Patent Application
20080165330
This application is based on and claims priority to International Application No. PCT/JP2006/300605 filed Jan. 18, 2006, and Japanese Application No. 2005-010093 filed Jan. 18, 2005, the disclosures of which are hereby incorporated herein by reference.
The present invention relates to a liquid removing apparatus for removing liquid adhered to an exposure target substrate, an exposure apparatus provided with the liquid removing apparatus and a device fabricating method.
In a photolithography process, one of the processes for fabricating a micro device such as a semiconductor device and liquid crystal device, use is made of an exposure apparatus that transfers a pattern formed on a mask to a photosensitive substrate. The exposure apparatus includes a mask stage capable of holding and moving a mask and a substrate stage having a substrate holder for holding a substrate and capable of displacing the substrate holder that holds the substrate. The exposure apparatus is adapted to project a pattern image of the mask on the substrate through a projection optical system while sequentially moving the mask stage and the substrate stage. In the manufacture of micro devices, miniaturization of a pattern formed on the substrate is required to increase density of the devices. In order to comply with such a requirement, there is a need to further enhance a resolution power of the exposure apparatus. As means for assuring the enhanced resolution power, there has been proposed a liquid immersion exposure apparatus that fills a light path space between a projection optical system and a substrate with liquid and exposes the substrate through the liquid, such as that disclosed in Patent Document 1 below.
Patent Document 1: PCT International Publication No. WO 99/49504.
In case a substrate held on a substrate holder is exposed through liquid, there is a possibility that the liquid reaches over into the side of a rear surface of the substrate to adhere thereto. If the liquid is left adhered to the rear surface of the substrate, damages can most likely be widely spread due to, e.g., the liquid being adhered to a conveyor system used for taking out the substrate from a substrate holder and then being splashed into a conveying route of the conveyor system.
A purpose of some aspects of the invention is to provide a liquid removing apparatus capable of reliably removing the liquid adhered to a substrate which has been exposed through the liquid. Another purpose is to provide an exposure apparatus provided with the liquid removing apparatus. A further purpose is to provide a device fabricating method for fabricating devices by use of the exposure apparatus.
In accordance with a first aspect of the present invention, there is provided a liquid removing apparatus that removes liquid adhered to an exposure target substrate irradiated with exposure light through the liquid and taken out from a substrate holder, wherein a specified space is formed on a rear surface side of the exposure target substrate taken out from the substrate holder, and wherein the liquid adhered to a rear surface of the exposure target substrate is removed by evacuating a gas present in the specified space through a suction port.
Further, in accordance with the first aspect of the present invention, it may possible to reliably remove the liquid adhered to the rear surface of the substrate taken out from the substrate holder.
In accordance with a second aspect of the present invention, there is provided an exposure apparatus, which includes a substrate holder and the liquid removing apparatus of the first aspect.
Further, in accordance with the second aspect of the present invention, it may be possible to reliably remove the liquid adhered to the exposure target substrate exposed.
In accordance with a third aspect of the present invention, there is provided a device fabricating method including a step of using the exposure apparatus of the above aspects.
Further, in accordance with the third aspect of the present invention, it may be possible to manufacture devices with a desired performance from the exposure target substrate from which the liquid has been removed.
In accordance with the present invention, it may be possible to reliably remove liquid adhered to a substrate that has been exposed through the liquid.
Hereinbelow, embodiments of the present invention will be described with reference to the accompanying drawings, but the present invention will not be limited to these embodiments. In the following description, an XYZ orthogonal coordinate system will be set in the drawings and a positional relationship between individual members will be described with reference to the XYZ orthogonal coordinate system. Furthermore, rotational directions (inclination directions) about an X-axis, a Y-axis and a Z-axis will be respectively referred to as θX, θY and θZ directions. Moreover, an XY plane is parallel to a horizontal plane and the z-axis is an axis extending in a vertical direction.
The exposure apparatus main body EX includes a mask stage MST for holding and moving a mask M, a substrate stage PST having a substrate holder PH for holding the substrate P in place and capable of displacing the substrate holder PH that holds the substrate P, an illumination optical system IL for illuminating exposure light EL on the mask M held by the mask stage MST and a projection optical system PL for projecting a pattern image of the mask M illuminated with the exposure light EL on the substrate P held by the substrate stage PST The exposure apparatus main body EX is installed within a first chamber apparatus CH1 whose level of cleanliness is controlled. The exposure apparatus main body EX irradiates the exposure light EL on a front surface Pa of the substrate P while a rear surface Pb of the substrate P is held by the substrate holder PH. The term “substrate” used herein includes a base member such as a semiconductor wafer whose surface is coated with a photosensitive material, and the term “mask” includes a reticle formed with a device pattern which is to be reduction-projected on the substrate.
The exposure apparatus main body EX of the present embodiment is a liquid immersion exposure apparatus that fills a light path space K1 of the exposure light EL between the projection optical system PL and the substrate P with liquid LQ and exposes the substrate P by irradiating the exposure light EL on the substrate P through the projection optical system PL and the liquid LQ. The exposure apparatus main body EX is provided with a liquid immersion mechanism 100 for filling the liquid LQ into the light path space K1 of the exposure light EL between the projection optical system PL and the substrate P. The liquid immersion mechanism 100 includes: a nozzle member 70 arranged in the vicinity of an image plane of the projection optical system PL and having supply ports 32 for supply of the liquid LQ and recovery ports 42 for recovery of the liquid LQ; a liquid supply part 31 for supplying the liquid LQ to an image plane side of the projection optical system PL through a supply pipe 33 and the supply ports 32 provided in the nozzle member 70; and a liquid recovery part 41 for recovering the liquid LQ on the image plane side of the projection optical system PL through the recovery ports 42 of the nozzle member 70 and a recovery pipe 43. Inside the nozzle member 70, there are provided a supply flow path for interconnecting the supply ports 32 and the supply pipe 33 and a recovery flow path for interconnecting the recovery ports 42 and the recovery pipe 43. Furthermore, the exposure apparatus main body EX of the present embodiment adopts a local immersion method by which a liquid immersion region LR of the liquid LQ larger than a projection region AR but smaller than the substrate P is locally formed by use of the liquid LQ on a part of the substrate P including the projection region AR of the projection optical system PL. The control unit CONT is adapted to supply a prescribed quantity of liquid LQ to the substrate P by use of the liquid supply part 31 of the liquid immersion mechanism 100 and recover a prescribed quantity of liquid LQ exiting on the substrate P by use of the liquid recovery part 41, thereby filling the liquid LQ into the light path space K1 between the projection optical system PL and the substrate P. In the exposure apparatus main body EX, the pattern of the mask M is transferred to the substrate P by allowing the exposure light EL passed through the mask M to be irradiated on the substrate P via the projection optical system PL and the liquid LQ existing between the projection optical system PL and the substrate P. In the present embodiment, pure water or purified water is used as the liquid LQ filled into the light path space K1 of the exposure light EL.
