JP2003222572A - Phase measuring system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a phase measuring system capable of measuring with ease and high precision the phase characteristics of a film provided on a curved or plane mirror. <P>SOLUTION: The phase measuring system has a light source, a branch grating for branching the flux from the light source into a plurality of fluxes and for guiding them to a plurality of positions on a subject with a film applied to its surface, a combination grating for combining two reflections from two neighboring points on the subject, and a detecting means for detecting interference data involving the combined fluxes. Based on the interference data collected by the detecting means, phase data which are dependent on the position of the film on the subject are determined. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical thin film phase measuring apparatus, for example, a semiconductor device such as an IC or LSI,
Optics attached to the reflective or transmissive surface of an optical system used in an exposure apparatus such as a step-and-repeat method or a step-and-scan method for manufacturing a device such as a photographing device such as a CCD or a display device such as a liquid crystal panel. It is suitable for measuring the phase of a thin film.

[0002]

2. Description of the Related Art With the miniaturization of device patterns, the exposure wavelength when projecting and exposing a device pattern on a photosensitive material is becoming shorter and shorter. For example, as the exposure wavelength, from KrF (wavelength 248 nm) to ArF (wavelength 193)
nm), F2 laser (wavelength 157 nm), and EUV
The light having a wavelength of 13.4 nm has come to be used.

The miniaturization of device patterns is the largest factor supporting the dynamics of the semiconductor industry.
Line widths of 180nm, 130nm, 1
The generation is rapidly changing to 00 nm. In lithography using i-line (wavelength 365 nm) as the exposure light, resolution with a line width less than the wavelength has not been used.

On the other hand, KrF is applied to lithography for a line width of 180 nm or even 150 nm even though the wavelength is 248 nm. Resolving line widths below the wavelength is being put to practical use by making full use of the results of resist improvement and super-resolution technology. By making full use of various super-resolution techniques, pattern resolution with 1/2 wavelength line width in lines and spaces has come into practical use.

However, the super-resolution technique is often accompanied by restrictions in the production of patterns, and the royal road for improving resolution is to shorten the wavelength of exposure light and improve the NA of the projection optical system. . The above fact has been a great motivation for shortening the wavelength of the exposure light.
This is the reason for developing EUV lithography that uses 5 nm light as exposure light.

[0006]

When EUV light is used as the exposure light, since there is no transparent substance in the EUV wavelength range, there are great restrictions on the materials that can be used in optical systems targeting the EUV range. In particular, in the EUV region where a transmission type optical element can no longer be used and a reflection system is formed, the reflectance of the mirror surface is low because the optical constant of the optical material is close to 1. A major issue is the characteristics of a reflection enhancing film attached to a reflecting mirror (mirror) to obtain a predetermined reflectance. The material of the film is also largely restricted, and it is substantially Mo.
A film (multi-layer film) made of alternating layers of Si and Si forms the basic structure. In addition to this, for example, Be-Si, Rh-
There are Si multilayer films and the like. Considering one pair of alternating layers of Mo and Si, the film is required to have a multilayer of about 40 pairs, and the change of the optical characteristics becomes extremely severe.

A characteristic of the film for the EUV region is that the management of the phase (phase distribution) of the film as well as the reflectance is required. When the EUV light is reflected by the film, its phase changes. The phase distribution of the film distorts the wavefront incident on the mirror surface, and if the cycle length of the film deviates within the mirror surface, it causes aberration (wavefront aberration). Therefore, it is desirable to measure the phase (phase distribution) of the film when the film is attached to the mirror surface. In particular, it is desirable to measure the phase at each position where the film is applied and the angular characteristics when the film is incident on the film at various angles.

In particular, in order to correct the aberration of the reflective imaging system, in addition to manufacturing the substrate shape such as the curvature of the mirror substrate and the amount of aspherical surface with high accuracy, the performance of the multilayer film for reflection enhancement is also accurate. Need to be well managed. At this time, the multilayer film needs to be accurately controlled so that the phase given to the light at the time of reflection does not greatly differ depending on the reflection position within one mirror surface.

In addition to this, before assembling the reflection imaging system, the shape of the mirror is finished, and it is inspected whether the reflection phase at each position where the multilayer film is laminated on the mirror surface is manufactured as the designed value. There is a need.

