JP2006134999A - Immersion-type exposure device and method for cleaning holding base in immersion-type exposure device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an immersion-type exposure device capable of inhibiting the adhesion, deposition or the like of foreign matters in a groove formed on a holding base. <P>SOLUTION: The immersion-type exposure device has (A) a lens opposed to an object to be exposed, (B) a shower head 10 for filling a section between the lens, on which a liquid-supply line 12 and a liquid-discharge line 13 are mounted, and the object to be exposed with a liquid, and (C) the holding base 21 for holding the object to be exposed. The immersion-type exposure device further has (D) the groove 26 formed on the holding base so as to correspond to the periphery of the object to be exposed, (E) a liquid discharge opening 27 formed to the groove 26, and (F) a cleaning-liquid supply means 28 for supplying the groove 26 with a washing liquid. The supplied washing liquid is discharged from the liquid-discharge opening 27. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an immersion exposure apparatus and a cleaning method for a holding table in the immersion exposure apparatus.

  With the recent miniaturization of semiconductor devices, there is a demand for improving the resolution of lithography processing. Regarding lithography processing using an exposure apparatus, two methods are known for improving the resolution. The first method is a method for shortening the wavelength of light used for exposure, and the second method is a method for increasing the numerical aperture. However, the first method affects the selection of an optical material (for example, a lens glass material) used in the exposure apparatus. In general, the light absorption property of an optical material has wavelength dependency. Therefore, the range of selection of the optical material is narrowed depending on the degree of wavelength reduction. The second method can be implemented simply by mechanically enlarging the optical system, but inevitably increases the size of the optical system of the exposure apparatus. For this reason, as a method for increasing the numerical aperture without increasing the size of the optical system, an immersion exposure technique for filling the space between the lens and the object to be exposed with a liquid has been proposed.

  The immersion exposure technique is a technique for increasing the resolution to double the refractive index of the liquid by filling the space between the lens and the exposure object with a liquid and exposing the exposure object. The principle of increasing the resolution by filling the space between the lens and the exposure object with a liquid will be briefly described below. The resolution increases as the so-called numerical aperture (NA) increases. The numerical aperture is a sine of a half angle of the maximum perpendicular angle (an object point or an angle extending from the focal point to the entrance pupil diameter or the exit pupil diameter) of the light beam entering or exiting the optical system or optical element. expressed. The numerical aperture NA is expressed by the following equation (1), where ± θ is the spread of the light beam focused on one point on the exposure object. Here, n is the refractive index of the medium on the exposure object side, and in the case of normal exposure, since the exposure object is placed in the air, n = 1. Therefore, in the exposure in the air, the numerical aperture NA is expressed by the following formula (2). On the other hand, when water is used as an example of the liquid for immersion exposure, the refractive index of water is n = 1.436. Accordingly, in exposure in water, the numerical aperture NA is expressed by the following formula (3), and the numerical aperture NA is larger than in exposure in air.

NA = n × sin (θ) (1)
NA = sin (θ) (2)
NA = 1.436 × sin (θ) (3)

  The immersion exposure technique has attracted a great deal of attention because it can increase the resolution without shortening the wavelength of the light source or increasing the size of the optical system. There has also been proposed a method in which the entire exposure object is immersed in a liquid for exposure (see, for example, JP-A-10-303114).

  There has also been proposed an exposure apparatus that uses a shower head provided with a liquid supply line and a drain line to perform exposure while filling only the inside of the shower head with a liquid. The immersion type exposure apparatus 190 shown in FIG. 5 includes a shower head 110, a holding table 120, a mask unit 140, an illumination unit 150, a control unit 160, an XY stage unit 170, and a reduction projection optical unit 180.

  As an exposure object, a substrate 130 provided with a photosensitive film is shown. The substrate 130 includes a disk-shaped semiconductor substrate 131 generally called a wafer, and a photosensitive film 132 provided thereon. In some cases, a base layer is provided on the semiconductor substrate 131, and the photosensitive film 132 is provided on the base layer. As a material for the photosensitive film 132, a cross-linked type, a photopolymerization type, a phase change type photoresist material, and the like can be generally used. The liquid immersion type exposure apparatus 190 holds the substrate 130 as an exposure object on the holding table 120 and exposes the photosensitive film 132 provided on the semiconductor substrate 131.

  The illumination unit 150 includes a light source 151, a condenser lens 152, and a mirror 153. The light source 151 includes, for example, an ArF excimer laser light source (not shown) having a wavelength of 193 nm and an aperture (not shown). The illuminance of the pulsed illumination light generated from the laser light source is made uniform, and the shape of the illumination light is shaped into a substantially rectangular shape by the diaphragm. The shaped illumination light is converged by the condenser lens 152, reflected by the mirror 153, and enters the mask unit 140.

  The mask unit 140 includes a reticle 141, a reticle stage 142, a reticle stage drive unit 143, and a reticle position information detection unit 144. The reticle 141 is provided with a mask pattern for exposure. The reticle 141 is fixed on the reticle stage 142 by, for example, vacuum suction. The reticle stage 142 can be moved in the Y-axis direction of FIG. 5 by a reticle stage driving unit 143 constituted by a motor or the like. Reticle stage driving means 143 operates in accordance with a command from controller 161 in control unit 160. The position information of the reticle 141 is measured by the reticle position information detecting means 144 including a laser interferometer or the like, and the position information of the reticle 141 in the Y direction is sent to the controller 161.