The exposure apparatus EX-SYS further includes a conveyor system H for conveying the substrate P between the interface part IF and the exposure apparatus main body EX and a liquid removing apparatus 1 provided on a substrate conveying route of the conveyor system H for removing the liquid LQ adhered to the substrate P which has been subjected to a liquid immersion exposure treatment or process.
The coater/developer apparatus C/D-SYS includes a coating unit (not shown) for coating a photosensitive material on a base member of an unexposed substrate P and a developing unit (not shown) for developing the substrate P which has been exposed in the exposure apparatus main body EX. The coating unit and the developing unit are provided within a second chamber apparatus CH2 installed independently of the first chamber apparatus CH1. The first chamber apparatus CH1 for accommodating the exposure apparatus main body EX and the second chamber apparatus CH2 for containing the coating unit and the developing unit are connected with each other through the interface part IF. In the following description, the coating unit and the developing unit installed in the second chamber apparatus CH2 are collectively referred to as a “coater/developer main body C/D”.
The conveyor system H includes a first conveyor system H1 for putting (loading) an unexposed substrate P onto the substrate holder PH of the substrate stage PST, a second conveyor system H2 for conveying the substrate P between the substrate holder PH and the liquid removing apparatus 1, and a third conveyor system H3 for conveying the substrate P between the liquid removing apparatus 1 and the interface part IF. The second conveyor system H2 takes out (unloads) an exposed substrate P from the substrate holder PH and then conveys it to the liquid removing apparatus 1.
The first, second and third conveyor systems H1, H2 and H3 are provided inside the first chamber apparatus CH1. The substrate P on which a photosensitive material has been coated by the coating unit of the coater/developer main body C/D is transferred to the third conveyor system H3 through the interface part IF. The third conveyor system H3 transfers the unexposed substrate P to the first conveyor system H1. The third conveyor system H3 may transfer the substrate P to the first conveyor system H1 through the liquid removing apparatus 1 or may transfer the substrate P to the first conveyor system H1 through a separate conveyor system or a relay device but not through the liquid removing apparatus 1. Alternatively, the third conveyor system H3 may directly transfer the substrate P to the first conveyor system H1. The first conveyor system H1 loads the unexposed substrate P onto the substrate holder PH of the exposure apparatus main body EX. The substrate P exposed in the exposure apparatus main body EX is unloaded from the substrate holder PH by means of the second conveyor system H2. The second conveyor system H2 conveys the unloaded substrate P to the liquid removing apparatus 1. The liquid removing apparatus 1 performs a treatment or processing for removing the liquid LQ adhered to the substrate P unloaded from the substrate holder PH. The third conveyor system H3 receives the substrate P from the liquid removing apparatus 1 and conveys it to the interface part IF. The substrate P conveyed to the interface part IF is transported to the developing unit of the coater/developer main body C/D. The developing unit performs a developing treatment or process for the substrate P thus received.
Next, description will be made on a first embodiment of the liquid removing apparatus 1. After the substrate P held on the substrate holder PH is exposed through the liquid LQ in the exposure apparatus main body EX, the control unit CONT removes the liquid LQ on the front surface Pa of the substrate P by use of the liquid recovery part 41 of the liquid immersion mechanism 100. However, the liquid LQ reached over to the rear surface Pb of the substrate P may possibly be taken out from the substrate holder PH by remaining to be adhered to the rear surface Pb of the substrate P. For this reason, after the substrate P irradiated with the exposure light EL through the liquid LQ is taken out from the substrate holder PH by means of the second conveyor system H2, the control unit CONT removes the liquid LQ adhered to the substrate P by use of the liquid removing apparatus 1. The liquid removing apparatus 1 is provided with a holder mechanism 10 for holding the substrate P taken out from the substrate holder PH and serves to remove the liquid LQ adhered to the rear surface Pb of the substrate P.
Referring to
The protruding portions 4 serve to support the rear surface Pb of the substrate P and form a part of the holder mechanism 10. The protruding portions 4 are formed in a pin-like shape and adapted to support the rear surface Pb of the substrate P at their top parts. The protruding portions 4 are uniformly provided in plural numbers on the upper surface 3 of the base member 2. The upper surface 3 of the base member 2 has a size and shape corresponding to the substrate P. The upper surface 3 of the base member 2 faces the rear surface Pb of the substrate P when the rear surface Pb of the substrate P is supported on the top parts of the protruding portions 4.
The holder mechanism 10 forms a specified space 8 on the side of the rear surface Pb of the substrate P by allowing the protruding portions 4 to support the rear surface Pb of the substrate P. The specified space 8 includes a space left between the rear surface Pb of the substrate P and the upper surface 3 of the base member 2. The protruding portions 4 provided on the upper surface 3 of the base member 2 create a gap G1 between the rear surface Pb of the substrate P and the upper surface 3 of the base member 2 by supporting the rear surface Pb of the substrate P. The gap G1 has a size decided by the height of the protruding portions 4 and may be set to be ranging from about 10 μm to 1 mm. In the present embodiment, the gap G1 (the height of the protruding portions 4) is set at about 50 μm.
As illustrated in
As shown in
The evacuation device 7 includes a vacuum system such as a vacuum pump and is capable of sucking up the gas (and the liquid) present in the specified space 8 through the flow path 6 and the suction port 5. The flow path 6 includes an internal flow path 6A formed within the base member 2 so that it can be connected to the suction port 5 and a flow path of a pipe member for interconnecting the internal flow path 6A and the evacuation device 7. As the gas in the specified space 8 is sucked up by the evacuation device 7 through the suction port 5, the gas in the specified space 8 is discharged to the outside. In the present embodiment, the evacuation device 7 draws the gas from the specified space 8 through the suction port 5 at a flow rate ranging from about 1 to 100 liter per minute.
In the present embodiment, the base member 2 and the protruding portions 4 are made of, e.g., ceramics. By subjecting the upper surface 3 of the base member 2 to, e.g., blasting, it is possible to form the protruding portions 4 with a height ranging from about 10 μm to 1 mm on the base member 2. Furthermore, the base member 2 and the protruding portions 4 may be made of metal such as stainless steel. Moreover, the upper surface 3 of the base member 2 and the surfaces of the protruding portions 4 are coated with, e.g., a liquid repellent material such as a fluorine-based material and an acrylic material, which means that the upper surface 3 of the base member 2 and the surfaces of the protruding portions 4 exhibit repellency against the liquid LQ. Examples of the liquid repellent material include polytetrafluoroethylene (PTFE), tertafluoroethylene-perfluoroalkoxyethylene copolymer (PFA) and Polyetheretherketone (PEEK). In addition, the base member 2 and the protruding portions 4 themselves may be made of the liquid repellent materials noted just above.
