HK1122611B - Plane position detecting apparatus, exposure apparatus and device manufacturing method - Google Patents

Description

Surface position detection device, exposure device, and device manufacturing method

Technical Field

The invention relates to a surface position detection device, an exposure device and a device manufacturing method. The present invention relates to a method for detecting a surface position of a photosensitive substrate in a projection exposure apparatus for transferring a photomask pattern onto the photosensitive substrate in a lithography step for manufacturing devices such as a semiconductor device, a liquid crystal display device, an image pickup device, and a thin film magnetic head.

Background

As a surface position detection device suitable for a projection exposure apparatus, there has been known an oblique incidence type surface position detection device disclosed in japanese patent laid-open No. 2001-296105 (patent document 1) proposed by the present applicant. In the oblique incidence profile position detection device, in order to theoretically improve the detection accuracy of the surface position of the test surface, it is necessary to increase the incidence angle of the light beam to the test surface (to approximately 90 °). In this case, in order to avoid the restriction of the surface to be inspected, it is proposed that a parallelogram prism (hereinafter, referred to as a "rhomboid prism") having a pair of inner surface reflection surfaces parallel to each other is disposed in each of the optical path of the projection optical system and the optical path of the condensing optical system, and the projection optical system and the condensing optical system are separated from the surface to be inspected (see fig. 7 of patent document 1).

[ patent document 1]

Japanese patent laid-open No. 2001-296105

However, in the conventional surface position detecting device disclosed in fig. 7 of patent document 1, the light beams totally reflected by the two inner reflection surfaces parallel to each other of the projection-side rhomboid prisms may be shifted in relative positions by the polarization component, and a clear pattern image is not formed on the detection surface. Similarly, a polarized light component may be generated in a light flux totally reflected by two inner reflection surfaces parallel to each other of the light receiving side rhomboid prism after being reflected from the detection surface, thereby causing a relative positional shift, and a secondary pattern image may become unclear.

On the other hand, it is known that when the conventional surface position detection device is applied to the detection of the surface position of the wafer (photosensitive substrate) having the photoresist applied on the surface in the exposure device, the reflectance with respect to the light of the specific polarization component changes depending on the thickness of the photoresist layer. As a result, in the conventional surface position detecting device, a relative positional shift due to a polarization component is generated in the light flux totally reflected by the inner surface reflection surface of the rhombic prism, and a change in reflectance is generated due to the thickness of the photoresist layer of the photosensitive substrate, so that a detection error of the surface position of the detection target surface is likely to occur.

Disclosure of Invention

The present invention has been made in view of the above problems, and an object of the present invention is to provide a surface position detection device capable of detecting the surface position of a test surface with high accuracy while suppressing the influence of relative positional deviation caused by polarization components, which is generated in a light beam totally reflected by an inner surface reflection surface of a prism member, on the detection of the surface position of the test surface. Another object of the present invention is to provide an exposure apparatus capable of aligning a pattern surface of a photomask and an exposure surface of a photosensitive substrate with respect to a projection optical system with high accuracy, using a surface position detection apparatus capable of detecting a surface position of a test surface with high accuracy.

Another object of the present invention is to provide an optical device and a measuring device that can suppress relative positional deviation of light generated on the total reflection surface of an optical member due to polarization components. Another object of the present invention is to provide an optical device and an adjustment method that can adjust relative positional deviation of light generated on a total reflection surface of an optical member due to polarization components.

In order to solve the above problem, a1 st aspect of the present invention provides a surface position detecting device including: a projection system for projecting the light beam onto the surface to be inspected from an oblique direction; and a light receiving system for receiving the light beam reflected by the detection surface; and the surface position of the detected surface is detected based on the output of the light receiving system,

the face position detection device is characterized in that:

the projection system includes a projection optical system for forming a primary image of a predetermined pattern on the test surface,

the light receiving system has a condensing optical system for condensing the light beam reflected by the test surface to form a secondary image of the predetermined pattern, and

at least one of the projection system and the light receiving system includes a total reflection prism member which is disposed in at least one of an optical path between the projection optical system and the inspection surface and an optical path between the condensing optical system and the inspection surface, has a total reflection surface for totally reflecting the light beam, and

in order to suppress an influence of a relative positional shift of the light beam totally reflected by the total reflection surface due to a polarization component on detection of a surface position of the detection target surface, a refractive index of an optical material forming the total reflection prism member and an incident angle of the light beam with respect to the total reflection surface are set to satisfy a predetermined relationship.

The invention of claim 2 provides an exposure apparatus for projection exposure of a predetermined pattern onto a photosensitive substrate via a projection optical system,

and the exposure apparatus is characterized by comprising:

the surface position detecting device according to claim 1, for detecting a surface position of the predetermined pattern surface or an exposure surface of the photosensitive substrate with respect to the projection optical system as a surface position of the test surface; and

and a position alignment device for aligning the predetermined pattern surface or the exposure surface of the photosensitive substrate with respect to the projection optical system based on the detection result of the surface position detection device.

The 3 rd aspect of the present invention provides a method for manufacturing an element, comprising: an exposure step of exposing the predetermined pattern onto the photosensitive substrate using the exposure apparatus of embodiment 2; and a developing step of developing the photosensitive substrate exposed by the exposure step.

The 4 th aspect of the present invention provides an optical device in which an optical member having a total reflection surface is disposed in an optical path, the optical device characterized in that:

the refractive index of the optical member and the incident angle of light with respect to the total reflection surface are set so as to suppress relative positional deviation due to polarization components of light totally reflected by the total reflection surface of the optical member.

The 5 th aspect of the present invention provides an optical device, comprising:

n total reflection surfaces are arranged in the light path, and

the incident angle of light with respect to each of the N total reflection surfaces and the refractive index of each optical member forming the N total reflection surfaces are set so that relative positional deviation of light totally reflected by the N total reflection surfaces due to polarization components is substantially zero.

The 6 th aspect of the present invention provides a measuring apparatus in which an optical member having a total reflection surface is disposed in a measuring optical path, the measuring apparatus characterized in that:

the refractive index of the optical member and the incident angle of the measurement light with respect to the total reflection surface are set so as to suppress relative positional deviation of the measurement light totally reflected by the total reflection surface of the optical member due to polarization components.

The 7 th aspect of the present invention provides a measuring apparatus for measuring a surface to be inspected, comprising:

a light receiving optical system for receiving the measurement light reflected by the test surface;

a detector that detects the measurement light passing through the light receiving optical system; and

an optical member including a total reflection surface which is arranged in an optical path of the measurement light between the test surface and the light receiving optical system and totally reflects the measurement light; and is

The refractive index of the optical member and the incident angle of the measurement light with respect to the total reflection surface of the optical member are set so as to suppress a relative positional shift of the measurement light due to polarization components.

An 8 th aspect of the present invention provides a measuring apparatus for measuring a surface to be inspected, comprising:

a projection optical system for guiding the measuring light to the surface to be inspected;

a light receiving optical system that receives the measurement light reflected by the test surface;

a detector that detects the measurement light passing through the light receiving optical system; and

an optical member including a total reflection surface that is disposed in at least one of an optical path of the measurement light between the projection optical system and the test surface and an optical path of the measurement light between the light reception optical system and the test surface and totally reflects the measurement light; and is

The refractive index of the optical member and the incident angle of the measurement light with respect to the total reflection surface of the optical member are set so as to suppress a relative positional shift of the measurement light due to polarization components.

The 9 th aspect of the present invention provides a measuring apparatus, comprising:

n total reflection surfaces are arranged in the light path, and

the incident angle of light with respect to each of the N total reflection surfaces and the refractive index of each optical member forming the N total reflection surfaces are set so that relative positional deviation of light totally reflected by the N total reflection surfaces due to polarization components is substantially zero.

The 10 th aspect of the present invention provides an exposure apparatus for exposing a predetermined pattern onto a photosensitive substrate,

the exposure apparatus is characterized in that the position of the photosensitive substrate is measured by using a measuring device including the 6 th, 7 th, 8 th or 9 th forms.

An 11 th aspect of the present invention provides a method for manufacturing an element, including:

an exposure step of exposing the predetermined pattern onto the photosensitive substrate using the exposure apparatus of the 10 th aspect; and

a developing step of developing the photosensitive substrate exposed by the exposure step.

The 12 th aspect of the present invention provides an optical device comprising:

at least one optical component which is configured in the light path and is provided with a total reflection surface; and

and an adjusting device for adjusting relative positional deviation caused by polarization components of the light totally reflected by the total reflection surface of the at least one optical member.

The 13 th aspect of the present invention provides an adjustment method including:

a step of disposing at least one optical member having a total reflection surface in an optical path; and

adjusting relative position deviation of light generated by the total reflection surface of the at least one optical member due to polarization components.

The 14 th aspect of the present invention provides an adjustment method including:

a step of directing light to at least one optical member having a total reflection surface; and

detecting a relative positional shift of light generated by the total reflection surface of the at least one optical member due to a polarization component; and

and adjusting an incident angle of light incident on the total reflection surface of the at least one optical member.

The 15 th aspect of the present invention provides a surface position detecting device for detecting a surface position of a surface to be detected, the surface position detecting device including:

a projection optical system for projecting a light beam onto the test surface from an oblique direction to form a primary image of a predetermined pattern on the test surface;

a light collecting optical system for receiving the light reflected by the test surface and collecting the light to form a secondary image of the predetermined pattern;

a detection unit for detecting a lateral shift amount of the secondary image and outputting information on a surface position of the inspected surface based on the lateral shift amount;

wherein at least one of the projection optical system and the condensing optical system includes an optical member having a total reflection surface for totally reflecting the light, and the optical member is disposed in an optical path between the projection optical system and the inspection surface and in an optical path of at least one of the condensing optical system and the optical path of the inspection surface,

wherein a relationship that the refractive index of the optical member and the incident angle of the light with respect to the total reflection surface of the optical member satisfy is such that the magnitude of the relative positional deviation amount of the polarization component of the light totally reflected by the total reflection surface is within a predetermined range.

The 16 th aspect of the present invention provides a measuring apparatus for measuring a surface to be inspected, comprising:

a light receiving optical system for receiving the measurement light reflected by the test surface;

a detector for detecting the measuring light passing through the light receiving optical system and outputting information on the position or surface shape of the surface to be detected; and

an optical member including a total reflection surface that totally reflects the measurement light, the optical member being disposed in an optical path of the measurement light between the detection surface and the light receiving optical system,

wherein a relationship that the refractive index of the optical member and the incident angle of the measurement light with respect to the total reflection surface of the optical member satisfy is such that the amount of relative positional deviation of the polarization component of the measurement light totally reflected by the total reflection surface is within a predetermined range.

The 17 th aspect of the present invention provides an exposure apparatus for exposing a pattern provided on an object onto a photosensitive substrate, the exposure apparatus comprising the above-described measuring device.

An 18 th aspect of the present invention provides a method for manufacturing an element, including:

an exposure step of exposing the pattern onto the photosensitive substrate using the exposure device; and

a developing step of developing the photosensitive substrate exposed by the exposure step.

[ Effect of the invention ]

In the typical surface position detecting device according to the present invention, the refractive index of the optical material forming the total reflection prism member and the incident angle of the incident beam with respect to the inner surface reflection surface are set to satisfy a predetermined relationship, whereby the relative positional deviation caused by the polarization component does not substantially occur in the beam totally reflected by the inner surface reflection surface. As a result, a clear primary pattern image can be formed on the test surface, and a clear secondary pattern image can be formed on the light-receiving surface (or the conjugate surface thereof), and the surface position of the test surface can be detected with high accuracy.

As described above, the surface position detection device of the present invention can detect the surface position of the detection target surface with high accuracy while suppressing the influence of relative positional deviation due to polarization components, which is generated by the light beam totally reflected by the inner surface reflection surface of the prism member, on the detection of the surface position of the detection target surface. Therefore, when the surface position detecting device of the present invention is applied to the detection of the surface position of the photosensitive substrate with respect to the projection optical system in the exposure apparatus, the surface position of the photosensitive substrate can be detected with high accuracy, and the pattern surface of the photomask and the exposure surface of the photosensitive substrate can be aligned with respect to the projection optical system with high accuracy, and thus a good device can be manufactured.