According to the present invention, it is possible to easily and highly accurately measure the phase characteristic at each position of the film formed on the reflecting mirror or the plane reflecting mirror having a curvature or / and the phase characteristic of the film depending on the incident angle. It is an object of the present invention to provide a phase measuring device capable of performing the above.

[0011]

According to a first aspect of the present invention, there is provided a phase measuring apparatus comprising: a light source means; and a light beam from the light source means. A branch grating that guides light to a plurality of positions, a coupling grating that couples two reflected lights reflected at two neighboring points among the plurality of positions on the object to be measured, and a coupling grating that couples the two components. Detecting means for detecting interference information based on two lights, and measuring the phase information depending on the position of the film applied on the object to be inspected, from the interference information obtained by the detecting means. There is.

According to a second aspect of the present invention, there is provided a phase measuring device comprising a light source means and an object to be inspected having a film formed on a surface thereof so as to collect a light beam from the light source means and have a width at an incident angle. The reflecting means for making the light incident on the upper side and the detecting means for detecting the wavefront of the light reflected by the object to be inspected are provided, and the wavefront information obtained by the detecting means is used to detect the film applied to the object to be inspected. The feature is that the phase information depending on the incident angle is measured.

According to a third aspect of the present invention, there is provided a phase measuring apparatus comprising a light source means and an object to be inspected having a film formed on the surface thereof so as to collect a light beam from the light source means and have a width at an incident angle. Reflecting means incident on the upper side, branching grating for branching the light reflected by the object to be examined into a plurality of light fluxes, and detecting means for detecting interference information based on two lights of the plurality of light fluxes branched by the branching gratings. And the phase information depending on the angle of incidence on the film formed on the object to be measured is measured from the interference information obtained by the detection means.

The invention of claim 4 is characterized in that, in the invention of claim 2 or 3, the light beam incident on the object to be inspected is incident on one point on the object to be inspected.

According to a fifth aspect of the present invention, there is provided a phase measuring apparatus, wherein light source means and light flux from the light source means are branched into a plurality of light fluxes, and the light fluxes are guided to a plurality of positions on an object to be inspected having a film on its surface. Branching grating Ga, a coupling grating that couples two reflected lights reflected at two neighboring points among the plurality of positions on the object to be inspected, and interference based on the two lights coupled by the coupling grating. Detecting means for detecting information, and from the interference information obtained by the detecting means,
While measuring the phase information depending on the position of the film applied on the object to be inspected, the branch grating Ga and the coupling grating are retracted from the optical path, and the light flux from the light source means is condensed instead of them. A reflection means for making the light incident on an object to be inspected having a film on the surface so as to have a width at an incident angle, and a branch grating Gb for branching the light reflected by the object to be inspected into a plurality of light beams. A film provided on the object to be inspected, the interference information based on two lights among a plurality of light beams branched by the branch grating Gb being detected by the detection means, and based on the interference information obtained by the detection means. It is characterized by measuring the phase information depending on the incident angle to the.

The invention of claim 6 is characterized in that, in the invention of any one of claims 1 to 5, it further comprises polarization selecting means, and measures the phase information in the selected polarization.

An exposure apparatus according to a seventh aspect of the invention is characterized in that it has an optical member measured by the phase measuring apparatus according to any one of the first to sixth aspects.

According to the eighth aspect of the phase measuring method of the present invention, a light beam is substantially incident on one point and the light beam from the one point is subjected to shearing interference with respect to an object to be inspected having a film on its surface. According to the above, the phase information depending on the position and / or angle of the film is roughly differentiated with respect to the position and / or the angle to measure the phase information depending on the incident angle to the film.

An exposure apparatus according to a ninth aspect of the present invention is characterized in that it has an optical member for which phase measurement is performed by the phase measurement method according to the eighth aspect.

A device manufacturing method according to a tenth aspect of the present invention comprises the steps of exposing the exposed object by the exposure apparatus according to the ninth aspect, and developing the exposed object. I am trying.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION In the measurement of the reflection phase distribution of a film (multilayer film) of the present invention, the reflection phase distribution of the film is specified by the location of the surface on which the film is applied, and the difference in the incident angle to the film is used. The reflection phase (incident angle dependence of the film) is measured.