Next, the liquid removing operation performed by the liquid removing apparatus 1 will be described with reference to
As illustrated in
As can be seen in
The liquid removing apparatus 1 forms the specified space 8 on the side of the rear surface Pb of the substrate P by allowing the substrate P to be held by the holder mechanism 10 including the protruding portions 4. Once the specified space 8 is formed on the side of the rear surface Pb of the substrate P, the control unit CONT operates the evacuation device 7 including a vacuum system to suck up the gas in the specified space 8 through the flow path 6 and the suction port 5. By operating the evacuation device 7, the control unit CONT performs evacuation of the gas from the suction port 5 connected to the specified space 8.
By performing the evacuation of the gas from the suction port 5, the liquid removing apparatus 1 can generate a gas stream moving toward the suction port 5 in the specified space 8. In other words, if the evacuation device 7 is in operation, the gas present around the suction port 5 (i.e., the gas in the specified space 8) is sucked up into the suction port 5. This allows the gas in the atmosphere space 500 to flow into the specified space 8 through the edge flow path 9 as illustrated in
The liquid LQ adhered to the rear surface Pb of the substrate P is moved to the suction port 5 by the gas stream moving toward the suction port 5 (see arrow y2 in
After the liquid removing treatment for the substrate P has been completed by the liquid removing apparatus 1, the control unit CONT raises the pin members 11 to thereby release the holder mechanism 10 of the liquid removing apparatus 1 from holding the substrate P. Then, the control unit CONT allows the third conveyor system H3 to convey the liquid LQ-removed substrate P to the interface part IF. The substrate P conveyed to the interface part IF is transported to the developing unit of the coater/developer main body C/D to be subjected to a developing treatment.
Removal of the liquid LQ adhered to the rear surface Pb of the substrate P by use of the liquid removing apparatus 1 helps to prevent the liquid LQ from disadvantageously splashing into the conveying route of the conveyor system H. If the liquid LQ is splashed into conveying route of the conveyor system H, the internal environment (humidity, cleanliness, etc.) of the first chamber apparatus CH1 could be changed, thus possibly deteriorating exposure accuracy and various kinds of measuring accuracy. However, such deterioration can be avoided by removing the liquid LQ adhered to the rear surface Pb of the substrate P by use of the liquid removing apparatus 1. Furthermore, if the liquid LQ is left adhered to the rear surface Pb of the substrate P, there is a possibility that the liquid LQ becomes adhered to the conveyor system for sustaining the rear surface Pb of the substrate P. If the substrate P is held by the conveyor system to which the liquid LQ is attached, before it being loaded onto the substrate holder PH (namely, prior to the exposure treatment) or being conveyed to the developing unit (namely, prior to the developing treatment), there is a possibility that the liquid LQ of the conveyor system is stuck to the substrate P, thereby making it impossible to efficiently conduct the exposure treatment or the developing treatment. However, such possibility can be prevented by removing the liquid LQ adhered to the substrate P by means of the liquid removing apparatus 1 as in the present embodiment.
Furthermore, in the present embodiment, the substrate P to which the liquid LQ may possibly be adhered is conveyed by the second conveyor system H2 and not by the first conveyor system H1. That is to say since the liquid LQ is kept from being adhered to the first conveyor system H1 it is possible to prevent the liquid LQ either from being transferred from the first conveyor system H1 to the substrate P which is not yet subjected to the exposure treatment (namely, not yet loaded onto the substrate holder PH), or from being splashed into the conveying route of the first conveyor system H1. Moreover, seeing that the third conveyor system H3 conveys the substrate P which is not yet subjected to the exposure treatment (namely not yet loaded onto the substrate holder PH) as well as the substrate P for which the liquid removing treatment has been performed by the liquid removing apparatus 1, the liquid LQ is also prevented from being adhered to the third conveyor system H3. Accordingly, the liquid LQ is kept either from being adhered to the rear surface Pb of the substrate P conveyed by the third conveyor system H3 or from being splashed into the conveying route of the third conveyor system H3.
Furthermore, as illustrated in
Although the liquid LQ may possibly fall from the substrate P during the course of conveying the liquid-adhered substrate P by the second conveyor system H2, the liquid treating mechanism 160 can collect the falling liquid LQ by using the gutter member 161. By collecting the falling liquid LQ by use of the gutter member 161 it is possible for the liquid treating mechanism 160 to avoid disadvantages such as splash of the liquid LQ to around the conveying route. Due to the fact that the liquid suction device 162 sucks up the liquid LQ in the gutter member 161 provided inside the first chamber apparatus CH1 and discharges the liquid LO failing into the gutter member 161 to the outside of the first chamber apparatus CH1, the liquid LQ does not stagnate in the gutter member 161 provided inside the first chamber apparatus CH1. Therefore, the liquid treating mechanism 160 can prevent disadvantages such as occurrence of a change in the internal environment (humidity, cleanliness, etc.) of the first chamber apparatus CH1.
Furthermore, the liquid treating mechanism 160 may be omitted in case the liquid LQ is less likely to fall from the substrate P.
As described above, the liquid LQ adhered to the rear surface Pb of the substrate P can be removed with a simple construction in which the specified space 8 is formed on the side of the rear surface Pb of the substrate P and the gas in the specified space 8 is evacuated through the suction port 5 provided on the side of the rear surface Pb of the substrate P.
Furthermore, in the present embodiment, the specified space 8 (gap G1) having a fine size ranging from about 10 μm to 1 mm is formed on the side of the rear surface Pb of the substrate P, and the gas is evacuated through the suction port 5 provided in the fine-sized specified space 8. Thus, a gas stream of high flow velocity is generated on the side of the rear surface Pb of the substrate P, which makes it possible to bring the liquid LQ adhered to the rear surface Pb of the substrate P up to the suction port 5 and to recover the same from the suction port 5. Moreover, owing to the fact that the specified space 8 (gap G1) is fine-sized, it is possible to sufficiently increase the flow velocity of the gas stream generated in the specified space 8 between the rear surface Pb of the substrate P and the upper surface 3 of the base member 2, even if the evacuation quantity per unit time of the gas through the suction port 5 is small, namely, even if the evacuation device 7 has a small suction power. Accordingly, the liquid removing apparatus 1 can recover the liquid LQ adhered to the rear surface Pb of the substrate P by smoothly moving the liquid LQ up to the suction port 5 within a shortened period of time by use of the gas stream of high flow velocity.
Furthermore, since the specified space 8 is opened to the atmosphere through the edge flow path 9, a gas is introduced into the specified space 8 from the outside through the edge flow path 9 even if the gas in the specified space 8 has been evacuated through the suction port 5, thereby making it possible to efficiently generate a desired gas stream.