Drawings

Fig. 1 is a view schematically showing the configuration of an exposure apparatus including a surface position detection apparatus according to an embodiment of the present invention.

Fig. 2 is an optical path diagram showing that both the projection optical system and the condensing optical system of fig. 1 are telecentric on both sides.

Fig. 3 is a diagram schematically showing a structure between a pair of pentagonal prisms in the surface position detecting device according to the present embodiment.

Fig. 4 is a perspective view showing a state in which a primary image of the grating pattern 3a is formed on the test surface Wa.

Fig. 5 is a schematic view showing the configuration of the light receiving slit S having 5 rectangular openings Sa1 to Sa5 elongated in the X direction.

Fig. 6 is a diagram showing a case where 5 silicon photodiodes PD1 to PD5 are provided on the light-receiving surface 14a of the light-receiving unit 14 so as to optically correspond to the openings Sa1 to Sa5 of the light-receiving slit S.

Fig. 7 is a diagram schematically showing relative positional deviation due to polarization components of a light beam totally reflected by the inner reflecting surface of the prism.

Fig. 8 is a graph showing a relationship between a relative positional displacement amount Δ (GHS) due to a polarization component generated by total reflection and a measurement value of the AF surface.

Fig. 9 is a partially enlarged view of fig. 8.

Fig. 10 is a diagram showing a relationship between an incident angle to the total reflection surface and a relative positional shift amount due to the polarization component.

Fig. 11 is a diagram showing a relationship between the refractive index of the prism and the amount of relative positional shift due to the polarization component.

Fig. 12 is a view schematically showing a configuration of a main part of a modification of the present embodiment.

Fig. 13 is a diagram illustrating a range of the incident angle θ where the absolute value of the relative positional displacement amount Δ is 0.3 μm or less when the refractive index n of the total reflection prism member is 1.45.

Fig. 14 is a diagram illustrating a range of the incident angle θ where the absolute value of the relative positional displacement amount Δ is 0.3 μm or less when the refractive index n of the total reflection prism member is 1.5.

Fig. 15 is a diagram illustrating a range of the incident angle θ where the absolute value of the relative positional displacement amount Δ is 0.3 μm or less when the refractive index n of the total reflection prism member is 1.6.

Fig. 16 is a diagram illustrating a range of the incident angle θ where the absolute value of the relative positional displacement amount Δ is 0.3 μm or less when the refractive index n of the total reflection prism member is 1.7.

FIG. 17 is a view showing an example in which the present invention is applied to an apparatus for measuring the surface shape of a test surface.

Fig. 18 is a diagram showing an example of an apparatus for measuring the position of a test surface to which the present invention is applied.

Fig. 19 is a diagram for explaining an idea that a relative positional displacement amount finally generated in light sequentially totally reflected by two total reflection surfaces is suppressed to be small by using a quadrangular prism as a total reflection prism member.

Fig. 20 is a partially enlarged view of fig. 13, and illustrates a range of the incident angle θ where the absolute value of the relative positional shift amount Δ is 0.05 μm or less, or 0.05 μm or less.

Fig. 21 is a partially enlarged view of fig. 14, and illustrates a range of the incident angle θ where the absolute value of the relative positional shift amount Δ is 0.05 μm or less, or 0.05 μm or less.

Fig. 22 is a partially enlarged view of fig. 15, and illustrates a range of the incident angle θ where the absolute value of the relative positional shift amount Δ is 0.05 μm or less, or 0.05 μm or less.

Fig. 23 is a partially enlarged view of fig. 16, and illustrates a range of the incident angle θ where the absolute value of the relative positional shift amount Δ is 0.05 μm or less, or 0.05 μm or less.

Fig. 24 is a flowchart of a method in obtaining a semiconductor element as a micro-element.

Fig. 25 is a flowchart of a method in obtaining a liquid crystal display element as a microelement.

1. 41: light source 2: condensing lens

3: deflection prism 3 a: raster pattern

4. 5: projection optical systems 6, 9: pentagonal prism

6a, 7a, 8a, 9a, 31a, 32 a: the 1 st transmission surface

6b, 9 b: 1 st reflection surfaces 6c, 9 c: 2 nd reflecting surface

6d, 7d, 8d, 9d, 31c, 32 c: no. 2 transmission surface

7. 8: rhomboid prisms 7b, 7c, 8b, 8c, 71: inner surface reflecting surface

10. 11: the condensing optical system 12: vibrating mirror

13: skew correction prism 13 a: incident surface

13 b: exit surfaces 14, 15: light receiving part

14a, 15 a: light-receiving surfaces 14a, 14 b: relay optical system

16: lens driving section 17: position detecting unit

18: correction amount calculation unit 21: wafer holder

22: holder holding mechanisms 22a, 22 b: support point

23: holder driving portions 31, 32, 54: schmidt prism

31b, 32b, 54 a: total reflection surface 42: light transmitting optical system (projection optical system)

43. 45, and (2) 45: total reflection optical members 44, 55: inspected surface

46: light receiving optical systems 47 and 56: image detector

51. IL: the lighting system 52: objective optical system

53: semi-mirror 61: quadrilateral prism

61 a: 1 st total reflection surface 61 b: 2 nd total reflection surface

70: prism Da 1-Da 5: detection point (detection area)

AX, AX1, AX2, AX3, AX4, AX5, AX6, AX21, AX 31: optical axis

L: light Lp: light of P polarization state

Ls: light P0 in S-polarized state: reference reflection position

PD 1-PD 5: silicon photodiode PL: projection optical system

R: main photomask RH: main photomask holder

S: light-receiving slits Sa1 to Sa 5: opening part

SL 1-SL 5: slit image W: wafer

Wa: front surface, exposure surface, and inspected surface of wafer W

n: refractive index Δ: offset of relative position

Δ p, Δ s: positional deviation amounts θ, θ 1, θ 2: angle of incidence

φ p, φ s: phase change

Detailed Description

Embodiments of the present invention are described with reference to the accompanying drawings. Fig. 1 is a view schematically showing the configuration of an exposure apparatus including a surface position detection apparatus according to an embodiment of the present invention. Fig. 2 is an optical path diagram showing both the projection optical system and the condensing optical system of fig. 1 being telecentric on both sides. Fig. 3 is a diagram schematically showing a configuration between a pair of pentagonal prisms (penta prisms) in the surface position detection device according to the present embodiment.

In fig. 1 and 2, the configuration between the pair of pentagonal prisms 6 and 9 is not shown in order to clarify the drawings. In fig. 1, a Z axis is set parallel to the optical axis AX of the projection optical system PL, a Y axis is set parallel to the paper surface of fig. 1 in a plane perpendicular to the optical axis AX, and an X axis is set perpendicular to the paper surface of fig. 1. In the present embodiment, the surface position detection device of the present invention is applied to the detection of the surface position of a photosensitive substrate in a projection exposure apparatus.

The illustrated exposure apparatus includes an illumination system IL for illuminating a main photomask (reticle) R, which is a photomask on which a predetermined pattern is formed, with illumination light (exposure light) emitted from an exposure light source (not illustrated). The main photomask R is held on a main photomask stage (not shown) in parallel with the XY plane through a main photomask holder (reticle) RH. The reticle stage is configured to be two-dimensionally movable along a reticle plane (i.e., XY plane) by a driving system (not shown), and its position coordinates are measured and position-controlled by a reticle interferometer (not shown).

Light from the pattern formed on the main photomask R forms a main photomask pattern image on a surface (exposure surface) Wa of a wafer W as a photosensitive substrate via the projection optical system PL. The wafer W is mounted on a wafer holder 21, and the wafer holder 21 is supported by a holder holding mechanism 22. The holder holding mechanism 22 supports the wafer holder 21 by three support points 22a to 22c (only two support points 22a and 22b are shown in fig. 1) movable in the vertical direction (Z direction) under the control of a holder driving portion 23.

In this manner, the holder driving unit 23 controls the vertical movement of the support points 22a to 22c of the holder holding mechanism 22, thereby leveling (leveling) and Z-direction (focusing) movement of the wafer holder 21, and leveling and Z-direction movement of the wafer W are performed. The wafer holder 21 and the holder holding mechanism 22 are further supported by a wafer stage (not shown). The wafer stage is configured to be two-dimensionally movable along a wafer plane (i.e., XY plane) by the action of a drive system, not shown, and rotatable about the Z axis, and its position coordinates are measured by a wafer interferometer (not shown) and the position is controlled.

Here, in order to transfer the circuit pattern (circuit pattern) provided on the pattern surface of the main photomask R to each exposure area of the exposure surface Wa of the wafer W, each time each exposure area is exposed, it is necessary to align the current exposure area of the exposure surface Wa within the range of the focal depth centered on the imaging surface formed by the projection optical system PL. Therefore, after the surface position of each point in the exposure area, that is, the surface position along the optical axis AX of the projection optical system PL is accurately detected, the wafer holder 21 is leveled and moved in the Z direction, and the wafer W is leveled and moved in the Z direction so that the exposure surface Wa is within the range of the focal depth of the projection optical system PL.

The projection exposure apparatus of the present embodiment includes a surface position detection device for detecting the surface position of each point in the current exposure area of the exposure surface Wa. Referring to fig. 1, the surface position detecting apparatus of the present embodiment includes a light source 1 for supplying detection light. Generally, the surface Wa of the wafer W as the test surface is covered with a thin film such as a photoresist. Therefore, in order to reduce the influence of interference due to the thin film, it is preferable that the light source 1 is a white light source having a wide wavelength interval (wavelength interval) (for example, a halogen lamp (halogen lamp) that supplies illumination light having a wavelength interval of 600 to 900nm, or a xenon light source (xenon light source) that supplies illumination light having the same wide frequency band). As the light source 1, a light-emitting diode (light-emitting diode) that supplies light in a wavelength band (wavelength band) that is less sensitive to the photoresist may be used.

A divergent light beam (divergent light of rays) from the light source 1 is converted into a substantially parallel light beam by the condenser lens 2, and then enters the deflection prism (deflection prism) 3. The deflection prism 3 deflects the substantially parallel light flux from the condenser lens 2 in the-Z direction by refraction. Further, a transmission type grating pattern 3a is formed on the emission side of the deflection prism 3, and elongated transmission portions extending in the X direction and elongated light shielding portions extending in the X direction are alternately provided at a fixed pitch (pitch). In addition, instead of the transmission type grating pattern, a reflection type diffraction grating having a concave-convex shape may be applied, or a reflection type grating pattern in which a reflection portion and a non-reflection portion are alternately formed may be applied.

The light transmitted through the transmission type grating pattern 3a is incident on projection optical systems (4, 5) arranged along an optical axis AX1 parallel to the optical axis AX of the projection optical system. The projection optical systems (4, 5) are constituted by a projection condenser lens (4) and a projection objective lens (objective lens) 5. The light beams passing through the projection optical systems (4, 5) are incident on the pentagonal prism 6. The pentagonal prism 6 is a pentagonal columnar deflection prism whose longitudinal axis extends along the X direction, and has a1 st transmission surface 6a for directly transmitting light incident along the optical axis AX1 without refraction. That is, the 1 st transmission surface 6a is set perpendicular to the optical axis AX 1.

The light transmitted through the 1 st transmission surface 6a and traveling along the optical axis AX1 inside the pentagonal prism 6 is reflected by the 1 st reflection surface 6b, and then reflected again by the 2 nd reflection surface 6c along the optical axis AX 2. The light reflected by the 2 nd reflecting surface 6c and propagating through the interior of the pentagonal prism 6 along the optical axis AX2 is transmitted without being refracted by the 2 nd transmitting surface 6 d. That is, the 2 nd transmission surface 6d is set perpendicular to the optical axis AX 2. Here, the pentagonal prism 6 is formed of an optical material having low thermal expansion and low dispersion, such as quartz glass (silica glass), and reflective films formed of aluminum, silver, or the like are formed on the 1 st reflective surface 6b and the 2 nd reflective surface 6 c.