  The reduction projection optical unit 180 includes a lens barrel, a plurality of lenses, and the like, and includes a lens facing the exposure target. Quartz is mainly used as the glass material of the lens, but fluorite is also used in part to reduce chromatic aberration.

  The shower head 110 is attached to the end of the reduction projection optical unit 180. The shower head 110 includes a cylinder 111, a liquid supply line 112, and a drainage line 113. A liquid for immersion exposure, for example, water is supplied to the inside of the cylinder 111 through the liquid supply line 112 and discharged to the outside of the cylinder 111 through the liquid discharge line 113. At the time of exposure, the liquid for immersion exposure is supplied to the inside of the cylinder 111 through the liquid supply line 112 at a predetermined flow rate, and is discharged through the liquid discharge line 113. By adjusting the flow rate of the liquid supply, the flow rate of the drainage liquid, etc., exposure can be performed without leaving the liquid on the substrate 130.

  The holding table 120 includes a holding table 121, a suction unit 122 that sucks an object to be exposed, and a discharge unit 123 that discharges a liquid. The holding table 121 can be moved in the X-axis direction and the Y-axis direction of FIG. 5 by the XY stage unit 170. The holding table 121 includes a suction surface 124 that holds an exposure target, a pipe 125 that communicates with the suction surface 124, a groove 126 that is provided to correspond to the peripheral edge of the substrate 130 that is the exposure target, and a groove 126. A liquid discharge port 127 is provided. Of the upper surface of the holding table 121, the portion that holds the substrate 130 is recessed compared to the other portions, and is substantially flush with the substrate 130 being held. The suction means 122 composed of a pump or the like is connected to the pipe 125, and when the suction means 122 is operated, the substrate 130 is held on the suction surface 124. The substrate 130 can also be held by an electrostatic adsorption means.

  In the exposure process, it is necessary to sequentially replace the substrates 130 as exposure objects. Therefore, the recessed area on the holding table 121 is slightly wider than the substrate 130. For this reason, a slight gap must be generated around the substrate 130. Although described in detail with reference to FIGS. 7A to 7C, it is difficult to prevent the liquid for immersion exposure from flowing into the gap. Therefore, a groove 126 is provided so as to correspond to the peripheral edge of the substrate 130. The liquid that has flowed into the groove 126 from the peripheral edge of the substrate 130 is discharged by the discharge means 123 configured by a pump or the like connected to the liquid discharge port 127.

  The XY stage unit 170 includes an XY stage 171, an XY stage driving unit 172, an exposure target object position information detecting unit 173, and a surface plate 174. The XY stage 171 can be moved on the surface plate 174 in the X-axis direction and the Y-axis direction of FIG. 5 by an XY stage driving unit 172 constituted by a motor or the like. The XY stage driving unit 172 operates in accordance with a command from the controller 161 in the control unit 160. The position information of the substrate 130 that is the exposure object is measured by the exposure object position information detection means 173 such as a laser interferometer, and the measured position information in the X direction and the Y direction is sent to the controller 161 of the control unit 160. Sent.

  In the immersion type exposure apparatus 190, the substrate 130 provided with the photosensitive film moves relative to the fixed reduction projection optical unit 180. The imaging state of the mask pattern on the reticle 141 on the photosensitive film 132 of the substrate 130 depends on the position of the photosensitive film 132 in the Z-axis direction. For this reason, the holding stand 121 can also be moved in the Z-axis direction by a driving means (not shown) such as a piezoelectric element that can be moved finely. Position information on the upper surface of the photosensitive film 132 is measured by a measuring means (not shown) such as a laser interferometer, and the position information is sent to the controller 161 of the control unit 160. The controller 161 controls the above-described finely movable driving means so that a good imaging state is always obtained on the photosensitive film 132.

  The liquid immersion type exposure apparatus 190 moves the reticle stage 142 and the XY stage 171 in the Y-axis direction during exposure, and scans and exposes the photosensitive film 132. It is to be noted that exposure can be performed with the reticle stage 142 and the XY stage 171 relatively stationary during exposure. In this case, the immersion type exposure apparatus 190 operates as a simple step-and-repeat type exposure apparatus.