In addition, since the suction port 5 formed on the upper surface 3 of the base member 2 faces nearly the center of the rear surface Pb of the substrate P, a gas can be introduced into the specified space 8 from the atmospheric space 500 through the entire extent of the edge flow path 9 at a substantially equal flow velocity. This makes it possible to recover the liquid LQ within a shortened period of time even though the liquid LQ is adhered to the whole region of the rear surface Pb of the substrate P. Moreover, in the present embodiment, owing to the fact that there is provided only one suction port 5 at a location to face nearly the center of the rear surface Pb of the substrate P, a gas stream of high flow velocity moving from the edge region of the substrate P toward the center thereof is generated without causing any unevenness in the gas stream moving toward the suction port 5 (in terms of a flow velocity distribution, etc.). This ensures 5 that the evacuation of the gas through the suction port 5 can efficiently contribute for removing the liquid LQ. Therefore, it is possible to reliably remove the liquid LQ adhered to the rear surface Pb of the substrate P, regardless of the position of adherence of the liquid LQ in the rear surface Pb of the substrate P.
Furthermore, by allowing the plurality of pin-like protruding portions 4 to support the rear surface Pb of the substrate P, the specified space 8 is formed on the side of the rear surface Pb of the substrate P without any flexural deformation of the substrate P. Thus, the gas can flow through the spaces between the protruding portions 4, thereby making it possible to efficiently generate a gas stream moving toward the suction port 5 from the edge flow path 9. Moreover, by allowing the plurality of pin-like protruding portions 4 to support the rear surface Pb of the substrate P, it is possible to reduce the contact area of the rear surface Pb of the substrate P with the holder mechanism 10 including the protruding portions 4. This makes it possible to reliably remove the liquid LQ adhered to the rear surface Pb of the substrate P, even if the liquid LQ makes contact with the pin-like protruding portions 4.
Next, a second embodiment of the liquid removing apparatus 1 will be described with reference to
Referring to
In this way, by providing the peripheral wall portion 12 having the top surface that faces the rear surface Pb of the substrate P, it becomes possible to further increase the flow velocity of a gas stream generated near the edge region Eb of the rear surface Pb of the substrate P. In the event that a liquid immersion treatment is performed by supplying the liquid LQ to the substrate P while the substrate P is held on the substrate holder PH, the liquid LQ is highly likely to be adhered to the edge region Eb of the rear surface Pb of the substrate P. For this reason, by providing the peripheral wall portion 12, the flow velocity of the gas stream generated near the edge region Eb of the rear surface Pb of the substrate P (namely, near the gap G1′) is increased to thereby ensure that the liquid LQ adhered to the edge region of the rear surface Pb of the substrate P can be more smoothly move to the suction port 5.
Next, a third embodiment of the liquid removing apparatus 1 will be described with reference to
Referring to
As shown in
Furthermore, the suction ports 5 are connected to the partition spaces 8A to 8H in a one-to-one correspondence. In the present embodiment, eight suction ports 5A to 5H are provided near the center of the upper surface 3 of the base member 2 in a corresponding relationship with the eight partition spaces 8A to 8H. Moreover, the suction ports 5A to 5H are nearly identical in size and shape with one another. As in the first and second embodiments described above, the respective suction ports 5A to 5H are connected to the evacuation device 7. In the present embodiment, the plurality of radially-formed first guide members 13 serve to guide gas streams moving toward the suction ports 5A to 5H.
Just like the first embodiment set forth above, by allowing the protruding portions 4 provided on the upper surface 3 of the base member 2 to support the rear surface Pb of the substrate P, a gap G1 is formed between the rear surface Pb of the substrate P and the upper surface 3 of the base member 2. The gap G1 is also formed between the edge region Eb of the rear surface Pb of the substrate P and the edge region of the upper surface 3 of the base member 2, thereby allowing a gas to flow (enter and leave) between the partition spaces 8A to 8H and the atmospheric space 500 lying outside the partition spaces 8A to 8H. That is to say near the edge region Eb of rear surface Pb of the substrate P, there are provided edge flow paths 9 through which the respective partition spaces 8A to 8H communicate with the atmospheric space 500 lying outside the partition spaces 8A to 8H. The edge flow paths 9 are formed in a one-to-one correspondence with the respective partition spaces 8A to 8H. In the meantime, the suction ports 5A to 5H are provided so as to face a near-center region of the rear surface Pb of the substrate P held on the holder mechanism 10. In other words, the respective suction ports 5A to 5H are provided in proximity to the apexes of the sector-like partition spaces 8A to 8H. Further, the positional relationships between the partition spaces 8A to 8H and the respective suction ports 5A to 5H corresponding to the partition spaces 8A to 8H are substantially the same.
Second guide members 14 for guiding gas streams generated in the respective partition spaces 8A to 8H are provided in the respective partition spaces 8A to 8H. As with the first guide members 13, the second guide members 14 serve to guide the gas streams moving toward the respective suction ports 5A to 5H and are provided in plural numbers on the upper surface 3 of the base member 2 in a corresponding relationship with the plurality of partition spaces 8A to 8H. In the present embodiment, the second guide members 14 are provided in a one-to-one correspondence with the partition spaces 8A to 8H. Each of the second guide members 14 is arranged to radially extend from the center portion of the upper surface 3 of the base member 2. In other words, each of the second guide members 14 is provided in such a way that it radially extends from the center portion of the rear surface Pb of the substrate P held by the holder mechanism 10 toward the edge region Eb of the latter. Each of the second guide members 14 is provided in a generally medial portion in a θZ direction of each of the sector-like partition spaces 8A to 8H, and each of the suction ports 5A to 5H is arranged on a longitudinal extension line of a corresponding one of the second guide members 14 when seen from the top. The positional relationships between the respective partition spaces 8A to 8H (suction ports 5A to 5H) and the respective second guide members 14 corresponding to the partition spaces 8A to 8H (suction ports 5A to 5H) are substantially the same. The second guide members 14 are adapted to face the rear surface Pb of the substrate P when the rear surface Pb of the substrate P is held by the holder mechanism 10 including the protruding portions 4.
The first and second guide members 13 and 14 are provided in a smaller height than the protruding portions 4. In other words, as illustrated in
Next, description will be made on the liquid removing operation performed by the liquid removing apparatus 1 of the third embodiment. If the evacuation device 7 is operated with the substrate P held by the holder mechanism 10, the gas from the atmospheric space 500 is introduced into the partition spaces 8A to 8H through the edge flow paths 9, as indicated by arrow y1 in
As described above, provision of the guide members 13 and 14 makes it possible to guide the gas streams that are introduced into the specified space 8 (partition spaces 8A to 8H) from the atmospheric space 500 through the edge flow paths 9 and moved toward the suction ports 5A to 5H. Therefore, it is possible to generate gas streams of reduced turbulence and increased flow velocity in the respective partition spaces 8A to 8H, which in turn assures better removal of the liquid LQ adhered to the rear surface Pb of the substrate P.
Furthermore, by dividing the specified space 8 into the plurality of partition spaces 8A to 8H by use of the first guide members 13 and providing the plurality of suction ports 5A to 5H in a corresponding relationship with the plurality of partition spaces 8A to 8H, gas streams having a velocity great enough to move the liquid LQ adhered to the rear surface Pb of the substrate P can be easily obtained in the respective partition spaces 8A to 8H without causing any unevenness in the gas streams moving toward the respective suction ports 5A to 5H (in terms of a flow velocity distribution, etc.).
