JP2002198281A - Illuminating device and projection aligner using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an illuminating device that easily calibrates the measurement system of output light from an excimer laser, accurately measures the quantity of light, and accurately controls the amount of exposure, and to provide a projection aligner using the illuminating device. SOLUTION: There are provided a polarization separation means, a P-polarization detection means, an S-polarization detection means, an optical system, and a control means in the aligner. In the polarization separation means, P-, and S-polarization components are separated from one of luminous fluxes that is separated by a luminous flux separation means provided in the light path of the luminous flux that is radiated from a light source. In the P-polarization detection means, the P-polarization component that is separated by the polarization separation means is detected. In the S- polarization detection means, the S-polarization component is detected. In the optical system, a specific surface is illuminated by the other luminous flux that is separated by the luminous flux separation means. In the control means, a coefficient for correcting polarization characteristics in an optical system is obtained by a signal obtained by both the detection means when the polarization state of the polarization light entering the P- and S-polarization detection means is changed, the intensity of light entering the specific surface is obtained, and the output of the light source is subjected to drive control.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illumination device and a projection exposure apparatus using the same, for example, a semiconductor device such as an IC or LSI, an imaging device such as a CCD, a display device such as a liquid crystal panel, or a device such as a magnetic head. In manufacturing, lithography to obtain a highly integrated device by projecting or exposing an electronic circuit pattern on a mask or a reticle (hereinafter collectively referred to as a “reticle”) through a projection optical system on a wafer surface. It is suitable for the process.

[0002]

2. Description of the Related Art In recent years, with the increasing integration of integrated circuits (devices) such as LSIs, an exposure apparatus capable of accurately forming a fine pattern of 1 μm or less on a wafer has been used.

In order to further reduce the resolution line width of a pattern image obtained by the exposure apparatus, an exposure apparatus equipped with an excimer laser that emits high-intensity light in the deep ultraviolet region as exposure light is used as an exposure light source. Development is also active.

In general, in order to transfer a fine circuit pattern using an exposure apparatus having a projection optical system, it is important to appropriately set an exposure amount on a wafer surface.

Therefore, in such an exposure apparatus,
A wafer is exposed at a predetermined exposure amount, and various techniques relating to this exposure amount control have been conventionally proposed. Usually, in order to control the exposure amount, a half mirror is provided in the optical path of the exposure light, and either one of the reflected light reflected by the half mirror or the transmitted light transmitted through the half mirror is used as a light receiving element for monitoring the exposure amount ( Photo detector)
In response to the output signal from the light receiving element, opening and closing a shutter installed in the optical path of the exposure light,
Exposure amount control is performed by stopping and controlling the set energy of the laser.

[0006]

As a method of controlling an exposure amount to obtain an optimum exposure amount on a wafer surface, a half mirror is provided in an optical path of exposure light, and light passing through the half mirror is detected. There is a method of detecting by using a container. Generally, the reflectance (transmittance) of this half mirror shows different values for the P-polarized light and the S-polarized light of the exposure light. Also, the exposure light separated by the half mirror is exposed on the light receiving element surface for measuring the exposure amount and the wafer surface for irradiating the exposure light by the polarization characteristics of the optical components provided in the optical path until reaching the wafer surface. The component ratios of P-polarized light and S-polarized light are different. In particular, if the optical member provided in the optical path to the light receiving element surface differs from the optical member provided in the optical path to the wafer surface, the polarization component ratio may greatly differ. Therefore, when the polarization state of the laser serving as the light source changes every moment, the ratio of the amount of light incident on the light receiving element to the exposure amount on the wafer surface changes, and the value detected by the light receiving element is changed. In this case, the amount of exposure incident on the wafer surface cannot be accurately monitored.