The scanning exposure operation will be described with reference to FIG. The reduction projection optical unit 180 is representatively represented by a front lens 181 and a rear lens 182. The rear lens 182 faces the substrate 130 that is an exposure target. The reticle 141 is provided with a mask pattern 145 for exposure. A substantially rectangular region 154 of illumination light incident on the reticle 141 from the illumination unit 150 irradiates a partial region of the mask pattern 145. The light that has passed through the mask pattern 145 passes through the front lens 181, the rear lens 182, and the space 114 filled with the liquid inside the tube 111 of the shower head 110, and forms an image on the photosensitive film 132. The imaged illumination light region 155 exposes the photosensitive film 132. Accordingly, for example, by moving the reticle 141 in the Y-axis positive direction in FIG. 6 at the constant speed V ₁ and moving the substrate 130 as the exposure target in the Y-axis negative direction at the constant speed V ₂ , the mask pattern 145 as a whole is moved. The shot region 133 of the photosensitive film 132 corresponding to the above is scanned and exposed. After the exposure of the shot area 133 is completed, the substrate 130 is moved so that the exposure start position of the adjacent shot area 134 is reached. During this movement, irradiation of illumination light from the illumination unit 150 is stopped. When the exposure of the end portion of the photosensitive film 132 is completed, the substrate 130 is moved by a predetermined amount in the X-axis direction, and then the above operation is repeated to perform scanning exposure. In this way, the entire surface of the photosensitive film 132 provided on the semiconductor substrate 131 is exposed.

  The shower head 110 is provided so as to cover the rear lens 182. Therefore, when the shot region 133 at the end of the photosensitive film 132 is exposed, the space 114 filled with the liquid extends outside the substrate 130.

  With reference to FIGS. 7A to 7C, the relationship among the shower head 110, the substrate 130, and the holding base 121 at this time will be described. As shown in FIG. 7A, the tube 111 of the shower head 110 is positioned above the groove 126 provided in the holding base 121. As shown in FIG. 7B, the inside of the cylinder 111 is filled with a liquid for immersion exposure. Therefore, this liquid flows into the groove 126 of the holding table 121. As shown in FIG. 7C, the inside of the cylinder 111 communicates with the liquid supply line 112 and the liquid discharge line 113. Most of the liquid that has flowed into the cylinder 111 via the liquid supply line 112 flows out from the drainage line 113, but part of the liquid flows into the groove 126. Since the entire photosensitive film 132 on the semiconductor substrate 131 is exposed, the liquid for immersion exposure flows into the groove 126 located below the tube 111 of the shower head 110.

With reference to FIGS. 8A to 8C, the flow of the liquid into the groove 126 when the entire photosensitive film 132 provided on the substrate 130 is exposed will be schematically described. When the entire surface of the photosensitive film 132 is exposed, as shown in FIG. 8A, the tube 111 of the shower head 110 is positioned above one end side of the substrate 130, and as shown in FIG. In addition, the tube 111 of the shower head 110 is positioned above the other end side of the substrate 130. Therefore, in any case, the liquid flows into the groove 126. The liquid that has flowed in is discharged by the discharge means 123 connected to the liquid discharge port 127. However, as shown in (B) or (C) of FIG. 8, the liquid 115 that is not discharged may remain in the groove 26.
JP-A-10-303114

  In the liquid immersion type exposure apparatus 190 described above, a liquid for liquid immersion exposure is caused to flow continuously through the cylinder 111 during exposure. However, the liquid for immersion exposure is in contact with the photosensitive film 132 provided on the semiconductor substrate 131. For this reason, the soluble substance contained in the photosensitive film 132 may be eluted into the liquid for immersion exposure filled in the cylinder 111. In addition, dust or the like adhering to the surface of the photosensitive film 132 may be flowed with a liquid for immersion exposure. Accordingly, the liquid that flows into the groove 126 of the holding table 121 may contain a soluble substance, dust, or the like that was included in the photosensitive film 132. As shown in FIG. 8 (B) or (C), the liquid 115 which is not discharged and remains in the groove 126 also includes these. In addition, when a long time elapses after the exposure of the exposure target is completed and replaced with a new exposure target and the next exposure is performed, the evaporation of the liquid 115 remaining in the groove 126 proceeds, Soluble substances, dust, etc. accumulate in the grooves 126. In such a case, when the holding table 121 moves, the deposits are peeled off and become new dust, which may cause a reduction in exposure yield.

  In general, the refractive index of a liquid increases when a soluble substance is melted. For this reason, it is also possible to intentionally melt a substance soluble in a liquid and use it as a liquid for immersion exposure. For example, various salts can be dissolved in water and used as a liquid for immersion exposure. In this case, the precipitation of soluble substances due to evaporation of the liquid becomes significant.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an immersion type exposure apparatus capable of suppressing foreign matter from adhering to and accumulating in a groove provided on the holding table, and a method for cleaning the holding table in the immersion type exposure apparatus. There is.

In order to achieve the above object, an immersion type exposure apparatus of the present invention comprises:
(A) a lens facing the object to be exposed;
(B) A shower head provided with a liquid supply line and a liquid discharge line, for filling the space between the lens and the object to be exposed with a liquid,
(C) a holding table for holding an exposure object;
(D) a groove provided on the holding table so as to correspond to the peripheral edge of the exposure object; and
(E) a liquid outlet provided in the groove;
An immersion type exposure apparatus having
(F) having cleaning liquid supply means for supplying the cleaning liquid to the groove;
The supplied cleaning liquid is discharged from a liquid discharge port.