FIG. 1 and FIG. 2 are schematic views of the essential parts of the first embodiment of the phase measuring apparatus of the present invention, based on the case of measuring the phase information of the film on the mirror surface in the EUV wavelength range. There is. FIG. 1 is a schematic view of a main part showing a measurement of a reflection phase distribution of a film according to a position on a mirror surface on which the film is applied. FIG. 2 is a schematic diagram of a main part showing a measurement of a reflection phase of a film depending on an incident angle of light on a mirror surface provided with the film.

In this embodiment, the measurement is carried out in two steps by the apparatus shown in FIGS. First, the measurement system of FIG. 1 will be described. The light L1 emitted from the light source 1 is reflected by a reflecting mirror 2 such as an ellipsoidal surface or a dihedral surface, and is made a wavefront from a point light source through a pinhole 3a provided in the member 3 to adjust the wavefront. Light source 1
For this, a laser plasma light source or synchrotron radiation (SR) is used. The light L2 from the pinhole 3a is passed through the diaphragm 4 to form a beam L3 having a diameter of about 1 mm. This beam L3 is split into two lights La and Lb by a demultiplexing grating G1 through a mirror M1 and is irradiated at two points 5a and 5b, which are slightly displaced on the object 6 to be inspected, applied to the multilayer film 5 at an angle. . Here, the incident angles of the lights La and Lb on the film 5 are slightly different, but here they are regarded as substantially the same angle θ for simplicity.

Further, since the difference between the incident positions 5a and 5b is slight, they are regarded as substantially the same position. Irradiated 2 points 5a, 5
The reflected light La and Lb from b are superposed by the coupling grating G2 and interfered with each other to detect the light by means of a detection means 7 such as CCD.
Is getting an interference signal at. When the wavelength of the light from the light source means 1 is outside the wavelength range that can be detected by the detecting means, for example, the light may be incident on the fluorescent plate and the interference information formed on the fluorescent plate may be detected by the detecting means.

The calculation means 8 uses the interference signal from the detection means 7 to measure the reflection phase distribution on the surface of the multilayer film 5 at the incident angle θ of light by changing the relative positions of the object 6 and the measurement system. is doing. The reflection phase distribution by position is x,
When the incident angle is represented by θ, the phase difference of the film at the position x is obtained by calculating the phase difference of φ (x + Δx, θ) −φ (x, θ) as the intensity of the interference signal.
Δx, that is, the beam shift amount is made extremely small (the wavefront is shifted by differentiation),

[0026]

[Equation 1]

To obtain

The beams La and Lb scan the entire surface of the multilayer film 5 by the relative movement of the object 6 to be measured and the measurement system, and integrate at the position x of the film 5 surface to obtain the film at the first incident angle θ. The reflection position distribution φ (x, θ) according to the position of the phase of 5 is calculated. The beam is made incident on the surface of the film 5 with a divergence, and data is collected as a two-dimensional signal, whereby the connection of the phase data by integration is improved, and a highly accurate measurement result can be obtained. Alternatively, the data may be acquired by scanning with a narrow beam and using a detecting means having a small light-receiving surface to perform high-speed scanning.

In this embodiment, by using the demultiplexing grating G1 and the coupling grating G2, the reflection phase information at each position of the film is measured without using the optical surface forming the reference wavefront.

Further, in FIG. 1, the light incident on the multilayer mirror has a spread of a range in which position differentiation is possible,
The light is incident on the multilayer mirror in a state where the light is condensed at almost one point. In other words, the light is focused on almost one point having a size of the range in which the position differentiation can be performed.

Next, the measurement of the incident angle distribution of the reflection phase by the film of FIG. 2 will be described. The light L1 from the light source 1 is reflected by the reflecting mirror 2 and becomes a point light source through the pinhole 3a provided in the member 3 to adjust the wavefront. The beam L4 diverged from the pinhole 3a is passed through the reflecting mirror 9 having an elliptical surface, a parabolic surface, a rotationally asymmetrical aspherical surface or the like on the film (test surface) 5 from the _first incident angle θ ₁ to the second incident angle θ ₁ . The light beam L5 having a width (range) up to the incident angle θ ₂ is irradiated so as to be focused on the measurement point 5c on the surface of the film 5. The light L6 reflected at the measurement point 5c on the film 5 is sheared by the light beam L6 reflected by the demultiplexing grating G1 to separate the light beams into two light beams, which interfere with each other, and the interference information is detected by the detection means 7 such as a CCD. .