Japanese Patent Application Laid-Open No. Hei 8-236439 discloses a method in which a polarizing plate is provided in an exposure optical path as a method for continuously setting an adjustment amount of an exposure amount. Also, Japanese Patent Laid-Open No. 1-2
Japanese Patent No. 20825 discloses a method in which a polarized light beam divided into two is rotated by 90 degrees and an optical polarization characteristic is removed by a combining unit. When these methods are used, in the former method, the degree of polarization changes for light amount adjustment, and it becomes difficult to measure the exposure amount with high accuracy. In the latter case, it is difficult to completely depolarize the light due to the difference in the optical elements that transmit and reflect the two divided lights. Further, glass components used in an exposure apparatus equipped with an excimer laser that emits high-intensity light in the deep ultraviolet region as an exposure light source have a high transmittance and a low transmittance with a small decrease in transmittance even for long-time exposure. Although UV glass parts are required, at present,
It is difficult to completely maintain this requirement.

According to the present invention, there is provided an illuminating apparatus capable of easily controlling a light exposure amount incident on a wafer surface without being affected by a change in the polarization state of exposure light to easily obtain a highly integrated circuit pattern. It is intended to provide a projection exposure apparatus used.

[0009]

According to a first aspect of the present invention, there is provided an illumination apparatus comprising: a light source; a light beam separating means provided in an optical path of a light beam emitted from the light source; and a light beam transmitted or reflected by the light beam separating means. Polarization separating means for separating a P-polarized component and an S-polarized component from one of the light beams, P-polarized light detecting means for detecting the P-polarized light component separated by the polarized light separating means, and S-polarized light detecting means for detecting the S-polarized light component When an optical system that illuminates a predetermined surface with the other light beam of the light beam transmitted or reflected by the light beam separating device, and the polarization state of polarized light incident on the P-polarized light detecting device and the S-polarized light detecting device is changed. Using the signals obtained by both detection means, a coefficient for correcting the polarization characteristics of the optical system is obtained, and using this coefficient, the intensity of light incident on a predetermined surface is obtained, and the output of the light source is obtained. Control means for controlling the drive. It is set to.

The lighting device according to the second aspect of the present invention includes a light source means,
A light beam separating unit for separating the light beam into reflected light and transmitted light, and one of the light beams separated by the light beam separating unit into P-polarized light and S-polarized light; Polarized light separating means, P polarized light detecting means for detecting the light intensity of P polarized light separated by the polarized light separating means, S polarized light detecting means for detecting the light intensity of S polarized light, and the other of the light beams separated by the light beam separating means Using an optical system that irradiates the surface to be irradiated, and each signal obtained by the P-polarized light detection means and the S-polarized light detection means, multiplied by a coefficient for correcting the polarization characteristics of the optical system, Obtain the irradiation intensity for irradiating the irradiated surface,
It is characterized by having control means for controlling the output of the light source means using the obtained irradiation intensity.

According to a third aspect of the present invention, in the first or second aspect, the control means multiplies a value obtained by multiplying an output value obtained by the P-polarized light detecting means by a coefficient with an output value obtained by the S-polarized light detecting means. The output of the light source means is controlled by using a total value obtained from the sum of a value obtained by multiplying the coefficient by a coefficient.

According to a fourth aspect of the present invention, in the first or second aspect, the light source means has a laser, and the control means changes the degree of polarization of the laser by changing a discharge voltage (set energy) of the laser. In this case, the coefficient is calculated.

According to a fifth aspect of the present invention, in the first or second aspect, the light source means has a laser, and the control means comprises:
The coefficient is calculated by changing the degree of polarization of the laser by changing the emission frequency of the laser.

According to a sixth aspect of the present invention, in the first or second aspect, the light source means has a laser, and the control means keeps emitting the laser light for several hours or more, by gas deterioration, gas exchange, injection or the like. The coefficient is calculated by utilizing a phenomenon in which the degree of polarization changes.

According to a seventh aspect of the present invention, in the first or second aspect, the light source means has a laser, and the control means designates the number of light emission pulses of the laser, and repeats light emission and stop, thereby obtaining a polarization degree. The coefficient is calculated using a phenomenon in which the coefficient changes.