In addition, the method for cleaning the holding table in the immersion type exposure apparatus according to the first aspect of the present invention includes:
(A) a lens facing the object to be exposed;
(B) A shower head provided with a liquid supply line and a liquid discharge line, for filling the space between the lens and the object to be exposed with a liquid,
(C) a holding table for holding an exposure object;
(D) a groove provided on the holding table so as to correspond to the peripheral edge of the exposure object; and
(E) a liquid outlet provided in the groove;
In addition,
(F) cleaning liquid supply means for supplying the cleaning liquid to the groove;
A method for cleaning a holding table in an immersion type exposure apparatus comprising:
The cleaning liquid is supplied to the groove by the cleaning liquid supply means and discharged from the liquid discharge port.

  In the immersion exposure apparatus of the present invention or the cleaning method of the holding table in the immersion exposure apparatus according to the first aspect of the present invention, the cleaning liquid supply means can supply the cleaning liquid to the groove provided in the holding table. Anything is acceptable. The number of the cleaning liquid supply means and the positions to be arranged are arbitrary, and one or a plurality of cleaning liquid supply means may be provided. The cleaning liquid supply means may be provided separately from the holding table, but is preferably provided integrally with the holding table, and more preferably configured with a cleaning liquid supply port provided in the groove. Further, the number of cleaning liquid supply ports and the position provided in the groove are arbitrary, and one or a plurality of cleaning liquid supply ports may be provided.

In order to achieve the above object, a method for cleaning a holding table in an immersion type exposure apparatus according to the second aspect of the present invention comprises:
(A) a lens facing the object to be exposed;
(B) A shower head provided with a liquid supply line and a liquid discharge line, for filling the space between the lens and the object to be exposed with a liquid,
(C) a holding table for holding an exposure object;
(D) a groove provided on the holding table so as to correspond to the peripheral edge of the exposure object; and
(E) a liquid outlet provided in the groove;
A method for cleaning a holding table in an immersion type exposure apparatus comprising:
(A) After holding the dummy wafer on the holding table,
(B) positioning the shower head above the groove;
(C) By supplying the cleaning liquid from the liquid supply line to the shower head, the cleaning liquid is supplied to the groove and discharged from the liquid discharge port.
It is characterized by that.

  In the method of cleaning the holding table in the immersion type exposure apparatus according to the second aspect of the present invention, the dummy wafer may be any one that does not elute soluble substances from the surface into the cleaning liquid. Examples of the dummy wafer include a plate made of a metal such as stainless steel and aluminum, and a semiconductor substrate on which no photosensitive film is provided.

  In the method for cleaning the holding table in the immersion type exposure apparatus according to the second aspect of the present invention, the cleaning liquid is poured into the groove by flowing the cleaning liquid from the liquid supply line to the shower head while the shower head is positioned above the groove. It may be supplied and discharged from the liquid outlet. Alternatively, after the shower head is positioned above the groove, the cleaning liquid may be supplied from the liquid supply line to the shower head so that the cleaning liquid is supplied to the groove and discharged from the liquid discharge port.

  The immersion type exposure apparatus of the present invention, or the method for cleaning the holder in the immersion type exposure apparatus according to the first or second aspect of the present invention (hereinafter collectively referred to as the present invention). The object to be exposed refers to a substrate provided with a photosensitive film. Examples of the material for the photosensitive film include cross-linked type, photopolymerization type, and phase change type photoresist materials. The photosensitive film may be provided directly on the substrate, or a base layer may be provided on the substrate, and the photosensitive film may be provided on the base layer. The material of the underlayer may be any of an insulator, a semiconductor, and a conductor, and examples thereof include silicon oxide materials, aluminum oxide, amorphous silicon, polysilicon, aluminum, copper, gold, and platinum. Examples of the material of the substrate include a semiconductor such as a silicon single crystal, but it may be made of an insulator or a conductor.

  In the present invention, “the groove provided so as to correspond to the peripheral portion of the exposure object” means that the groove is at least outside the edge of the projected image of the exposure object. Here, “at least outside” means that the inside and outside of the groove may be outside the edge of the projection image of the exposure object, or the inside of the groove is the edge of the projection image of the exposure object. It means that it is inside and the outside of the groove may be outside the projected image of the exposure object. In the present invention, “the shower head is positioned above the groove” refers to a state in which the projected image of the shower head includes the groove.

  In the present invention, the cleaning liquid only needs to be able to remove foreign matter, and the foreign matter may be physically removed or chemically removed. As long as foreign substances can be removed, the composition of the cleaning liquid is arbitrary. For example, water with few impurities, alcohol, such as methanol, can be illustrated. A liquid having the same composition as the liquid for immersion exposure can also be used as the cleaning liquid. In this case, since the liquid used in the immersion type exposure apparatus is made common, handling is easy and preferable. In the present invention, “foreign matter” broadly refers to substances that cause adverse effects on exposure, such as deposits of soluble substances, liquids containing soluble substances, dust, liquids containing dust, and the like.

  In the present invention, the liquid discharge port is provided in the groove of the holding table, but it is optional in which part of the groove and in which position. As long as the liquid inside the groove provided on the holding table can be discharged, one groove may be provided or a plurality of liquids may be provided. Further, it may be provided at a position corresponding to the cleaning liquid supply means. Here, the “corresponding position” refers to, for example, an angle of 180 degrees when one cleaning liquid supply means is provided at a position of an angle of 0 degrees in a groove surrounding the peripheral edge of the exposure object in an annular shape. Means position. In the case where n cleaning liquid supply units are provided at an angular position (unit: degree) represented by the following expression (4), the “corresponding position” means an angular position represented by the following expression (5) ( Unit: Degree). However, m is an integer of 1-n.