Thus, the light incident in the-Z direction along the optical axis AX1 is greatly deflected by the pentagonal prism 6 and guided to the detection surface Wa along the optical axis AX 2. At this time, the direction of the optical axis AX2 is set, and the deflection angle of the pentagonal prism 6 is set so that the incident angle to the test surface Wa becomes sufficiently large. Specifically, as shown in fig. 3, the light flux emitted from the pentagonal prism 6 along the optical axis AX2 enters the projection-side rhombic prism 7.

The rhombic prism 7 is a prism having a quadrangular prism shape (or rhombus shape) in cross section, and its longitudinal axis is arranged along the X direction similarly to the pentagonal prism 6. In the rhombic prism 7, the light transmitted through the 1 st transmission surface 7a perpendicular to the optical axis AX2 is sequentially reflected by the pair of mutually parallel reflection surfaces 7b and 7c, then transmitted through the 2 nd transmission surface 7d parallel to the 1 st transmission surface 7a, and then emitted from the rhombic prism 7 along the optical axis AX21 parallel to the optical axis AX 2. The light flux emitted from the diamond prism 7 along the optical axis AX21 enters the test surface Wa.

Here, the projection optical systems (4, 5) are configured such that the formation surface of the grating pattern 3a (i.e., the emission surface of the deflection prism 3) and the test surface Wa are arranged in conjugate with each other in a state where the test surface Wa and the image forming surface of the projection optical system PL coincide with each other. The forming surface of the grating pattern 3a and the detected surface Wa are configured so as to satisfy the Scheimpflug condition with respect to the projection optical system (4, 5). As a result, the light from the grating pattern 3a is accurately formed into an image over the entire pattern image forming surface on the test surface Wa via the projection optical systems (4, 5).

In fig. 2, the optical path is shown by a broken line, and the projection optical systems (4, 5) including the projection condenser lens 4 and the projection objective lens 5 are so-called bilateral telecentric optical systems. Therefore, each point on the formation surface of the grating pattern 3a and each conjugate point on the test surface Wa have the same magnification over the entire surface. As described above, as shown in fig. 4, a primary image of the grating pattern 3a is accurately formed on the entire surface Wa.

Referring again to fig. 1, the light beam reflected on the detection surface Wa along the optical axis AX31 enters the light receiving side rhomboid prism 8, and the optical axis AX31 and the optical axis AX21 are symmetrical with respect to the optical axis AX of the projection optical system PL. The diamond prism 8 is a prism having a rectangular prism shape with a longitudinal axis along the X direction and a parallelogram-shaped (or rhombus-shaped) cross section, similarly to the diamond prism 7. Therefore, in the rhombic prism 8, the light transmitted through the 1 st transmission surface 8a perpendicular to the optical axis AX31 is sequentially reflected by the pair of mutually parallel reflection surfaces 8b and 8c, then transmitted through the 2 nd transmission surface 8d parallel to the 1 st transmission surface 8a, and then emitted from the rhombic prism 8 along the optical axis AX3 parallel to the optical axis AX 31.

The light emitted from the rhombic prism 8 along the optical axis AX3 enters the condensing optical system (10, 11) through the pentagonal prism 9 having the same configuration as the pentagonal prism 6. That is, the light reflected on the detection surface Wa enters the pentagonal prism 9 along the optical axis AX3, and the optical axis AX3 and the optical axis AX2 are symmetrical to each other about the optical axis AX of the projection optical system PL. In the pentagonal prism 9, light transmitted through the 1 st transmission surface 9a perpendicular to the optical axis AX3 is reflected sequentially by the 1 st reflection surface 9b and the 2 nd reflection surface 9c, and then reaches the 2 nd transmission surface 9d along the optical axis AX4 extending in the Z direction. The light transmitted through the 2 nd transmission surface 9d perpendicular to the optical axis AX4 enters the condenser optical system (10, 11) in the + Z direction along the optical axis AX 4.

The condensing optical systems (10, 11) are composed of a light receiving objective lens 10 and a light receiving condensing lens 11. In the optical path between the objective lens 10 for light reception and the condenser lens 11 for light reception, a vibrating mirror (vibrating mirror)12 as a scanning element is provided. Therefore, the light incident on the light receiving objective lens 10 along the optical axis AX4 is deflected by the oscillating mirror 12 and reaches the light receiving condenser lens 11 along the optical axis AX 5. In the present embodiment, the oscillating mirror 12 is disposed at a position substantially corresponding to a pupil plane (pupil plane) of the condensing optical systems (10, 11), but the present invention is not limited to this, and the oscillating mirror 12 may be disposed at an arbitrary position in an optical path between the test surface Wa and a skew correction prism 13 described below or in an optical path between the test surface Wa and the deflection prism 3.

The light passing through the condensing optical systems (10, 11) enters a skew correction prism 13 having the same configuration as the above-described deflection prism 3. Here, the condensing optical systems (10, 11) are configured to be disposed in conjugate with the detection target surface Wa and the incident surface 13a of the skew correction prism 13 in a state where the detection target surface Wa and the imaging surface of the projection optical system PL coincide with each other. In this way, a secondary image of the grating pattern 3a is formed on the incident surface 13a of the skew correction prism 13.

Further, a light receiving slit S as a light blocking element is provided on the incident surface 13a of the skew correction prism 13. As shown in fig. 5, the light receiving slit S has, for example, 5 rectangular openings Sa1 to Sa5 elongated in the X direction. The reflected light from the test surface Wa via the condensing optical systems (10, 11) passes through the openings Sa1 to Sa5 of the light receiving slit S, and enters the skew correction prism 13.

Here, the number of the openings Sa of the light receiving slit S corresponds to the number of detection points on the test surface Wa. That is, in fig. 4 showing a state where the primary image of the grating pattern 3a is formed on the test surface Wa, the detection points (detection regions) Da1 to Da5 on the test surface Wa optically correspond to the 5 openings Sa1 to Sa5 of the light-receiving slit S shown in fig. 5. Therefore, when the number of detection points on the test surface Wa is to be increased, the number of the openings Sa may be increased, and the structure is not complicated even if the number of detection points is increased.

Further, an image forming surface formed by the projection optical system PL and the incident surface 13a of the skew correction prism 13 are configured so as to satisfy the Scheimpflug condition with respect to the condensing optical systems (10, 11). Therefore, in a state where the test surface Wa coincides with the image forming surface, the light from the grating pattern 3a is accurately re-imaged through the condensing optical systems (10, 11) over the entire pattern image forming surface on the prism incident surface 13 a.

In fig. 2, the optical path is shown by a broken line, and the condensing optical systems (10, 11) are configured by bilateral telecentric optical systems. Therefore, each point on the test surface Wa and each conjugate point on the prism incident surface 13a have the same magnification over the entire surface. In this way, the secondary image of the grating pattern 3a is accurately formed on the entire incident surface 13a of the skew correction prism 13.

However, if the light receiving surface is disposed at the position of the incident surface 13a of the skew correction prism 13, the incident angle θ of the light beam with respect to the test surface Wa is large, and therefore the incident angle of the light beam on the light receiving surface also becomes large. In this case, if, for example, a silicon photodiode (silicon photodiode) is disposed on the light receiving surface, the incident angle of the light beam to the silicon photodiode becomes large, and therefore, there is a fear that surface reflection in the silicon photodiode becomes large, and a shading (shading) phenomenon of the light beam occurs, and the amount of light received is significantly reduced.

In the present embodiment, in order to avoid a decrease in the amount of received light due to the incident angle of the light beam on the light receiving surface, as shown in fig. 1, an incident surface 13a of a skew correction prism 13 as a deflection optical system is disposed on a conjugate surface with the detection target surface Wa of the condensing optical system (10, 11). As a result, the light flux incident on the incident surface 13a of the skew correction prism 13 along the optical axis AX5 through the condensing optical system (10, 11) is deflected at the same refraction angle as the vertex angle of the skew correction prism 13 (the angle formed by the incident surface and the exit surface), and is emitted from the exit surface 13b along the optical axis AX 6. Here, the emission surface 13b is set perpendicular to the optical axis AX 6.

Light emitted from the emission surface 13b of the skew correction prism 13 along the optical axis AX6 enters relay optical systems (14a, 14b) including a pair of lenses 14a and 14 b. The secondary image of the grating pattern 3a formed on the incident surface 13a of the skew correction prism 13 and the conjugate image with the openings Sa1 to Sa5 of the light receiving slit S are formed on the light receiving surface 15a of the light receiving unit 15 by the light passing through the relay optical systems (14a, 14 b). On the light receiving surface 15a, as shown in fig. 6, 5 silicon photodiodes PD1 to PD5 are provided so as to optically correspond to the openings Sa1 to Sa5 of the light receiving slit S. Instead of the silicon photodiode, a CCD (Charge coupled device) (two-dimensional Charge coupled imaging device) or a photomultiplier may be used.

As described above, in the present embodiment, since the skew correction prism 13 as a deflection optical system is used, the incident angle of the light beam incident on the light receiving surface 15a becomes sufficiently small, and a decrease in the amount of light received due to the incident angle of the light beam on the light receiving surface 15a is avoided. Further, it is preferable that the relay optical systems (14a, 14b) are both telecentric optical systems as shown in fig. 2. Further, it is preferable that the incident surface 13a and the light receiving surface 15a of the skew correction prism 13 are configured to satisfy the Scheimpflug condition for the relay optical systems (14a, 14 b).

As described above, the light receiving slits S having 5 openings Sa1 to Sa5 are provided on the incident surface 13a of the skew correction prism 13. Therefore, the secondary image of the grating pattern 3a formed on the incident surface 13a is partially shielded from light via the light receiving slit S. That is, only the light flux of the secondary image from the grating-like pattern 3a formed in the region of the openings Sa1 to Sa5 of the light-receiving slit S reaches the light-receiving surface 15a via the skew correction prism 13 and the relay optical systems (14a, 14 b).

As shown in fig. 6, slit images SL1 to SL5, which are images of the openings Sa1 to Sa5 of the light receiving slit S, are formed in the silicon photodiodes PD1 to PD5 arranged on the light receiving surface 15a of the light receiving unit 15. The slit images SL1 to SL5 are set so as to be formed inside the rectangular light receiving regions of the silicon photodiodes PD1 to PD5, respectively.

Here, when the test surface Wa moves up and down in the Z direction along the optical axis AX of the projection optical system PL, the secondary image of the grating pattern 3a formed on the incident surface 13a of the skew correction prism 13 is shifted laterally in the pitch direction of the pattern in accordance with the up and down movement of the test surface Wa. In the present embodiment, for example, the lateral shift amount of the secondary image of the grating pattern 3a is detected based on the principle of the photoelectric microscope as disclosed in japanese patent laid-open No. 6-97045, which is proposed by the present applicant, and the surface position of the detected surface Wa along the optical axis AX of the projection optical system PL is detected based on the detected lateral shift amount.

Further, the operation of the following members is the same as that of the device disclosed in japanese patent laid-open No. 2001-296105, which is proposed by the present applicant, and therefore, the description thereof, that is, the lens driving section 16 for driving the oscillating mirror 12; a position detection unit 17 for synchronously detecting detection signals from the silicon photodiodes PD1 to PD5 based on an ac signal from the lens drive unit 16; a correction amount calculation unit 18 that calculates a tilt correction amount and a Z-direction correction amount necessary to accommodate the detection surface Wa within the range of the depth of focus of the projection optical system PL; and a holder driving unit 23 for driving and controlling the holder holding mechanism 22 based on the tilt correction amount and the Z-direction correction amount, and leveling and Z-direction movement of the wafer holder 21.