According to an eighth aspect of the present invention, in the first or second aspect, the light source means has a laser, and a polarizing plate is mounted in an optical path between the light source means and the light beam separating means. The coefficient is calculated by changing the degree of polarization of the laser by the polarizing plate.

According to a ninth aspect of the present invention, in the first or second aspect of the present invention, the control means periodically calculates the coefficient so as to periodically change the characteristic of the optical system such as transmittance and reflectance. It is characterized by calibration.

According to a tenth aspect of the present invention, there is provided an illuminating apparatus for irradiating an illuminated surface with an illumination system using laser light emitted from a laser, wherein the laser light is separated into reference light and illumination light by a light beam separating means. The reference light is separated into P-polarized light and S-polarized light by polarization separation means, of which the light intensity of P-polarized light is detected by P-polarized light detection means, and the light intensity of S-polarized light is detected by S-polarized light detection means,
The control means multiplies the outputs of the P-polarized light detecting means and the S-polarized light detecting means by a coefficient so as to correct the polarization characteristics of the optical components used in the illumination system, and takes the sum of the coefficients to obtain the sum on the surface to be illuminated. Light intensity is obtained, and the output intensity of the laser is controlled so that the light intensity has a desired value.

The eleventh aspect of the present invention is characterized in that, in the tenth aspect of the present invention, the degree of polarization of the laser light emitted from the laser is changed to calibrate a coefficient used when obtaining the light intensity on the surface to be irradiated. And

According to a twelfth aspect of the present invention, there is provided an exposure apparatus according to any one of the first to eleventh aspects.
Using the illumination device according to any one of the above, irradiates a reticle provided on the surface to be irradiated in the illumination device, the pattern formed on the reticle on the wafer surface by the projection optical system,
It is characterized by projection exposure.

According to a thirteenth aspect of the present invention, in the twelfth aspect of the present invention, one of the P-polarized light and the S-polarized light is monitored by separating the exposure light by a polarizing plate on a wafer stage on which the wafer is mounted. It is characterized in that the polarization of the component is measured by a reference light monitor, and changes in the transmittance of the projection optical system are periodically monitored.

According to a fourteenth aspect of the present invention, there is provided a device manufacturing method, comprising: projecting a pattern on a reticle surface onto the wafer surface using the exposure apparatus according to the twelfth or thirteenth aspect; Developing a photosensitive material.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic diagram showing the configuration of a first embodiment of the present invention. In the present embodiment, a reticle (first object) is irradiated with a light beam emitted from a light source of a continuous wave laser or a pulsed laser via an illumination optical system (illuminating means), and a circuit pattern formed on the reticle is projected onto a projection lens ( A scanning type exposure apparatus that performs reduction projection while scanning onto a substrate (second object) coated with a photoreceptor by a projection optical system and prints the semiconductor device, such as a semiconductor device such as an IC or LSI, an imaging device such as a CCD, or a magnetic device. This is suitable for manufacturing a device such as a head.

This embodiment shows a case where the correction coefficient is calculated by changing the set energy relating to the output of the light source means.

In FIG. 1, a light beam from a light source (light source means) 1 which emits continuous wave light or pulse light such as an excimer laser is shaped into a desired shape by a beam shaping optical system 2, and a fly-eye lens or the like is used. Optical integrator 3
Is directed to the light incident surface 3a.

The present embodiment will be described below with reference to the case where a pulse laser is used as the light source 1, or the same can be applied to the case where a continuous wave laser is used. The fly-eye lens 3 is configured by arranging a plurality of minute lenses two-dimensionally, and a plurality of secondary light sources are formed near the light exit surface 3b. Reference numeral 4 denotes a condenser lens, and the condenser lens 4 is a light beam separating means 5 composed of a half mirror.
The masking blade (movable slit) 6 is Koehler-illuminated with a light beam from a secondary light source near the light exit surface 3b of the optical integrator 3 via the optical integrator 3.