(M−1) × (360 / n) (4)
(M−1) × (360 / n) + (180 / n) (5)

  According to the immersion type exposure apparatus of the present invention and the method for cleaning the holding table in the immersion type exposure apparatus according to the first aspect of the present invention, the cleaning liquid is supplied to the groove of the holding table by the cleaning liquid supply means and held. Since the cleaning liquid is discharged from the liquid discharge port provided in the groove of the table, the foreign matter is removed from the groove. Thereby, it is possible to prevent foreign matters adhering to and accumulating in the grooves from affecting the exposure process.

  According to the method for cleaning the holding table in the immersion type exposure apparatus according to the second aspect of the present invention, since the cleaning liquid is supplied from the shower head after the dummy wafer is held by the holding table, the exposure object on the holding table is held. The cleaning liquid does not adhere to the part. Further, it is not necessary to newly provide a cleaning liquid supply means on the holding table, and this can be implemented in a conventional immersion exposure apparatus.

  Hereinafter, the present invention will be described based on examples with reference to the drawings.

  Example 1 relates to an immersion type exposure apparatus of the present invention and a cleaning method of a holding table in the immersion type exposure apparatus according to the first aspect of the present invention. An overall view of the immersion type exposure apparatus of Example 1 is shown in FIG. 1, and a cleaning process of a groove provided on the holding table is schematically shown in FIGS. 2A to 2C, and is provided on the holding table. The arrangement of the liquid discharge port and the cleaning liquid supply means is schematically illustrated in FIGS.

  The immersion type exposure apparatus according to the first embodiment is an apparatus that exposes an exposure object by filling a space between the exposure object and the lens facing the exposure object. The lens and liquid supply facing the exposure object A shower head provided with a line and a drainage line for filling the space between the lens and the exposure object with a liquid and a holding table for holding the exposure object.

  As shown in FIG. 1, the immersion type exposure apparatus 90 of the first embodiment more specifically holds a shower head 10 for filling a space between a lens and an exposure target object with a liquid, and the exposure target object. A holding table 20, a mask unit 140, an illumination unit 150, a control unit 160, an XY stage unit 170, and a reduction projection optical unit 180 having a lens facing the object to be exposed. The exposure object is, for example, a substrate 30 composed of a disk-shaped semiconductor substrate 31 and a photosensitive film 32 provided thereon.

  The mask unit 140, illumination unit 150, control unit 160, XY stage unit 170, and reduction projection optical unit 180 in FIG. 1 are the same as the mask unit 140 and illumination unit 150 in the conventional immersion type exposure apparatus 190 described with reference to FIG. The control unit 160, the XY stage unit 170, and the reduction projection optical unit 180 have the same configuration and structure. Since these configurations, operations, and actions are the same as those already described in the background art, description thereof is omitted here.

  The reduction projection optical unit 180 includes a lens barrel, a plurality of lenses, and the like, and includes a lens facing the substrate 30 that is an exposure target.

  The shower head 10 is attached to the end of the reduction projection optical unit 180. The shower head 10 includes a cylinder 11, a liquid supply line 12, and a liquid discharge line 13. A liquid for immersion exposure, for example, water is supplied to the inside of the cylinder 11 through the liquid supply line 12 and discharged to the outside of the cylinder 11 through the liquid discharge line 13, thereby reducing the projection optical unit. A space between the 180 lenses and the substrate 30 as an exposure target is filled with a liquid for immersion exposure. By adjusting the flow rate of the liquid supply, the flow rate of the drainage liquid, etc., exposure can be performed without leaving the liquid for immersion exposure on the substrate 30.

  The holding table 20 includes a holding table 21, an adsorption unit 22 for adsorbing an object to be exposed to the holding table 21, and a liquid discharging unit 23. The holding table 21 can be moved in the X-axis direction and the Y-axis direction in FIG. 1 by the XY stage unit 170. The holding table 21 is provided in a suction surface 24 that holds an exposure object, a pipe 25 that communicates with the suction surface 24, a groove 26 that is provided to correspond to the peripheral edge of the substrate 30 that is the exposure object, and a groove 26. A liquid outlet 27 is provided. A portion of the upper surface of the holding table 21 that holds the substrate 30 is recessed compared to other portions, and is substantially flush with the substrate 30 being held. The suction means 22 composed of a pump or the like is connected to the pipe 25, and when the suction means 22 is operated, the substrate 30 as an exposure object is held on the suction surface 24.

  The immersion type exposure apparatus 90 according to the first embodiment includes a cleaning liquid supply port 28 in addition to these. The cleaning liquid supply port 28 is connected to a cleaning liquid supply device 29 via a pipe. A cleaning liquid supply port 28 as a cleaning liquid supply means is provided in the groove 26. The cleaning liquid sent from the cleaning liquid supply device 29 is supplied to the groove 26 from the cleaning liquid supply port 28 which is a cleaning liquid supply means. The cleaning liquid supplied to the groove 26 is discharged by the discharge means 23 through the liquid discharge port 27. Thereby, the foreign material remaining in the groove 26 is removed. When the liquid supplied to the shower head 10 is water, water having the same composition as the cleaning liquid may be used.

