JP2008124065A - Photolithography unit and process for device fabrication - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photolithography unit in which the quantity of light of nonexposure wavelength component contained in projection light from an exposure optical system can be detected accurately, and to provide a process for fabricating a device with high throughput. <P>SOLUTION: The photolithography unit for exposing an article to be exposed with projection light from a main optical system (6) comprises a sensor (13') for detecting the quantity of light of nonexposure wavelength component contained in the projection light from the exposure optical system (6), a sub-optical system (14) for projecting light having a wavelength different from the exposure wavelength to an exposure region of the main optical system (6), and a noise prevention means for blocking incidence of the projecting light from the sub-optical system (14) to the sensor (13') at least when the sensor (13') is detecting the quantity of light. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an exposure apparatus applied to a photolithography process for manufacturing a device such as a semiconductor device. The present invention also relates to a device manufacturing method for manufacturing a device.

  Usually, an exposure apparatus used for manufacturing a semiconductor device is equipped with a focus detection system for adjusting the focus of the projection optical system. In particular, a focus detection system on the wafer side of the projection optical system (eg, reference numerals 60 to 69 in Patent Document 1) emits focus detection light (hereinafter referred to as “AF light”) toward the wafer surface. A focus signal is generated based on the reflected light. Usually, the wavelength of the AF light is set to a wavelength different from the exposure wavelength so that the resist on the wafer is not exposed.

The exposure apparatus is also equipped with a light quantity sensor (see reference numeral 32 in Patent Document 2) in order to detect fluctuations in the characteristics of the projection optical system due to irradiation heat. The light quantity sensor is arranged on both the reticle side and the wafer side of the projection optical system, and usually has sensitivity to the exposure wavelength.
In recent years, EUVL (EUVL: Extreme Ultra Violet Lithography) with an exposure wavelength of 50 nm or less has been proposed for miniaturization of an exposure pattern. The EUVL exposure apparatus (see Patent Document 3) also needs to be equipped with a focus detection system and a light amount sensor. Also in this case, the wavelength of the AF light is set to a wavelength (visible wavelength, infrared wavelength, etc.) different from the exposure wavelength (50 nm or less). On the other hand, two types of light quantity sensors are required: a light quantity sensor for exposure wavelengths and a light quantity sensor for non-exposure wavelengths. There are two reasons for this.

First, a special light source called an EUV light source is used in an EUVL exposure apparatus, and the emitted light includes light of a non-exposure wavelength component (such as visible light and infrared light). Second, a special mirror having an optical multilayer film is used in the exposure apparatus for EUVL, and the mirror is affected not only by the exposure wavelength component but also by the non-exposure wavelength component.
JP-A-6-283403 Japanese Patent Laid-Open No. 11-16816 JP 2004-29314 A

However, when two types of light quantity sensors are actually mounted on an EUVL exposure apparatus, it has been found that the light quantity sensor for non-exposure wavelengths does not operate normally and the characteristic variation of the projection optical system cannot be accurately estimated. .
SUMMARY OF THE INVENTION An object of the present invention is to provide an exposure apparatus that can accurately detect the light amount of a non-exposure wavelength component contained in light emitted from an optical system for exposure. Another object of the present invention is to provide a method for manufacturing a high-throughput device.

  An exposure apparatus of the present invention is an exposure apparatus that exposes an object to be exposed with light emitted from a main optical system, and detects a light amount of a non-exposure wavelength component contained in light emitted from the main optical system; A sub-optical system that projects light having a wavelength different from the exposure wavelength to the exposure region of the main optical system, and noise that prevents light emitted from the sub-optical system from entering the sensor at least during detection by the sensor. And a prevention means.

The sensor may perform the detection only when the object to be exposed is not exposed, and the noise prevention unit may be configured by a control unit that controls on / off of the light source of the sub optical system.
The sensor performs the detection only when the object to be exposed is not exposed, and the noise preventing unit controls a shutter disposed in the optical path of the sub optical system and opens / closes the shutter. You may comprise from a control part.

The noise preventing means may be formed of a filter member that is provided on the opening of the sensor and transmits the light emitted from the main optical system and reflects the light emitted from the sub optical system.
The noise preventing means may be formed of a light shielding member that is provided in the vicinity of the opening of the sensor and that blocks the light emitted from the main optical system and blocks the light emitted from the sub optical system.