The luminous flux illuminating the masking blade 6 passes through an imaging lens 7 and a mirror 8 to form a reticle (surface to be irradiated) 9.
Lighting. The imaging lens 7, the mirror 8, and the like constitute a part of the illumination system.

The masking blade 6 and the reticle 9 are arranged in a conjugate relationship with the image forming lens 7 and the mirror 8, and the shape and size of the illumination area on the reticle 9 are determined by the shape of the opening of the masking blade 6. The illumination area of the reticle 9 has a rectangular slit shape with a short direction set in the scanning direction of the reticle 9. Reference numeral 11 denotes a projection optical system, which projects a circuit pattern drawn on the reticle 9 onto a wafer 12 in a reduced size. Reference numeral 101 denotes a stage drive control system for controlling the reticle stage 10 and the wafer stage 13 to move accurately at a constant speed at the same ratio as the magnification of the projection optical system 11.

In this embodiment, instead of the step-and-scan method, a step-and-repeat type exposure apparatus may be used to expose the pattern on the reticle surface onto the wafer surface at a time.

On the wafer stage 13, the photodetectors B, 1
5 for measuring the amount of laser light and the integrated exposure amount via the projection lens 11.

Reference numeral 14 denotes an exposure amount detection unit (light detection unit) A, which monitors, via a lens 15, a part of the laser beam split by the half mirror 5.

The signal from the photodetector unit A is input to the exposure calculator 102.

The exposure calculator 102 is a photodetector unit A
And an electrical signal photoelectrically converted by the photodetector B is output to the laser control system 103 as an illuminance monitor signal 203.

The signal is output to the main control system 104 and the main control system 1
04 in the storage means.

The laser control system 103 controls one pulse energy of the laser and a light emission interval by a trigger signal 201 and a discharge voltage signal 202 according to a desired exposure amount.
When generating the trigger signal 201 and the discharge voltage signal 202, the illuminance monitor signal 20 from the exposure calculator 102 is used.
3 and the stage current position signal from the stage drive control system 101, history information from the main control system 104, and the like are used as parameters.

The desired exposure amount is input by the input device 105, and the light amount detector unit A14 and the light amount detector B
The result obtained from I5 can be displayed on the display unit 106.

FIG. 2 is a detailed view of the light amount detection unit A14. The light is separated by the half mirror 5, and the reference light passing through the lens 15 is transmitted through a lotion prism (polarization separating means) 18 so that the P-polarized light (having a polarization direction perpendicular to the paper surface) and the S-polarized light (in the paper surface) Polarization direction). The separated light is received by a sensor S (S-polarized light detecting means) 16 and a sensor P (P-polarized light detecting means) 17, respectively, and the output of the sensor P17 that receives P-polarized light is represented by Spou.
t, the output of the sensor S16 that receives S-polarized light is Ssout. At this time, it is desirable that the sensitivity of each sensor be calibrated in advance. The transmittance of the S-polarized light of the lotion prism 18 is Trs, and the transmittance of the P-polarized light is Trp. The intensity Pp of P-polarized light before entering the lotion prism 18 and the intensity Ps of S-polarized light can be respectively expressed as follows.

(Equation 1) Pp = Spout / Trp (Equation 2) Ps = Ssout / Trs Then, the reflectivity of the half mirror 5 for P-polarized light and S-polarized light is R5p, and the transmittance for R-polarized light and S-polarized light is T5p. , T
If 5 s, the transmitted light intensity from the half mirror 5 is P ou
t can be obtained by (Equation 3) P out = P p / R5p * T5p + Ps / R5s * T5s When the transmittance of the optical system such as a lens after transmission through the half mirror 5 to the P-polarized light and the S-polarized light is T6p and T6s, the irradiation intensity on the surface of the wafer 12 (that is, detected by the photodetector B). (Light intensity) is Pwout (Equation 4) Pwout = A * Spout + B * Ssout A = T5p * T6p / (Trp * R5p), B = T5s * T6s / (Trs * R5s)

As described above, the irradiation intensity on the surface of the wafer 12 can be obtained from (Equation 4). The reflectance of (Equation 4)
The coefficients A and B determined by the transmittance may be derived based on design values. However, when it is derived from the design value, it is difficult to obtain an accurate value due to manufacturing errors and changes over time. Therefore,
In the present embodiment, the output from the laser 1 is controlled by the laser control system 103 to change the degree of polarization of the laser light, to derive the coefficients A and B, and to enable highly accurate exposure. When the charging voltage (set energy) is changed by the laser control system 103, the degree of polarization changes. In this embodiment, the coefficients A and B are obtained by utilizing this phenomenon.