Furthermore, the gap G2 is formed between the top surfaces of the first and second guide members 13 and 14 and the rear surface Pb of the substrate P held on the holder mechanism 10, and the rear surface Pb of the substrate P does not make contact with the first and second guide members 13 and 14. This helps to prevent contamination of the substrate P which would otherwise be caused by the contact of the rear surface Pb of the substrate P with the first and second guide members 13 and 14. In this regard, the gap G2 has a fine size ranging from about 2 μm to 5 μm, which results in an increased gas flow resistance in the gap G2. Accordingly, the gas streams moving toward the suction ports 5A to 5H along the first and second guide members 13 and 14 can be generated in a smooth manner.
In the present embodiment, the respective partition spaces 8A to 8H are formed by the first guide members 13 into a sectorial shape when seen from the top, and the suction ports 5 are provided on the upper surface 3 of the base member 2 so as to face the generally central portion of the rear surface Pb of the substrate P. This ensures that the gas introduced into the respective partition spaces 8A to 8H from the atmospheric space 500 through the edge flow paths 9 can flow up to the suction ports 5A to 5H at an increased velocity.
Furthermore, by providing the second guide members 14 in the generally central portion in a θZ direction of each of the sector-like partition spaces 8A to 8H and disposing each of the suction ports 5A to 5H on the longitudinal extension line of the corresponding second guide member 14 when seen from the top, it is possible to more reliably generate the gas streams moving toward the respective suction ports 5A to 5H. This enables the liquid LQ adhered to the rear surface Pb of the substrate P to be moved to suction ports 5A to 5H in a surer manner. Moreover, the second guide members 14 may be provided in plural numbers in each of the partition spaces 8A to 8H, and the second guide members 14 may be omitted if the desired gas streams can be obtained without the second guide members 14.
Although eight first guide members 13 are arranged to form the eight partition spaces 8A to 8H in the present embodiment, the number of the first guide members 13 may be arbitrarily determined depending on circumstances.
Furthermore, in the present embodiment, the size and shape of the partition spaces 8A to 8H, the size and shape of the suction ports 5A to 5H and the evacuation quantity per unit time of the gas through the suction ports 5A to 5H are set in such a way that the gas has a generally equal flow velocity in the respective partition spaces 8A to 8H. That is to say, in order to assure a generally equal gas flow velocity in the respective partition spaces 8A to 8H, substantially equally set are the size and shape of the respective partition spaces 8A to 8H, the size and shape of the respective suction ports 5A to 5H, the positional relationship between the partition spaces 8A to 8H and the respective suction ports 5A to 5H provided in a corresponding relationship with the partition spaces 8A to 8H, and the evacuation quantity per unit time of the gas through the suction ports 5A to 5H. By doing so, it becomes possible to generally equalize the capacity of removing the liquid LQ in the respective partition spaces 8A to 8H. Alternatively, the gas may be allowed to have different flow velocities in the respective partition spaces 8A to 8H. As an example, the evacuation quantities per unit time of the gas through the respective suction ports 5A to 5H may be made different. In this case, the evacuation quantities per unit time of the gas through the respective suction ports 5A to 5H can be made different by, e.g., connecting mutually independent evacuation devices 7 to the respective suction ports 5A to 5H and differently setting the evacuation quantities per unit time of the respective evacuation devices 7.
Furthermore, in the present embodiment, the peripheral wall portion 12 is not provided and the gap G1 ranging from 10 μm to 1 mm is provided between the edge region Eb of the rear surface Pb of the substrate P and the edge region of the upper surface 3 of the base member 2. Instead, as in the second embodiment described above, the peripheral wall portion 12 may be provided so that the prescribed gap G1′ can be formed between the rear surface Pb of the substrate P and the top surface of the peripheral wall portion 12. In this case, the peripheral wall portion 12 is provided outside the first and second guide members 13 and 14 so as to enclose first and second guide members 13 and 14.
Furthermore, although the first and second guide members 13 and 14 are substantially identical in height with each other in the present embodiment, they may have different heights. As an example, the top surfaces of the second guide members 14 may be formed in a smaller height than the first guide members 13 so that, when the rear surface Pb of the substrate P is held by the holder mechanism 10, the prescribed gap G2 can be formed between the rear surface Pb of the substrate P and the top surfaces of the first guide members 13 and a gap greater than the gap G2 can be formed between the rear surface Pb of the substrate P and the top surfaces of the second guide members 14.
Furthermore, although the rear surface Pb of the substrate P held by the holder mechanism 10 including the plurality of pin-like protruding portions 4 is spaced apart from the top surfaces of the first and second guide members 13 and 14 in the present embodiment, the rear surface Pb of the substrate P may be brought into contact with at least one of the first and second guide members 13 and 14. Even if the rear surface Pb of the substrate P makes contact with at least one of the first and second guide members 13 and 14, gas streams moving toward the suction ports 5 (5A to 5H) can be generated by performing evacuation of the gas through the suction ports 5 (5A to 5H). In case the rear surface Pb of the substrate P is brought into contact with the top surfaces of the first and second guide members 13 and 14, it becomes possible to eliminate the protruding portions 4 because the rear surface Pb of the substrate P can be supported by the top surfaces of the first and second guide members 13 and 14.
Furthermore, although the plurality of the first guide members 13 are formed so that they can be joined together near the center of the upper surface 3 of the base member 2 in the present embodiment, the first guide members 13 may be formed in such a way that they do not make connection to one another near the center of the upper surface 3 as the second guide members 14 do so. In this case, it may suffice to provide a single suction port 5 near the center of the upper surface 3 of the base member 2, in lieu of the plurality of suction ports 5A to 5H.
Furthermore, in the liquid removing apparatuses of the first through third embodiments, the gas stream(s) moving toward the suction ports 5(5A to 5H) is generated in the specified space 8 by introducing the gas from the edge flow path(s) 9 formed in the edge region of the substrate P held on the holder mechanism 10. Instead, an atmospherically-opened hole communicating with the atmospheric space 500 may be disposed on the upper surface 3 of the base member 2, and the liquid LQ adhered to the rear surface Pb of the substrate P may be removed by a gas stream moving from the atmospherically-opened hole toward the suction port 5.
Next, a fourth embodiment of the liquid removing apparatus 1 will be described with reference to
Referring to
As shown in
Suction ports 5 are provided inside the respective partition spaces 8A to 8H. The suction ports 5 are provided in plural numbers in the respective partition spaces 8A to 8H. In the present embodiment, the suction ports 5 are arranged in a one-to-one correspondence with the respective partition spaces 8A to 8H. In the present embodiment, eight suction ports 5A to 5H are provided on the upper surface 3 of the base member 2 in a corresponding relationship with the eight partition spaces 8A to 8H. The respective suction ports 5A to 5H are substantially identical in size and shape with one another. As in the first through third embodiments described above, the respective suction ports 5A to 5H are connected to the evacuation device 7.
The base member 2 of the present embodiment has flow paths 9′ through which the specified space 8 communicates with the atmospheric space 500 lying outside the specified space 8. The flow paths 9′ are internal flow paths formed within the base member 2 and are provided in plural numbers in a corresponding relationship with the respective partition spaces 8A to 8H. The flow paths 9′ are connected at one ends thereof to the respective partition spaces 8A to 8H of the specified space 8 and at the other ends thereof to the atmospheric space 500.
Atmospherically-opened holes 16 formed at the one ends of the flow paths 9′ are connected to the respective partition spaces 8A to 8H. The atmospherically-opened holes 16 are provided in plural numbers in a corresponding relationship with the respective partition spaces 8A to 8H In the present embodiment, the atmospherically-opened holes 16A to 16H are arranged in a one-to-one correspondence with the respective partition spaces 8A to 8H. In the present embodiment, eight atmospherically-opened holes 16A to 16H are provided on the upper surface 3 of the base member 2 in a corresponding relationship with the respective eight partition spaces 8A to 8H. The atmospherically-opened holes 16A to 16H have a prescribed positional relationship with the respective suction ports 5A to 5H. In the present embodiment, the suction ports 5A to 5H are provided on the −X side of the annular partition spaces 8A to 8H and the atmospherically-opened holes 16A to 16H are provided on the +X side thereof. That is to say the suction ports 5A to 5H and the respective atmospherically-opened holes 16A to 16H are provided in symmetrical positions with respect to the center portion of the upper surface 3 of the base member 2.
As illustrated in
The guide members 15 are provided in a smaller height than the protruding portions 4. That is to say, as depicted in
Furthermore, in the present embodiment, juncture portions 4S of the upper surface 3 of the base member 2 joined to the respective protruding portions 4 and juncture portions 15S of the upper surface 3 of the base member 2 joined to the respective guide members 15 are formed in an arcuate shape when seen in cross section, as can be noted in
Next, description will be made on the liquid removing operation performed by the liquid removing apparatus 1 of the fourth embodiment. If the evacuation device 7 is operated with the substrate P held by the holder mechanism 10, the gas in the atmospheric space 500 is introduced into the partition spaces 8A to 8H through the flow paths 9′ and the atmospherically-opened holes 16A to 16H, as indicated by arrow y1 in
As described above, provision of the annular guide members 15 makes it possible to guide the gas streams that are introduced into the specified space 8 (partition spaces 8A to 8H) from the atmospheric space 500 through the atmospherically-opened holes 16 (flow paths 9′) and moved toward the suction ports 5A to 5H. Therefore, it is possible to more reliably remove the liquid LQ adhered to the rear surface Pb of the substrate P.
Furthermore, by dividing the specified space 8 into the plurality of partition spaces 8A to 8H by use of the guide members 15 and providing the plurality of suction ports 5A to 5H and the plurality of atmospherically-opened holes 16A to 16H in a corresponding relationship with the plurality of partition spaces 8A to 8H, gas streams having a velocity great enough to move the liquid LQ can be easily obtained in the respective partition spaces 8A to 8H without causing any unevenness in the gas streams moving toward the respective suction ports 5A to 5H (in terms of a flow velocity distribution, etc.).
Furthermore, in the present embodiment, the juncture portions 4S of the upper surface 3 of the base member 2 joined to the respective protruding portions 4 and the juncture portions 15S of the upper surface 3 of the base member 2 joined to the respective guide members 15 are formed in an arcuate shape when seen in cross section, as can be seen in
Furthermore, it is also true in the present embodiment that the gap G2 is formed between the top surfaces of the guide members 15 and the rear surface Pb of the substrate P held on the holder mechanism 10, and the rear surface Pb of the substrate P does not make contact with the guide members 15. This helps to prevent contamination of the substrate P which would otherwise be caused by the contact of the rear surface Pb of the substrate P with the guide members 15. In this regard, the gap G2 has a fine size ranging from about 2 μm to 5 μm, which results in an increased gas flow resistance in the gap G2. Accordingly, the gas streams moving toward the suction ports 5A to 5H along the guide members 15 can be generated in a smooth manner.
Furthermore, although the rear surface Pb of the substrate P held by the holder mechanism 10 including the protruding portions 4 is spaced apart from the top surfaces of the guide members 15 in the present embodiment, the rear surface Pb of the substrate P may be brought into contact with at least one of the plurality of guide members 15. Moreover, the protruding portions 4 may be omitted in case the rear surface Pb of the substrate P and the top surfaces of the guide members 15 are kept in contact with each other.
Furthermore, the control unit CONT is able to set the respective evacuation quantities per unit time of the gas through the suction ports 5A to 5H so that the gas flow velocities in the respective partition spaces 8A to 8H can become nearly equal to one another. This makes it possible to substantially equalize the capability of removing the liquid LQ in the respective partition spaces 8A to 8H. As can be seen in
Furthermore, as illustrated in
Furthermore, in the fourth embodiment, the flow velocities of the gas in the partition spaces 8A to 8H may be set arbitrarily. As an example, the evacuation quantity per unit time of the gas from the suction port 5A and/or the position and number of the suction port 5A and the atmospherically-opened hole 16A may be set so that the flow velocity of the gas can become greatest in the partition space 8A facing the edge region of the rear surface Pb of the substrate P which is susceptible to adherence of the liquid LQ.
Furthermore, in the third and fourth embodiments described above, the guide members and the base member 2 may be integrally formed with each other or separably formed as independent units. Moreover, prior to loading the exposed substrate P onto the base member 2 of the liquid removing apparatus 1, the guide members may be attached to the rear surface Pb of the substrate P, in which state the guide members and the substrate P may be loaded together onto the base member 2.
Furthermore, in the first through fourth embodiments described above, the upper surface 3 of the base member 2 and the surfaces of the protruding portions 4 have liquid repellency with respect to the liquid LQ. However, even if they are not liquid repellent, the liquid LQ can be moved to the suction port 5 by performing the evacuation of the gas from the suction port 5 and consequently generating a gas stream of high flow velocity moving toward the suction port 5.
Furthermore, in the first through fourth embodiments described above, the suction port 5 is provided on the upper surface 3 of the base member 2. Instead, a member having a suction port may be disposed in the specified space 8 independently of the base member 2 and the gas in the specified space 8 may be evacuated through the suction port provided in that member.
Furthermore, in the first through fourth embodiments described above, the holder mechanism 10 for holding the substrate P includes the protruding portions 4 provided on the base member 2, and the specified space 8 is created on the side of the rear surface Pb of the substrate P by having the protruding portions 4 to support the rear surface Pb of the substrate P. Instead, the substrate P may be held by a holder mechanism provided independently of the base member 2, thereby forming the specified space 8 on the side of the rear surface Pb of the substrate P. As an example, the substrate P may be held by a holder mechanism capable of holding a side surface of the substrate P and the upper surface 3 of the base member 2 may be disposed to face the rear surface Pb of the substrate P held by the holder mechanism, thus forming the specified space 8 between the rear surface Pb of the substrate P and the upper surface 3 of the base member 2.
Furthermore, in the first through fourth embodiments described above, the specified space 8 is provided over the nearly entire region of the rear surface Pb of the substrate P. Thus, in case the liquid immersion exposure is performed in a state that the substrate P is held on the substrate holder PH, the liquid LQ is highly likely to adhere to the edge region Eb of the rear surface Pb of the substrate P. In view of this, the specified space 8 for removal of the liquid LQ may be formed only in a region corresponding to the edge region Eb of the rear surface Pb of the substrate P and the suction port 5 may be provided in the specified space 8 thus formed, whereby evacuation of the gas can be conducted through the suction port 5. By doing so, it is possible to remove the liquid LQ adhered to the edge region Eb of the rear surface Pb of the substrate P.
Referring next to
Referring to
As described earlier, in the present embodiment, pure water is used as the liquid LQ filling the light path space K1. The pure water permits transmission of, e.g., distant ultraviolet light (DUV light) such as emission lines (a g-line, a h-line and an i-line) emitted from a mercury lamp, KrF excimer laser light (with a wavelength of 248 nm) or the like, as well as ArF excimer laser light.
The mask stage MST is capable of holding and moving the mask M. While holding the mask M in place, the mask stage MST can be two-dimensionally moved within a plane perpendicular to the optical axis AX of the projection optical system PL, i.e., within an X-Y plane and also can be finely rotated in the θZ direction by a mask stage drive unit MSTD, including a linear motor or the like, controlled by the control unit CONT. A movable mirror 91 is provided on the mask stage MST and a laser interferometer 92 is provided in a position oppositely facing the movable mirror 91. The position in the two-dimensional direction and the rotation angle in the θZ direction (possibly including rotation angles in the θX and θX directions) of the mask M placed on the mask stage MST are measured by means of the laser interferometer 92 on a real time basis. The measurement result of the laser interferometer 92 is outputted to the control unit CONT. Based on the measurement result from the laser interferometer 92, the control unit CONT controls the position of the mask M held in place on the mask stage MST, through the mask stage drive unit MSTD.
The projection optical system PL is adapted to project the pattern image of the mask M on the substrate P with a predetermined projection magnification ratio β. The projection optical system PL includes a plurality of optical elements, wherein the optical elements are kept in place by a lens barrel PK. In the present embodiment, the projection optical system PL is a reduction system whose projection magnification ratio β is equal to, e.g., ¼, ⅕ or ⅛. Alternatively the projection optical system PL may be either an equal magnification system or an enlargement system. Moreover, in the present embodiment, among the plurality of optical elements included in the projection optical system PL, a first optical element LS1 lying nearest to an image plane of the projection optical system PL is exposed to the outside from the lens barrel PK.
Referring to
The substrate holder PH includes a base member 80, a plurality of protruding portions 81 formed on the base member 80 and adapted to support the rear surface Pb of the substrate P, and a peripheral wall portion 82 formed on the base member 80 and adapted to face the rear surface Pb of the substrate P and also to enclose the protruding portions 81. The peripheral wall portion 82 is formed in a generally annular shape similar to the shape of the substrate P and has a top surface facing the edge region Eb of the rear surface Pb of the substrate P. Furthermore, suction ports not shown in the drawings are uniformly arranged in plural numbers on the base member 80 inside the peripheral wall portion 82. Each of the plurality of suction ports is connected to a vacuum system. The control unit CONT operates the vacuum system to suck up (evacuate) the gas (air) in a space 83 enclosed by the substrate P, the peripheral wall portion 82 and the base member 80. By doing so, a pressure due to a vacuum generated in the space 83 is exerted on the substrate P, whereby the rear surface Pb of the substrate P is pressed to be sucked up against the protruding portions 81. The rear surface Pb of the substrate P makes close contact with the top surface of the peripheral wall portion 82 when the rear surface Pb of the substrate P is pressed to be sucked up against the protruding portions 81.
Holding the substrate P by use of the substrate holder PH, the substrate stage PST can be two-dimensionally moved along the base member BP within the X-Y plane and also can be finely rotated in a θZ direction by means of the substrate stage drive unit PSTD, including a linear motor and the like, controlled by the control unit CONT. In addition, the substrate stage PST is movable in Z-axis, θX and θX directions Thus, the surface of the substrate P supported on the substrate stage PST can be moved with six degrees of freedom of movement in the X-axis, Y-axis, Z-axis, θX, θX and θZ directions. A movable mirror 93 is provided on a side surface of the substrate stage PST and a laser interferometer 94 is provided in a position oppositely facing the movable mirror 93. The two-dimensional direction position of the substrate P placed on the substrate stage PST and the rotation angle thereof are measured by means of the laser interferometer 94 on a real time basis. The exposure apparatus main body EX further includes an oblique incidence type focus leveling detection system for detecting information on the position of an upper surface of the substrate P supported on the substrate stage PST. The measurement result from the laser interferometer 94 is outputted to the control unit CONT. Also, the measurement result from the focus leveling detection system is outputted to the control unit CONT. Based on the measurement result of the focus leveling detection system, the control unit CONT operates the substrate stage drive unit PSTD and controls the focus position (Z-axis position) and the inclination angles (θX and θX) of the substrate P to thereby align the upper surface of substrate P with the image plane of the projection optical system PL. Based on the measurement result from the laser interferometer 94, the control unit CONT controls the position of the substrate P in the X-axis, Y-axis and θZ directions.
The liquid supply part 31 of the liquid immersion mechanism 100 includes a tank for storing the liquid LQ, a compression pump, a temperature control unit for controlling the temperature of the liquid LQ supplied, a filter unit for removing foreign materials present in the liquid LQ, and so forth. The liquid supplying operation of the liquid supply part 31 is controlled by the control unit CONT. Furthermore, it is not imperative for the exposure apparatus EX-SYS to possess the tank, the compression pump, the temperature control unit and the filter unit of the liquid supply part 31 in their entirety. Facilities existing in a factory in which the exposure apparatus EX-SYS is installed may be utilized in place thereof.
The liquid recovery part 41 includes a vacuum system (suction device) such as a vacuum pump or the like, a gas-liquid separator for separating the liquid LQ and the gas recovered, a tank for storing the thus-recovered liquid LQ, and so forth. The liquid recovery operation of the liquid recovery part 41 is controlled by the control unit CONT. It is not imperative for the exposure apparatus EX-SYS to possess the vacuum system, the gas-liquid separator and the tank of the liquid recovery part 41 in their entirety. Facilities existing in a factory in which the exposure apparatus EX-SYS is installed may be utilized in place thereof.