Further, the Scheimpflug condition, the configuration and operation of the deflection prism 3 and the skew correcting prism 13, and the specific application of the principle of the photoelectric microscope are disclosed in detail in japanese patent laid-open No. 6-97045. The structure and operation of the pentagonal prisms 6 and 9 are disclosed in detail in Japanese patent laid-open No. 2001-296105. One or both of the pentagonal prisms 6 and 9 may be omitted.

In the present embodiment, pentagonal prisms 6 and 9 are provided in the optical paths between the projection optical systems 4 and 5 and the test surface Wa and in the optical paths between the condensing optical systems 10 and 11 and the test surface Wa, respectively, and the optical paths of the incident light beam to the test surface Wa and the reflected light beam from the test surface Wa are greatly bent by the action of the pentagonal prisms 6 and 9, and the projection optical systems 4 and 5 and the condensing optical systems 10 and 11 are sufficiently separated from the test surface Wa. As a result, the configuration and arrangement of the projection optical systems (4, 5) and the condensing optical systems (10, 11) are not limited by the object surface Wa.

In the present embodiment, since the rhombic prisms 7 and 8 are respectively provided on the optical path between the pentagonal prism 6 and the test surface Wa and on the optical path between the pentagonal prism 9 and the test surface Wa, the optical path of the incident beam to the test surface Wa and the optical path of the reflected beam from the test surface Wa are respectively moved in parallel by the action of the rhombic prisms 7 and 8. As a result, the pair of pentagonal prisms 6 and 9 can be separated from the surface Wa to be inspected, and the configuration and arrangement of the pair of pentagonal prisms 6 and 9 and the holding members thereof are not substantially restricted by the surface Wa to be inspected.

The surface position detecting device of the present embodiment includes a rhombic prism 7 as a projection side prism member and a rhombic prism 8 as a light receiving side prism member, the projection side prism member 7 is disposed in an optical path of a projection system and has a pair of inner surface reflection surfaces (7b, 7c) for moving an optical path of an incident light flux in parallel, and the light receiving side prism member 8 is disposed in an optical path of a light receiving system so as to correspond to the projection side prism member 7 and has a pair of inner surface reflection surfaces (8b, 8c) for moving an optical path of an incident light flux from a detection surface Wa in parallel. At this time, as described above, the light beams totally reflected by the two inner reflection surfaces (7b, 7c) parallel to each other of the diamond prism 7 on the projection side are shifted in relative positions by the polarization component, and a clear pattern image is not formed on the detection surface Wa. Further, since the detection surface sides of the projection optical systems (4, 5) and the detection surface sides of the condensing optical systems (10, 11) are telecentric, all the principal rays incident on the total reflection surfaces (7b, 7c, 8b, 8c) of the rhombic prisms (7, 8) have the same incident angle.

Fig. 7 is a diagram schematically showing a relative positional shift of a light flux (a main light ray passing through the optical axis) totally reflected by the inner reflecting surface of the prism due to the polarization component. As shown in fig. 7, light L propagating inside the prism 70 and entering the inner reflective surface 71 at an angle of incidence larger than a predetermined value is totally reflected by the inner reflective surface 71. At this time, of the light beams totally reflected by the inner reflection surface 71, light Ls in the S-polarized state having a polarization direction in a direction perpendicular to the paper surface of fig. 7 and light Lp in the P-polarized state having a polarization direction in a direction parallel to the paper surface of fig. 7 propagate inside the prism 70 along two optical paths parallel to each other at an interval of a distance Δ.

Here, a relative positional Shift amount Δ due to a polarization component of a light flux totally reflected by the inner surface reflecting surface 71 of the prism 70 is referred to as Goos-Haenchen Shift (Goos-Haenchen Shift). As described above, the light beam reaching the detection surface Wa due to total reflection by the two inner surface reflection surfaces (7b, 7c) parallel to each other of the diamond prism 7 on the projection side causes a relative positional shift between the P-polarized light and the S-polarized light with respect to the detection surface Wa, and further causes a relative positional shift between the pattern image formed on the detection surface Wa by the P-polarized light and the pattern image formed on the detection surface Wa by the S-polarized light.

Similarly, the light beams totally reflected by the two inner reflection surfaces (8b, 8c) parallel to each other of the rhombic prism 8 on the light receiving side after being reflected from the detection surface Wa are also shifted in relative positions by the polarization components, and the secondary image of the pattern formed on the incident surface 13a of the skew correction prism 13 becomes unclear. In other words, due to the influence of total reflection by the inner reflection surfaces (8b and 8c) of the light receiving side rhomboid prism 8, the relative positional shift between the pattern secondary image formed on the incident surface 13a by the P-polarized light and the pattern secondary image formed on the incident surface 13a by the S-polarized light is increased (multiplied).

The surface position detection apparatus of the present embodiment is suitable for detecting the surface position of a wafer W having various surface states (for example, a plurality of substances constituting a structure on the wafer W, or a plurality of structures (multilayer structures) themselves on the wafer W) in a semiconductor exposure process. Generally, the surface of the wafer is coated with a photoresist. In such a situation, when there are variations in the surface state (for example, variations in the thickness of a layer formed on a wafer, or variations in the properties such as the purity of a material forming the layer), or variations in the thickness of a photoresist, the reflectance with respect to light of a specific polarization component (for example, P-polarized light, S-polarized light, etc.) changes according to the variations.

As a result, unless special measures are taken, the surface position detection device of the present embodiment is likely to cause a detection error of the surface position of the test surface Wa due to relative positional shift due to polarization components caused by the light beams totally reflected by the inner reflection surfaces (7b, 7 c; 8b, 8c) of the rhombic prisms (7; 8) and a change in reflectance of specific polarization components caused by the above-described nonuniformity of the surface state of the wafer W and the nonuniformity of the resist thickness.

In recent years, with the miniaturization of projection exposure patterns, the requirements for flatness of the wafer surface have become strict, and the requirements for surface position detection accuracy have become very high. In an exposure apparatus or the like using an ArF excimer laser (eximer laser) light source, the thickness of the resist on the surface tends to be thin, and the surface position detection error due to the above-described various surface states and the unevenness of the resist thickness is not negligible.

Therefore, in the present embodiment, the influence of the relative positional shift of the light flux totally reflected by the inner reflection surfaces (7b, 7 c; 8b, 8c) of the rhombic prisms (7; 8) due to the polarization component on the detection of the surface position of the detection target surface Wa is suppressed by setting the refractive index n of the optical material forming the rhombic prisms (7; 8) as the total reflection prism members and the incident angle θ of the incident light flux (principal ray advancing along the optical axis) with respect to the inner reflection surfaces (7b, 7 c; 8b, 8c) to satisfy a predetermined relationship. The relationship that the refractive index n of the optical material forming the rhombic prism (7; 8) and the incident angle theta of the incident beam (along the principal ray on the optical axis) to the inner reflection surface (7b, 7 c; 8b, 8c) should satisfy will be described below.

Now, in each of the inner reflective surfaces (7b, 7c, 8b, 8c) as total reflective surfaces, when θ is an incident angle of a principal ray to the reflective surface (0 ° - θ ≦ 90 °), λ is a wavelength of light, and n is a refractive index of an optical material such as glass, phase changes Φ P and Φ S in components of P-polarized light and S-polarized light are expressed by the following expressions (1) and (2).

[ number 1]

(P polarization) (1)

(S Polaroid) (2)

In the reflected light of the P-polarized light component, a relative positional shift amount Δ P (referred to as "goos-henry phase shift (GHS)" of the P-polarized light component) with respect to a reference reflection position P0 of the P-polarized light component in the direction along the reflection surface changes the phase of the P-polarized light component to β n/λ · cos θ, and becomes a partial differential of the P-polarized light component in phase change Φ to β. In the reflected light of the S-polarized light component, a relative positional shift amount Δ S (referred to as a guy-henry phase shift (GHS)) with respect to a reference reflection position P0 of the S-polarized light component in the direction along the reflection surface changes the phase of the S-polarized light component to β n/λ · cos θ, and becomes a partial differential of the phase change Φ to β of the S-polarized light component

The relative positional displacement amounts Δ p and Δ s of the reflected light of the respective polarization components are expressed by the following expressions (3) and (4).

[ number 2]

(P Polaroid) (3)

(S Polaroid) (4)

When the difference Δ (gus-henry phase shift (GHS)) in the relative phase shift amount in the vertical direction between the light of the P-polarization component and the light of the S-polarization component in the reflected light beam is obtained from the above, the relative phase shift amount GHS between the reflected lights of the respective polarization components along the direction of the reflection surface becomes Δ P- Δ S, and the relationship of the following formula (5) is established.

Δ＝cosθ×(Δp-Δs)(5)

Therefore, as shown in the following formula (6), a difference Δ is generated between the optical axes of P-polarized light and S-polarized light.

[ number 3]

Therefore, the relative positional displacement amount Delta caused by the polarization component generated by the first total reflection (inner surface reflection) inside the prism (7; 8) can be expressed by the above formula (6). Therefore, the following expression (7) is satisfied as a condition that the relative positional shift due to the polarization component does not occur in the total reflection, that is, a condition that the relative positional shift amount Δ (gus-henry phase shift (GHS)) due to the polarization component occurring in the total reflection is zero.

[ number 4]

sin²θ(n²+1)＝2 (7)

In this embodiment, the refractive index n of the optical material forming the rhomboid prisms (7; 8) as the total reflection prism members and the incident angle theta of the incident light beams to the inner reflection surfaces (7b, 7 c; 8b, 8c) thereof are set to substantially satisfy the relationship shown in the formula (7), and thus the relative positional deviation caused by the polarization components does not substantially occur in the light beams totally reflected by the inner reflection surfaces (7b, 7 c; 8b, 8c) of the rhomboid prisms (7; 8). As a result, a clear primary pattern image is formed on the surface Wa of the wafer W as the inspection surface, and a clear secondary pattern image is formed on the incident surface 13a of the skew correction prism 13, and the surface position of the inspection surface Wa can be detected with high accuracy.

Therefore, in the exposure apparatus of the present embodiment, the surface position of the exposure surface Wa of the wafer (photosensitive substrate) W can be detected with high accuracy by using the surface position detection apparatus capable of detecting the surface position of the test surface with high accuracy, and the pattern surface of the main photomask (photomask) R and the exposure surface Wa of the wafer W can be aligned with respect to the projection optical system PL with high accuracy.

When the surface position detecting device of the present embodiment is applied to the detection of the surface position of the photosensitive substrate or the detection of the surface position of the photomask in the exposure apparatus, the magnitude (absolute value) of the relative positional deviation amount Δ due to the polarization component generated by the primary total reflection is preferably limited to, for example, 0.3 μm or less, and thus the surface position detecting device is practically preferable. That is, when the following conditional expression (8) is satisfied, there is no practical problem in detecting the surface position of the photosensitive substrate, detecting the surface position of the photomask, or the like. In formula (8), the unit of the wavelength λ of light is μm.

[ number 5]

Here, the practical applicability that the magnitude of the relative positional shift amount Δ (guse-henry phase shift (GHS)) due to the polarization component generated by the total reflection is 0.3 μm or less will be described. The accuracy required for the focus detection AF (surface detection, focus measurement) is required to be small as the depth of focus with respect to the projection optical system PL, but the currently unacceptable width of AF error due to the resist film thickness is 50nm or more in consideration of other errors with respect to the most recent projection lens with a large NA (depth of focus: about 300nm or less). FIG. 8 shows the change of the AF measurement value with respect to the change of the resist film thickness when the relative positional shift amount Δ due to the polarization component is 0.3 μm. It is known that the width is around 250nm and the AF measurement value changes.

Fig. 9 is a diagram of an enlarged region of a part of fig. 8. The thickness of the photoresist film varies by about + -10 nm within the wafer or between wafers depending on the performance of the film forming machine. Therefore, if the photoresist film thickness is read from the graph in FIG. 9 as a width change of 20nm, it can be seen that the AF measurement value is changed by almost 50nm at most. Therefore, it is understood that it is preferable that the relative positional shift amount Δ due to the polarization component is set to 0.3 μm or less in advance. In order to achieve high accuracy and more stable detection, it is preferable that the relative positional shift amount Δ due to the polarization component is 0.2 μm or less, as shown in the following formula (9).