As described above, in the present embodiment, the reference light separated by the half mirror 5 is
Separately into polarized light and s-polarized light, the respective intensities are measured by sensors 16 and 17, and the respective measurement results Ssout and Spout are multiplied by coefficients A and B so as to correct the polarization characteristics of the optical components up to the wafer surface. The intensity of the exposure light is obtained by taking the sum. By controlling the illumination device based on the value of the exposure light intensity, highly accurate exposure amount control not affected by polarization is realized. In addition, the configuration is such that the correction coefficient can be easily calibrated on the apparatus, thereby coping with the characteristic fluctuation of the glass component.

Next, a method for deriving the coefficients A and B will be described.

As shown in FIG. 3, the set energy of the laser (the number of laser emission pulses) is changed. One sample for one
The data was displayed as an average value of data for 00 pulses, and the set energy was changed every 10 samples. The relative value (相 対) of the laser beam obtained by the photodetector B15 is shown on the left axis, and the energy setting was changed in three stages during irradiation. The right axis represents the progress of the degree of polarization (■) (shown by black squares) when the set energy was changed at this time. As described above, when the energy of the laser is changed, the degree of polarization changes. When light from an excimer laser is irradiated, the transmittance and reflectance of a glass material such as a lens are not always constant.
However, it does not change transiently during laser irradiation. Therefore, the photodetector B provided on the wafer stage 13
Is expressed as Swout and the ratio of exposure amount / reference light amount is represented by T. (Equation 5) T = Swout / (A * Spout + B * Ssout) The variation of the value of the ratio T becomes the smoothest (the variation is the smallest with respect to the approximate curve).
Thus, the values of the coefficients A and B are calculated. In the present embodiment, the set energy of the laser is changed. However, when the setting of the discharge voltage of the laser is changed, a phenomenon that the degree of polarization changes similarly occurs, so that the values of the coefficients A and B are similarly changed. It is possible to calculate.

A degree of polarization that changes the degree of polarization of the laser light passing through the optical path between the laser 1 and the half mirror 5;
A conversion member (for example, a polarizing plate) may be provided.

FIG. 4 is a diagram comparing the ratio of the exposure amount / reference light amount between the conventional method and the present embodiment. Conventional method (■)
While the ratio greatly changes with the change in the degree of polarization, the method (方式) of the present embodiment shows a very stable result.

By periodically performing such coefficient derivation processing, it is possible to cope with the characteristic fluctuation of the glass component which fluctuates due to the irradiation of the laser beam.

Next, a second embodiment of the present invention will be described. This embodiment shows a case where the correction coefficient is calculated by changing the emission frequency of the laser light.

The first embodiment has described the adjustment method when the set energy of the laser is changed. In this method, there is no problem if the linearity (the relationship between the amount of incident light and the sensor output) of the sensor to be used is calibrated, but if calibration is not performed, the error due to the difference in the amount of incident energy to the sensor will cause an error. May occur.

Therefore, in the present embodiment, the degree of polarization is changed by changing the emission frequency of the laser.
Similarly, correction coefficients A and B are obtained.

As shown in FIG. 5, the emission frequency of the laser is changed. One sample was displayed as an average value of data for 100 pulses, and the emission frequency was changed every 10 samples. The emission frequency (O) is shown on the left axis, and the emission frequency was changed in three stages during irradiation. The right axis represents the progress of the degree of polarization (■) when the emission frequency was changed at this time.
As described above, when the light emission frequency of the laser is changed, the degree of polarization changes. Therefore, as in the first embodiment, the values of the coefficients A and B are calculated so that the variation in the ratio of the exposure amount / reference light amount is minimized with respect to the approximate curve.