Then, the calculating means 8 uses the signal from the detecting means 7 to make incident angles θ _{1 to} θ ₂ of the reflection phase at the measuring point 5c.
The incident angle distribution at is obtained. In the incident angle distribution, the phase difference of φ (x, θ ₁ + Δθ) −φ (x, θ ₁ ) is obtained as the intensity of the interference signal.

Δθ is determined by the shift angle of the beam L6, and the above equation shows the value at the first incident angle. However, since the incident angle θ ₁ has a width, the first incident angle θ ₁ Second
This value is obtained in the range up to the incident angle θ ₂ . Δ is very small,

[0034]

[Equation 2]

Is measured at the first position x ₁ .

The beam L5 scans the entire surface of the multilayer film by the relative movement of the object 6 to be measured and the measuring system, and obtains the incident angle characteristic on the entire surface. Further, by differentiating this integrated value, the incident angle distribution φ (x ₁ , θ) at the position x ₁ is obtained.

As described above, in this embodiment, a constant NA
A light having a width (range) at an incident angle is made incident on the surface of the film 5 by the condensing optical system (reflecting mirror) 9 having the light, and the reflected light from the surface of the film 5 is sheared by the grating G1 to cause interference. Then, the phase information based on the incident angle of the film 5 is obtained from the interference information.

In this embodiment, the relative phase of the reflected light at a certain incident angle θ is obtained as a function of the position of the mirror (film) by the data of the first measurement obtained by the system shown in FIG. By the data of the second measurement obtained by the system shown in (1), the relative phase of reflection at each position is obtained as a function of the incident angle θ, and all the data are connected by two relative phase measurements. For example, if necessary, the phase data of the position at the _third incident angle θ ₃ between the first and second incident angles θ ₁ and θ ₂ is calculated.

Depending on the type of the mirror provided with the film, the incident angle distribution of light that contributes to actual image formation depends on the position in the mirror, and therefore it is not necessary to measure the incident angle θ ₁ on all surfaces. In some cases.

In the measuring apparatus of this embodiment, the incident angle of light on the surface of the film 5 is variable, and in the first measurement shown in FIG. 1, the measurement is performed while changing the incident angle depending on the place. The relative phase difference at the reference incident angle in the vicinity of each position is obtained, while the incident angle θ ₁ and the incident angle θ ₂ are changed in the second measurement shown in FIG. At the position, the reference incident angle at which the first measurement is performed is measured with the relationship such that the reference incident angle is between the incident angle θ ₁ and the incident angle θ ₂ .
Thus, the connection of the relative phase of the position through the reference incident angle and the connection of the relative phase of the incident angle range including the reference incident angle in the second measurement are performed.

In the configuration of FIG. 2, the diaphragm 4 and the mirror M1 in the configuration of FIG. 1 are replaced by the condensing optical system 9 in place of the branch grating G1, and the branch grating is replaced in place of the coupling grating G2. Used as
These respective members may be exchangeable according to the purpose and used in one device.

The demultiplexing grating G1 and the coupling grating G2 may be transmission type or reflection type. Further, a member other than the grating may be used as long as it is a member for dividing or combining the beams.

For example, the two gratings G1 shown in FIG.
G2 is a desirable form for the plane mirror M1 because a grating having the same lattice constant is used to make the incident angles of the wavefronts on the CCD 7 uniform. When the wavefront of FIG. 2 also has a large angle of interference wavefront, it is possible to use two gratings in an overlapping manner so as to match the angles.

In the above embodiment, the film surface may be scanned with a slightly defocused light beam without condensing the light on the surface of the film 5, whereby both the position and the incident angle are combined. To obtain phase data sheared by. That is, φ (x + Δx, θ + Δθ) −φ (x, θ ₁ ). By making the amount of deviation of the luminous flux very small,

[0045]

[Equation 3]

Is obtained. The position and angle phase distribution data may be obtained by integrating the position and angle from this measurement data.