[ number 6]

Here, it is preferable that the magnitude of the relative positional shift amount Δ (guse-henry phase shift (GHS)) due to the polarization component generated by the total reflection is 0.2 μm or less, and the practical applicability is explained. The change in the AF measurement value is proportional to the relative positional shift amount Δ due to the polarization component, and when the relative positional shift amount Δ due to the polarization component is 0.2 μm or less, the change in the AF measurement value is about 30 nm. If the error is 30nm, it is possible to make a margin of about 20nm with respect to 50nm, which is the minimum necessary amount, and this amount corresponds to an AF measurement error when chromatic aberration (co1or aberration) occurs due to manufacturing errors in the AF optical system. Therefore, even if an error due to chromatic aberration occurs due to a manufacturing error, it is possible to always perform a highly accurate and stable measurement as long as the relative positional shift amount Δ due to the polarization component is 0.2 μm or less than 0.2 μm.

Next, the relationship that the refractive index n of the optical material forming the rhomboid prisms (7; 8) and the incident angle theta of the incident beam with respect to the inner reflecting surfaces (7b, 7 c; 8b, 8c) should satisfy is examined according to a specific embodiment. Fig. 10 is a diagram showing a relationship between an incident angle to the total reflection surface and a relative positional shift amount due to the polarization component. In fig. 10, the vertical axis represents the relative positional displacement amount Δ (μm) due to the polarization component, and the horizontal axis represents the incident angle θ (degree) to the total reflection surface.

When the totally reflected S-polarized light Ls and P-polarized light Lp are in the positional relationship of fig. 7 (when the S-polarized light Ls is more inside than the P-polarized light Lp), the relative positional deviation amount Δ takes a positive value, and when the P-polarized light Lp is more inside than the S-polarized light Ls, the relative positional deviation amount Δ takes a negative value. This point is also the same as in fig. 11 and 13 to 16 described below.

Fig. 10 shows a relationship between the incident angle θ and the relative positional shift amount Δ when the refractive index n of the optical material (e.g., quartz) of the prism to be formed is 1.45 and the center wavelength λ c of the used light (detection light) is 750 nm. Referring to fig. 10, total reflection starts when the incident angle θ is about 43 degrees, and the relative positional displacement amount Δ, which is a positive value as the incident angle θ becomes larger than the total reflection angle, monotonically decreases. After that, when the incident angle θ reaches about 53 degrees, the relative positional shift amount Δ becomes substantially 0, and as the incident angle θ becomes larger from about 53 degrees, the relative positional shift amount Δ becomes a negative value and the magnitude thereof monotonously increases.

At this time, when the center wavelength λ c of the used light is changed, the value of the relative positional shift amount Δ with respect to the same incident angle θ is changed. However, as can be seen from the above equations (6) and (7), even if the central wavelength λ c of the used light is changed, the value of the incident angle θ when the relative positional shift amount Δ is 0 does not substantially change. In other words, the value of the incident angle θ when the relative positional shift amount Δ is 0 does not substantially depend on the center wavelength λ c of the used light.

In this way, in the present embodiment, when the rhombic prisms (7; 8) are formed by an optical material having a predetermined refractive index n, the incident angle θ of the incident light flux with respect to the inner reflective surfaces (7b, 7 c; 8b, 8c) is determined so that the relative positional shift amount Δ of the light flux totally reflected by the inner reflective surfaces (7b, 7 c; 8b, 8c) due to the polarization component is substantially 0, that is, the absolute value of the relative positional shift amount Δ is, for example, 0.3 μm or less, more preferably 0.2 μm or less, 0.2 μm or less. Further, as can be seen from FIG. 10, the degree of change in the relative positional deviation amount Δ with respect to the variation in the incident angle θ is small, and the influence of the mounting error of the diamond prisms (7; 8) and the like on the detection accuracy is small.

Fig. 11 is a diagram showing a relationship between the refractive index of the prism and the amount of relative positional shift due to the polarization component. In fig. 11, the vertical axis represents the relative positional shift amount Δ (μm) due to the polarization component, and the horizontal axis represents the refractive index n of the optical material forming the prism. Fig. 11 shows the relationship between the refractive index n and the relative positional shift amount Δ when the incident angle θ to the total reflection surface is 45 degrees and the central wavelength λ c of the used light is 750 nm. Referring to fig. 11, as the refractive index n increases from 1.45, the relative positional shift amount Δ that is a positive value monotonically decreases, and when the refractive index n reaches about 1.73, the relative positional shift amount Δ is substantially 0. Further, as the refractive index n becomes larger from about 1.73, the relative positional displacement amount Δ becomes a negative value, and the magnitude thereof monotonically increases.

At this time, if the central wavelength λ c of the use light is also changed, the value of the relative positional shift amount Δ with respect to the same refractive index n is changed, but the value of the refractive index n when the relative positional shift amount Δ is 0 is not actually changed. In this way, in the present embodiment, when the rhombic prisms (7; 8) are configured such that light incident at a predetermined incident angle θ with respect to the inner reflective surfaces (7b, 7 c; 8b, 8c) is totally reflected, the refractive index n of the optical material forming the rhombic prisms (7; 8) can be determined such that the relative positional shift amount Δ of the totally reflected light beam due to the polarization component is substantially 0, that is, such that the absolute value of the relative positional shift amount Δ is, for example, 0.2 μm or less than 0.2 μm.

In the above-described embodiment shown in fig. 1 to 3, four total reflection surfaces (7b, 7 c; 8b, 8c) are arranged in the optical path, and the light from the projection optical systems (4, 5) is guided to the test surface Wa via the pentagonal prism 6 and the rhombic prism 7, and the light from the test surface Wa is guided to the condensing optical systems (10, 11) via the rhombic prism 8 and the pentagonal prism 9. However, the number and arrangement of the total reflection surfaces are not limited, and, as shown in FIG. 12, for example, a configuration may be adopted in which two total reflection surfaces (31 b; 32b) are arranged in the optical path.

In the modification of fig. 12, light from the projection optical systems (4, 5) is guided to the test surface Wa via a triangular prism 31 which is a Schmitt prism (Schmitt prism), and light from the test surface Wa is guided to the condensing optical systems (10, 11) via a triangular prism 32 which is a Schmitt prism. In fig. 12, the projection condenser lens 4 and the light receiving condenser lens 11 are not shown, corresponding to fig. 3.

In the modification of fig. 12, light emitted from the projection optical systems (4, 5) along the optical axis AX1 enters the optical schmitt prism 31. In the schmitt prism 31, the light transmitted through the 1 st transmission surface 31a is totally reflected by the total reflection surface 31b, and then transmitted through the 2 nd transmission surface 31c to be emitted from the schmitt prism 31 along the optical axis AX 2. Light emitted from the schmitt prism 31 along the optical axis AX2 enters the test surface Wa.

The light reflected by the detection surface Wa enters the schmitt prism 32 along the optical axis AX3 symmetrical to the optical axis AX2 with respect to the optical axis AX of the projection optical system PL. In the schmitt prism 32, the light transmitted through the 1 st transmission surface 32a is totally reflected by the total reflection surface 32b, and then transmitted through the 2 nd transmission surface 32c, and is emitted from the schmitt prism 32 along the optical axis AX 4. The light emitted from the schmitt prism 32 along the optical axis AX4 enters the condensing optical system (10, 11).

In the modification of fig. 12, by setting the refractive index n of the optical material forming the schmitt prism (31; 32) as the total reflection prism member and the incident angle θ of the light with respect to the total reflection surface (31 b; 32b) thereof to substantially satisfy the relationship shown in expression (7), it is possible to suppress the influence of the relative positional shift caused by the polarization component of the light totally reflected by the total reflection surface (31 b; 32b) of the schmitt prism (31; 32) on the detection of the surface position of the detection target surface Wa and to detect the surface position of the detection target surface Wa with high accuracy.

In other words, in order to suppress the influence of the relative positional shift due to the polarization component of the light totally reflected by the total reflection surface (31 b; 32b) of the schmitt prism (31; 32) on the detection of the surface position of the detection target surface Wa and to detect the surface position of the detection target surface Wa with high accuracy, the refractive index n of the schmitt prism (31; 32) and the incident angle θ of the incident light to the total reflection surface (31 b; 32b) are determined so that the relative positional shift Δ due to the polarization component of the light totally reflected by the total reflection surface (31 b; 32b) is substantially 0, that is, so that the absolute value of the relative positional shift Δ due to the polarization component of the light totally reflected by the total reflection surface (31 b; 32b) is, for example, 0.3 μm or less, more preferably 0.2 μm or less than 0.2 μm.

Hereinafter, the range of the incident angle θ where the absolute value of the relative positional shift amount Δ due to the polarization component generated by the primary total reflection is 0.3 μm or less when the refractive index n of the total reflection prism member is changed will be described with reference to fig. 13 to 16. Fig. 13 shows a relationship between the amount of relative positional shift Δ and the incident angle θ due to the primary total reflection when the refractive index n of the total reflection prism member is 1.45 and the central wavelength λ c of light is 750 nm. Referring to fig. 13, in order to suppress the absolute value of the relative positional shift amount Δ due to the polarization component generated by the primary total reflection to 0.3 μm or less and satisfy the conditional expression (8), the range of the incident angle θ can be set to about 48 degrees to 90 degrees. The incident angle θ at which the relative positional displacement amount Δ is substantially 0 is about 53 degrees.

Fig. 14 shows a relationship between the amount of relative positional shift Δ and the incident angle θ due to the primary total reflection when the refractive index n of the total reflection prism member is 1.5 and the central wavelength λ c of light is 750 nm. Referring to fig. 14, in order to suppress the absolute value of the relative positional shift amount Δ due to the polarization component generated by the primary total reflection to 0.3 μm or less and satisfy the conditional expression (8), the range of the incident angle θ can be set to about 45 degrees to 90 degrees. The incident angle θ at which the relative positional displacement amount Δ is substantially 0 is about 52 degrees.

Fig. 15 shows a relationship between the amount of relative positional shift Δ and the incident angle θ due to the primary total reflection when the refractive index n of the total reflection prism member is 1.6 and the central wavelength λ c of light is 750 nm. Referring to fig. 15, in order to suppress the absolute value of the relative positional shift amount Δ due to the polarization component generated by the primary total reflection to 0.3 μm or less and satisfy the conditional expression (8), the range of the incident angle θ can be set to about 42 degrees to 90 degrees. The incident angle θ at which the relative positional displacement amount Δ is substantially 0 is about 49 degrees.

Fig. 16 shows a relationship between the relative positional displacement amount Δ and the incident angle θ due to the primary total reflection when the refractive index n of the total reflection prism member is 1.7 and the central wavelength λ c of light is 750 nm. Referring to fig. 16, in order to suppress the absolute value of the relative positional shift amount Δ due to the polarization component generated by the primary total reflection to 0.3 μm or less and satisfy the conditional expression (8), the range of the incident angle θ can be set to about 39 degrees to 90 degrees. The incident angle θ at which the relative positional displacement amount Δ is substantially 0 is about 46 degrees.

In the above embodiment, the example in which the exposure device includes a single surface position detection device has been described, but the present invention is not limited to this, and the detection field of view may be divided in a plurality of surface position detection devices as necessary. In this case, calibration (calibration) of each apparatus may be performed based on a detection result in a common field of view of the 1 st plane position detection apparatus and the 2 nd plane position detection apparatus.

In the above-described embodiments, the present invention is applied to the detection of the surface position of the photosensitive substrate in the projection exposure apparatus, but the present invention may also be applied to the detection of the surface position of the photomask in the projection exposure apparatus. In the above-described embodiment, the present invention is applied to the detection of the surface position of the photosensitive substrate in the projection exposure apparatus, but the present invention may be applied to the detection of the surface position of a general test surface.