FIG. 6 shows a comparison of the ratio of the exposure amount / reference light amount between the conventional method and the present embodiment. In the conventional method (■), the ratio greatly changes with the change in the degree of polarization, whereas the method (○) of the present embodiment shows a very stable result.

Next, a third embodiment of the present invention will be described. This embodiment shows a case where a correction coefficient is calculated by irradiating a laser beam for several hours.

When the laser continuously emits light for several hours, the gas in the laser chamber deteriorates. When a gas is injected to suppress gas deterioration at this time, the degree of polarization changes. In the present embodiment, the correction coefficient A,
B is derived.

As shown in FIG. 7, the laser is continuously emitted for several hours. (In the case of the figure, it is about 10 hours, but actually, gas injection is performed every several hours due to gas deterioration, so measurement of several hours is sufficient.) In this case, the degree of polarization is accompanied by gas deterioration. It decreases and returns to near the initial value by gas injection. As described above, the correction coefficient of Equation 5 is calculated using the change in the degree of polarization generated by emitting the laser for several hours. As in the previous embodiments, the values of the coefficients A and B are calculated so as to minimize the variation with respect to the approximate curve of the ratio of the exposure amount / reference light amount.

FIG. 8 shows a comparison of the ratio of the exposure amount / reference light amount between the conventional method and the present embodiment. In the conventional method (■), the ratio greatly changes according to the change in the degree of polarization, whereas the method (O) of the present embodiment shows a very stable result.

In addition, by setting the number of laser light emission pulses, emitting light for the number of pulses, stopping, and repeating light emission for the number of pulses again, a phenomenon occurs in which the degree of polarization changes. By utilizing this phenomenon, the correction coefficient of Equation 5 may be calculated.

In the embodiments described above, the degree of polarization is changed by changing the light emission conditions of the laser.
The correction coefficient of Equation 5 has been calculated. As a method other than such a method, a method of changing the degree of polarization by inserting and using a polarizing plate (between the laser 1 and the half mirror 5) before separating the reference light and the exposure light is used. Can be calculated.

Further, a more accurate correction coefficient can be obtained by obtaining the correction coefficient in combination with several derivation methods.

FIG. 9 shows a projection optical system 1 according to the fourth embodiment of the present invention.
FIG. This embodiment differs from the first embodiment in FIG. 1 in the configuration of the photodetector B.

In this embodiment, in order to monitor the change in the transmittance of the projection optical system 11, the photodetector B is connected to the wafer stage 13.
Moves to the exposure region, and monitors the transmittance of the projection optical system 11 from the measurement results of the photodetector B and the photodetection unit A according to the oscillation of the laser 1. In the photodetector B, the wafer 12
The polarizing plate 41 is arranged so that only the P-polarized or S-polarized component that reaches the upper side can be monitored, and only the same polarized component is monitored by the light detection unit A, so that the transmittance measurement of the projection optical system that is not deceived by the polarized light can be performed. Making it possible.

Next, a method of manufacturing a semiconductor device using the above-described projection exposure apparatus will be described.

FIG. 10 is a manufacturing flowchart of a semiconductor device (a semiconductor chip such as an IC or an LSI, or a liquid crystal panel or a CCD).

Step 1 (circuit design) in this embodiment
Now, the circuit design of the semiconductor device will be performed. Step 2
(Mask production) produces a mask on which the designed circuit pattern is formed.

On the other hand, in step 3 (wafer manufacturing), a wafer is manufactured using a material such as silicon. Step 4
The (wafer process) is called a pre-process, and an actual circuit is formed on the wafer by lithography using the prepared mask and wafer.

The next step 5 (assembly) is called a post-process, and is a process of forming a semiconductor chip using the wafer prepared in step 4, and includes an assembly process (dicing and bonding) and a packaging process (chip encapsulation). And the like.

