JP2002350914A - Light source device and irradiation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate light at <=210 nm wavelength with high efficiency in a simple structure. SOLUTION: Light at <=1050 nm wavelength is used as the basic waves, which are successively passed through nonlinear optical elements 181, 182, 183 to convert the wavelength by steps by the second harmonic wave generation or sum frequency generation to generate the fifth harmonic waves (at <=210 nm wavelength) of the basic waves. Therefore, UV light at <=210 nm wavelength can be generated by using the second harmonic wave generation or sum frequency generation by the nonlinear optical effect, controlling the number of steps for wavelength conversion to three steps and by using the minimum one step of the sum frequency generation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source device and a light irradiation device, and more particularly, to a light source device that generates ultraviolet light of 210 nm or less, and a light irradiation device including the light source device.

[0002]

2. Description of the Related Art Conventionally, a light irradiation device has been used for inspection of a fine structure of an object, fine processing of an object, and treatment of vision correction. For example, in a lithography process for manufacturing a semiconductor element or the like, a mask or a reticle (hereinafter, referred to as a reticle) is used.
The pattern formed on the “reticle” is transferred onto a substrate such as a wafer or a glass plate (hereinafter, referred to as “substrate” or “wafer” as appropriate) coated with a resist or the like via a projection optical system. For this purpose, an exposure apparatus, which is a kind of light irradiation apparatus, is used. As such an exposure apparatus, a static exposure type projection exposure apparatus using a step-and-repeat method and a scanning exposure type projection exposure apparatus using a step-and-scan method are mainly used. For correction of vision, ablation of the corneal surface (PRK: Photorefractive Keratectom)
y) Or ablation inside the cornea (LASIK: L
A laser treatment device, which is a type of light irradiation device, is used to perform treatment for myopia, astigmatism, and the like by performing aser intrastromal keratomileusis).

For such a light irradiation device, many developments have been made on a light source that generates short-wavelength light. The direction of development of such short-wavelength light sources is mainly classified into the following two types. One is the development of an excimer laser light source in which the laser oscillation wavelength itself is a short wavelength, and the other is the development of a short wavelength light source utilizing harmonic generation of an infrared or visible light laser.

[0004] Of these, KrF
A light source device using an excimer laser (wavelength 248 nm) has been developed. At present, a light source device using an ArF excimer laser (wavelength 193 nm) or the like as an ultraviolet light source having a shorter wavelength of 210 nm or less has been developed. ing. However, these excimer lasers are large, and the maintenance of the laser is complicated and expensive because of the use of toxic fluorine gas.
There are disadvantages as a light source device.

[0005] Therefore, by utilizing the nonlinear optical effect of a nonlinear optical element such as a nonlinear optical crystal, which is a method of shortening the wavelength along the latter direction, generation of a second harmonic or sum frequency generates long wavelength light. Attention has been focused on a method of converting to shorter wavelength ultraviolet light. As a light source device using such a method, for example, International Publication WO9 adopting a method of converting an infrared laser beam into a fundamental wave and converting the fundamental wave into ultraviolet light.
9/46835 (hereinafter simply referred to as “conventional example”).

[0006]

When the wavelength conversion is performed by the second harmonic generation or the sum frequency generation using the nonlinear optical effect by the nonlinear optical element as in the above-mentioned prior art, the present inventor has proposed the following. According to the findings obtained from the research results, the lower limit of the wavelength of light that can be obtained as the second harmonic generation with a practically acceptable efficiency is currently 21%.
It is about 0 nm. Therefore, if light having a wavelength of 210 nm or less is to be generated by the second harmonic generation or sum frequency generation, the second harmonic generation alone cannot be used, and at least the final stage wavelength conversion is performed by sum frequency generation. It is necessary.

For this reason, for example, an infrared laser beam having a wavelength of 1.55 μm band, which is frequently used in optical fiber communication, is adopted as a fundamental wave, and light of the same wavelength (193 nm) as that of the ArF excimer laser is generated. Then, the fundamental wave 8
Although it is necessary to generate a harmonic, generation of such an eighth harmonic requires wavelength conversion by generation of a second harmonic or sum frequency in four or more stages. Also, 4
It was necessary to generate the sum frequency in two or more stages of the wavelength conversion in more than one stage.

By the way, it is difficult to say that the second harmonic generation or the sum frequency generation has a very high wavelength conversion efficiency at present. In addition, in the generation of the sum frequency, the optical axes of two incident lights are usually aligned. Required. As a result, if light having a wavelength of 210 nm is obtained by the generation of the eighth harmonic using the second harmonic generation and the sum frequency generation, it can be said that the wavelength converter and thus the light source device can be simply configured. It was difficult to obtain light having a wavelength of 210 nm efficiently.

On the other hand, with recent demands for improvement of exposure accuracy and exposure throughput, high brightness of 210 n
There is a strong demand for a technology capable of efficiently generating light having a wavelength of m or less with a simple configuration.

The present invention has been made under the above circumstances, and a first object of the present invention is to provide a simple configuration and a 210n
An object of the present invention is to provide a light source device capable of efficiently generating wavelength-converted light having a wavelength of m or less.

A second object of the present invention is to provide a light irradiation apparatus capable of irradiating an object with efficiently generated wavelength converted light having a wavelength of 210 nm or less.

[0012]

In order to efficiently generate short wavelength light of practical power by performing wavelength conversion by second harmonic generation or sum frequency generation, a wavelength of sufficient wavelength can be obtained. It is necessary to use light as a fundamental wave, to have a nonlinear optical element for second harmonic generation or sum frequency generation, and to reduce the number of stages of wavelength conversion.

On the other hand, according to the knowledge obtained by the present inventors from the results of the research, as described above, light having a wavelength of 210 nm or less as a second harmonic of the fundamental wave cannot be generated with practical efficiency. At the same time, it is not possible to generate light having a wavelength of 210 nm or less as a third harmonic of the fundamental wave with practical efficiency by the second harmonic generation or the sum frequency generation using the currently known nonlinear optical element. That is, in the wavelength conversion using the second harmonic generation or the sum frequency generation, it is not possible to generate light of 210 nm or less from the fundamental wave by setting the number of stages of the wavelength conversion to two or less.

On the other hand, the present inventor has made the number of stages of wavelength conversion three, and while using a currently known nonlinear optical element,
It has been found that light having a wavelength of 210 nm or less can be generated as a fourth or fifth harmonic of the fundamental wave. Here, in a configuration in which light having a wavelength of 210 nm or less is generated as a fourth harmonic, it is necessary to generate a sum frequency in two of three stages, and light having a wavelength of 210 nm or less is generated as a fifth harmonic. It was also found at the same time that it was necessary to generate a sum frequency in one of the three stages. As described above, since the generation of the sum frequency generally requires optical axis alignment, the smaller the number of stages for performing the sum frequency generation, the higher the possibility that the configuration of the wavelength conversion unit can be simplified.