In the above-described embodiment, the present invention is applied to detection of the surface position of the test surface (position along the normal line of the test surface). However, the present invention is not limited to this, and for example, the present invention can be applied to a measuring apparatus in which an optical member having a total reflection surface is disposed in a measuring optical path, and in general, the present invention can be applied to an optical apparatus in which an optical member having a total reflection surface is disposed in an optical path. Specifically, the present invention can be applied to an apparatus for measuring the surface shape of a test surface as shown in fig. 17, or an apparatus for measuring the position of a test surface (two-dimensional position of a test surface along the in-plane direction) as shown in fig. 18.

In the measuring apparatus shown in fig. 17, measurement light from a light source 41 is incident on a total reflection optical member (optical member having a total reflection surface) 43 such as a rhombic prism via a light transmission optical system (projection optical system) 42. The measurement light totally reflected by the total reflection surface (not shown) of the total reflection optical member 43 enters the detection surface 44. The measurement light reflected by the detection surface 44 enters, for example, a total reflection optical member 45 having the same configuration as the total reflection optical member 43. The measurement light totally reflected by the total reflection surface (not shown) of the total reflection optical member 45 is incident on an image detector 47 such as a CCD through a light receiving optical system 46.

In this apparatus, when the height position of the test surface 44 on which the measurement light is incident changes, the incident position (image position) of the measurement light to the image detector 47 changes. Therefore, the surface shape (height distribution of each position in the plane) of the test surface 44 is measured by measuring the incident position of the measurement light to the image detector 47 while two-dimensionally moving the test surface 44 in the in-plane direction and changing the incident position of the measurement light to the test surface 44 or while changing the incident position of the measurement light to the test surface 44 by the action of the oscillating mirror or the polygon mirror (polygon mirror) in the light-transmitting optical system 42. When a thin film is present on the test surface 44 or when polarization is present on the test surface 44, if a relative positional shift due to the polarization component occurs in the total reflection of the total reflection optical members 43 and 45, the surface shape of the test surface 44 cannot be measured with high accuracy.

In order to suppress the influence of the relative position due to the polarization component of the light totally reflected by the total reflection optical members 43 and 45 on the measurement of the deviation of the surface shape of the test object surface 44 and to measure the surface shape of the test object surface 44 with high accuracy, the refractive index n of the total reflection optical members 43 and 45 and the incident angle θ of the incident light to the total reflection surface are determined so that the relative positional deviation Δ due to the polarization component of the light totally reflected by the total reflection optical members 43 and 45 is substantially 0, that is, the absolute value of the relative positional deviation Δ due to the polarization component of the light totally reflected by the total reflection optical members 43 and 45 is, for example, 0.3 μm or less, and more preferably 0.2 μm or less.

In the measuring apparatus shown in fig. 18, the measurement light from the illumination system 51 is reflected by a half mirror (half mirror)53 in the objective optical system 52, then emitted from the objective optical system 52, and then incident on a schmitt prism (optical member having a total reflection surface) 54. The measurement light totally reflected by the total reflection surface 54a of the schmitt prism 54, such as a triangular prism, illuminates the test surface 55. The measurement light reflected by a photomask (not shown) provided on the test surface 55 is again incident on the schmitt prism 54. The measurement light totally reflected by the total reflection surface 54a of the schmitt prism 54 is incident on an image detector 56 such as a CCD through the objective optical system 52 and the half mirror 53 in the objective optical system 52.

In the measuring apparatus shown in fig. 18, the position of the photomask on the test surface 55 and the position of the test surface 55 (the two-dimensional position of the test surface 55 along the in-plane direction) are measured based on the output of the image detector 56. When the test surface 55 has polarization properties, if a relative positional shift due to the polarization component occurs in the total reflection of the schmitt prism 54, the position of the test surface 55 cannot be measured with high accuracy.

In order to suppress the influence of relative positional shift due to polarization components of the light totally reflected by the schmitt prism 54 on the measurement of the position of the detection surface 55 and to measure the position of the detection surface 55 with high accuracy, the refractive index n of the schmitt prism 54 and the incident angle θ of the incident light to the total reflection surface 54a are determined so that the relative positional shift Δ due to polarization components of the light totally reflected by the schmitt prism 54 is substantially 0, that is, the absolute value of the relative positional shift Δ due to polarization components of the light totally reflected by the schmitt prism 54 is, for example, 0.3 μm or less, and more preferably 0.2 μm or less.

As described above, when the detection surface has a film or polarization characteristics that affect polarization, a Goos-henchen phase Shift (Goos-Haenchen Shift) occurs on the inner surface reflection surface (total reflection surface) disposed in the optical path (irradiation optical path, detection optical path, or the like), and therefore, in order to prevent the Goos-henchen phase Shift from occurring, it is preferable to appropriately set the refractive index of the optical member constituting the inner surface reflection surface (total reflection surface) and the incident angle with respect to the inner surface reflection surface (total reflection surface).

However, in the above-described embodiments shown in fig. 1 to 3, a parallelogram prism (rhombic prism) having two total reflection surfaces parallel to each other is used as the total reflection prism member. The refractive index n of the prism and the incident angle θ of incident light on each total reflection surface are determined so as to suppress the amount of relative positional shift Δ generated in each total reflection surface from being small. However, without being limited thereto, for example, a quadrangular prism 61 having two total reflection surfaces (generally, two total reflection surfaces which are not parallel) facing each other as shown in FIG. 19 may be used as the total reflection prism member, and the refractive index n of the prism and the incident angles θ 1 (0. ltoreq. θ 1. ltoreq.90 °) and θ 2 (0. ltoreq. θ 2. ltoreq.90 °) of incident light with respect to the two total reflection surfaces are determined so as to suppress the amount of relative positional shift finally generated by light after the sequential total reflection by the two total reflection surfaces 61a and 61b, that is, the sum Δ 1+ Δ 2 of the amount of relative positional shift Δ 1 generated by the 1 st total reflection surface 61a and the amount of relative positional shift Δ 2 generated by the 2 nd total reflection surface 61b from being small.

At this time, the amount of relative positional displacement Δ 12, which is finally generated by the light after being totally reflected sequentially by the two total reflection surfaces 61a and 61b, is Δ 1+ Δ 2, and is expressed by the following expression (10). The right 1 st term of the expression (10) corresponds to a relative positional displacement amount Δ 1 generated in the 1 st total reflection surface 61a, and the right 2 nd term corresponds to a relative positional displacement amount Δ 2 generated in the 2 nd total reflection surface 61 b.

[ number 7]

Here, in order to suppress the influence of the relative positional shift due to the polarization component of the totally reflected light on the detection accuracy and the like, the idea of the above-described embodiment that the relative positional shift amount generated in one total reflection surface is suppressed to 0.3 μm or less than 0.3 μm is applied to the relative positional shift amount Δ 12 represented by the formula (10), and as a conditional expression for suppressing the relative positional shift amount Δ 12 finally generated in the light after the total reflection sequentially by the two total reflection surfaces 61a and 61b to be small, the following conditional expression (11) in which the upper limit is 0.3 μm × 2 to 0.6 μm and the lower limit is-0.3 μm × 2 to 0.6 μm is obtained.

[ number 8]

As a specific numerical example, when the quadrangular prism 61 is made of quartz having a refractive index n of 1.45, and the incident angle θ 1 to the 1 st total reflection surface 61a is 47 degrees and the incident angle θ 2 to the 2 nd total reflection surface 61b is 70 degrees, the amount of relative positional displacement Δ 1 generated in the 1 st total reflection surface 61a is +0.48 μm and the amount of relative positional displacement Δ 2 generated in the 2 nd total reflection surface 61b is-0.21 μm. That is, the relative positional deviation Δ 1 generated by the 1 st total reflection surface 61a and the relative positional deviation Δ 2 generated by the 2 nd total reflection surface 61b cancel each other, and the relative positional deviation Δ 12 finally generated by the light after the sequential total reflection by the two total reflection surfaces 61a and 61b is +0.27 μm and is less than or equal to 0.3 μm.

As another numerical example, when the quadrangular prism 61 is formed of quartz having a refractive index n of 1.45, and the incident angle θ 1 to the 1 st total reflection surface 61a is 50 degrees and the incident angle θ 2 to the 2 nd total reflection surface 61b is 60 degrees, the amount of relative positional displacement Δ 1 generated in the 1 st total reflection surface 61a is +0.155 μm and the amount of relative positional displacement Δ 2 generated in the 2 nd total reflection surface 61b is-0.136 μm. That is, the relative positional deviation Δ 1 generated by the 1 st total reflection surface 61a and the relative positional deviation Δ 2 generated by the 2 nd total reflection surface 61b cancel each other, and the relative positional deviation Δ 12 finally generated by the light after the sequential total reflection by the two total reflection surfaces 61a and 61b is +0.019 μm and is less than or equal to 0.05 μm.

In the explanation with reference to fig. 19, the quadrangular prism 61 having two total reflection surfaces is used as the total reflection prism member, but a polygonal prism having two or more total reflection surfaces can be similarly considered when it is generally used. That is, in order to suppress the amount of relative positional shift finally generated in light after total reflection sequentially performed on a plurality of total reflection surfaces (N: N is an integer of 2 or more) of one polygonal prism (generally, an optical member), the refractive index N of the prism and the incident angle θ a (0 ° ≦ θ a ≦ 90 °; a ≦ 1 to N) of incident light to the a-th total reflection surface (inner surface reflection surface) may be determined. In this case, the amount of relative positional displacement Δ 1N finally generated by the light totally reflected by the N total reflection surfaces in sequence is expressed by the following expression (12).

[ number 9]

Here, in order to suppress the influence of relative positional shift due to polarization components of totally reflected light on detection accuracy and the like, the idea of the above-described embodiment that the amount of relative positional shift generated in one total reflection surface is suppressed to 0.3 μm or less is applied to the amount of relative positional shift Δ 1N represented by expression (12), and as a conditional expression for suppressing the amount of relative positional shift Δ 1N finally generated in light after total reflection sequentially by N total reflection surfaces, the following conditional expression (13) is obtained in which the upper limit is 0.3 μm × N is 0.3N μm and the lower limit is-0.3 μm × N is-0.3N μm.

[ number 10]

In addition, the refractive index na of the optical member forming the a-th total reflection surface (inner reflection surface) and the incident angle θ a of incident light to the a-th total reflection surface (0 ° ≦ θ a ≦ 90 °; a ≦ 1 to N) may be determined so as to suppress the amount of relative positional deviation finally occurring in light after total reflection sequentially performed by a plurality of total reflection surfaces (N: N is an integer of 2 or more) among the plurality of optical members. In this case, the amount of relative positional displacement Δ 1N that is finally generated by the light that is totally reflected in the plurality of optical members sequentially by the N total reflection surfaces is expressed by the following expression (14).

[ number 11]

Here, in order to suppress the influence of relative positional shift due to polarization components of totally reflected light on detection accuracy and the like, the idea of the above-described embodiment that the amount of relative positional shift generated by one total reflection surface is suppressed to 0.3 μm or less than 0.3 μm is applied to the amount of relative positional shift Δ 1N represented by expression (14), and as a conditional expression for suppressing the amount of relative positional shift Δ 1N finally generated by light after total reflection sequentially by N total reflection surfaces, the following conditional expression (15) is obtained in which the upper limit is 0.3 μm × N is 0.3N μm and the lower limit is-0.3 μm × N is-0.3N μm.

[ number 12]

Although the lower limit values are not set in the conditional expressions (8) and (9), it is preferable that the lower limit value of the conditional expression (8) is set to "0.3 μm or more" and that the lower limit value of the conditional expression (9) is set to "0.2 μm or more" and that the lower limit value of the conditional expression (9. If the value is less than the lower limit of conditional expression (8), the configuration of oblique incidence with a large incidence angle is achieved, and the optical member such as a prism becomes complicated and large-sized, and further the entire device becomes complicated and large-sized, which is not preferable. On the other hand, if the lower limit of the conditional expression (9) is exceeded, the incident angle tends to be larger in the oblique incidence configuration, and the optical member such as a prism tends to be more complicated and larger in size, and further the entire device tends to be complicated and larger in size, which is not preferable.