  The cleaning of the groove 26 will be described with reference to FIGS. Although already schematically described with reference to FIGS. 8A to 8C, after the exposure of the entire surface of the photosensitive film 32, the liquid is immersed in the groove 26 positioned below the tube 11 of the shower head 10. The exposure liquid flows in. The liquid that has flowed in includes a soluble substance contained in the photosensitive film 32, dust attached to the surface of the photosensitive film 32, and the like. This liquid is discharged by the discharge means 23 connected to the liquid discharge port 27. However, the liquid 15 that is not discharged may remain in the groove 26. FIG. 2A schematically shows this state.

  In this state, the cleaning liquid is sent from the cleaning liquid supply device 29, and the cleaning liquid is supplied from the cleaning liquid supply port 28 to the groove 26. The groove 26 is filled with the cleaning liquid, and the state shown in FIG. The liquid 15 is discharged out of the groove 26 through a liquid discharge port 27 provided in the groove 26 together with the cleaning liquid. Accordingly, the foreign matter is removed from the groove 26. FIG. 2C schematically shows this state.

  A part of the cleaning liquid may remain in the groove 26. However, most of the impurities and the like contained in the liquid 15 are discharged from the liquid discharge port 27 together with the cleaning liquid. Therefore, it is not a problem in practice that the cleaning liquid remains in the groove 26.

  2A to 2C, after the exposure of the entire surface of the photosensitive film 32 is completed, the cleaning liquid is supplied from the cleaning liquid supply port 28 to the groove 26 and is discharged from the liquid discharge port 27. However, the cleaning liquid may be supplied from the cleaning liquid supply port 28 to the groove 26 during the exposure of the photosensitive film 32 and discharged from the liquid discharge port 27. Alternatively, the cleaning liquid may be steadily poured into the groove 26 from the cleaning liquid supply port 28 at the time of exposure and then discharged from the liquid discharge port 27 steadily. How the cleaning liquid is supplied and how it is discharged can be arbitrarily determined.

  In the first embodiment, the liquid discharge port 27 is provided in the groove 26 of the holding base 21, but it is arbitrary in which part of the groove 26 the liquid discharge port 27 is provided. As long as the liquid inside the groove 26 can be discharged, one liquid discharge port 27 may be provided in the groove 26 or a plurality of liquid discharge ports 27 may be provided. It may be provided at a position corresponding to the cleaning liquid supply means.

  An arrangement example of the liquid discharge port 27 and the cleaning liquid supply port 28 provided in the groove 26 will be described with reference to FIGS. A plurality of liquid discharge ports 27 and cleaning liquid supply ports 28 provided in the groove 26 may be provided as shown in FIG. 3A, or one as shown in FIG. It may be provided. When a plurality of liquid discharge ports 27 are provided, they may be connected to the liquid discharge means 23 in FIG. 1 through a common pipe, or may be connected through individual pipes. . Similarly, when a plurality of cleaning liquid supply ports 28 are provided, the cleaning liquid supply ports 28 may be connected to the cleaning liquid supply device 29 of FIG. 1 via a common pipe, or may be connected via individual pipes. The route of these pipes in the holding table 21 is arbitrary. However, since the holding table 21 is provided with a suction surface or the like in the area where the exposure object is held, it may be difficult to provide these pipes in this area. Therefore, it is preferable for the piping to avoid this region. For example, these pipes may pass through a common path (not shown) after passing through a path extending radially from the groove 26 as indicated by a broken line in FIG.

  Example 2 relates to a method for cleaning a holding table in an immersion type exposure apparatus according to the second aspect of the present invention. The cleaning method of the second embodiment can be carried out using the immersion type exposure apparatus 90 of the first embodiment shown in FIG. 1, but can also be carried out using the conventional immersion type exposure apparatus 190 shown in FIG. FIGS. 4A to 4D show an example in which a conventional immersion type exposure apparatus 190 is used.

  A shower head 110 for filling a space between a lens and an exposure object provided in a conventional immersion type exposure apparatus 190 with a liquid, a holding table 120 having a holding table for holding the exposure object, a mask unit 140, and an illumination The configuration, operation, and action of the unit 150, the control unit 160, the XY stage unit 170, and the reduction projection optical unit 180 having a lens facing the exposure target are the same as those already described in the background art. The description is omitted here.

  With reference to FIGS. 4A to 4D, a cleaning method for the holding table in the immersion exposure apparatus according to the embodiment 2 will be described.

  As shown in FIG. 4A, after the entire surface of the photosensitive film 132 is exposed, the liquid for immersion exposure may flow into the groove 126 and the liquid 115 that is not discharged may remain in the groove 126. As described in the description of FIG. 8C, the liquid 115 includes a soluble substance contained in the photosensitive film 132, dust attached to the surface of the photosensitive film 132, and the like.