Further, the wavelength is 21 as the fourth harmonic or the fifth harmonic.
When generating light of 0 nm or less, 1 which is a fundamental wave
There are many laser light sources that generate light having a wavelength of 050 nm or less with sufficient power. There is also an optical amplifier that amplifies light having the wavelength of the fundamental wave.

The present invention has been made based on such findings.

That is, the present invention provides a light source device (16) for generating ultraviolet light having a first wavelength of 210 nm or less, and generating infrared or visible light having a second wavelength of 1050 nm or less. Fundamental wave generator (160, 161)
And a wavelength conversion unit (163) that generates a fifth harmonic of the fundamental wave having the first wavelength using light emitted from the fundamental wave generation unit as a fundamental wave.

According to this, the fundamental wave generating section is generated,
The wavelength conversion unit generates a fifth harmonic of the fundamental wave using light in the infrared or visible range having a wavelength of 1050 nm or less as the fundamental wave. Therefore, by utilizing the second harmonic generation and the sum frequency generation by the nonlinear optical effect, it is possible to reduce the number of wavelength conversion stages to three, and to reduce the number of sum frequency generation stages to the minimum one. With a simple configuration, it is possible to efficiently generate ultraviolet light having a wavelength of 210 nm or less.

In the light source device according to the present invention, the fundamental wave generating section may be a laser light source (160) for generating light of the first wavelength.
A); and an optical amplifier (167) for amplifying light emitted from the laser light source.

Here, the laser light source may include a solid-state laser.

The optical amplifier may include at least one of an optical fiber amplifier and a semiconductor optical amplifier.

In the light source device according to the present invention, the wavelength conversion unit receives the fundamental wave and generates a second harmonic of the fundamental wave by generating a second harmonic.
1, 181 ′); the second nonlinear optical element (182, 182 ′) that receives the second harmonic and generates a fourth harmonic of the fundamental wave by generation of the second harmonic, and the fundamental wave and the second harmonic wave. 4
A third nonlinear optical element (183, 183 ') that receives a harmonic and generates a fifth harmonic of the fundamental wave by generating a sum frequency.
And;

Here, the first nonlinear optical element is a GdC
a ₄ O (BO ₃ ) ₃ crystal, wherein the fundamental wave is the GdC
It is possible to adopt a configuration in which the light travels in the a ₄ O (BO ₃ ) ₃ crystal substantially parallel to the main dielectric axis direction (the z-axis direction of the main dielectric axis).

The first nonlinear optical element is GdCa
₄ O (BO ₃ ) ₃ crystal, wherein the fundamental wave is the GdCa ₄
A configuration in which the effective nonlinear optical coefficient proceeds in the O (BO ₃ ) ₃ crystal in a direction in which the effective nonlinear optical coefficient becomes almost maximum can be adopted.

In addition, the first nonlinear optical element is Gd _X Y
_1-X Ca ₄ O (BO ₃ ) ₃ crystal, wherein the fundamental wave is the G
d _X Y _1-X Ca to ₄ O (BO _{3) 3} crystal, can be configured to the effective nonlinear optical coefficient proceeds in a direction becomes substantially maximum.

Further, the second nonlinear optical element is made of K ₂ Al ₂
The structure may be a B ₂ O ₇ crystal.

Further, the third nonlinear optical element is formed of K ₂ Al ₂
The structure may be a B ₂ O ₇ crystal.

[0028] The wavelength converter may further include a dispersion compensating element (191, 192) for correcting coaxiality between the fundamental wave and the fourth harmonic wave incident on the third nonlinear optical element. Can be.

The light irradiation device of the present invention is a light irradiation device for irradiating an object with light, and the light source device (16) of the present invention.
And an irradiation optical system (12) for emitting light emitted from the light source device toward the object. According to this, since the light emitted from the light source device of the present invention is radiated to the target object through the irradiation optical system, the wavelength-converted light having the wavelength of 210 nm or less that is efficiently converted is radiated to the target object. be able to.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows a schematic configuration of an exposure apparatus 10 which is a light irradiation apparatus according to an embodiment including a light source apparatus according to the present invention. This exposure apparatus 10
This is a step-and-scan type scanning exposure apparatus.

The exposure apparatus 10 includes an illumination system including a light source device 16 and an illumination optical system 12, and illumination light for exposure (hereinafter, referred to as "illumination light" or "exposure light") IL from the illumination system.
A reticle stage RST for holding a reticle R illuminated by a reticle, a projection optical system PL for projecting exposure light IL via the reticle R onto a wafer W as a substrate, and an XY mounted with a Z tilt stage 58 for holding the wafer W A stage 14 and their control systems are provided.

The light source device 16 has a wavelength of 193, for example.
This is a harmonic generator that outputs ultraviolet pulse light of nm (almost the same wavelength as the ArF excimer laser light). The light source device 16 includes the illumination optical system 12, the reticle stage RS
T, the projection optical system PL, the Z tilt stage 58, the XY stage 14, and an exposure apparatus main body including a main body column (not shown) on which these components are mounted, and an environment in which temperature, pressure, humidity, and the like are adjusted with high precision. It is housed in a mental chamber (hereinafter, referred to as “chamber”) 11. In the present embodiment, all the light source devices 16 are arranged in the chamber 11. However, a part of the light source device 16, for example, only a wavelength converter
1, the wavelength conversion unit 163 and the main body of the light source device 16 may be connected by an optical fiber or the like.

FIG. 2 is a block diagram showing the internal structure of the light source device 16 together with a main control device 50 for controlling the entire device. As shown in FIG. 2, the light source device 16 includes a light source unit 16A, a laser control device 16B, a light amount control device 16C, and the like.

The light source section 16A includes a pulse light generation section 16
0, an optical amplifier 161, a wavelength converter 163, and a beam monitor mechanism 164.

The pulse light generator 160 includes a laser light source 160 A, an optical coupler BS, and an optical isolator 160.
B etc.

As the laser light source 160A, for example, a titanium sapphire laser having an oscillation wavelength of 967 nm is used. The titanium sapphire laser can perform both pulse oscillation and continuous light oscillation, but the laser light source 160A of the present embodiment employs pulse oscillation.

The optical coupler BS has a transmittance of 9%.
About 7% is used. Therefore, the laser light from the laser light source 160A is split into two by the optical coupler BS, and about 97% of the laser light travels toward the next-stage optical isolator 160B, and the remaining about 3% enters the beam monitor mechanism 164. It has become.

The beam monitor mechanism 164 includes an energy monitor (not shown) including a photoelectric conversion element such as a photodiode. The output of this energy monitor is
The power is supplied to the main controller 50 via the laser controller 16B. The main controller 50 detects the energy power of the laser beam based on the output of the energy monitor, and oscillates at the laser light source 160A via the laser controller 16B. The amount of the laser beam to be controlled is controlled as needed.

The optical isolator 160B allows only light in the direction from the optical coupler BS to the optical amplifier 161 to pass, and blocks light in the opposite direction. The optical isolator 160B prevents a change in the oscillation mode of the laser light source 160A and the generation of noise due to the reflected light (return light).