In the conditional expression (8), the upper limit is set to "0.3 μm or less" but in order to simplify (reduce) the optical member or device and to further realize highly accurate and stable detection, it is preferable to set the upper limit of the conditional expression (8) to "0.05 μm or less" and the lower limit of the conditional expression (8) to "0.05 μm or more" respectively. That is, in order to simplify or reduce the size of the optical member or device and to further realize high-precision and stable detection, it is preferable that the following conditional expression (16) is satisfied.

[ number 13]

Hereinafter, the range of the incident angle θ where the absolute value of the relative positional shift amount Δ due to the polarization component generated by the primary total reflection is 0.05 μm or less when the refractive index n of the total reflection prism member is changed will be described with reference to fig. 20 to 23 corresponding to fig. 13 to 16. Fig. 20 is an enlarged view of a part of fig. 13, and shows a relationship between a relative positional displacement amount Δ and an incident angle θ due to primary total reflection when a refractive index n of the total reflection prism member is 1.45 and a central wavelength λ c of light is 750 nm. Referring to fig. 20, in order to suppress the absolute value of the relative positional shift amount Δ due to the polarization component generated by the primary total reflection to 0.05 μm or less and satisfy the conditional expression (16), the range of the incident angle θ can be set to about 52 degrees to 55 degrees.

Fig. 21 is an enlarged view of a part of fig. 14, and shows a relationship between a relative positional displacement amount Δ and an incident angle θ due to primary total reflection when a refractive index n of the total reflection prism member is 1.5 and a central wavelength λ c of light is 750 nm. Referring to fig. 21, in order to suppress the absolute value of the relative positional shift amount Δ due to the polarization component generated by the primary total reflection to 0.05 μm or less and satisfy the conditional expression (16), the range of the incident angle θ can be set to about 49.5 degrees to 56 degrees.

Fig. 22 is an enlarged view of a part of fig. 15, and shows a relationship between a relative positional displacement amount Δ and an incident angle θ due to primary total reflection when a refractive index n of the total reflection prism member is 1.6 and a central wavelength λ c of light is 750 nm. Referring to fig. 22, in order to suppress the absolute value of the relative positional shift amount Δ due to the polarization component generated by the primary total reflection to 0.05 μm or less and satisfy the conditional expression (16), the range of the incident angle θ can be set to about 46.5 degrees to 53 degrees.

Fig. 23 is an enlarged view of a part of fig. 16, and shows a relationship between a relative positional displacement amount Δ and an incident angle θ due to primary total reflection when a refractive index n of the total reflection prism member is 1.7 and a central wavelength λ c of light is 750 nm. Referring to fig. 23, in order to suppress the absolute value of the relative positional shift amount Δ due to the polarization component generated by the primary total reflection to 0.05 μm or less and satisfy the conditional expression (16), the range of the incident angle θ can be set to about 43.5 degrees to 50 degrees.

Similarly, if the upper limit value of conditional expression (13) when total reflection is performed sequentially on a plurality of total reflection surfaces in one optical member is set to 0.05 μm × N equal to 0.05N μm and the lower limit value thereof is set to-0.05 μm × N equal to-0.05N μm, conditional expression (17) better than conditional expression (13) is obtained as a conditional expression for simplifying or simplifying the optical member or the apparatus and further realizing highly accurate and stable detection.

[ number 14]

Similarly, if the upper limit value of conditional expression (15) when the optical members sequentially totally reflect light on the total reflection surfaces is set to 0.05 μm × N to 0.05N μm and the lower limit value is set to-0.05 μm × N to-0.05N μm, conditional expression (18) better than conditional expression (15) is obtained as a conditional expression for simplifying or simplifying the optical members or devices and further realizing highly accurate and stable detection.

[ number 15]

In the present invention, the GHS generated in the plurality of total reflection surfaces is suppressed by appropriately setting the incident angle and the refractive index forming each total reflection surface, but the amount of the gulf-henry phase shift (GHS) may be adjusted and controlled by making one or more of the optical members having the total reflection surfaces (one or more of the optical members having the total reflection surfaces) have a configuration in which the incident angle is adjustable by an adjusting device and changing the incident angle of each total reflection surface. Here, the adjusting means may be configured so that the optical member can be manually (manually) or automatically adjusted, but it is preferable that the adjusting means is configured so that the optical member can be automatically adjusted. In this case, the light passing through each total reflection surface is detected by the detection device, and the adjustment device including the motor and the like is driven based on the output information (detection signal, drive signal and the like) from the detection device, so that the appropriate amount of the phase shift (GHS) of the guse-henqin can be automatically set.

For example, in the embodiment shown in fig. 12, a light splitting member (a half mirror surface or the like) is disposed on the detector side of the lens 10 (above the lens 10), and a detection device (a detector or the like) for detecting the amount of the guse-henry phase shift (GHS) is disposed in the optical path branched by the light splitting member. Further, a driving device (adjusting device) for independently inclining each schmitt prism (31, 32) is arranged according to the output from the detecting device (detector, etc.), and the incidence angle of the light incident on each total reflection surface (31b, 32b) of each schmitt prism (31, 32) is independently adjusted through the driving device (adjusting device), thereby the GHS amount of the whole device can be properly set.

In the exposure apparatus of the above embodiment, a main photomask (photomask) is illuminated by an illumination device (illumination step), and a pattern for transfer formed on the photomask is exposed onto a photosensitive substrate using a projection optical system (exposure step), whereby a micro device (semiconductor device, image pickup device, liquid crystal display device, thin film magnetic head, or the like) can be manufactured. Hereinafter, an example of a method for obtaining a semiconductor device as a microdevice by forming a predetermined circuit pattern on a wafer or the like as a photosensitive substrate using the exposure apparatus according to the present embodiment will be described with reference to a flowchart of fig. 24.

First, in step 301 of fig. 24, a metal film is deposited on a batch of wafers. In step 302, a photoresist is coated on the metal film on the wafer of the lot. Then, in step 303, the image of the pattern on the photomask is sequentially exposed and transferred to the shot (shot) regions on the wafer of the one lot via the projection optical system using the exposure apparatus of the present embodiment. Thereafter, after the photoresist on the wafer of the lot is developed in step 304, the photoresist pattern is etched on the wafer of the lot as a photomask in step 305, whereby a circuit pattern corresponding to the pattern on the photomask is formed on each shot region on each wafer.

Thereafter, a circuit pattern and the like are formed in an upper layer to manufacture a device such as a semiconductor device. According to the above-described method for manufacturing a semiconductor device, a semiconductor device having an extremely fine circuit pattern can be obtained with high yield (through put). In steps 301 to 305, metal is deposited on the wafer, a photoresist is applied to the metal film, and then each step of exposure, development, and etching is performed, but before these steps, a silicon oxide film is formed on the wafer, a photoresist is applied to the silicon oxide film, and then each step of exposure, development, etching, and the like may be performed.

In the exposure apparatus of the present embodiment, a liquid crystal display device as a microdevice can be obtained by forming a predetermined pattern (circuit pattern, electrode pattern, or the like) on a plate (glass substrate). An example of this method will be described below with reference to the flowchart of fig. 25. In fig. 25, in a pattern forming step 401, a so-called photolithography step is performed in which a pattern of a photomask is transferred and exposed onto a photosensitive substrate (such as a glass substrate coated with a resist) using the exposure apparatus of the present embodiment. By the photolithography step, a predetermined pattern including a plurality of electrodes and the like is formed on the photosensitive substrate. Thereafter, the exposed substrate is subjected to a developing step, an etching step, a photoresist stripping step, and the like, thereby forming a predetermined pattern on the substrate, and the process proceeds to a color filter forming step 402.

Next, in the color filter forming step 402, a color filter is formed by arranging a plurality of sets of three dots (matrix) corresponding to r (red), g (green), and b (blue) in a matrix, or by arranging a set of R, G, B three stripe (stripe) filters in a plurality of horizontal scanning line directions. Then, after the color filter forming step 402, a unit assembling step 403 is performed. In the cell assembling step 403, a liquid crystal panel (liquid crystal cell) is assembled using the substrate having the predetermined pattern obtained in the pattern forming step 401, the color filter obtained in the color filter forming step 402, and the like.

In the cell assembling step 403, for example, liquid crystal is injected between the substrate having the predetermined pattern obtained in the pattern forming step 401 and the color filter obtained in the color filter forming step 402, thereby manufacturing a liquid crystal panel (liquid crystal cell). Thereafter, in a module assembling step 404, components such as an electric circuit and a backlight for performing a display operation of the assembled liquid crystal panel (liquid crystal cell) are mounted as liquid crystal display elements, and the assembly is completed. According to the above method for manufacturing a liquid crystal display element, a liquid crystal display element having an extremely fine circuit pattern can be obtained with high yield.

Claims (50)

1. A face position detecting apparatus comprising: a projection system for projecting the light beam onto the surface to be inspected from an oblique direction; and a light receiving system for receiving the light beam reflected by the detection surface; and detecting the surface position of the detected surface based on the output of the light receiving system,

the face position detection device is characterized in that:

the projection system includes a projection optical system for forming a primary image of a predetermined pattern on the test surface,

the light receiving system has a condensing optical system for condensing the light beam reflected by the test surface to form a secondary image of the predetermined pattern, and

at least one of the projection system and the light receiving system includes a total reflection prism member which is disposed in at least one of an optical path between the projection optical system and the inspection surface and an optical path between the condensing optical system and the inspection surface, has a total reflection surface for totally reflecting the light beam, and

the relationship between the refractive index of the optical material forming the total reflection prism member and the incident angle of the light beam with respect to the total reflection surface is such that the amount of relative positional deviation of the light beam totally reflected by the total reflection surface due to the polarization component is within a predetermined range.

2. The face position detection apparatus according to claim 1, wherein:

the total reflection prism member is formed of an optical material having a predetermined refractive index, and

the incident angle of the light beam on the total reflection surface of the total reflection prism member is determined so that the relative positional deviation amount of the light beam totally reflected by the total reflection surface due to the polarization component is substantially 0.

3. The face position detection apparatus according to claim 1, wherein:

the total reflection prism member is configured to totally reflect the light beam incident at a predetermined incident angle with respect to the total reflection surface, and

the refractive index of the optical material forming the total reflection prism member is determined so that the relative positional deviation amount of the light beam totally reflected by the total reflection surface due to the polarization component is substantially 0.

4. The face-position detecting device according to any one of claims 1 to 3, wherein:

when the wavelength of the light beam is lambda (mum), the refractive index of the total reflection prism member is n, and the incident angle of the principal ray along the optical axis of the light beam incident on the total reflection surface is theta (0 DEG to theta 90 DEG), the optical system satisfies the following condition

[ number 16]

5. The face-position detecting device according to any one of claims 1 to 3, wherein:

when the wavelength of the light beam is lambda (mum), the refractive index of the total reflection prism member is n, and the incident angle of the principal ray along the optical axis of the light beam incident on the total reflection surface is theta (0 DEG to theta 90 DEG), the optical system satisfies the following condition

[ number 17]

6. The face-position detecting device according to any one of claims 1 to 3, wherein:

the total reflection prism member has N total reflection surfaces

When the wavelength of the light beam is lambda (mum), the refractive index of the total reflection prism member is n, and the incident angle theta a of the principal ray along the optical axis in the light beam incident on the a-th total reflection surface is 0 DEG-theta a-90 DEG, the optical axis satisfies

[ number 18]

7. The face-position detecting device according to any one of claims 1 to 3, wherein:

the total reflection prism member has N total reflection surfaces

When the wavelength of the light beam is lambda (mum), the refractive index of the total reflection prism member is n, and the incident angle theta a of the principal ray along the optical axis in the light beam incident on the a-th total reflection surface is 0 DEG-theta a-90 DEG, the optical axis satisfies

[ number 19]

8. The face-position detecting device according to any one of claims 1 to 3, wherein:

the projection system includes a projection side prism member as the total reflection prism member, the projection side prism member having a plurality of total reflection surfaces for moving the optical paths of the light beams substantially in parallel,

the light receiving system includes a light receiving side prism member as the total reflection prism member, the light receiving side prism member being disposed so as to correspond to the projection side prism member, and the light receiving system includes a plurality of total reflection surfaces for moving the optical paths of the light beams from the detection surface substantially in parallel.