The sub optical system may be a part of a focus detection system that detects a focus adjustment state of the main optical system.
The focus detection system is preferably a grazing incidence type focus detection system.
The exposure wavelength is preferably 50 nm or less.
The device manufacturing method of the present invention includes a procedure for exposing a resist on a substrate by any of the exposure apparatuses of the present invention.

  According to the present invention, an exposure apparatus capable of accurately detecting the light amount of the non-exposure wavelength component included in the exposure optical system is realized. In addition, according to the present invention, a high-throughput device manufacturing method is realized.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described. This embodiment is an embodiment of a projection exposure apparatus for EUVL.
FIG. 1 is a schematic block diagram of the projection exposure apparatus. As shown in FIG. 1, the projection exposure apparatus includes a radiation device 1 including an EUV light source, a reflective integrator 3, a condenser mirror 4, and an optical path bending mirror M as an illumination system for exposure. . Further, the projection exposure apparatus includes a reticle stage MS, a reflection type projection optical system 6, and a wafer stage WS. The reticle stage MS holds a reflection type reticle 5, and the wafer stage WS has a resist. The wafer 7 coated with is held. A light amount sensor 12 for exposure wavelength and a light amount sensor 13 for non-exposure wavelength are arranged on the reticle side of the projection optical system 6, and a light amount sensor 12 ′ for exposure wavelength and non-exposure are disposed on the wafer side of the projection optical system 6. A light amount sensor 13 ′ for wavelength is disposed, and a mirror adjustment mechanism 8 is attached to the projection optical system 6.

  In addition, the projection exposure apparatus has a grazing incidence focus including a light source 14-1, an optical fiber 14-2, a light projecting system 14A, and a light receiving system 14B as a focus detection system on the wafer side of the projection optical system 6. A detection system is provided. In the projection exposure apparatus, the optical path related to exposure and the optical path of the focus detection system are stored in the vacuum chamber 100. Each unit of the projection exposure apparatus is connected to a control unit (not shown).

  The radiation device 1 in the illumination system emits light having an exposure wavelength. Since it is for EUVL, the exposure wavelength is 50 nm or less, for example, 13.5 nm. The light reflects the integrator 3, the condenser mirror 4, and the optical path bending mirror M in order, and then uniformly illuminates the illuminated area of the reticle 5. The light reflected from the illuminated area of the reticle 5 is reflected by the projection optical system 6 and forms a reduced image of the illuminated area on the wafer 7. A control unit (not shown) controls the wafer stage WS, a shutter (not shown) in the illumination system, and the like, and sequentially exposes or scan-exposes the entire exposure area of the wafer 7 with the reduced image. When the exposure of the entire exposure area of the wafer 7 is completed, the wafer 7 is replaced with the next wafer by a transfer device (not shown), and the exposure of the next wafer is resumed. Hereinafter, a period until the entire exposure area of one wafer is exposed is simply referred to as an “exposure period”.

  The light source 14-1 of the focus detection system emits light having a wavelength different from the exposure wavelength. The wavelength is a wavelength at which the resist on the wafer 7 is not exposed (visible wavelength, infrared wavelength, etc.), for example, 650 nm. When the light enters the light projecting system 14A via the optical fiber 14-2, the light is converted into AF light in the light projecting system 14A. The AF light travels toward the image plane of the projection optical system 6 at an incident angle of 45 ° or more (for example, an incident angle of 84 °). The AF light is reflected on the wafer 7 and is converted into a focus signal when entering the light receiving system 14B. A control unit (not shown) controls the wafer stage WS based on the focus signal, and performs automatic focus adjustment to make the surface of the wafer 7 coincide with the image plane of the projection optical system 6. Normally, this autofocus function is turned on continuously.

  Here, the EUV light source in the radiation device 1 is a laser plasma light source, a discharge plasma light source, or the like, and the emitted light includes not only the exposure wavelength component (13.5 nm light) but also the non-exposure wavelength component. Non-exposure wavelength components include ultraviolet wavelengths, visible wavelengths, infrared wavelengths, and the like. Moreover, the light quantity ratio between the exposure wavelength component and the non-exposure wavelength component is likely to vary depending on the operating state of the EUV light source.