The optical amplifying section 161 includes the optical isolator 1
The pulse light from the optical isolator 160B is periodically distributed and time-divided as shown in FIG. 3 (for example, 128 branches).
Optical splitter 166 and a plurality of optical fiber amplifiers 167
It is comprised including.

As shown in FIG. 3, the optical fiber amplifier 167 includes an amplifying optical fiber 17 as an amplifying medium.
5. Excitation semiconductor laser 178 ₁ for generating pump light,
178 ₂ , a wavelength division multiplexer (Wavele multiplexer) that combines the output light of the optical isolator 160B and the pump light, and supplies the combined light thus obtained to the amplification optical fiber 175.
ngth Division Multiplexer: WDM) 179 ₁ , 179 ₂
It has. Here, the pumping semiconductor laser 178 ₁ and WDM 179 ₁ are used for forward pumping, while the pumping semiconductor laser 178 ₂ and WDM 179 ₂ are used for backward pumping. As a result, the linearity of the optical amplification factor with respect to the input light intensity is maintained, and the optical amplification factor is improved.

The amplification optical fiber 175 is mainly composed of silica glass or phosphate glass, has a core and a clad, and has a core doped with ytterbium (Yb) ions at a high density.

In the optical fiber amplifier 167 configured as described above, the pump light generated by the pumping semiconductor lasers 178 ₁ and 178 ₂ is supplied to the amplification optical fiber 175 by WD.
M179 ₁ , 179 ₂ , and the WDM
179 _{1 The} pulsed light is incident on the optical fiber 1 for amplification.
As it travels through the 75 cores, stimulated radiation is generated and the pulsed light is amplified. In such optical amplification, since the amplification optical fiber 175 has a high amplification rate, high-intensity pulsed light having high wavelength uniformity is output. For this reason, narrow-band light can be obtained efficiently.

The pumping semiconductor lasers 178 ₁ and 178 ₂
Generates light having a wavelength shorter than the oscillation wavelength of the laser light source 160A as pump light. This pump light is WD
M179 _1, 179 ₂ are supplied to the amplification optical fiber 175 via, thereby Karagai electrons Yb are excited, inversion of the so-called energy level occurs. The pumping semiconductor lasers 178 ₁ and 178 ₂ are provided with a light amount control device 16C.
Is controlled by the

In this embodiment, in order to suppress the difference in gain between the optical fiber amplifiers 167, a part of the output is branched by the optical fiber amplifier 167, and the photoelectric conversion elements 171 provided at the respective branch ends. Each is photoelectrically converted. These photoelectric conversion elements 17
1 is supplied to the light quantity control device 16C.

In the light quantity control device 16C, each of the pumping semiconductor lasers 178 ₁ and 178 ₁ is controlled so that the light output from each of the optical fiber amplifiers 167 is constant (that is, balanced).
78 ₂ drives current is adapted to the feedback control.

The wavelength conversion section 163 includes a plurality of nonlinear optical elements, and outputs pulse light (wavelength 9) from the optical amplification section 161.
67 nm) is converted into a fifth harmonic thereof to generate pulsed ultraviolet light having substantially the same output wavelength (193 nm) as the ArF excimer laser.

FIG. 4 shows an example of the configuration of the wavelength converter 163. Here, a specific example of the wavelength conversion unit 163 will be described with reference to FIG.

The wavelength converter 163 in FIG. 4 performs wavelength conversion in the order of fundamental wave (wavelength 967 nm) → second harmonic wave (wavelength 484 nm) → fourth harmonic wave (wavelength 242 nm) → fifth harmonic wave (wavelength 193 nm).

More specifically, the light (fundamental wave) having a wavelength of 967 nm (frequency ω) emitted from the optical amplifier 161 enters the first-stage nonlinear optical element 181 via the condenser lens 186. I do. When the fundamental wave passes through this nonlinear optical element 181, the second harmonic generation generates a double wave of the frequency ω of the fundamental wave, that is, a double wave of a frequency 2ω (wavelength 484 nm).

As the first-stage nonlinear optical element 181, a GdCa ₄ O (BO ₃ ) ₃ crystal (hereinafter “GdCOB”) is used.
(Abbreviated as “crystal”). This GdCOB
Crystal 181 is arranged in a direction in which light from optical amplifying section 161 travels substantially along the principal axis of dielectric (z axis of the principal axis of dielectric), and is a second harmonic for converting the wavelength of the fundamental wave into a second harmonic. The phase matching that occurs is non-critical phase matching (NCP
M: Non-Critical Phase Matching). The NCPM does not cause an angle shift (Walk-off) between the fundamental wave and the generated second harmonic in the nonlinear optical element, and enables conversion to a second harmonic with high efficiency. Further, the generated second harmonic wave is advantageous because the beam is not deformed by the walk-off. Since no walk-off occurs in the second harmonic generation by the NCPM, the fundamental wave and the second harmonic are emitted from the nonlinear optical element 181 substantially coaxially. The fundamental wave and the second harmonic are emitted from the nonlinear optical element 181 in directions in which the polarization directions are orthogonal to each other.

The fundamental wave and the second harmonic emitted from the nonlinear optical element 181 enter the second-stage nonlinear optical element 182 via the condenser lens 187. When the second harmonic passes through this nonlinear optical element 182, the second harmonic generation generates a fourth harmonic having a frequency of 4ω (wavelength: 242 nm).

As the second-stage nonlinear optical element 182, a K ₂ Al ₂ B ₂ O ₇ crystal (hereinafter abbreviated as “KAB crystal”) is used. In the KAB crystal 182, the phase matching of the second harmonic generation for converting the wavelength of the second harmonic of the frequency 2ω from the nonlinear optical element 181 to the fourth harmonic is a critical phase matching (CPM).
g) is arranged in the orientation performed by. In the generation of the second harmonic by the CPM, generally, an angle shift (W) between the second harmonic in the nonlinear optical element and the fourth harmonic thereof, that is, the fourth harmonic.
alk-off) occurs and the beam shape of the fourth harmonic becomes elliptical, but in the case of a KAB crystal, the angle shift due to walk-off is small. Therefore, the fundamental wave,
The second and fourth harmonics are emitted substantially coaxially. Note that the fundamental wave and the fourth harmonic wave are directions in which the polarization directions are parallel to each other and are emitted from the nonlinear optical element 182, and the fundamental wave and the second harmonic wave are directions in which the polarization directions are orthogonal to each other. Then, the light is emitted from the nonlinear optical element 182.

The fundamental wave, the second harmonic, and the fourth harmonic emitted from the nonlinear optical element 182 enter the third-stage nonlinear optical element 183 via the condenser lens 188. When the incident light passes through the nonlinear optical element 183, the sum frequency generation of the fundamental wave and the fourth harmonic generates five times the frequency ω of the fundamental wave, that is, the fifth harmonic of the frequency 5ω (wavelength 193 nm).

In the present embodiment, a KAB crystal is used as the third-stage nonlinear optical element 183. The KAB crystal 183 is arranged in an orientation in which phase matching of sum frequency generation by type 1 for performing wavelength conversion from the fourth harmonic to the fifth harmonic from the fundamental wave from the nonlinear optical element 182 is performed.

The wavelength conversion unit 163 configured as described above
In the above, the fundamental wave (wavelength 987 nm) amplified by the optical amplifier 161 is wavelength-converted in three stages to obtain light having a target wavelength of 193 nm.

Returning to FIG. 1, the illumination optical system 12 includes an optical integrator, a variable ND filter, a reticle blind and the like (all not shown). Here, a fly-eye lens, an internal reflection type integrator (such as a rod integrator), a diffractive optical element, or the like is used as the optical integrator. The configuration of such an illumination optical system is described in, for example,
Japanese Patent Application Publication No. 0-112433 discloses an optical integrator employing a fly-eye lens. Exposure light IL emitted from this illumination optical system 12
The reticle stage R passes through the condenser lens 32 after the optical path is bent vertically downward by the mirror M.
Rectangular illumination area 42 on reticle R held on ST
R is illuminated with a uniform illuminance distribution.

A reticle R is mounted on the reticle stage RST, and is held by suction via a vacuum chuck (not shown). The reticle stage RST is movable in a horizontal plane (XY plane) so that the reticle stage driving unit 49 scans the reticle stage RST in a predetermined stroke range in a scanning direction (here, the Y direction which is the horizontal direction in FIG. 1). It has become. The position and the rotation amount of the reticle stage RST during the scanning are determined by the reticle stage RS.
Measurement is performed by an external laser interferometer 54R via a movable mirror 52R fixed on T, and the laser interferometer 54R
Are supplied to the main controller 50.

The projection optical system PL is, for example, a bilateral telecentric reduction system, and has a common optical axis AX in the Z-axis direction.
And a plurality of lens elements having the following. As the projection optical system PL, one having a projection magnification β of, for example, １ ／, ５, 、, or the like is used. Therefore, as described above, when the illumination region 42R of the reticle R is illuminated by the exposure light IL, the illumination region 42R of the pattern formed on the reticle R
An image obtained by reducing a part of the inside at a projection magnification β by the projection optical system PL is formed in a rectangular projection area 42W conjugate to the illumination area 42R within the field of view of the projection optical system PL, and is applied to the surface of the wafer W. The reduced image is transferred to a resist (photosensitive agent).

The XY stage 14 is two-dimensionally driven by a wafer stage driving section 56 in a Y direction which is a scanning direction and an X direction orthogonal to the scanning direction (a direction orthogonal to the plane of FIG. 1). A wafer W is held on a Z tilt stage 58 mounted on the XY stage 14 via a wafer holder (not shown) by vacuum suction or the like. The Z tilt stage 58 adjusts the position (focus position) of the wafer W in the Z direction by, for example, three actuators (piezo elements or voice coil motors), and also adjusts the position of the wafer W with respect to the XY plane (the image plane of the projection optical system PL). It has the function of adjusting the inclination angle of. Also, XY
The position of the stage 14 is controlled by an external laser interferometer 54W via a movable mirror 52W fixed on a Z tilt stage 58.
, And the measured value of the laser interferometer 54W is supplied to the main controller 50.

Here, the moving mirrors actually include an X moving mirror having a reflecting surface perpendicular to the X axis and a Y moving mirror having a reflecting surface perpendicular to the Y axis. Interferometers for X-axis position measurement, Y-axis position measurement, and rotation (including yawing amount, pitching amount, and rolling amount) are provided, respectively. , A moving mirror 52W, and a laser interferometer 54W.

On the Z tilt stage 58, there is provided a reference mark plate FM used for performing reticle alignment and the like which will be described later. The surface of the reference mark plate FM has substantially the same height as the surface of the wafer W. Reference marks such as a reticle alignment reference mark and a baseline measurement reference mark are formed on the surface of the reference mark plate FM.

Further, in the exposure apparatus 10 of the present embodiment, as shown in FIG. 1, under the control of the main controller 50, a large number of images are set on the image plane (XY plane) of the projection optical system PL. An irradiation optical system 60a for irradiating an imaging light beam for forming an image of a pinhole or a slit toward the measurement point from an oblique direction with respect to the optical axis AX, and the imaging light beam on the surface of the wafer W. Light receiving optical system 60b for receiving the reflected light beam
And an oblique incidence type multi-point focal position detection system (focus sensor). The detailed configuration of the multipoint focus position detection system (focus sensor) similar to that of the present embodiment is disclosed in, for example, Japanese Patent Application Laid-Open No. 6-283403.

At the time of scanning exposure or the like, main controller 50 determines the Z position of the partial surface of the shot area where the measurement point exists based on the Z position detected for each measurement point from light receiving optical system 60b. By controlling the Z position of the Z tilt stage 58 via a drive system (not shown) based on the calculation result while performing the calculation of the tilt amount, auto-focus (auto-focusing) and auto-leveling are executed.

The main controller 50 includes a CPU (Central Processing Unit), a ROM (Read Only Memory),
M (random access memory) or the like, and includes a so-called microcomputer (or workstation). In addition to performing the various controls described above, the reticle R is used to perform the exposure operation properly. , Scanning of the wafer W, stepping of the wafer W, exposure timing, and the like. Further, in the present embodiment, the main control device 50 controls the exposure amount at the time of scanning exposure as described later, and also performs overall control of the entire device.

More specifically, main controller 50 scans reticle R with respect to illumination area 42R in the + Y direction (or -Y direction) at a speed V _R = V through reticle stage RST, for example, during scanning exposure. In synchronism therewith, the velocity of the wafer W in the −Y direction (or + Y direction) with respect to the projection area 42W via the XY stage 14 is V _W = β · V (β is the projection magnification from the reticle R to the wafer W ), The positions and speeds of the reticle stage RST and the XY stage 14 are controlled via the reticle stage driving unit 49 and the wafer stage driving unit 56 based on the measured values of the laser interferometers 54R and 54W, respectively. . Also,
At the time of stepping, main controller 50 controls wafer stage driving section 56 based on the measurement value of laser interferometer 54W.
The position of the XY stage 14 is controlled via the.

Next, an exposure sequence in the case where a predetermined number (N) of reticle patterns are exposed on a predetermined number (N) of wafers W in exposure apparatus 10 of the present embodiment will be described.
The following description focuses on the control operation.

First, main controller 50 loads reticle R to be exposed onto reticle stage RST using a reticle loader (not shown).

Next, reticle alignment is performed using a reticle alignment system (not shown), and baseline measurement of an off-axis type alignment system (not shown) is performed using the above-described reference marks.

Next, main controller 50 instructs a wafer transfer system (not shown) to replace wafer W. As a result, the wafer transfer system and the wafer transfer mechanism (not shown) on the XY stage 14 exchange the wafer (or simply load the wafer if there is no wafer on the stage). Next, a series of alignment processes such as fine alignment (eg, EGA) are performed using the alignment system for which the above-described baseline measurement has been performed. Since the wafer exchange and wafer alignment are performed in the same manner as in a known exposure apparatus, further detailed description is omitted here.

Next, based on the alignment result and the shot map data, the operation of moving the wafer W to the scanning start position for exposure of each shot area on the wafer W and the above-described scanning exposure operation are repeated. Then, the reticle pattern is transferred to a plurality of shot areas on the wafer W by a step-and-scan method. During the scanning exposure, the main controller 50 gives a command to the light quantity controller 16C to control the exposure light quantity in order to give the target integrated exposure quantity determined according to the exposure condition and the resist sensitivity to the wafer W.

When the exposure of the first wafer W is completed, main controller 50 instructs a wafer transfer system (not shown) to replace wafer W. As a result, the wafer is exchanged by the wafer transfer system and the wafer transfer mechanism (not shown) on the XY stage 14, and thereafter, search alignment and fine alignment are performed on the replaced wafer in the same manner as described above.

Then, similarly to the above, this wafer W
A reticle pattern is transferred to the upper plurality of shot areas by a step-and-scan method.

When the illuminance changes due to the change of the exposure condition and / or the reticle pattern, the frequency and the peak power of the light emitted from the light source 16 are adjusted so that an appropriate exposure amount is given to the wafer (resist). Is desirably controlled. At this time, in addition to at least one of the frequency and the peak power, the scanning speed of the reticle and the wafer may be adjusted.

As described above, according to the light source device 16 of the present embodiment, after the optical amplifier 161 amplifies the continuous optical pulse train generated by the pulse light generator 160, the wavelength converter 163 2 using nonlinear optical element
The second harmonic generation in one stage and the sum frequency generation in one stage are performed to generate a fifth harmonic, and a wavelength 1 having a wavelength of 210 nm or less is used.
Since light of 93 nm is obtained, the wavelength is 210 with a simple configuration.
The light of nm or less can be generated efficiently.

Further, since a solid-state laser called titanium sapphire laser is used as the laser light source 160A, the size of the light source device 16 can be reduced, and the maintainability can be improved.

The pulse light generated by the pulse light generator 160 is amplified by the optical amplifier 161 and converted into a fundamental wave by the wavelength converter 1.
63 is supplied to the wavelength converter 16.
No. 3, the wavelength converted light having sufficient luminance can be obtained.

Further, according to the exposure apparatus of the present embodiment, the reticle R can be irradiated with the high-luminance illumination light IL during the scanning exposure, so that the pattern formed on the reticle R can be accurately and efficiently transferred to the wafer W. be able to.

When the pulse width of the fundamental wave is narrow,
Time shift between the fundamental wave and the fourth harmonic due to the difference in the optical path length due to the dispersion of the optical components (nonlinear optical elements 181 to 183, condenser lenses 186 to 188, etc.) in the optical path and the optical components When there is a spatial shift between the fundamental wave and the fourth harmonic due to a processing error or an adjustment error of the nonlinear optical element 183,
There is a possibility that the wavelength conversion efficiency at is small or conversion is not possible. In order to compensate for such a temporal / spatial shift, a configuration in which a dispersion compensating element 191 is arranged between the condenser lens 188 and the nonlinear optical element 183 as shown in FIG. This dispersion compensating element 19
As the first material, almost common optical glass such as synthetic quartz can be used, and the material may be determined in consideration of the amount of temporal and spatial shift and the dispersion of the material. It should be noted that the time lag can be corrected by changing the thickness of the dispersion compensating element 191. If precise control is required, the temperature may be adjusted. Further, the spatial displacement can be corrected by tilting the dispersion compensating element 191 or performing wedge processing.

In the above-described embodiment, the KAB crystal 182 that generates the fourth harmonic generates the Wa due to the second harmonic generation.
Although the wavelength conversion unit 163 is configured such that the angle shift due to lk-off can be ignored, the influence of the angle shift due to walk-off can be almost completely avoided by employing the configuration illustrated in FIG.

The wavelength converter 163 of FIG. 6 is different from the wavelength converter of FIG. 4 in that a condensing lens 188 'is used instead of the condensing lens 188.
A dichroic mirror 196 that functions as a light splitting element that reflects a fundamental wave and transmits a second harmonic, and a dichroic mirror 19, between the lens 81 and the condenser lens 187.
6, the nonlinear optical element 182
Mirrors 197 and 198 that set an optical path to bypass the optical path, a dichroic mirror 199 that is disposed immediately before the nonlinear optical element 183 and functions as a light combining element that combines the fundamental wave and the fourth harmonic coaxially, A different point is further provided with a condenser lens 189 arranged in the bypass optical path.
Although the condenser lens 188 'is depicted as a single lens in FIG. 6, the condenser lens 188' is actually a combination of a plurality of cylindrical lenses or a combination of a cylindrical lens and a spherical lens. The beam shape of the fourth harmonic wave that has been made elliptical by Walk-off can be shaped into a desired beam shape.

In the wavelength conversion section 163 of FIG. 6, the optical amplification section 16 is provided similarly to the wavelength conversion section in the above embodiment.
When the fundamental wave having a wavelength of 967 nm emitted from 1 is incident on the first-stage nonlinear optical element 181 via the condenser lens 186, the second harmonic is generated by the second harmonic generation by the NCPM in the nonlinear optical element 181. appear. And
The fundamental wave and the second harmonic are emitted from the nonlinear optical element 181 almost coaxially.

The fundamental wave and the second harmonic emitted from the nonlinear optical element 181 are separated by the dichroic mirror 196, and the second harmonic transmitted through the dichroic mirror 196 passes through the condenser lens 187 to the second stage. The light enters the nonlinear optical element 182. Then, the nonlinear optical element 182
The fourth harmonic is generated by the generation of the second harmonic by the CPM, and is emitted from the nonlinear optical element 182. The fourth harmonic emitted from the nonlinear optical element 182 in this manner has Wa
Although the angular displacement due to lk-off has occurred, the fourth harmonic passes through the condenser lens 188 ′, and after correcting the angular displacement due to Walk-off, reaches the dichroic mirror 199.

On the other hand, the fundamental wave reflected by the dichroic mirror 196 passes through the mirror 197, the condenser lens 189, and the mirror 198 in order, and reaches the dichroic mirror 199.

After the fundamental wave and the fourth harmonic whose angular deviation has been corrected are accurately coaxially combined by the dichroic mirror 199, the third-stage nonlinear optical element 183 is formed.
Incident on. As a result, the phase matching for the type 1 sum frequency generation can be accurately performed, and the fifth harmonic is efficiently generated.