In step 6 (inspection), inspections such as an operation confirmation test and a durability test of the semiconductor device manufactured in step 5 are performed. Through these steps, a semiconductor device is completed and shipped (step 7).

FIG. 11 is a detailed flowchart of the wafer process in step 4 described above. First, in step 11 (oxidation), the surface of the wafer is oxidized. Step 12 (C
In VD), an insulating film is formed on the wafer surface.

In step 13 (electrode formation), electrodes are formed on the wafer by vapor deposition. In step 14 (ion implantation), ions are implanted into the wafer. Step 15
In (resist processing), a photosensitive agent is applied to the wafer. Step 16 (exposure) uses the above-described exposure apparatus to print and expose the circuit pattern of the mask onto the wafer.

In step 17 (development), the exposed wafer is developed. In step 18 (etching), portions other than the developed resist are removed. In step 19 (resist stripping), the resist that has become unnecessary after the etching is removed. By repeating these steps, multiple circuit patterns are formed on the wafer.

By using the manufacturing method of this embodiment, a highly integrated semiconductor device can be easily manufactured.

[0070]

As described above, according to the present invention, the amount of light incident on the wafer surface can be controlled with high precision without being affected by the change in the polarization state of the exposure light, and a highly integrated circuit pattern can be easily obtained. An apparatus and a projection exposure apparatus using the same can be achieved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a main part of a first embodiment of the present invention.

FIG. 2 is an enlarged explanatory view of a part of FIG. 1;

FIG. 3 is an explanatory diagram of the laser energy and the degree of polarization of the laser according to the present invention.

FIG. 4 is an explanatory diagram of a ratio between an exposure amount and a reference light amount in the number of laser pulses according to the related art and the present invention.

FIG. 5 is a diagram illustrating the laser emission frequency and the degree of polarization of the laser according to the present invention.

FIG. 6 is an explanatory diagram of a ratio between an exposure amount and a reference light amount in the number of pulses according to the related art and the present invention.

FIG. 7 is an explanatory diagram of a change in the degree of polarization of the optical member over time.

FIG. 8 is a diagram illustrating a change in the degree of polarization of an optical member over time in the related art and the present invention.

FIG. 9 is a schematic view of a part of Embodiment 4 of the present invention.

FIG. 10 is a flowchart of a device manufacturing method of the present invention.

FIG. 11 is a flowchart of a device manufacturing method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Laser light source 2 Beam shaping optical system 3 Optical integrator 4 Condenser lens 6 Masking blade 7 Imaging lens 8 Mirror 9 Reticle 11 Projection lens 12 Semiconductor substrate 10 Reticle stage 13 Wafer stage 201 Trigger signal 202 Charge voltage signal 101 Stage drive control system Reference Signs List 102 Exposure amount calculator 103 Laser control system 104 Main control system 105 Input device 108 Display 5 Light flux separation means (half mirror) 18 Polarization separation means 15 Lens 16 S polarization detection means 17 P polarization detection means

Claims (14)