In addition, an optical multilayer film having reflectivity with respect to light having an exposure wavelength (13.5 nm) is formed on the reflective surface arranged in the optical path from the radiation device 1 to the wafer 7. Such a reflective surface is deformed under the influence of both the exposure wavelength light and the non-exposure wavelength light. This also applies to each reflecting surface of the projection optical system 6.
Therefore, in order to accurately grasp the characteristic variation of the projection optical system 6, the influence of the projection optical system 6 from the light of the exposure wavelength and the influence of the projection optical system 6 from the light of the non-exposure wavelength are detected independently. There is a need to. For this purpose, the projection exposure apparatus includes not only exposure light quantity sensors 12 and 12 'but also non-exposure light quantity sensors 13 and 13'.

The light quantity sensors 12 and 12 'for the exposure wavelength are insensitive to the non-exposure wavelength and are sensitive only to the exposure wavelength. The light quantity sensors 13 and 13 'for the non-exposure wavelength are insensitive to the exposure wavelength and have sensitivity only to the non-exposure wavelength.
The arrangement location of the light quantity sensor 12 for exposure wavelength and the light quantity sensor 13 for non-exposure wavelength is, for example, in a light beam that does not reach the upstream side of the reticle 5 and the downstream side of the reticle 5. According to the light quantity sensor 12 for exposure wavelength and the light quantity sensor 13 for non-exposure wavelength, it is possible to monitor the exposure wavelength component and the non-exposure wavelength component of light incident on the projection optical system 6.

  On the other hand, the arrangement location of the light quantity sensor 12 'for the exposure wavelength and the light quantity sensor 13' for the non-exposure wavelength is the wafer stage WS. The exposure wavelength light quantity sensor 12 ′ and the non-exposure wavelength light quantity sensor 13 ′ are arranged side by side at a position off the wafer 7 on the wafer table WT as shown in FIG. 2. FIG. 2 shows only two sensors, a light quantity sensor 12 'for exposure wavelength and a light quantity sensor 13' for non-exposure wavelength, but in reality, an aerial image sensor, a sensor for measuring exposure unevenness, etc. Other sensors are also installed on wafer table WT. A control unit (not shown) can set these sensors and the wafer 7 selectively on the emission optical path of the projection optical system 6 by controlling the wafer stage WS. Therefore, according to the light quantity sensor 12 ′ for exposure wavelength and the light quantity sensor 13 ′ for non-exposure wavelength, the exposure wavelength component and the non-exposure wavelength component of the light emitted from the projection optical system 6 are detected only outside the exposure period. Can do.

A control unit (not shown) controls the mirror adjusting mechanism 8 based on the output values of the exposure wavelength light quantity sensor 12 and the non-exposure wavelength light quantity sensor 13 arranged on the reticle side during the exposure period, and the projection optical system 6. Automatic mirror adjustment is performed to suppress fluctuations in characteristics. Normally, this automatic mirror adjustment function is continuously turned on during the exposure period.
Further, the control unit sets the exposure wavelength light quantity sensor 12 ′ disposed on the wafer side outside the exposure period to the emission optical path of the projection optical system 6 to perform test exposure, and the exposure wavelength light quantity at that time. The output value of the sensor 12 ′ is referred to. Further, the control unit sets the non-exposure wavelength light quantity sensor 13 ′ disposed on the wafer side to the emission optical path of the projection optical system 6 to perform test exposure, and the non-exposure wavelength light quantity sensor 13 ′ at that time. Refer to the output value of. The control unit also refers to the output values of the exposure wavelength light quantity sensor 12 and the non-exposure wavelength light quantity sensor 13 arranged on the reticle side substantially simultaneously. Then, the control unit corrects the above-described automatic mirror adjustment characteristics (that is, conversion characteristics when the output values of the light quantity sensors 12 and 13 are converted into control amounts of the mirror adjustment mechanism 8) based on the four output values referred to. . This correction is a correction for coping with the change over time of the absorption characteristic of the projection optical system 6. Usually, this correction function is turned on once outside the exposure period.

  FIG. 3 is a diagram showing a state of the light amount sensor 13 'for the non-exposure wavelength during the exposure period. As shown in FIG. 3, the wafer 7 is fixed to the wafer table WT while being held by the wafer holder WH. The light amount sensor 13 ′ for non-exposure wavelength is fixed in a recess 13 A provided on the surface of the wafer table WT, and the height of the detection surface of the light amount sensor 13 ′ for non-exposure wavelength is higher than the surface of the wafer 7. Is slightly lower. The opening of the recess 13A is covered with a mask 13B having a circular opening smaller than the opening. The configuration around the light amount sensor 12 ′ for the exposure wavelength as described above is similarly applied to the configuration around the light amount sensor 13 ′ for the non-exposure wavelength.