  Here, the operation of the suction means 122 shown in FIG. 5 is stopped, and the substrate 130 whose entire surface is exposed is removed from the holding table 121. Next, as shown in FIG. 4B, the dummy wafer 33 is placed on the holding table 121, and the suction means 122 is operated to hold the dummy wafer 33. The dummy wafer 33 is made of a material that does not elute soluble substances even in contact with the liquid filled in the cylinder 111 of the shower head 110. As the dummy wafer 33, for example, a plate made of a metal such as stainless steel or aluminum, a semiconductor substrate without a photosensitive film, and the like can be exemplified.

  Next, the XY stage unit 170 of FIG. 5 is operated, and the tube 111 of the shower head 110 is positioned above the groove 126 on one end side of the dummy wafer 33 as shown in FIG. State. In this state, the cleaning liquid is supplied to the cylinder 111 through the liquid supply line 112. A liquid for immersion exposure, for example, water can be supplied as a cleaning liquid as it is. As a result, the cleaning liquid is supplied to the groove 126 located below the cylinder 111. The cleaning liquid comes into contact with the dummy wafer 33, but no soluble substance is eluted from the dummy wafer 33. Next, as indicated by the arrow in FIG. 4C, the XY stage unit 170 is operated, and the “Q” in which the cylinder 111 of the shower head 110 is positioned above the groove 126 on the other end side of the dummy wafer 33. State. In this state, when the cleaning liquid is supplied to the cylinder 111 via the liquid supply line 112, the cleaning liquid is similarly supplied to the groove 126 located below the cylinder 111. Since the dummy wafer 33 is attached to the holding base 121, the cleaning liquid adheres to the suction surface 124 of the holding base 121 shown in FIG. 5, or the suction means 122 including a pump sucks the cleaning liquid. There is nothing.

  Next, as shown in FIG. 4D, the discharging means 123 is operated to discharge the cleaning liquid containing the liquid 115 from the groove 126 through the liquid discharge port 127. The liquid 115 is discharged out of the groove 126 through the liquid discharge port 127 provided in the groove 126 together with the cleaning liquid. Accordingly, the foreign matter is removed from the groove 126. A part of the cleaning liquid may remain in the groove 126. However, most of the impurities and the like contained in the liquid 115 are discharged from the liquid discharge port 127 together with the cleaning liquid. Accordingly, it is not a practical problem that the cleaning liquid remains in the groove 126.

  4C, the cylinder 111 is positioned above one end of the dummy wafer and the cleaning liquid is supplied to the groove 126. Thereafter, the cylinder 111 is positioned above the other end of the dummy wafer and the cleaning liquid is supplied to the groove 126. Thereafter, the liquid is discharged from the liquid outlet 127. However, it can be arbitrarily determined which portion of the groove 126 provided on the holding stand 121 is supplied with the cleaning liquid.

  For example, when all the grooves 126 provided on the holding table are cleaned, an operation similar to the operation of exposing the entire surface of the exposure object may be performed with the dummy wafer 33 held. However, in this case, since actual exposure is unnecessary, the operation of the illumination unit 150 may be stopped. The liquid immersion type exposure apparatus 190 continuously flows the liquid for liquid immersion exposure to the cylinder 111 during exposure, so that the liquid for liquid immersion exposure acts as a cleaning liquid as it is.

  Further, the cleaning liquid can be supplied to the entire groove 126 by moving the XY stage 171 so as to draw a circle so that the cylinder 111 follows the groove 126.

  As another example, when the cleaning liquid is supplied to the groove 126 on one end side of the dummy wafer 33 and the cleaning liquid spreads over the entire groove 126, the cleaning liquid may be supplied to the groove 126 only from one end side of the dummy wafer 33.

  In addition, the number of the liquid discharge ports 127 provided in the grooves 126 can be arbitrarily determined as well as the number and positions of the liquid discharge ports 127 disposed in the grooves 126. In addition, it is possible to arbitrarily determine at what timing the cleaning liquid is discharged from the groove. For example, the cleaning liquid may be supplied in a state where the discharging unit 123 is constantly operated. That is, the operation shown in FIG. 4C may be performed while the operation shown in FIG. Further, the operation shown in FIG. 4D may be performed while the operation shown in FIG.

  The dummy wafer 33 is not used during the exposure process. Accordingly, the dummy wafer 33 may be stored outside the exposure apparatus during the exposure process. However, if the dummy wafer 33 is stored outside the exposure apparatus, the attachment and detachment may be complicated. Therefore, a place for storing the dummy wafer 33 may be provided in the exposure apparatus. Furthermore, when exposure is not performed for a long time, the dummy wafer 33 may be automatically held on the holding table, and then a program for performing a normal exposure operation may be executed by the controller 161 of the exposure apparatus. However, in this case, since actual exposure is unnecessary, the operation of the illumination unit 150 may be stopped.

  As mentioned above, although this invention was demonstrated based on the preferable Example, this invention is not limited to these Examples. The specific configuration and structure of the components of the immersion type exposure apparatus in the embodiment are merely examples, and can be changed as appropriate. The specific method of cleaning the holding table described in the embodiments is also illustrated. Yes, it can be changed appropriately. Furthermore, a movable nozzle can be provided above the holding table, and this can be used as a cleaning liquid supply means.