The wavelength converter 163 in FIG.
Modifications similar to those of the above embodiment in the case of a short pulse width can be made. That is, on the optical path of the fundamental wave or the fourth harmonic incident on the nonlinear optical element 183,
A configuration in which a dispersion compensating element is arranged can be adopted. FIG.
Is an example of such a configuration.
The configuration in which the dispersion compensating element 192 is arranged between the mirror and the mirror 198 is shown. Similar to the dispersion compensating element 191 (see FIG. 5), general optical glass such as synthetic quartz can be almost used as the material of the dispersion compensating element 192. The material may be determined in consideration of the amount and the dispersion of the material. It should be noted that the dispersion compensating element can be arranged at a position different from the arrangement position in FIG. 7 in consideration of the amount of temporal and spatial deviation actually generated and the dispersion of the material.

In the above embodiment, a GdCOB crystal is used as the first-stage nonlinear optical element
The second harmonic generation was performed by the CPM. Instead, a non-linear optical element having a periodic domain inversion structure (hereinafter, referred to as a “QPM element”) is used to perform quasi-phase matching (QPM: Quasi-Phase Matching). ), The second harmonic generation may be performed. In this case, as in the case of NCPM, no walk-off occurs.

As shown in FIG. 8, the QPM element 181 ′ is formed in the region 1 in which the polarization directions indicated by the vertical arrows in FIG. 8 are opposite to each other along the light traveling direction.
50A and the region 150B have a periodic domain inversion structure formed alternately and periodically. Here, area 1
The width of the 50A and the region 150B along the traveling direction of light is:
It is set to Λ which is defined as follows.

In the case of the generation of the second harmonic, which is required as the first-stage nonlinear optical element, the width Λ is set such that the absolute value of the wave vector of the incident light is k _{1 in} the QPM element 181 ′, Assuming that the absolute value of the wave number vector of the generated second harmonic is k _{2, it} is determined by Λ = 2π / (k ₂ −2k ₁ ) (1).

In the case of sum frequency generation, the width Λ is Q
In the PM element 181 ′, assuming that the absolute values of the wave vectors of the incident light are k ₃ and k ₄ and the absolute values of the wave vectors of the generated sum frequency are k ₅ , Λ = 2π / (k ₅ − (k ₃ + K ₄ ))... (2)

As such a QPM element 181 ′,
Periodical domain inversion LN (LiNbO _Three) Crystal (PPLN)
Crystal), periodic domain inversion LT (LiTaO_Three)crystal
(PPLT crystal), periodic domain inversion KTP (KTi
OPO_Four) Crystal (PPKTP crystal) and using stress
Crystal with a periodic domain inversion structure
"Quartz QPM element").

In the case of forming the domain regions such as the regions 150A and 150B, in the case of the PPLN crystal, the PPLT crystal, and the PPKTP crystal, the direction of the dielectric polarization is usually applied to only one of the types of regions (no voltage is applied). When)
This is performed by applying a high voltage in a direction opposite to the dielectric polarization direction. In the case of a crystal QPM element, the stress is generated by generating a periodic stress distribution in the crystal along the traveling direction of light. It is preferable that the temperature of the QPM element other than the crystal QPM element be adjusted in order to prevent the adverse effect of the photorefractive effect.

When the above-mentioned QPM elements are used, the largest nonlinear optical coefficient (PPLN crystal, PPLN crystal,
In the case of T crystal and PPKTP crystal, d ₃₃ , crystal QP
In the case of the M element, the second harmonic can be efficiently generated by using d ₁₁ ). In such a case, the polarization direction of the second harmonic generated by the nonlinear optical element 181 is the fundamental wave. And the same direction. Therefore, for example, as shown in FIG. 9, it is necessary to arrange a half-wave plate 193 for the fundamental wave immediately after the QPM element 181 ′ to rotate the polarization direction of the fundamental wave by 90 °. Becomes

The position where the half-wave plate 193 is arranged is different from the above-described embodiment and the modification of FIG. 5 when the QPM element 181 ′ is used as the first-stage nonlinear optical element. The QPM element 1 may be disposed between the optical lens 187 and the nonlinear optical element 182, or as the first-stage nonlinear optical element in the modified example of FIG.
When using 81 ′, the fundamental wave is the nonlinear optical element 1
What is necessary is just to arrange on the optical path which follows from 81 to the nonlinear optical element 183. Further, only the polarization direction of the second harmonic wave is 90
It is also possible to use an optical element that rotates by °. In this case, the second harmonic wave generated in the nonlinear optical element 181 may be arranged on an optical path that traces to the nonlinear optical element 182.

On the other hand, as the first-stage nonlinear optical element, P
When using a QPM element made of a PLN crystal, a PPLT crystal, or a PPKTP crystal, the nonlinear optical coefficient d ₃₁
Can also be used. In this case, since the polarization direction of the second harmonic generated in the QPM element is orthogonal to the polarization direction of the fundamental wave, an optical element for controlling the polarization direction such as the above-mentioned half-wave plate 193 becomes unnecessary. .

As the nonlinear optical element 181, Li
Second harmonic generation can also be performed by NCPM using B ₃ O ₅ (LBO) crystal. Since the LBO crystal has high resistance, it is preferably used when the power of the fundamental wave is very large.

Further, GdC is used as the nonlinear optical element 181.
Instead of using the OB crystal and propagating the fundamental wave substantially along the principal axis of the dielectric (the z-axis direction of the principal axis of the dielectric) as in the above embodiment, the effective nonlinear optical coefficient d _eff
The fundamental wave may be made to travel substantially along the direction in which the maximum value is obtained. In such a case, the efficiency of second harmonic generation can be improved. Note that the nonlinear optical coefficient d _eff
When the phase matching wavelength in a direction substantially along the direction in which is maximized slightly deviates from the desired wavelength (484 nm), the temperature of the GdCOB crystal 181 is adjusted to adjust the phase matching wavelength to the desired wavelength. I just need.

Further, Gd _{x is used} as the nonlinear optical element 181.
It is also possible to use a Y ₁ -x Ca ₄ O (BO ₃ ) ₃ (GdYCOB) crystal and make the fundamental wave travel substantially along the direction in which the effective nonlinear optical coefficient d _eff is maximized. It should be noted that the phase matching wavelength in a direction substantially along the direction in which the nonlinear optical coefficient d _eff is maximum is the desired wavelength (484n
m), the GdYCOB crystal 181
The phase matching wavelength may be adjusted to a desired wavelength by adjusting the temperature or the composition parameter X.

In the above embodiment, the KAB crystal is used as the second-stage nonlinear optical element 182.
sLiB ₆ O ₁₀ (CLBO) crystal or β-BaB ₂ O
It is also possible to use ₄ (BBO) crystals. In addition,
When deliquescence of CLBO crystal or BBO crystal becomes a problem, the surrounding atmosphere is purged with nitrogen, dry air, or the like,
The temperature of the CLBO crystal or BBO crystal may be adjusted to a high temperature.

The above-mentioned quartz QPM element can be used as the second-stage nonlinear optical element. In this case, since the polarization direction of the fourth harmonic generated by the crystal QPM element is parallel to the polarization direction of the second harmonic, only the modification using the crystal QPM element instead of the nonlinear optical element 182 in the above embodiment is performed. Sometimes, for example, as shown in FIG. 10, immediately after the quartz crystal QPM element 182 'instead of the nonlinear optical element 182, the half-wave plate 19
4, it is necessary to rotate the polarization direction of the fundamental wave by 90 °.

The position where the half-wavelength plate 194 is arranged is determined by using the quartz QPM element 182 ′ as the second-stage nonlinear optical element in the above embodiment and the modification of FIG. Condensing lens 188 and nonlinear optical element 18
3 or a quartz QPM element 1 as the second-stage nonlinear optical element in the modification of FIG. 6 or FIG.
When 82 'is used, the fundamental wave is the nonlinear optical element 1
It may be anywhere on the optical path from 81 to the nonlinear optical element 183. It is also possible to use an optical element that rotates only the polarization direction of the fourth harmonic by 90 °. In this case, it may be arranged on the optical path where the fourth harmonic generated in the crystal QPM element 182 ′ reaches the nonlinear optical element 183.

As the first-stage nonlinear optical element, a PPLN crystal using the largest nonlinear optical coefficient d ₃₃ ,
PPLT crystal or PPKTP crystal or crystal QP
When an M element is used and a quartz QPM element is used as the second-stage nonlinear optical element, the above 1/1
Optical components, such as the two-wavelength plates 193 and 194, for controlling the polarization direction become unnecessary as in the above-described embodiment.

In the above embodiment, the KAB crystal was used as the third-stage nonlinear optical element 183.
LBO crystals, BBO crystals, or quartz QPM devices can be used. If deliquescent of the CLBO crystal or BBO crystal becomes a problem, the surrounding atmosphere may be purged with nitrogen, dry air, or the like, or the temperature of the CLBO crystal or BBO crystal may be adjusted to a high temperature.

In the above embodiment, the laser light source 1
Although 60A is used as the pulse light source, it may be used as a continuous light source. In such a case, by arranging the optical pulse modulator between the optical isolator 160B and the optical amplifying unit 161, it is possible to obtain the same output light as the light source device 16 according to the above embodiment. An electro-optical modulator (EOM) utilizing the electro-optical effect is used as such an optical pulse modulator.
Optical modulator (AOM) using acousto-optic effect
Can be adopted. It is needless to say that continuous light can be output as a light source device without disposing an optical pulse modulator.

In the above embodiment, the laser light source 1
Although a titanium sapphire laser was used as 60A, a semiconductor laser can be used. For example, a semiconductor laser having an external resonator configuration can be used, or a distributed feedback (DFB) laser or a distributed reflection (DB) laser can be used.
R) A semiconductor laser having no external resonator configuration such as a laser can be used. Further, a fiber laser such as an ytterbium (Yb) -doped fiber laser having an oscillation wavelength of around 990 nm can be used.

Further, in the above embodiment, the optical fiber amplifier 167 is used as the optical amplifier, but a semiconductor optical amplifier can be used.

In the above-described embodiment, the optical fiber in which Yb is added to the core portion is used as the amplification medium. For example, a rod-shaped glass body to which Yb is added is used, and the excitation light is May be irradiated.

The number of optical fiber amplifiers 167 arranged in parallel in the optical amplifier 161 may be arbitrary, and the number may be determined according to the specifications required for the product to which the light source device according to the present invention is applied. Just fine. In particular, when high output is not required for the light source device, the number of optical fiber amplifiers 167 can be reduced, and the configuration can be simplified. When simplifying to include only one optical fiber amplifier 167, the splitter 166 is not required.

[0110] In the above embodiments, the wavelength of the ultraviolet light source device is emitted, it is assumed to be set to almost the same as ArF excimer laser, for example, an F ₂ laser with substantially the same wavelength (wavelength 157 nm) The setting wavelength may be arbitrary, and the oscillation wavelength of the laser light source 160A and the configuration of the wavelength converter 163 may be determined according to the wavelength to be set. However, the configuration of the above embodiment is particularly effective when the set wavelength is about 210 nm or less. The set wavelength may be determined, for example, according to the design rule (line width, pitch, etc.) of the pattern to be transferred onto the wafer. (Phase shift type or not) may be considered.

In the above embodiment, the case where the light source device according to the present invention is applied to a step-and-scan type scanning exposure apparatus has been described. The light source device according to the present invention can be applied to an apparatus, for example, a laser repair apparatus used for cutting a part (such as a fuse) of a circuit pattern formed on a wafer. In addition, the present invention is not limited to the step-and-scan type scanning exposure apparatus, but also includes a static exposure type, for example, a step-and-repeat type exposure apparatus (such as a stepper).
It can also be suitably applied to Further, the present invention can be applied to a step-and-stitch type exposure apparatus, a mirror projection aligner, and the like.

Further, in the above embodiment, an example was described in which the light source device according to the present invention is used as a light source device for generating illumination light for exposure. However, light having substantially the same wavelength as the illumination light for exposure is required. A light source device for a reticle alignment described above, or a light source device for a spatial image detection system for detecting a projection image of a mark arranged on an object plane or an image plane of a projection optical system and obtaining the optical characteristics of the projection optical system, etc. It is also possible to use as.

The light source device of the present invention can be used for various devices other than the exposure device. For example, a light source used in a laser treatment device that irradiates a cornea with a laser beam to perform ablation of the surface (or ablation inside the incised cornea), corrects the curvature or unevenness of the cornea, and treats myopia, astigmatism, and the like. It can be used as a device. Also, the light source device of the present invention can be used as a light source device in an optical inspection device or the like.

The light source device of the present invention can also be used for optical adjustment (optical axis alignment, etc.) or inspection for an optical system such as the projection optical system in the above embodiment. Further, in various devices having an excimer laser as a light source, the light source device of the present invention can be applied in place of the excimer laser.

Note that the configuration of the light source device 16 shown in FIG. 2 is based on the assumption that the light source device 16 is used in the exposure apparatus 10 of FIG. 1, and the light source device 16 is not limited to the configuration of FIG. The exposure apparatus requires high-precision wavelength control, light amount control, and the like. For example, if strict light amount control or the like is not required except for the exposure apparatus, the light amount monitor and the light amount control device 16C may not be provided.

Next, devices (semiconductor chips such as ICs and LSIs, liquid crystal panels, CCDs, thin-film magnetic heads, micromachines, etc.) using the exposure apparatus and method of the present embodiment
Will be described.

First, in a design step, a function design of a device (for example, a circuit design of a semiconductor device) is performed, and a pattern design for realizing the function is performed. Subsequently, in a mask manufacturing step, a mask on which the designed circuit pattern is formed is manufactured. On the other hand, in a wafer manufacturing step, a wafer is manufactured using a material such as silicon.

Next, in a wafer processing step, an actual circuit or the like is formed on the wafer by lithography using the mask and the wafer prepared in the above step, as described later.