  As shown in FIG. 3, during the exposure period, the wafer 7 is set in the emission optical path of the projection optical system 6, so the light amount sensor 13 ′ for non-exposure wavelength is out of the emission optical path of the projection optical system 6. Therefore, there is no possibility that AF light from the light projecting system 14A is incident on the light quantity sensor 13 '. However, if the non-exposure wavelength light quantity sensor 13 'is set in the exit optical path of the projection optical system 6 as shown in FIG. 4 outside the exposure period, AF light enters the vicinity of the non-exposure wavelength light quantity sensor 13'. Then, there is a possibility that the AF light passes through the circular opening of the mask 13B and is reflected by the inner wall of the recess 13A and reaches the light amount sensor 13 ′ for the non-exposure wavelength. At this time, noise is superimposed on the output value of the light amount sensor 13 'for the non-exposure wavelength, and the output value becomes inaccurate.

  Even when the exposure wavelength light quantity sensor 12 'is set in the emission optical path of the projection optical system 6, there is a possibility that AF light may enter the exposure wavelength light quantity sensor 12', but the output value is noise. Are not likely to be superimposed. This is because the exposure light quantity sensor 12 'does not have sensitivity to the wavelength of the AF light. Therefore, the problem of noise caused by AF light is a problem peculiar to the light amount sensor 13 'for non-exposure wavelengths.

Therefore, in order to avoid this problem, the control unit of the projection exposure apparatus, when the correction function described above is turned on outside the exposure period, before and after using the light amount sensor 13 ′ for the non-exposure wavelength, the light source of the focus detection system. 14-1 is turned on / off by the procedure shown in FIG. 5.
As shown in FIG. 5, when the control unit sets the non-exposure wavelength light quantity sensor 13 ′ to the emission optical path of the projection optical system 6 (step S <b> 101), the light source 14-1 is turned off immediately thereafter (step S <b> 102). In this state, the output value of the light quantity sensor 13 ′ is referred to (step S103). Immediately thereafter, the control unit turns on the light source 14-1 (step S104), and removes the light amount sensor 13 ′ for the non-exposure wavelength from the emission optical path of the projection optical system 6 (step S105).

That is, when performing exposure on a plurality of wafers continuously, the control unit of the present embodiment turns off the light source 14-1 only when the light amount sensor 13 ′ for non-exposure wavelength is used, and the light source in other periods. Continue to turn on 14-1.
Therefore, the problem of the light amount sensor 13 ′ for the non-exposure wavelength caused by the AF light is surely avoided, and the accuracy of the correction function is increased. As a result, the accuracy of the automatic mirror adjustment function is improved, and the projection exposure apparatus becomes a high-performance projection exposure apparatus.

  In this projection exposure apparatus, since the AF light is not emitted when the light amount sensor 13 'for the non-exposure wavelength is used, the automatic focus adjustment function is turned off. Therefore, at this time, the control unit needs to manage the offset of the control amount of the wafer stage WS with respect to the reference surface S of the wafer table WT. Therefore, the control unit stores in advance an offset amount in the optical axis direction between the surface of the mask 13B and the reference surface of the wafer table WT. Such offset management is also performed in the second, third, and fourth embodiments described later.

[Second Embodiment]
Hereinafter, a second embodiment of the present invention will be described. This embodiment is also an embodiment of the projection exposure apparatus. Here, only differences from the first embodiment will be described.
FIG. 6 is a diagram illustrating the focus detection system of the present embodiment. As shown in FIG. 6, the main difference is that a shutter 20A is arranged in the light emission path of the light projecting system 14A. When the shutter 20A is driven by the motor 20B, the shutter 20A opens / closes the emission optical path of the light projecting system 14A. The arrangement position of the mechanism related to the shutter 20A is selected so as not to obstruct at least the emission optical path of the projection optical system 6.

  The control unit of the present embodiment controls opening / closing of the shutter 20A via the motor 20B while turning on the light source 14-1. The timing at which the shutter 20A is opened / closed is the same as the timing at which the light source 14-1 is turned on / off in the first embodiment (see FIG. 5). As a result, the same effects as in the first embodiment can be obtained in this embodiment. In addition, in the present embodiment, since the light source 14-1 is not turned on / off, the power of the AF light can be stabilized and the stability of the automatic focus adjustment can be ensured.

In the present embodiment, the insertion position of the shutter 20A is the emission light path of the light projecting system 14A, but it may be replaced with any light path from the light source 14-1 to the light emission end of the light projection system 14A.
In this embodiment, a mechanical shutter driven by a motor is used to open / close the optical path. However, an optical element that changes transmittance according to an electrical signal may be used as the shutter.

[Third Embodiment]
The third embodiment of the present invention will be described below. This embodiment is also an embodiment of the projection exposure apparatus. Here, differences from the first embodiment will be described. The difference is that a filter is disposed on the incident side of the light amount sensor 13 ′ for the non-exposure wavelength, instead of the controller performing on / off control of the light source 14-1 (see FIG. 1).

  FIG. 7 is an enlarged cross-sectional view of the periphery of the light amount sensor 13 'for non-exposure wavelengths according to the present embodiment. In FIG. 7, reference numeral 13 </ b> C denotes a circular opening provided in the mask 13 </ b> B. The filter 21 is fixed on the upper surface of the mask 13B, and the circular opening 13C is completely covered. The filter 21 is a parallel plate made of, for example, optical glass. The size in the surface direction of the filter 21 is selected to be sufficiently large so as to cover both the exit optical path of the light projecting system 14A and the exit optical path of the projection optical system 6.

  As described above, since the focus detection system is an oblique incidence system, AF light emitted from the light projecting system 14A enters the surface of the filter 21 at a large incident angle of 45 ° or more (for example, an incident angle of 84 °). Therefore, most of the AF light is reflected by the surface of the filter 21 and does not reach the light amount sensor 13 'for the non-exposure wavelength. Further, there is little possibility that the reflected light reaches the projection optical system 6.

On the other hand, the light emitted from the projection optical system 6 enters the surface of the filter 21 at a sufficiently small incident angle. Accordingly, the emitted light passes through the filter 21 and reaches the light amount sensor 13 ′ for the non-exposure wavelength.
Therefore, also in this embodiment, the problem of the light amount sensor 13 ′ for the non-exposure wavelength caused by the AF light is surely avoided. In addition, according to the present embodiment, the trouble of turning on / off the light source 14-1 can be saved, so that the time required for the correction function described above can be shortened.

In this embodiment, optical glass is used as the material of the filter 21, but other materials may be used as long as they can reflect AF light and transmit light emitted from the projection optical system 6. It doesn't matter. However, optical glass is considered to be preferable to other materials at the present time because it is less likely to cause contamination by irradiation with EUV light.
[Fourth Embodiment]
The fourth embodiment of the present invention will be described below. This embodiment is also an embodiment of the projection exposure apparatus. Here, differences from the third embodiment will be described. The difference is that a light shielding member is used instead of the filter 21.

  FIG. 8 is an enlarged cross-sectional view of the periphery of the non-exposure wavelength light amount sensor 13 ′ of this embodiment, and FIG. 9 is a front view of the mask 13 </ b> B as viewed from the projection optical system 6 side. As shown in FIGS. 8 and 9, a light shielding member 13D is attached to the periphery of the circular opening 13C on the upper surface of the mask 13B and to the light projecting system 14A side. The light shielding member 13D has a light shielding property against light having the same wavelength as the AF light. The outer shape of the light shielding member 13D is adjusted so as to open the optical path from the projection optical system 6 to the non-exposure wavelength light quantity sensor 13 'and cover the emission optical path of the light projecting system 14A. Here, as shown in FIG. 8, it is assumed that the side surface 13E of the light shielding member 13D covers the emission optical path of the light projecting system 14A.

  Since the incident angle of the AF light with respect to the reference surface S of the wafer table is large, the thickness of the light shielding member 13D in the optical axis direction need not be so large. For example, when the incident angle of the AF light with respect to the reference surface S is 84 ° (the oblique incident angle is 6 °) and the distance from the center of the circular opening 13C to the side surface 13E of the light shielding member 13D is about 1 mm, the light shielding member A thickness in the direction of the optical axis of 13D is about 0.1 mm. Further, when the incident angle of the AF light with respect to the reference surface S is 84 ° (oblique incident angle is 6 °) and the distance from the center of the circular opening 13C to the side surface 13E of the light shielding member 13D is about 2 mm, the light shielding member A thickness in the direction of the optical axis of 13D is about 0.2 mm.

As described above, in the present embodiment, the AF light from the light projecting system 14A is blocked by the light blocking member 13D and does not reach the light amount sensor 13 ′ for the non-exposure wavelength. On the other hand, the light emitted from the projection optical system 6 reaches the light amount sensor 13 ′ for the non-exposure wavelength.
Therefore, also in this embodiment, the problem of the light amount sensor 13 ′ for non-exposure wavelength caused by the AF light is surely avoided.

  In the present embodiment, the light shielding member 13D is provided on a part of the periphery of the circular opening 13C. However, the light shielding member 13D may be provided on the entire periphery of the circular opening 13C. However, it is desirable that the formation location of the light shielding member 13D is limited to a necessary location. This is because if the depth of the circular opening 13C in the optical axis direction is large, excess light may be reflected by the inner wall of the circular opening 13C and travel toward the recess 13A.

  Moreover, in this embodiment, although the mask 13B and the light shielding member 13D were comprised by the separate member, you may comprise by the same member. In that case, in order to make the shape of the mask 13B as simple as possible, the height of the surface of the mask 13B may be made as high as the thickness of the light shielding member 13D. However, it should be noted that in that case, excess light may be reflected by the inner wall of the circular opening 13C and travel toward the recess 13A.

[Others]
In each of the above-described embodiments, the problem of the non-exposure wavelength light quantity sensor 13 ′ caused by the wafer-side focus detection system is avoided. However, the reticle-side focus detection system (not shown) has a non-exposure wavelength detection system. When the light amount sensor 13 (see FIG. 1) is affected, the problem of the light amount sensor 13 for the non-exposure wavelength may be avoided in the same manner as the method for avoiding the problem of the light amount sensor 13 ′ for the non-exposure wavelength.

Further, in each of the above-described embodiments, in order to independently detect the light amount of the exposure wavelength component and the light amount of the non-exposure wavelength component of the incident light, the light amount sensor having sensitivity only to the exposure wavelength and the non-exposure wavelength only Although two types of light quantity sensors are used together with a light quantity sensor having sensitivity, the combination of the two kinds of light quantity sensors may be changed as shown in (1) or (2) below.
(1) A combination of a first light quantity sensor having sensitivity only to the exposure wavelength and a second light quantity sensor having sensitivity to all wavelengths. In this case, since noise may be superimposed on the output value of the second light quantity sensor, it may be avoided. The avoidance method is the same as the avoidance method described in any of the above-described embodiments.

(2) A combination of a first light quantity sensor having sensitivity to all wavelengths and a second light quantity sensor having sensitivity only to non-exposure wavelengths. In this case, since noise may be superimposed on both the output value of the first light quantity sensor and the output value of the second light quantity sensor, these may be avoided individually. Each avoidance method is the same as the avoidance method described in any of the above-described embodiments.
[Fifth Embodiment]
Hereinafter, a fifth embodiment of the present invention will be described. The present embodiment is an embodiment of a microdevice manufacturing method. The microdevice is a semiconductor chip such as an IC or LSI, a liquid crystal panel, a CCD, a thin film magnetic head, a micromachine, or the like. In the following description, it is assumed that the micro device is a semiconductor device.

  FIG. 10 is a flowchart showing a manufacturing process of a micro device. As shown in FIG. 10, first, in step S210 (design step), the function / performance design (circuit design etc. of the semiconductor device) of the micro device is performed, and the pattern design for realizing the function is performed. In the subsequent step S202 (mask manufacturing step), a mask (reticle) having the designed circuit pattern is manufactured. On the other hand, in step S203 (wafer manufacturing step), a wafer is manufactured using a semiconductor material such as silicon.

  Next, in step S204 (wafer processing step), a circuit or the like is formed on the wafer by photolithography using the above mask and wafer. In the subsequent step S205 (device assembly step), a device is assembled using the processed wafer. Step S205 includes processes such as a dicing process, a bonding process, and a packaging process (chip encapsulation) as necessary. Finally, in step S206 (inspection step), inspections such as an operation confirmation test and a durability test of the assembled micro device are performed. After these steps, the microdevice is completed and shipped.

FIG. 11 is a diagram showing a detailed flow of the wafer processing step (step S204) in FIG.
As shown in FIG. 11, in the wafer processing step, a pre-processing process and a post-processing process are repeated over a plurality of stages to stack circuit patterns on the wafer. In the pre-processing process at each stage, only necessary processes among the following processes are selectively executed.

  In step S211 (oxidation step) of the pretreatment process, an oxidation process is performed on the surface of the wafer. In step S212 (CVD step) of the pretreatment process, an insulating film is formed on the surface of the wafer. In step S213 (electrode formation step) of the pretreatment process, electrodes are formed on the surface of the wafer by vapor deposition. In step S214 (ion implantation step) of the pretreatment process, ions are implanted into the wafer.

  In the first step S215 (resist formation step) of the post-processing process, a resist is applied to the wafer. In subsequent step S216 (exposure step), the resist on the wafer is exposed by the circuit pattern of the mask by the projection exposure apparatus. This projection exposure apparatus is the projection exposure apparatus according to any one of the embodiments described above. In subsequent step S217 (developing step), a developing process for developing the resist is performed on the wafer, and in step S218 (etching step), an etching process using the resist as an etching mask is performed on the wafer. In the last step S219 (resist removal step), the resist remaining after the etching process is removed.

  As described above, in this embodiment, since the projection exposure apparatus according to any one of the above-described embodiments is used in step S216 (exposure step) in FIG. 11, microdevices can be manufactured with high throughput.

It is a schematic block diagram of a projection exposure apparatus. It is the schematic diagram which looked at the wafer table WT from the front. It is a figure which shows the mode of the light quantity sensor 13 'for non-exposure wavelengths during an exposure period. FIG. 6 is a diagram illustrating a state when a light amount sensor 13 ′ for a non-exposure wavelength is set on the emission optical path of the projection optical system 6. It is a flowchart which shows the control procedure of a control part. It is a figure explaining the focus detection system of 2nd Embodiment. It is an expanded sectional view of the periphery of the light amount sensor 13 'for the non-exposure wavelength of the third embodiment. It is an expanded sectional view of the periphery of the light amount sensor 13 'for the non-exposure wavelength of the fourth embodiment. It is the front view which looked at the mask 13B of 4th Embodiment from the projection optical system 6 side. It is a flowchart which shows the manufacturing process of a microdevice. It is a figure which shows the detailed flow of a wafer processing step (step S204).

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Radiation device, 3 ... Integrator, 4 ... Condenser mirror, MS ... Reticle stage, 6 ... Projection optical system, WS ... Wafer stage, 14-1 ... Light source, 12, 12 '... Light quantity sensor for exposure wavelength, 13, 13 '... light quantity sensor for non-exposure wavelength, 8 ... mirror adjustment mechanism

Claims (9)

An exposure apparatus that exposes an object to be exposed with light emitted from a main optical system,
A sensor for detecting a light amount of a non-exposure wavelength component contained in light emitted from the main optical system;
A sub optical system that projects light having a wavelength different from the exposure wavelength to the exposure region of the main optical system;
An exposure apparatus comprising: noise preventing means for preventing light emitted from the sub-optical system from entering the sensor at least during detection by the sensor. The exposure apparatus according to claim 1,
The sensor is
The detection is performed only when the object to be exposed is not exposed,
The noise preventing means is
An exposure apparatus comprising: a control unit that controls on / off of the light source of the sub optical system. The exposure apparatus according to claim 1,
The sensor is
The detection is performed only when the object to be exposed is not exposed,
The noise preventing means is
An exposure apparatus comprising: a shutter disposed in an optical path of the sub optical system; and a control unit that controls opening / closing of the shutter. The exposure apparatus according to claim 1,
The noise preventing means is
An exposure apparatus comprising: a filter member that is provided on an opening of the sensor and transmits light emitted from the main optical system and reflects light emitted from the sub optical system. The exposure apparatus according to claim 1,
The noise preventing means is
An exposure apparatus, comprising: a light shielding member that is provided in the vicinity of the opening of the sensor and that allows light emitted from the main optical system to pass therethrough and blocks light emitted from the sub optical system. In the exposure apparatus according to any one of claims 1 to 5,
The sub optical system is
An exposure apparatus that is a part of a focus detection system that detects a focus adjustment state of the main optical system. The exposure apparatus according to claim 6, wherein
The focus detection system is
An exposure apparatus characterized by being an oblique incidence type focus detection system. In the exposure apparatus according to any one of claims 1 to 7,
The exposure wavelength is 50 nm or less. A device manufacturing method comprising: exposing a resist on a substrate by the exposure apparatus according to any one of claims 1 to 8.

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