Further, in each of the embodiments, a reflection phase distribution for a desired polarized light can be measured by inserting a polarizing element in the incident optical system. The specific insertion position is, for example, before or after the demultiplexing grating G1 in FIG. 1, or after the condenser mirror 9 in FIG. Alternatively, the same effect can be obtained by inserting the polarizing element immediately after reflection.
In this case, the polarizing element is inserted, for example, before or after the coupling grating G2 in FIG. 1 or before or after the demultiplexing grating G1 in FIG.

As the polarizing element, for example, W. Hu, M. Ya
mamoto, M. Watanabe, "Development of EUV free-stan
ding multilayer polarizers, "Proc. SPIE Vol. 2873,
There are a transmission type introduced on p.74-77 and a reflection type that generally uses a multilayer mirror designed and manufactured as a high reflection film for vertical incidence at an incident angle of 45 degrees.

In each of the above embodiments, the measurement of the phase distribution of the film ML is not limited to EUV light, and the same measurement can be performed with visible light.

FIG. 3 shows an EUV wavelength range (10 to 1) using a reflecting mirror (mirror) to be measured by the phase measuring apparatus of the present invention.
E for device manufacturing using light of 5 nm) as exposure light
It is a principal part schematic diagram of a UV exposure apparatus.

The EUV exposure apparatus shown in FIG. 3 has an EUV light source, an illumination optical system, a reflection type reticle, a projection optical system, a reticle stage, a wafer stage, an alignment optical system and a vacuum system.

A laser plasma light source is used as the EUV light source of this embodiment. This is to irradiate the target material TA supplied into the vacuum container 701 with high-intensity pulsed laser light to generate high-temperature plasma 705, and use EUV light with a wavelength of, for example, about 13 nm emitted from this. . A metal thin film, an inert gas, droplets, or the like is used as the target material, and a vacuum container 701 is provided by a target supply device 702 equipped with a means such as a gas jet.
Supplied within. Further, the pulsed laser light is output from the excitation pulsed laser 703 and is irradiated on the target material TA via the condenser lens 704. In order to increase the average intensity of the emitted EUV light, the pulse laser preferably has a high repetition frequency, and the excitation pulse laser 703 is normally operated at a repetition frequency of several kHz.

It is also possible to use a discharge plasma light source as the EUV light source. The discharge plasma light source emits a gas around an electrode placed in a vacuum container, applies a pulse voltage to the electrode to generate a high-temperature plasma, and emits a high-temperature plasma, for example, an EU having a wavelength of about 13 nm.
It utilizes V light. In order to increase the average intensity of the emitted EUV light, the higher the discharge repetition frequency is, the better, and the operation is usually performed at a repetition frequency of several kHz.

The illumination optical system has a plurality of multilayer films or oblique incidence mirrors and an optical integrator.
The illumination optical system of the present embodiment includes an illumination system first mirror 706,
It has an optical power integrator 707, an illumination system second mirror 708, and an illumination system third mirror 709, and these members guide the EUV light emitted from the plasma 705 to a reticle (mask) 711.

The first-stage focusing mirror (first illumination system mirror) 706 of the illumination optical system plays a role of collecting the EUV light emitted isotropically from the laser plasma 705. The optical integrator 707 has a role of uniformly illuminating the reticle 711 with a predetermined numerical aperture. An aperture 710 having an arc opening is provided at a position conjugate with the reticle 711 of the illumination optical system to limit the area illuminated by the reticle surface to an arc shape.

The reticle 711 is irradiated with the arc-shaped light flux that has passed through the aperture 710, and the reflected light is irradiated onto the wafer 731 through the projection optical system including the reflecting mirrors 721 to 724. Since a mirror provided with a multilayer film (multilayer film mirror) used in the EUV region has a larger light loss than a visible light mirror, it is necessary to minimize the number of mirrors. 725 is a diaphragm for limiting the aperture.

In the present embodiment, in order to realize a projection optical system having a wide exposure area with a small number of mirrors, only a thin arc-shaped area (ring field) separated from the optical axis by a certain distance is used. Utilizes an optical system. Then, a method (scan exposure) in which the reticle 711 and the wafer 731 are simultaneously scanned synchronously and transferred in a wide exposure area is used. The arc-shaped illumination area on the reticle 711 surface is an optical integrator 70 in the illumination optical system.
7 and front and rear mirrors 708 and 709.

A plurality of mirrors are also used in the projection optical system. In FIG. 3, the projection system first to fourth mirrors (721 to 72
4), the reflected light from the reticle 711 is guided onto the wafer 731 mounted on the wafer chuck 733. The smaller the number of mirrors, the higher the EUV light utilization efficiency, but it becomes difficult to correct aberrations. In order to perform good aberration correction, the number of mirrors is set to about 4 to 6. The shape of the reflecting surface of the mirror is a convex or concave spherical surface, an aspherical surface, or a rotationally asymmetrical aspherical surface. The numerical aperture NA of the projection optical system is about 0.1 to 0.3.

Each mirror is formed by grinding and polishing a substrate made of a material having a high rigidity and a high hardness and a small coefficient of thermal expansion such as low expansion coefficient glass or silicon carbide to create a predetermined reflection surface shape, and then reflect it. A multi-layered film of molybdenum / silicon or the like is formed on the surface. When the incident angle is not constant depending on the position on the mirror surface, the wavelength of the EUV light having a high reflectance varies depending on the position in a multilayer film having a constant film period, as is clear from the Bragg equation. Therefore, a film period distribution is provided so that EUV light having the same wavelength is efficiently reflected on the mirror surface.

The reticle stage 712 and the wafer stage 732 have a mechanism for synchronously scanning at a speed ratio proportional to the reduction magnification of the projection optical system. Here, as the coordinate system, the scanning direction is the X axis in the plane of the reticle 711 or the wafer 732.
The direction perpendicular to it is the Y axis, and the direction perpendicular to the reticle or wafer surface is the Z axis.

The reticle 711 is a reticle stage 71.
2 is held by the reticle chuck 713 above. The reticle stage 712 has a mechanism that moves at high speed in the X direction. In addition, the reticle 711 can be positioned by having a fine movement mechanism in the X direction, the Y direction, the Z direction, and the rotation directions around the respective axes. The position and orientation of the reticle stage 712 are measured by a known method by a laser interferometer (not shown), and the position and orientation are controlled based on the result.

The wafer 731 is held on the wafer stage 732 by the wafer chuck 733. The wafer stage 732 has a mechanism that moves at high speed in the X direction similarly to the reticle stage 712. Further, a fine movement mechanism is provided in the X direction, the Y direction, the Z direction, and the rotation directions around the respective axes so that the wafer can be positioned. The position and orientation of the wafer stage 732 are measured by a known method by a laser interferometer (not shown), and the position and orientation are controlled based on the result.

In order to detect the relative positional relationship between the reticle 711 and the wafer 731, an alignment detection mechanism 714,
734 measures the positional relationship between the position of the reticle 711 and the optical axis of the projection optical system, and the positional relationship between the position of the wafer 731 and the optical axis of the projection optical system, and the projected image of the reticle 711 is measured at a predetermined position on the wafer 731. The positions and angles of the reticle stage 712 and the wafer stage 732 are set so as to coincide with.

Further, the focus position detecting mechanism 735 for detecting the best image forming position of the projection optical system is used to move the Z position on the wafer surface.
Direction focus position is measured and the wafer stage 73
By controlling the position and angle of 2, the wafer surface is always kept at the best imaging position by the projection optical system during exposure.

When one scan exposure is completed on the wafer 731, the wafer stage 732 moves stepwise in the X and Y directions and moves to the next scan exposure start position, and the reticle stage 712 and the wafer stage 732 again project the projection light. Synchronous scanning in the X direction at a speed ratio proportional to the reduction ratio of the system,
The pattern of the reticle 711 is exposed on the wafer 731.

In this way, the operation of synchronously scanning the reduced projection image of the reticle 711 while it is formed on the wafer 731 is repeated (step and
(Scan), the transfer pattern of the reticle is transferred onto the entire surface of the wafer.

As described above, according to each embodiment, the phase of the optical thin film formed on the surface of the optical element can be accurately measured with a simple structure. Further, since the configuration of each embodiment does not depend on the wavelength, it can be applied even to a system in which the types of optical elements to be used extremely are limited, such as EUV.

The optical element measured by using the phase measuring apparatus described above may be incorporated in the exposure apparatus or may be incorporated in other optical equipment. Further, the device may be manufactured through the step of exposing the exposed object (wafer or the like) by the phase measuring method or the exposure apparatus using the phase measuring apparatus described above, and the step of developing the exposed object. You can The manufacturing method of this device includes various known steps in addition to the above steps.