This wafer processing step includes, for example, an oxidation step for oxidizing the surface of the wafer and a CV for forming an insulating film on the wafer surface in the manufacture of semiconductor devices.
It has a pre-processing step of each stage of the wafer process such as a D step, an electrode forming step of forming electrodes on the wafer by vapor deposition, an ion implantation step of implanting ions into the wafer, and a post-processing step described later. The pre-processing step is selected and executed in accordance with processing required in each stage of the wafer process.

At each stage of the wafer process, when the pre-processing step is completed, a photosensitive agent is applied to the wafer in a resist processing step, and subsequently, the circuit pattern of the mask is printed on the wafer by the exposure apparatus 10 described above in the exposure step. Expose. Next, the exposed wafer is developed in the developing step, and subsequently, in the etching step, the exposed members other than the part where the resist remains are removed by etching. Then, in the resist removing step, the unnecessary resist after etching is removed.

As described above, by repeatedly performing the pre-processing step and the post-processing step from the resist processing step to the resist removing step, multiple circuit patterns are formed on the wafer.

When the wafer processing step is completed in this way, in the assembling step, chips are formed using the wafer processed in the wafer processing step. This assembly includes processes such as an assembly process (dicing and bonding) and a packaging process (chip encapsulation).

Finally, in the inspection step, inspections such as an operation confirmation test and a durability test of the device manufactured in the assembly step are performed. After these steps, the device is completed and shipped.

As described above, a device on which a fine pattern is accurately formed is manufactured with high mass productivity.

[0125]

As described above in detail, according to the light source device of the present invention, the wavelength of 21 is obtained by generation of the fifth harmonic of the fundamental wave.
Since ultraviolet light of 0 nm or less is generated, light having a wavelength of 210 nm or less can be efficiently generated with a simple configuration.

Further, according to the light irradiation device of the present invention, the light emitted from the light source device of the present invention is irradiated to the object through the irradiation optical system, so that the wavelength that is efficiently generated is 21.
The object can be irradiated with light having a wavelength of 0 nm or less.

[Brief description of the drawings]

FIG. 1 is a view schematically showing a configuration of an exposure apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an internal configuration of the light source device of FIG. 1 together with a main controller.

FIG. 3 is a diagram schematically showing an optical fiber amplifier constituting the optical amplification unit of FIG. 2 and a peripheral portion thereof together with a part of a wavelength converter.

FIG. 4 is a diagram illustrating a configuration of a wavelength conversion unit in FIG. 2;

FIG. 5 is a diagram (part 1) for describing a modified example of the wavelength conversion unit.

FIG. 6 is a diagram (part 2) for describing a modified example of the wavelength conversion unit.

FIG. 7 is a diagram (part 3) for describing a modified example of the wavelength conversion unit;

FIG. 8 is a diagram (part 4) for explaining a modification of the wavelength conversion unit;

FIG. 9 is a diagram (No. 5) for describing a modified example of the wavelength conversion unit;

FIG. 10 is a view (No. 6) for describing a modified example of the wavelength conversion unit.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Exposure apparatus (light irradiation apparatus), 12 ... Illumination optical system (irradiation optical system), 16 ... Light source apparatus, 160 ... Pulse light generation part (part of fundamental wave generation part), 160A ... Laser light source, 16
Reference Signs List 1 ... Optical amplifier (part of fundamental wave generator), 163 ... wavelength converter, 167 ... optical fiber amplifier (optical amplifier), 181
… Nonlinear optical element (first nonlinear optical element), 182 nonlinear optical element (second nonlinear optical element), 183 nonlinear optical element (third nonlinear optical element), 191, 192 dispersion compensation element.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01S 3/10 H01L 21/30 515A F-term (Reference) 2H052 BA02 BA06 BA12 2H097 CA17 GB01 LA10 2K002 AA04 AB12 BA03 BA04 CA02 CA03 EA07 FA27 GA04 HA20 5F046 CA03 CB01 CB22 5F072 AB07 AB13 AB20 AK06 FF09 HH06 JJ05 KK12 PP07 YY09

Claims (12)

[Claims] 1. A light source device for generating ultraviolet light having a first wavelength of 210 nm or less, comprising: a fundamental wave generator for generating infrared light or visible light having a second wavelength of 1050 nm or less; A wavelength converter that generates a fifth harmonic of the fundamental wave having the first wavelength, using the light emitted from the fundamental wave generator as a fundamental wave. 2. The device according to claim 1, wherein the fundamental wave generator includes: a laser light source that generates the light of the first wavelength; and an optical amplifier that amplifies the light emitted from the laser light source. 2. The light source device according to 1. 3. The light source device according to claim 2, wherein the laser light source includes a solid-state laser. 4. The light source device according to claim 2, wherein the optical amplifier includes at least one of an optical fiber amplifier and a semiconductor optical amplifier. 5. A first nonlinear optical element that receives the fundamental wave and generates a second harmonic of the fundamental wave by generating a second harmonic; and the second harmonic wave enters the wavelength conversion unit; Second
A second harmonic generating a fourth harmonic of the fundamental wave by harmonic generation;
A nonlinear optical element; and a third nonlinear optical element that receives the fundamental wave and the fourth harmonic and generates a fifth harmonic of the fundamental wave by generating a sum frequency. 5. The light source device according to claim 4. 6. The method according to claim 1, wherein the first nonlinear optical element is GdCa _4.
O (BO ₃ ) ₃ crystal, wherein the fundamental wave is generated in the GdCa ₄ O (BO ₃ ) ₃ crystal,
The light source device according to claim 5, wherein the light source device travels substantially parallel to the direction of the main dielectric axis. 7. The method according to claim 1, wherein the first nonlinear optical element is GdCa _4.
O (BO ₃ ) ₃ crystal, wherein the fundamental wave is generated in the GdCa ₄ O (BO ₃ ) ₃ crystal,
The light source device according to claim 5, wherein the light source device travels in a direction in which an effective nonlinear optical coefficient becomes substantially maximum. 8. The optical system according to claim 1, wherein the first nonlinear optical element is Gd _X Y _{1 -X.}
A Ca ₄ O (BO ₃ ) ₃ crystal, wherein the fundamental wave travels through the Gd _X Y ₁ -x Ca ₄ O (BO ₃ ) ₃ crystal in a direction in which the effective nonlinear optical coefficient becomes substantially maximum. The light source device according to claim 5, wherein: 9. The optical system according to claim 8, wherein the second nonlinear optical element is K ₂ Al ₂ B.
The light source device according to claim 5, wherein the light source device is a ₂ O ₇ crystal. 10. The device according to claim 10, wherein the third nonlinear optical element is K ₂ Al ₂
The light source device according to claim 5, wherein the light source device is a B ₂ O ₇ crystal. 11. The wavelength conversion unit according to claim 5, further comprising a dispersion compensation element for correcting coaxiality between the fundamental wave and the fourth harmonic wave incident on the third nonlinear optical element. The light source device according to claim 10. 12. A light irradiation device for irradiating an object with light, wherein the light source device according to claim 1; and light emitted from the light source device is directed to the object. An irradiation optical system that emits light.