[Claims] 1. A light source, a light beam separating means provided in an optical path of a light beam emitted from the light source, and a P-polarized component and an S-polarized component from one of the light beams transmitted or reflected by the light beam separating device. Polarization separating means for separating, P-polarized light detecting means for detecting the P-polarized light component separated by the polarized light separating means, S-polarized light detecting means for detecting the S-polarized light component, and light flux transmitted or reflected by the light flux separating means. An optical system that illuminates a predetermined surface with the other light beam of the above, using a signal obtained by both detection means when changing the polarization state of the polarized light incident on the P polarization detection means and S polarization detection means, Control means for obtaining a coefficient for correcting the polarization characteristic of the optical system, obtaining the intensity of light incident on a predetermined surface using the coefficient, and controlling the output of the light source. Lighting device characterized by the following. 2. A light source means, a light beam separating means arranged in an optical path of a light beam emitted from the light source means for separating the light beam into reflected light and transmitted light, and one of the light beams separated by the light beam separating means Polarization separation means for separating light into P-polarized light and S-polarized light, P-polarized light detection means for detecting the light intensity of the P-polarized light separated by the polarization separation means, S-polarized light detection means for detecting the light intensity of the S-polarized light, Using the other of the light beams separated by the light beam separation means,
An optical system for irradiating the surface to be irradiated, and each signal obtained by the P-polarized light detecting means and the S-polarized light detecting means, are multiplied by a coefficient for correcting the polarization characteristics of the optical system. Obtain the irradiation intensity to irradiate the upper, using the obtained irradiation intensity,
An illumination device comprising a control unit for controlling an output of the light source unit. 3. The control means is obtained from the sum of a value obtained by multiplying an output value obtained by the P-polarized light detecting means by a coefficient and a value obtained by multiplying the output value obtained by the S-polarized light detecting means by a coefficient. The lighting device according to claim 1, wherein the output of the light source unit is controlled using the total value. 4. The light source means has a laser, and the control means changes the degree of polarization of the laser by changing the discharge voltage (set energy) of the laser to calculate the coefficient. 3. The lighting device according to claim 1, wherein 5. The apparatus according to claim 1, wherein said light source means has a laser, and said control means calculates said coefficient by changing a degree of polarization of said laser by changing an emission frequency of said laser. 1 or 2 lighting devices. 6. The light source means has a laser, and the control means keeps emitting the laser light for several hours or more, utilizing a phenomenon in which the degree of polarization changes due to gas deterioration, gas exchange, injection, or the like. The lighting device according to claim 1, wherein the coefficient is calculated. 7. The light source means has a laser, and the control means designates the number of light emission pulses of the laser, and repeats light emission and stop, thereby utilizing the phenomenon that the degree of polarization changes, and thereby calculating the coefficient. The lighting device according to claim 1, wherein the calculation is performed. 8. The light source means has a laser, a polarizing plate is mounted in an optical path between the light source means and the light beam separating means, and the control means changes the degree of polarization of the laser by the polarizing plate. The lighting device according to claim 1, wherein the coefficient is calculated. 9. The method according to claim 1, wherein the control unit periodically calculates the coefficient to periodically calibrate a characteristic change of the optical system such as a transmittance and a reflectance. Lighting equipment. 10. An illumination device for irradiating a surface to be illuminated with an illumination system using laser light emitted from a laser, wherein the laser light is separated into reference light and illumination light by a light beam separation means, and the reference light is separated by a polarization separation means. The light is separated into P-polarized light and S-polarized light. Of these, the light intensity of P-polarized light is detected by P-polarized light detecting means, and the light intensity of S-polarized light is detected by S-polarized light detecting means. The output of the detection means is multiplied by a coefficient so as to correct the polarization characteristics of the optical components used in the illumination system, and by taking the sum thereof, the light intensity on the illuminated surface is obtained.
An illumination device, wherein the output intensity of the laser is controlled so that the light intensity becomes a desired value. 11. The illumination device according to claim 10, wherein the degree of polarization of the laser light emitted from the laser is changed to calibrate a coefficient used when obtaining the light intensity on the surface to be irradiated. 12. A reticle provided on a surface to be illuminated in the illuminating device is illuminated using the illuminating device according to claim 1, and a pattern formed on the reticle is projected onto a wafer by a projection optical system. An exposure apparatus that performs projection exposure on a surface. 13. A P-polarized light or an S-polarized light is monitored by polarizing and separating an exposure light by a polarizing plate on a wafer stage on which the wafer is mounted, and the polarization of the same component is measured by a reference light monitor. 13. The exposure apparatus according to claim 12, wherein a change in transmittance of the projection optical system is periodically monitored. 14. A step of projecting and exposing a pattern on a reticle surface onto the wafer surface using the exposure apparatus according to claim 12 or a step of developing a photosensitive material on the exposed wafer surface. A method for manufacturing a device, comprising: