Source: http://www.google.fr/patents/US8169591
Timestamp: 2017-12-16 19:03:13
Document Index: 381576052

Matched Legal Cases: ['Application No. 05767342', 'Application No. 05767342', 'Application No. 2005', 'Application No. 05767342', 'Application No. 2007', 'Application No. 2010', 'Application No. 201010129961']

Brevet US8169591 - Exposure apparatus, exposure method, and method for producing device - Google Brevets
An exposure apparatus is provided with a projection optical system, and the projection optical system includes a first optical element disposed most closely to an image plane of the projection optical system. The exposure apparatus includes a first liquid immersion mechanism which forms a first liquid...http://www.google.fr/patents/US8169591?utm_source=gb-gplus-shareBrevet US8169591 - Exposure apparatus, exposure method, and method for producing device
Numéro de publication US8169591 B2
Numéro de demande US 11/659,321
Numéro PCT PCT/JP2005/014011
Date de publication 1 mai 2012
Date de dépôt 1 août 2005
Autre référence de publication CN101799636A, CN101799636B, CN102998910A, CN105204296A, DE602005021653D1, EP1791164A1, EP1791164A4, EP1791164B1, EP1791164B2, EP2226682A2, EP2226682A3, EP3048485A1, EP3048485B1, US9063436, US20080084546, US20120176589, WO2006013806A1
Numéro de publication 11659321, 659321, PCT/2005/14011, PCT/JP/2005/014011, PCT/JP/2005/14011, PCT/JP/5/014011, PCT/JP/5/14011, PCT/JP2005/014011, PCT/JP2005/14011, PCT/JP2005014011, PCT/JP200514011, PCT/JP5/014011, PCT/JP5/14011, PCT/JP5014011, PCT/JP514011, US 8169591 B2, US 8169591B2, US-B2-8169591, US8169591 B2, US8169591B2
Citations de brevets (119), Citations hors brevets (23), Référencé par (1), Classifications (11), Événements juridiques (2)
US 8169591 B2
a projection optical system including a first optical element disposed most closely to an image plane of the projection optical system;
a liquid immersion system having a liquid supply inlet and a liquid recovery outlet, which forms the liquid immersion area of the liquid in a space between the first optical element and a surface of a transparent member provided on a side of the image plane of the projection optical system, the surface of the transparent member being positioned on an optical path of the exposure light from the first optical element; and
an observation unit which observes a state of the liquid immersion area through the transparent member;
wherein the observation unit observes a state of a gas portion in the liquid forming the liquid immersion area.
2. The exposure apparatus according to claim 1, further comprising a first stage movable on the side of the image plane of the projection optical system, and an upper surface of the first stage includes the surface of the transparent member.
3. The exposure apparatus according to claim 2, wherein at least a part of the observation unit is provided inside the first stage.
4. The exposure apparatus according to claim 2, wherein the substrate is held on the first stage.
5. The exposure apparatus according to claim 2, further comprising a second stage which is movable, the first stage moves while holding the substrate, the second stage moves while holding a measuring instrument which performs measurement concerning an exposure process, and an upper surface of the second stage includes the surface of the transparent member.
6. The exposure apparatus according to claim 1, wherein:
the projection optical system includes a second optical element disposed second most closely to the image plane of the projection optical system with respect to the first optical element;
the liquid immersion system includes a first liquid immersion system which forms a first liquid immersion area in a space between the first optical element and the surface of the transparent member and a second liquid immersion system which forms a second liquid immersion area in a space between the first optical element and the second optical element; and
the observation unit is capable of observing each of the first liquid immersion area and the second liquid immersion area.
7. The exposure apparatus according to claim 6, wherein the observation unit observes the second liquid immersion area through the first optical element and the transparent member.
8. The exposure apparatus according to claim 6, wherein the observation unit includes an adjusting system which adjusts a focal position of an optical system of the observation unit, and adjusts the focal position so as to observe each of the first liquid immersion area and the second liquid immersion area.
9. The exposure apparatus according to claim 1, wherein the observation unit has a field of view larger than the liquid immersion area.
10. The exposure apparatus according to claim 1, wherein the observation unit has a field of view smaller than the liquid immersion area, and performs observation while the liquid immersion area and the field of view are moved relative to each other.
11. The exposure apparatus according to claim 1, wherein the observation unit obtains an image through the transparent member.
12. The exposure apparatus according to claim 11, wherein the observation unit includes a display unit which displays the image.
13. The exposure apparatus according to claim 11, wherein the observation unit includes an image pickup device.
14. The exposure apparatus according to claim 1, further comprising a control unit, wherein:
the liquid immersion system includes a degassing unit which degasses the liquid, and
the control unit controls the liquid immersion system so as to supply degassed liquid when a judgment is made that the gas portion is present in the liquid forming the liquid immersion area, based on a result of observation performed by the observation unit.
15. The exposure apparatus according to claim 14, wherein the degassing unit degasses the liquid so that a dissolved gas concentration in the liquid becomes not more than 5 ppm.
16. The exposure apparatus according to claim 14, wherein the control unit supplies the degassed liquid while observing the state of the liquid immersion area with the observation unit.
17. The exposure apparatus according to claim 14, wherein the control unit adjusts a time during which the degassed liquid is supplied in accordance with a size or amount of the gas portion in the liquid immersion area.
18. The exposure apparatus according to claim 1, wherein the observation unit includes an illumination unit.
19. The exposure apparatus according to claim 1, wherein the projection optical system includes a second optical element disposed second most closely to the image plane of the projection optical system with respect to the first optical element;
and the first optical element is made of one of CaO and MgO, and the second optical element is made of the other of CaO and MgO.
20. The exposure apparatus according to claim 19, comprising an antireflection coat of MgO on a surface of one of the first and second optical elements which is made of CaO, and an antireflection coat of CaO on a surface of the other of the first and second optical elements which is made of MgO.
21. A method for producing a device, comprising:
exposing a substrate using the exposure apparatus as defined in claim 1; and
22. An exposure apparatus which exposes a substrate through a liquid in a liquid immersion area, the exposure apparatus comprising:
a projection optical system including a first optical element disposed most closely to an image plane of the projection optical system and a second optical element disposed second most closely to the image plane with respect to the first optical element;
a liquid immersion system having a liquid supply inlet and a liquid recovery outlet, which forms the liquid immersion area of the liquid in a space between the first optical element and the second optical element; and
an observation unit which observes a state of the liquid immersion area via the first optical element;
23. The exposure apparatus according to claim 22, wherein the observation unit includes an illumination unit.
24. The exposure apparatus according to claim 22, wherein the first optical element is made of one of CaO and MgO, and the second optical element is made of the other of CaO and MgO.
25. The exposure apparatus according to claim 24, comprising an antireflection coat of MgO on a surface of one of the first and second optical elements which is made of CaO, and an antireflection coat of CaO on a surface of the other of the first and second optical elements which is made of MgO.
26. A method for producing a device, comprising:
exposing a substrate using the exposure apparatus as defined in claim 22; and
27. An exposure apparatus which exposes a substrate through a liquid in a liquid immersion area, the exposure apparatus comprising:
a liquid immersion system including a liquid supply inlet and a liquid recovery outlet which fills, with the liquid, a space between the optical element and a surface of a transparent member disposed on a light-outgoing side of the optical element, the transparent member being disposed on an optical path of exposure light from the optical element; and
an observation unit which observes a state of the liquid in the space between the optical element and the surface of the transparent member through the transparent member;
wherein the observation unit observes a state of a gas portion in the liquid in the space between the optical element and the surface of the transparent member.
28. The exposure apparatus according to claim 27, further comprising a projection optical system, and the optical element is an optical element disposed most closely to an image plane of the projection optical system.
exposing a substrate using the exposure apparatus as defined in claim 27; and
30. An exposure method for exposing a substrate through a liquid in a liquid immersion area formed on a light-outgoing side of an optical element, the exposure method comprising:
performing exposure for the substrate through the liquid in the liquid immersion area;
performing exchange of the substrate which has been exposed with an unexposed substrate;
positioning a transparent member on an optical path of exposure light from the optical element; and
performing detection of a gas portion in the liquid in the liquid immersion area through the transparent member during the exchange of the substrate.
31. The exposure method according to claim 30, further comprising reducing the gas portion in the liquid immersion area when the gas portion is detected in the liquid in the liquid immersion area.
32. The exposure method according to claim 31, wherein the reducing includes performing recovery of the liquid in the liquid immersion area while supplying degassed liquid to the liquid immersion area.
33. The exposure method according to claim 30, wherein the exposure for the substrate and the exchange of the substrate are performed on a first stage, and the detection of the gas portion in the liquid in the liquid immersion area is performed through the transparent member on a second stage.
34. The exposure method according to claim 33, further comprising moving the liquid immersion area between the first stage and the second stage.
35. The exposure method according to claim 30, wherein:
the optical element includes a first optical element and a second optical element; and
a liquid immersion area is formed in a space between the first optical element and the second optical element.
36. The exposure method according to claim 35, further comprising detecting a gas portion in the liquid in the liquid immersion area formed in the space between the first optical element and the second optical element.
37. The exposure method according to claim 30, wherein the gas portion in the liquid in the liquid immersion area is detected each time an exposure process for a predetermined number of the substrate is completed.
38. A method for producing a device, comprising:
exposing a substrate by the exposure method as defined in claim 30; and
δ=±k 2 λ/NA 2 (2)
According to the first through third aspects of the invention, an observation unit which observes the state of the liquid immersion area is provided, so that it can be confirmed whether the formed liquid immersion area is in a desired state, based on the result of observation performed by the observation unit. Then, by exposing, for example, a substrate after it is judged that the formed liquid immersion area is in the desired state based on the result of observation performed by the observation unit, the substrate can be satisfactorily exposed through the liquid in the liquid immersion area. On the other hand, when it is judged that the formed liquid immersion area is not in the desired state based on the result of observation performed by the observation unit, an appropriate procedure for obtaining the desired state of the liquid immersion area, for example, exchange of the liquid can be performed.
According to a fifth aspect of the invention, there is provided an exposure method for exposing a substrate through a liquid in the liquid immersion area formed on a light-outgoing side of an optical element, the method comprising: performing exposure for the substrate through the liquid in the liquid immersion area; performing exchange of the substrate which has been exposed with an unexposed substrate; and performing detection of a gas portion in the liquid in the liquid immersion area during the exchange of the substrate.
In the measuring stage PST2, an observation unit 60 which can observe the states of the first liquid immersion area LR1 and the second liquid immersion area LR2, respectively, is provided. The observation unit 60 is provided inside the measuring stage 60.
The embodiment of the present invention will now be explained as exemplified by a case using the scanning type exposure apparatus (so-called scanning stepper) as the exposure apparatus EX in which the substrate P is exposed with the pattern formed on the mask M while synchronously moving the mask M and the substrate P in mutually different directions (opposite directions) in the scanning directions. In the following explanation, the X axis direction is the synchronous movement direction (scanning direction) of the mask M and the substrate P in a horizontal plane, the Y axis direction (non-scanning direction) is the direction orthogonal to the X axis direction in the horizontal plane, and the Z axis direction is the direction which is perpendicular to the X axis direction and the Y axis direction and is coincident with the optical axis AX of the projection optical system PL.
The directions of rotation (inclination) about the X axis, the Y axis, and the Z axis are θX, θY, and θZ directions, respectively. The term “substrate” referred to herein includes substrates obtained by coating a semiconductor wafer surface with a resist, and the term “mask” includes a reticle formed with a device pattern to be subjected to the reduction projection onto the substrate.
The exposure apparatus EX includes an oblique incidence type focus detection system which detects surface position information of the surface of the substrate P, for example, as disclosed in Japanese Patent Application Laid-open No. 8-37149. The focus detection system detects a position (focus position) in the Z axis direction of the surface of the substrate P with respect to the image plane of the projection optical system PL. The focus detection system is also capable of obtaining a posture in an inclination direction of the substrate P by obtaining focus positions at a plurality of points on the surface of the substrate P. The control unit CONT operates to drive the substrate stage PST1 via the substrate stage driving mechanism PSTD1 based on the result of detection of the focus detection system and controls the position in the Z axis direction (focus position) and the positions in the θX and θY directions of the substrate P so that the surface (exposure surface) of the substrate P matches the image plane formed via the projection optical system PL and the liquid LQ.
In this embodiment, the exposure apparatus EX adopts a local liquid immersion method in which the first liquid immersion area LR1 larger than the projection area AR and smaller than the substrate P is locally formed on a part of the surface of the substrate P including the projection area AR of the projection optical system PL. Here, the lower surface 70A of the nozzle member 70 and the lower surface T1 of the first optical element LS1 are approximately flat surfaces, and the lower surface 70A of the nozzle member 70 and the lower surface T1 of the first optical element LS1 are approximately flush with each other. Accordingly, the first liquid immersion area LR1 can be satisfactorily formed in a predetermined range. The lower surface T1 of the first optical element LS1 which makes contact with the first liquid LQ1 in the first liquid immersion area LR1 and the lower surface 70A, of the nozzle member 70, which makes contact with the first liquid LQ1 in the first liquid immersion area LR1 have lyophilic or liquid-attracting property with respect to the first liquid LQ1.
The control unit CONT performs arithmetic processing (image processing) for the signals outputted from the image pickup device 63 in step SA3 and step SA5, respectively, and judges whether or not the first and second liquid immersion areas LR1 and LR2 are in desired states, based on the results of processing (step SA6). The control unit CONT especially judges whether particles and/or a gas portion or portions (air mass and bubbles) are present in the liquids (LQ1 and LQ2). For example, the control unit CONT judges whether each pixel of the output from the image pickup device 63 is bright or dark, and regards or considers an isolated pixel or pixel group as the presence of bubbles in the liquid and obtains the number and amount of bubbles from the number of such isolated pixels or pixel groups. Alternatively, the control unit CONT may store in advance image data of a plurality of liquid, samples of which number and/or amount of bubbles are known, in the memory of the control unit CONT, and may judge the number and amount of bubbles by comparison with the data. In this case, the image data may be made correspondent to an average area and an average number of the bright sections or dark sections of the pixels. The image data and reference data may be stored in the memory of the control unit, or may be stored in a memory separately provided in the exposure apparatus. In the same manner, the positions and sizes of voids in the liquid can also be detected.
In this embodiment, the control unit CONT operates to supply the degassed second liquid LQ2 to the second space K2 for a predetermined period of time while observing the state of the second liquid immersion area LR2 by the observation unit 60. However, it is not necessarily indispensable that the state of the second liquid immersion area LR2 is continuously observed by using the observation unit 60 during the supply of the degassed second liquid LQ2 to the second space K2. For example, it is also allowable that, at a first point of time, the control unit CONT operates to observe the state of the second liquid immersion area LR2 by using the observation unit 60, and after judging that babbles are present in the second liquid LQ2 forming the second liquid immersion area LR2 based on the result of observation performed by the observation unit 60, the control unit CONT operates to supply the degassed second liquid LQ2 from the second liquid supply unit 31 for a predetermined period of time without performing the observation by the observation unit 60. Then, after the predetermined period of time elapses, at a second point of time, by confirming whether or not the bubbles in the second liquid LQ2 in the second liquid immersion area LR2 have been reduced or eliminated by using the observation unit 60, the control unit CONT can judge whether or not the substrate of the next lot of substrates are to be exposed or the supply of the degassed second liquid LQ2 are to be continued. Also in this case, since the control unit CONT can operate to obtain the size or amount of the bubbles in the second liquid immersion area LR2 based on the result of observation performed by the observation unit 60 at the first point of time, the control unit CONT can adjust the supply time during which the degassed second liquid LQ2 is supplied according to the size or amount of the bubbles. When adjusting the supply time of the degassed second liquid LQ2, the control unit CONT can adjust the supply time while monitoring the timer TM.
In this embodiment, when it is judged that bubbles are present in the second liquid LQ2 forming the second liquid immersion area, the degassed second liquid LQ2 is supplied to the second space K2 for a predetermined period of time to reduce or eliminate the gas portions. However, it is also allowable that, when it is judged that bubbles are present in the second liquid LQ2 forming the second liquid immersion area LR2, without managing the liquid supply time during which the degassed second liquid LQ2 is supplied, the second liquid LQ2 forming the second liquid immersion area LR2 is continuously or intermittently observed by the observation unit 60 while supplying the degassed second liquid LQ2 to the second space K2, and when it is judged that the gas portions in the second liquid LQ2 have been reduced to a level affecting no influence on the exposure or measurement or disappeared, the supply of the degassed second liquid LQ2 is stopped and/or the exposure light beam EL is radiated.
It is approved that the refractive index n of pure water (water) with respect to the exposure light beam EL having a wavelength of about 193 nm is approximately to an extent of 1.44. When the ArF excimer laser beam (wavelength: 193 nm) is used as the light source of the exposure light beam EL, the wavelength is shortened on the substrate P by 0.1/n, i.e., to about 134 nm, and a high resolution is obtained. Further, the depth of focus is magnified about n times, i.e., about 1.44 times as compared with the value obtained in the air. Therefore, when it is sufficient to secure an approximately equivalent depth of focus as compared with the case of the use in the air, it is possible to further increase the numerical aperture of the projection optical system PL. Also in this viewpoint, the resolution is improved.
In the above-described embodiments the first optical element LS1 arranged most closely to the image plane (substrate P side) is a plane-parallel having no refractive power. However, when this first optical element LS1 has a refractive power, it is preferable that this first optical element LS1 arranged most closely to the side of the image plane is made of at least one of CaO and MgO.
As described above, when the liquid immersion method is used, the numerical aperture NA of the projection optical system becomes 0.9 to 1.5 in some cases. In the case where the numerical aperture NA of the projection optical system is thus increased, the image formation performance is sometimes deteriorated by the polarization effect with the random polarized light beam having been hitherto used as the exposure light beam. Therefore, it is desirable to use the polarized illumination. In this case, the following procedure is preferred. That is, the linear polarized illumination is effected, which is adjusted to the longitudinal direction of the line pattern of the line-and-space pattern of the mask (reticle) so that a large amount of diffracted light of the S-polarized component (TE polarized component), that is, polarized light component along the longitudinal direction of the line pattern is allowed to outgo from the pattern of the mask (reticle). When the space between the projection optical system PL and the resist coated on the surface of the substrate P is filled with the liquid, the diffracted light of the S-polarized component (TE polarized component), which contributes to the improvement in the contrast, has the transmittance through the resist surface that is raised to be high as compared with a case in which the space between the projection optical system PL and the resist coated on the surface of the substrate P is filled with the air (gas). Therefore, even when the numerical aperture NA of the projection optical system exceeds 1.0, it is possible to obtain the high image formation performance. It is more effective to make an appropriate combination, for example, with the phase shift mask and the oblique incidence illumination method (especially the dipole illumination method) adjusted to the longitudinal direction of the line pattern as disclosed in Japanese Patent Application Laid-open No. 6-188169. In particular, the combination of the linear polarized illumination method and the dipole illumination method is effective when the periodic direction of the line-and-space pattern is limited to a predetermined one direction or the hole pattern is concentrated along a predetermined one direction. For example, in the case where the halftone phase shift mask (pattern with half pitch of 45 nm) with a transmittance of 6% is illuminated by combining the linear polarized illumination method and the dipole illumination method, when illumination σ defined by a circumscribing circle of two light fluxes forming a dipole on the pupil plane of the illumination system is 0.95, the radiuses of the respective light fluxes on the pupil plane are 0.125σ, and the numerical aperture of the projection optical system PL is NA=1.2, the depth of focus (DOF) can be increased by about 150 nm in comparison to the case using the random polarized light.
The substrate P, which is usable in the respective embodiments described above, is not limited to the semiconductor wafer for producing the semiconductor device. Those applicable include, for example, the glass substrate for the display device, the ceramic wafer for the thin film magnetic head, and the master plate (synthetic silica glass, silicon wafer) for the mask or the reticle to be used for the exposure apparatus.
US4505569 * 1 mai 1984 19 mars 1985 Canon Kabushiki Kaisha Projection apparatus which compensates for the spectral sensitivity of an image receiving member
US6362887 * 8 juin 1999 26 mars 2002 Fresenius Ag Device for measuring changes in parameters within transparent objects
US20040263809 * 22 juin 2004 30 déc. 2004 Canon Kabushiki Kaisha Immersion exposure technique
US20050041225 * 12 juil. 2004 24 févr. 2005 Asml Netherlands B.V. Lithographic apparatus and device manufacturing method
US20050264778 * 1 juin 2004 1 déc. 2005 Asml Netherlands B.V. Lithographic apparatus and device manufacturing method
EP1041357A1 * 17 déc. 1998 4 oct. 2000 Nikon Corporation Stage device and exposure apparatus
JPH0972943A Titre non disponible
JPH08166475A Titre non disponible
JPH08330229A Titre non disponible
JPH10163099A Titre non disponible
JPH10214783A Titre non disponible
JPH10335235A Titre non disponible
JPH10335236A Titre non disponible
JPH11126747A Titre non disponible
2 Communication of a Notice of Opposition issued for EP Patent Application No. 05767342.8 dated Mar. 24, 2011.
3 Communication pursuant to Article 94(3) EPC for EP Patent Application No. 05767342.8 dated Mar. 24, 2009.
4 Dec. 20, 2010 Office Action issued Japanese Patent Application No. 2005-217188 (English Translation).
5 Decision to grant European patent issued in European Patent Application No. 05767342.8 on May 7, 2010.
6 * English translation of Mizutani et al. WO 2004/053958.
7 * English translation of Owa WO 2004/053950.
8 * English translation of Pforr et al. DD 221563.
11 Gau T. et al., "Image Characterization of bubbles in water for 193-nm immersion lithography-far-field approach", Journal of Microlithography, Microfabrication and Microsystems, vol. 3, No. 1, pp. 61-67, published Jan. 2004.
12 Gau T. et al., "Image Characterization of bubbles in water for 193-nm immersion lithography—far-field approach", Journal of Microlithography, Microfabrication and Microsystems, vol. 3, No. 1, pp. 61-67, published Jan. 2004.
13 International Preliminary Report on Patentability issued in International Application No. PCT/JP2005/014011 on Feb. 6, 2007 (with translation).
14 International Search Report issued in International Application No. PCT/JP2005/014011 on Nov. 8, 2005.
15 Jan. 20, 2012 Notice of Grounds for Rejection for KR Appln. No. 2011-7031692 w/translation.
16 John H. Burnett et al., "High Index Materials for 193 nm and 157 nm Immersion Lithography" International Symposium on Immersion & 157nm Lithography, Vancouver, Aug. 2, 2004.
17 Jun. 30, 2011 Office Action issued in Korean Patent Application No. 2007-7002662 (with English Translation).
18 Mar. 16, 2011 Notice of Reasons for Rejection issued in Chinese Patent Application No. 2010-10129961.4 (with partial English translation).
19 Nov. 11, 2010 Office Action issued in Chinese Patent Application No. 201010129961.4 (with English Translation).
20 Owa S. et al., "Imersion lithography: its potential performances and issues" Proceeding of the SPIE, SPIE, vol. 5040, Feb. 28, 2003, pp. 724-733.
21 Streefkerk et al., "Extending Optical Lithography with Immersion" Optical Microlithography XVII, edited by Bruce W. Smith, Proceedings of SPIE vol. 5377, published Feb. 2004, pp. 285-305.
22 Yongfa Fan et al., "Study of Air Bubble Induced Light Scattering Effect on Image Quality in 193 nm Immersion Lithography", Proceedings of SPIE, vol. 5377, pp. 477-486, published May 28, 2004.
23 Zhu Y. et al., "Rapid Measurement of Bubble Size in Gas-Liquid Flows Using a Bubble Detection Technique", 14th Australian Fluid Mechanics Conference, Dec. 10-14, 2001, pp. 541-544.
US9063436 22 mars 2012 23 juin 2015 Nikon Corporation Exposure apparatus, exposure method, and method for producing device
Classification internationale G03B27/42, G03B27/52
Classification coopérative G03F7/70733, G03F7/70341, G03F7/7085, G03F7/70716
Classification européenne G03F7/70F24, G03F7/70N4, G03F7/70P4
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:OWA, SOICHI;NAGASAKA, HIROYUKI;SUGAWARA, RYU;REEL/FRAME:019219/0555