FIG. 1 is an overall view for explaining an immersion type exposure apparatus according to the first embodiment. (A) thru | or (C) of FIG. 2 are typical partial end views of a holding stand etc. for demonstrating the washing | cleaning process of the holding stand of Example 1. FIG. FIGS. 3A and 3B are perspective views conceptually illustrating the arrangement of the liquid discharge port and the cleaning liquid supply unit provided in the holding table of the first embodiment. 4A to 4D are schematic partial end views of a holding table and the like for explaining a method of cleaning the holding table in the immersion type exposure apparatus of the second embodiment. FIG. 5 is an overall view for explaining a conventional immersion exposure apparatus. FIG. 6 is a perspective view for schematically explaining scanning exposure. (A) thru | or (C) of FIG. 7 are partial end views of a holding stand etc. for demonstrating the relationship between a shower head, a board | substrate, and a holding stand. 8A to 8C are partial end views of the holding table and the like for explaining the flow of the liquid for immersion exposure into the groove provided in the holding table.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Shower head, 11 ... Tube, 12 ... Liquid supply line, 13 ... Drainage line, 15 ... Liquid, 20 ... Holding stand part, 21 ... Holding stand, 22 ... Adsorption means, 23 ... Discharge means, 24 ... Adsorption surface, 25 ... Piping, 26 ... Groove, 27 ... Liquid discharge port, 28 ... Cleaning liquid supply port, 29 ... Cleaning liquid supply device, 30 ... Substrate, 31 ... Semiconductor substrate, 32 ... Photosensitive film, 33 ... Dummy wafer, 90 ... Immersion type exposure apparatus, 110 ... Shower head 111 ... Cylinder, 112 ... Liquid supply line, 113 ... Drain line, 114 ... Space, 115 ... Liquid, 120 ... Holding base, 121 ... Holding base 122: suction means, 123 ... discharge means, 124 ... suction surface, 125 ... piping, 126・ Groove, 127... Liquid discharge port, 130... Substrate, 131... Semiconductor substrate, 132... Photosensitive film, 133. Mask unit, 141 ... reticle, 142 ... reticle stage, 143 ... reticle stage driving means, 144 ... reticle position information detecting means, 145 ... mask pattern, 150 ... illumination unit, 151 ... Light source, 152 ... Condenser lens, 153 ... Mirror, 154 ... Area, 155 ... Area, 160 ... Control part, 161 ... Controller, 170 ... XY stage 171 ... XY stage, 172 ... XY stage driving means, 173 ... exposure object position information detecting means, 174 ... surface plate, 180 ... reduction projection optical part, 81 ... front lens, 182 ... rear stage lens, 190 ... liquid immersion type exposure apparatus

Claims (5)

(A) a lens facing the object to be exposed;
(B) A shower head provided with a liquid supply line and a liquid discharge line, for filling the space between the lens and the object to be exposed with a liquid,
(C) a holding table for holding an exposure object;
(D) a groove provided on the holding table so as to correspond to the peripheral edge of the exposure object; and
(E) a liquid outlet provided in the groove;
An immersion type exposure apparatus having
(F) having cleaning liquid supply means for supplying the cleaning liquid to the groove;
An immersion type exposure apparatus, wherein the supplied cleaning liquid is discharged from a liquid discharge port.   2. The immersion type exposure apparatus according to claim 1, wherein the cleaning liquid supply means comprises a cleaning liquid supply port provided in the groove. (A) a lens facing the object to be exposed;
(B) A shower head provided with a liquid supply line and a liquid discharge line, for filling the space between the lens and the object to be exposed with a liquid,
(C) a holding table for holding an exposure object;
(D) a groove provided on the holding table so as to correspond to the peripheral edge of the exposure object; and
(E) a liquid outlet provided in the groove;
In addition,
(F) cleaning liquid supply means for supplying the cleaning liquid to the groove;
A method for cleaning a holding table in an immersion type exposure apparatus comprising:
A cleaning method of a holding table in an immersion type exposure apparatus, wherein a cleaning liquid is supplied to a groove by a cleaning liquid supply means and discharged from a liquid discharge port.   4. The method of cleaning a holding table in an immersion type exposure apparatus according to claim 3, wherein the cleaning liquid supply means comprises a cleaning liquid supply port provided in the groove. (A) a lens facing the object to be exposed;
(B) A shower head provided with a liquid supply line and a liquid discharge line, for filling the space between the lens and the object to be exposed with a liquid,
(C) a holding table for holding an exposure object;
(D) a groove provided on the holding table so as to correspond to the peripheral edge of the exposure object; and
(E) a liquid outlet provided in the groove;
A method for cleaning a holding table in an immersion type exposure apparatus comprising:
(A) After holding the dummy wafer on the holding table,
(B) positioning the shower head above the groove;
(C) By supplying the cleaning liquid from the liquid supply line to the shower head, the cleaning liquid is supplied to the groove and discharged from the liquid discharge port.
A method for cleaning a holding table in an immersion type exposure apparatus.

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