9. The surface position detecting apparatus according to any one of claims 1 to 3, wherein the projection optical system and the condensing optical system are telecentric on the side of the detection surface.

10. The face-position detecting device according to any one of claims 1 to 3, wherein:

the light receiving system has a detecting section for detecting a lateral shift amount of the secondary image and outputting information on a surface position of the surface to be inspected based on the lateral shift amount.

11. The surface position detecting apparatus as claimed in any one of claims 1 to 3, wherein the projection optical system is telecentric on the side of the detection surface.

12. The surface position detecting apparatus as claimed in any one of claims 1 to 3, wherein the condensing optical system constitutes telecentricity on the side of the detection surface.

13. The surface position detecting device as claimed in any one of claims 1 to 3, wherein said total reflection prism member has a1 st total reflection surface and a 2 nd total reflection surface which are opposed to each other, and

the relation between the refractive index and the incident angle is such that the amount of positional deviation of the 1 st total reflection surface and the amount of positional deviation of the 2 nd total reflection surface at least partially cancel each other out.

14. The surface position detecting device as claimed in claim 13, wherein the refractive index, the incident angle with respect to the 1 st total reflection surface and the incident angle of the 2 nd total reflection surface satisfy a relationship such that a sum of a relative positional displacement amount by a polarization component of the light beam generated at the 1 st total reflection surface and a relative positional displacement amount by a polarization component of the light beam at the 2 nd total reflection surface is within the prescribed range.

15. The surface position detecting device as claimed in claim 14, wherein said total reflection prism member is formed of quartz, and

the incident angle to the 1 st total reflection surface is 47-50 degrees

The incident angle to the 2 nd total reflection surface is 60 degrees or more and 70 degrees or less.

16. The face position detecting device as claimed in claim 13, wherein the optical member has a1 st total reflection surface and a 2 nd total reflection surface which are opposed in parallel to each other.

17. An exposure apparatus for projection-exposing a predetermined pattern onto a photosensitive substrate via a projection optical system,

and the exposure apparatus is characterized by comprising:

the surface position detecting apparatus according to any one of claims 1 to 9, wherein a surface position of the predetermined pattern surface or an exposure surface of the photosensitive substrate with respect to the projection optical system is detected as a surface position of the test surface; and

and a position alignment device for aligning the predetermined pattern surface or the exposure surface of the photosensitive substrate with respect to the projection optical system based on the detection result of the surface position detection device.

18. A method of manufacturing a component, comprising:

an exposure step of exposing the predetermined pattern onto the photosensitive substrate using the exposure apparatus according to claim 17; and

a developing step of developing the photosensitive substrate exposed by the exposure step.

19. An optical device in which an optical member having a total reflection surface is arranged in an optical path,

the optical device is characterized in that:

the relationship between the refractive index of the optical member and the incident angle of the light with respect to the total reflection surface is such that the amount of relative positional deviation of the light totally reflected by the total reflection surface due to the polarization component is within a predetermined range.

20. The optical device of claim 19, wherein:

the optical member is formed of an optical material having a predetermined refractive index, and

the incident angle of the light with respect to the total reflection surface of the optical member is set so that the relative positional displacement amount of the light totally reflected by the total reflection surface of the optical member due to the polarization component is substantially zero.

21. The optical device of claim 19 or 20, wherein:

when the wavelength of the light is lambda (mum), the refractive index of the optical member is n, and the incident angle of the principal ray along the optical axis in the light incident on the total reflection surface is theta (0 DEG to theta 90 DEG), the optical member satisfies the following condition

[ number 20]

22. The optical device of claim 19 or 20, wherein:

the wavelength of the light is lambda (mum), the refractive index of the optical member is n, and the incident angle of the principal ray along the optical axis in the light incident on the total reflection surface is theta (0 DEG-theta)

When the angle is less than or equal to 90 degrees, the angle is satisfied

[ number 21]

23. The optical device of claim 19 or 20, wherein:

the optical member has N total reflection surfaces, and

when the wavelength of the light is lambda (mum), the refractive index of the optical member is n, and the incident angle of the principal ray along the optical axis in the light incident on the a-th total reflection surface is theta a (0 DEG to theta a) 90 DEG, the optical member satisfies

[ number 22]

24. The optical device of claim 19 or 20, wherein:

the optical member has N total reflection surfaces, and

when the wavelength of the light is lambda (mum), the refractive index of the optical member is n, and the incident angle of the principal ray along the optical axis in the light incident on the a-th total reflection surface is theta a (0 DEG to theta a) 90 DEG, the optical member satisfies

[ number 23]

25. An optical device, characterized by:

n total reflection surfaces are arranged in the light path, and

the incident angle of light with respect to each of the N total reflection surfaces and the refractive index of each optical member forming the N total reflection surfaces are set so that the magnitude of the relative positional deviation amount due to the polarization component of light totally reflected by the N total reflection surfaces is within a predetermined range.

26. The optical device of claim 25, wherein:

when the wavelength of the light is lambda (mum), the refractive index of the optical member forming the a-th total reflection surface is na, and the incident angle of the principal ray along the optical axis in the light incident on the a-th total reflection surface is theta a (0 DEG to theta a < 90 DEG), the optical member satisfies

[ number 24]

27. The optical device of claim 25, wherein:

when the wavelength of the light is lambda (mum), the refractive index of the optical member forming the a-th total reflection surface is na, and the incident angle of the principal ray along the optical axis in the light incident on the a-th total reflection surface is theta a (0 DEG to theta a < 90 DEG), the optical member satisfies

[ number 25]

28. A measuring apparatus is provided with an optical member having a total reflection surface in a measuring optical path,

the measuring device is characterized in that:

the relationship between the refractive index of the optical member and the incident angle of the measurement light with respect to the total reflection surface is such that the amount of relative positional deviation of the light totally reflected by the total reflection surface due to the polarization component is within a predetermined range.

29. A measuring device for measuring a surface to be inspected,

it is characterized by comprising:

a projection optical system for guiding the measuring light to the surface to be inspected;

a light receiving optical system that receives the measurement light reflected by the test surface;

a detector that detects the measurement light passing through the light receiving optical system; and

an optical member including a total reflection surface that is disposed in at least one of an optical path of the measurement light between the projection optical system and the test surface and an optical path of the measurement light between the light reception optical system and the test surface and totally reflects the measurement light; and is

The relationship between the refractive index of the optical member and the incident angle of the measurement light with respect to the total reflection surface of the optical member is such that the amount of relative positional deviation of the measurement light totally reflected by the total reflection surface due to the polarization component falls within a predetermined range.

30. The measurement device of claim 29, wherein:

the measuring device measures the position of the test surface based on the output of the detector.

31. The measurement device of claim 29, wherein:

the measuring device measures the surface position of the test surface based on the output of the detector.

32. The measurement device of claim 29, wherein:

the measuring device measures the surface shape of the test surface based on the output of the detector.

33. The measurement device of any one of claim 29, wherein:

the optical member is formed of an optical material having a predetermined refractive index, and

the incident angle of the measurement light with respect to the total reflection surface of the optical member is set so that the relative positional displacement amount of the measurement light totally reflected by the total reflection surface of the optical member due to the polarization component is substantially zero.

34. The measurement device of claim 29, wherein:

when the wavelength of the measuring light is lambda (mum), the refractive index of the optical member is n, and the incident angle of the principal ray along the optical axis in the incident measuring light incident on the total reflection surface is theta (0 DEG to theta 90 DEG), the optical system satisfies the following condition

[ number 26]

35. The measurement device of claim 29, wherein:

when the wavelength of the measuring light is lambda (mum), the refractive index of the optical member is n, and the incident angle of the principal ray along the optical axis in the measuring light incident on the total reflection surface is theta (0 DEG theta ≦ 90 DEG), the optical system satisfies the following conditions

[ number 27]

36. The measurement device of claim 29, wherein:

the number of the total reflection surfaces of the optical member is N, and

when the wavelength of the measuring light is lambda (mum), the refractive index of the optical member is n, and the incident angle of the principal ray along the optical axis in the measuring light incident on the a-th total reflection surface is theta a (0 DEG to theta a < 90 DEG), the optical member satisfies

[ number 28]

37. The measurement device of claim 29, wherein:

the number of the total reflection surfaces of the optical member is N, and

when the wavelength of the measuring light is lambda (mum), the refractive index of the optical member is n, and the incident angle of the principal ray along the optical axis in the measuring light incident on the a-th total reflection surface is theta a (0 DEG to theta a < 90 DEG), the optical member satisfies

[ number 29]

38. The measurement device of claim 29, comprising:

a detector for outputting information on the position or surface shape of the surface to be inspected.

39. The measuring apparatus according to claim 29, wherein the optical member has a1 st total reflection surface and a 2 nd total reflection surface which face each other, and

the relation between the refractive index and the incident angle is such that the amount of positional deviation of the 1 st total reflection surface and the amount of positional deviation of the 2 nd total reflection surface at least partially cancel each other out.

40. The measuring device according to claim 39, wherein the refractive index, the incident angle with respect to the 1 st total reflection surface, and the incident angle with respect to the 2 nd total reflection surface satisfy a relationship such that a sum of a relative positional displacement amount due to the polarization component generated at the 1 st total reflection surface and a relative positional displacement amount due to the polarization component generated at the 2 nd total reflection surface is within the prescribed range.

41. The measurement device of claim 40 wherein the optical member is formed of quartz and

the incident angle to the 1 st total reflection surface is 47-50 degrees

The incident angle to the 2 nd total reflection surface is 60 degrees or more and 70 degrees or less.

42. The measuring device according to claim 40, wherein the 1 st total reflection surface and the 2 nd total reflection surface are disposed parallel to each other.

43. The measuring apparatus according to claim 39, wherein the position information on the inspected surface includes a surface position of the inspected surface, or a position along the in-plane direction.

44. A measuring device, characterized by: n total reflection surfaces are arranged in the light path, and

the incident angle of light with respect to each of the N total reflection surfaces and the refractive index of each optical member forming the N total reflection surfaces are set so that the relative positional deviation amount of light totally reflected by the N total reflection surfaces due to the polarization component falls within a predetermined range.

45. The measurement device as set forth in claim 44 wherein

When the wavelength of the light is lambda (mum), the refractive index of the optical member forming the a-th total reflection surface is na, and the incident angle of the principal ray along the optical axis in the light incident on the a-th total reflection surface is theta a (0 DEG to theta a < 90 DEG), the optical member satisfies

[ number 30]

46. The measurement device as set forth in claim 44 wherein

When the wavelength of the light is lambda (mum), the refractive index of the optical member forming the a-th total reflection surface is na, and the incident angle of the principal ray along the optical axis in the light incident on the a-th total reflection surface is theta a (0 DEG to theta a < 90 DEG), the optical member satisfies

[ number 31]

47. An exposure apparatus for exposing a predetermined pattern onto a photosensitive substrate,

the exposure apparatus is characterized by comprising a measuring device according to any one of claims 29 to 37 and 44 to 46 for measuring the position of the photosensitive substrate.

48. A method of manufacturing a component, comprising:

an exposure step of exposing the predetermined pattern onto the photosensitive substrate using the exposure apparatus according to claim 47; and

a developing step of developing the photosensitive substrate exposed by the exposure step.

49. An exposure apparatus for exposing a pattern provided on an object onto a photosensitive substrate, the exposure apparatus comprising:

a measurement device as claimed in any one of claims 38 to 43.

50. A method of manufacturing a component, comprising:

an exposure step of exposing the pattern onto the photosensitive substrate using the exposure apparatus according to claim 49; and

a developing step of developing the photosensitive substrate exposed by the exposure step.