total of 41 layers were formed by 27 and 36 people, respectively. A reflecting mirror C was obtained by using MO as the second layer and the outermost layer of the substrate. When soft X-rays of 124 wavelengths were incident on the fabricated multilayer reflector at an angle of 10° from the surface normal, a reflectance of 552% was obtained. This reflectance is compared to the reflectance (7.8%) of soft X-rays of 124 wavelengths for a multilayer film reflecting mirror obtained by depositing the same film thickness as in the above example without cooling the substrate. The reflectance was approximately 7 times higher.

When we observed the cross sections of these reflecting mirrors C and D using a transmission electron microscope, we found that in reflecting mirror C, there was a Mo layer, an S
Both i-layers are amorphous, and when the roughness of the interface was measured from a transmission electron microscope image of a photographic film, r m s
There were 4.8 people in 4 shifts. (The negative film is measured in the direction perpendicular to the layer surface using a microdensitomate, and the concentration is smoothed as a function from the substrate surface. The point with the concentration between the highest and lowest concentration points is defined as the interface. The roughness of the surface was determined based on how much the interface varied in the direction perpendicular to the layer plane.Also, in the reflector, the Si layer was amorphous, but the Mo layer was crystallized, and the surface was parallel to the layer plane. In the direction perpendicular to the layer surface, the film thickness is approximately 2
A grain boundary with a size of about 5 people) was formed. It was observed that the grain boundaries had an island-like structure, and the roughness at the interface propagated from the lower layer to the upper layer to form a columnar structure, with the roughness expanding in the upper layer. The roughness of the interface between the top layer and the layer below had an rms value of 16.7. Reflector C, D
The crystallinity of was also confirmed by selected area electron diffraction.

From the above, the reason for the large difference in reflectance is that in sample C, by lowering the substrate temperature, it was possible to suppress the crystallization of the Mo layer and the generation of island-like structures, making it possible to suppress the roughness of the interface. .

Example 5 100 processed to surface accuracy λ/20 (λ=6328 A)
A silicon substrate (2″φ, 10 m) coated with μm-thick silicon carbide (hereinafter referred to as 5iC)
m t ) was polished with diamond paste, and then floating polishing was performed. When the surface roughness was measured using a heterodyne interference type surface roughness meter, the r m s value was 2.
3 people, which was smaller than 1/16 of the wavelength used by 124 people. A sample for transmission electron microscopy with a thickness of about 500 people was prepared, and a photograph of the image was taken using a transmission electron microscope to measure the surface roughness, and almost no surface roughness was observed.

Set this on the heater surface of the substrate holder of the device shown in Figure 4, and set the vacuum to
And so.

Prior to vapor deposition, it was heated to 1400°C (2 hours). After that, I left it to cool down to room temperature, then I left the board in contact with the copper claws coming out of the liquid nitrogen shroud for 3 hours, and when I measured the board temperature with a thermocouple thermometer, it was -50°C. .

In the apparatus shown in Fig. 4, two electron beam evaporation sources are arranged at symmetrical positions with respect to the substrate, and 99.9% ruthenium (hereinafter referred to as Ru) and 99.9% ruthenium are placed in each electron gun hearth.
．． 999% silicon (hereinafter referred to as Si) was set.

After waiting until the vacuum level was restored to 3 x 10-'' torr, deposition was started.

Both Ru and Si were preheated with an electron beam in advance (the shutters on each hearth and the main shutter were closed), and after preheating for 30 minutes to 1 hour, the evaporation rate for each was reduced to 3 people/min and 5 people/min. A field hack was conducted to ensure that the above deposition rate could be maintained using a crystal oscillator (not shown in the figure) installed near each hearth. After this, the shutters of each hearth were opened alternately, and the J material in FIG.

The number of people was 36.2, and a total of 41 layers were formed. The degree of vacuum during film formation was maintained at 8X] and 0-10 torr.

When soft X-rays of 124 wavelengths were incident on the multilayer mirror thus obtained at an angle of 10° from an axis perpendicular to the surface, a reflectance of 612% was obtained.

This value is compared to the soft X-ray reflectance (11.9%) when a commercially available silicon wafer is used as a substrate and the same film thickness as in Example 1 is deposited (without cooling the substrate in any way). The reflectance was about 5 times higher than that of the previous one.This result was due to the fact that the surface roughness of the substrate was small, and at the same time, the substrate was cooled during the deposition, so the deposited atoms moved around within the deposition surface, resulting in an island-like structure. This is because the mechanism of generation is suppressed, and the interface becomes an amorphous film and roughness is suppressed.

When the surface of the multilayer reflector manufactured by the method of the present invention was measured using a heterodyne interference surface roughness meter, the rms value was 2.
．． There were 6 people, which was sufficiently smaller than 1/16 of the wavelength used. We made a sample for transmission electron microscopy with a thickness of about 500 people, took a photograph of the image using a transmission electron microscope, and measured the surface roughness.The roughness of the interface was larger as it went to the second layer, but between the top layer and the layer below it. The rms value was 9.8 at the interface. Furthermore, the surface roughness was 9.8 in r m s value, both of which were smaller than 1/8 of the wavelength used.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of a multilayer reflector for X-rays and vacuum ultraviolet rays according to the present invention, and FIG. 2 is a diagram showing a decrease in reflectance due to interface roughness in the multilayer reflector. FIG. 3 is a diagram showing an ultra-high vacuum electron beam evaporation apparatus that can be used to implement the present invention. l is the substrate, 2.4 is the first material, 3.5 is the second material, 6, 7.8.9. 10 are respectively m=]-, 2, 3,
4,. 11 is the liquid nitrogen cloud, 12 is the substrate holder, 13 is the substrate, 14 is the substrate cooling claw, 15 is the main shutter, 16 is the shutter, 17.19 is the ratio of reflectance to the roughness of the interface in case 5. Each has an electron gun hearth, and 17 has an Mo
, Si is set at 19. 20 is a crystal resonator type film thickness meter. Procedural formalities (formula) September 29, 1988 1. Case description 1988 Patent Application No. 134585 2. Name of the invention Method for manufacturing a multilayer reflector for X-rays and vacuum ultraviolet rays 3. Make amendments. Patent applicant address: 3-30-26 Shimomaruko, Ota-ku, Tokyo, specification and drawing 7 to be amended, content of amendment (1) Engraving and attachment of the specification and drawings originally attached to the application As per (no change in content)

Claims (2)

[Claims] (1) In a method for manufacturing a multilayer film reflector for X-rays and vacuum ultraviolet light, which has a multilayer reflector on a substrate, which is made up of alternating layers of substances with different refractive indexes, the formation of the multilayer film is performed using ion beams.
A method for manufacturing a multilayer film reflecting mirror for X-rays and vacuum ultraviolet rays, characterized in that the method is carried out using a beam sputtering method, and the film formation rate is in the range of 0.1 Å/S to 5 Å/S. (2) In a method for manufacturing a multilayer reflector for X-rays and vacuum ultraviolet light, which has a multilayer structure reflector made of alternating layers of materials with different refractive indexes on a substrate, the multilayer film is formed using an electron beam evaporation method. was carried out, and the substrate temperature during film formation was -2
A method for producing a multilayer reflector for X-rays and vacuum ultraviolet rays, characterized in that the temperature is maintained in the range of 00°C to -50°C.