[0069]

According to the present invention, the phase characteristic at each position of the film formed on the reflecting mirror or the plane reflecting mirror having a curvature or / and the phase characteristic of the film depending on the incident angle can be easily and highly accurately obtained. A phase measuring device that can measure can be achieved.

[Brief description of drawings]

FIG. 1 is a schematic view of a main part of phase measurement according to a position according to a first embodiment of the present invention.

FIG. 2 is a schematic view of a main part of phase measurement according to an incident angle according to the first embodiment of the present invention.

FIG. 3 is a schematic view of a main part of an exposure apparatus of the present invention.

[Explanation of symbols]

1 light source means 2 reflector 3 members 4 aperture 5 membranes 5c Object plane 6 Object to be inspected 7 Detection means 8 computing means 9 Focusing optical system G1 branch grating G2 coupled grating

Claims (10)

[Claims] 1. A light source unit, a branching grating for branching a light beam from the light source unit into a plurality of light beams, and guiding the light beam to a plurality of positions on an object to be inspected having a film on a surface thereof, and the object to be inspected. A coupling grating that couples two reflected lights reflected at two neighboring points among the plurality of positions above, and a detection unit that detects interference information based on the two lights coupled by the coupling grating. Then, the phase measuring device is characterized in that the phase information depending on the position of the film formed on the object to be measured is measured from the interference information obtained by the detecting means. 2. A light source means, and a reflection means for collecting a light beam from the light source means and making it have a width at an incident angle to be incident on an object to be inspected having a film on the surface thereof. Detecting means for detecting the wavefront of the light reflected by the object to be inspected,
And a phase measuring device which measures the phase information depending on the incident angle to the film formed on the object to be measured, from the wavefront information obtained by the detecting means. 3. A light source means, and a reflection means for condensing a light beam from the light source means and making it have a width at an incident angle to be incident on an object to be inspected having a film on the surface thereof. The detection means includes: a branching grating for branching the light reflected by the object to be examined into a plurality of light fluxes, and a detection means for detecting interference information based on two lights of the plurality of light fluxes branched by the branching grating. A phase measuring device, which measures the phase information depending on the incident angle to the film formed on the object to be inspected, from the interference information obtained in (1). 4. The phase measuring device according to claim 2, wherein the light beam incident on the object to be inspected is incident on one point on the object to be inspected. 5. A light source means, a branch grating Ga for branching a light flux from the light source means into a plurality of light fluxes, and guiding the light flux to a plurality of positions on an object to be inspected having a film on a surface thereof, and the branch grating Ga. Of the plurality of positions on the object, a combined grating that combines two reflected lights reflected at two neighboring points, and a detection unit that detects interference information based on the two lights combined by the combined grating are provided. And measuring the phase information depending on the position of the film applied on the object to be measured from the interference information obtained by the detecting means, and retracting the branch grating Ga and the coupling grating from the optical path, Instead of, the light flux from the light source means is condensed, and is made to have a width at an incident angle, and is incident on an object to be inspected having a film on the surface thereof, and is reflected by the object to be inspected. Multiple light A branching grating Gb for branching into a light beam is provided in the optical path, interference information based on two lights of a plurality of light beams branched by the branching grating Gb is detected by the detecting means, and the interference information obtained by the detecting means is A phase measuring apparatus, which measures phase information depending on an incident angle to a film formed on the object to be inspected. 6. The phase measuring device according to claim 1, further comprising polarization selecting means for measuring phase information of the selected polarized light. 7. An exposure apparatus comprising an optical member measured by the phase measuring apparatus according to any one of claims 1 to 6. 8. An object to be inspected having a film on its surface,
By substantially differentiating the position and / or angle-dependent phase information of the film with respect to the position and / or the angle by injecting the light beam into substantially one point and causing shearing interference of the light beam from the one point to the film. A phase measuring method characterized by measuring phase information depending on an incident angle of. 9. An exposure apparatus comprising an optical member having a phase measured by the phase measuring method according to claim 8. 10. A method for manufacturing a device, comprising the steps of exposing the exposed object by the exposure apparatus according to claim 9, and developing the exposed object.