The supply ports 32 for supply of the liquid LQ and the recovery ports 42 for recovery of the liquid LQ are formed on a lower surface of the nozzle member 70. The nozzle member 70 is an annular member adapted to enclose a side surface of the first optical element LS1. The supply ports 32 are provided in plural numbers so that they can surround the first optical element LS1 of the projection optical system PL (the optical axis AX of the projection optical system PL). Moreover, the recovery ports 42 are provided more outwardly than the supply ports 32 with respect to the first optical element LS1 so that they can surround the first optical element LS1 and the supply ports 32.
At the time of forming the liquid immersion region LR of the liquid LQ, the control unit CONT operates both the liquid supply part 31 and the liquid recovery part 41. Once being supplied from the liquid supply part 31 under the control of the control unit CONT, the liquid LQ flows through the supply pipe 33 to be fed to the image plane side of the projection optical system PL from the supply ports 32 via the supply flow path of the nozzle member 70. Furthermore, if the liquid recovery part 41 is operated under the control of the control unit CONT, the liquid LQ present on the image plane side of the projection optical system PL is introduced into the recovery flow path of the nozzle member 70 through the recovery ports 42 and is then collected in the liquid recovery part 41 through the recovery pipe 43.
At least during the time when the pattern image of the mask M is projected on the substrate P, the control unit CONT fills the liquid LQ into the light path space K1 of the exposure light EL between the projection optical system PL and the substrate P held on the substrate holder PH by use of the liquid immersion mechanism 100. The substrate P is exposed to the exposure light EL irradiated on the substrate P through the projection optical system PL and the liquid LQ.
In the event that the edge region Eb of the rear surface Pb of the substrate P is subjected to liquid immersion exposure, for instance, it is often the case that the liquid immersion region LR of the liquid LQ lies on the gap Ge formed between the front surface Pa of the substrate P held on the substrate holder PH and the upper surface 97 of the substrate stage PST. If such is the case, there is a possibility that the liquid LQ infiltrates into the gap Ge and also into the side of the rear surface Pb of the substrate P. As described above, since the rear surface Pb of the substrate P makes close contact with the surface of the peripheral wall portion 82 when the substrate P is held on the substrate holder PH, there is a high possibility that the liquid LQ infiltrating into the gap Ge and entering the side of the rear surface Pb of the substrate P adheres predominantly to the edge region Eb of the rear surface Pb of the substrate P (a region outside the peripheral wall portion 82). There is a further possibility that the liquid LQ infiltrates into the space 83 through between the rear surface Pb of the substrate P and the top surface of the peripheral wall portion 82 of the substrate holder PH and then adheres to the center portion of the rear surface Pb of the substrate P The control unit CONT unloads the substrate P, which has been subjected to the liquid immersion treatment, from the substrate holder PH by use of the second conveyor system H2 and, subsequently, transports it to the liquid removing apparatus 1 of the first to fourth embodiments set forth above, after which the treatment of removing the liquid LQ adhering to the rear surface Pb of the substrate P is performed by the liquid removing apparatus 1.
Although the liquid removing apparatus 1 is mounted to the exposure apparatus EX-SYS in the foregoing embodiments, it may be disposed on the coater/developer apparatus C/D-SYS. Alternatively, the liquid removing apparatus 1 may be disposed on the interface part IF.
Furthermore, in the foregoing embodiments, an inspection device for inspecting adherence of the liquid LQ to the rear surface Pb of the substrate P which has undergone the liquid immersion treatment may be disposed on the exposure apparatus EX-SYS to ensure that the exposed substrate P is conveyed to the afore-mentioned liquid removing apparatus 1 only when the liquid LQ adhered to the rear surface Pb of the substrate P is impermissible.
As set forth above, the liquid LQ used in the present embodiment is pure water. The pure water provides an advantage that it can be easily acquired in large quantities in a semiconductor fabricating factory and the like, and does not adversely affect a photoresist on the substrate P or an optical element (lens). Moreover, the pure water has no adverse effect on the environment and contains an extremely small amount of impurities, which comes up to an expectation that the pure water serves to cleanse the surface of the substrate P and the surface of the optical element provided on the tip end surface of the projection optical system PL.
And, the pure water (typical water) is said to have a refractive index “n” of about 1.44 with respect to the exposure light EL whose wavelength is about 193 nm in case ArF excimer laser light (with a wavelength of 193 nm) is used as the exposure light EL, the wavelength thereof on the substrate P is reduced to 1/n, i.e., 134 nm, thus providing an increased resolution power. Furthermore, the depth of focus becomes “n” times, i.e., 1.44 times, as great as that in the air. Thus, the aperture number of the projection optical system PL can be further increased in case it is desirable to secure about the same depth of focus as is available in the air. This also helps to enhance the resolution power.
In the present embodiment, the optical element (lens) LS1 is attached to the tip end of the projection optical system PL. Optical characteristics, e.g., aberrations (a spherical aberration, a coma aberration and the like), of the projection optical system PL can be adjusted by means of this lens. Furthermore, the optical element attached to the tip end of the projection optical system PL may be either an optical plate used in adjusting the optical characteristics of the projection optical system PL or a parallel flat panel that permits transmission of the exposure light EL therethrough.
Furthermore, in the event that the flow of the liquid LQ creates a high pressure between the optical element at the tip end of the projection optical system PL and the substrate P, it may be possible to fixedly secure the optical element against any movement otherwise caused by the pressure, instead of making the optical element replaceable.
Furthermore, in the present embodiment, the liquid LQ is filled between the projection optical system PL and the surface of the substrate P. Instead, the liquid LQ may be filled, e.g., in a state that a glass cover formed of a parallel flat panel is attached to the surface of the substrate P.
Moreover, with the projection optical system of the foregoing embodiments, the light path space on the image plane side of the optical element arranged at the tip end thereof is filled with the liquid. Alternatively it may be possible to employ a projection optical system in which the light path space on the mask side of the optical element arranged at the tip end thereof is also filled with the liquid, as disclosed in PCT International Publication No. WO 2004/019128.
Furthermore, other liquid than water may be used as the liquid LQ, although the liquid LQ is water in the present embodiment. As an example, in case a source of the exposure light EL is an F2 laser that generates F2 laser light with no ability to penetrate water, the liquid LQ may be, e.g., fluorine-based liquid, such as perfluorinated polyether (PFPE) and fluorinated oil, which can be penetrated through by the F2 laser light. In this case, the portion making contact with the liquid LQ is subjected to a hydrophilic treatment by, e.g., forming a thin film on that portion with a material of low-polarity molecular structure including fluorine. In addition to the above, it may be possible to use, as the liquid LQ, a material (e.g., cedar oil) that permits transmission of the exposure light EL, has a refractive index as high as possible and exhibits stability with respect to the projection optical system PL or a photoresist coated on the surface of the substrate P.
Moreover, as the substrate P of the respective embodiments described above, it is possible to use not only a semiconductor wafer for the manufacture of semiconductor devices but also a glass substrate for display devices, a ceramics wafer for thin film magnetic heads and a original plate of mask or reticle (a synthetic quartz wafer or a silicon wafer) used in an exposure apparatus.
As for the exposure apparatus EX-SYS, the present invention may be applied to a step-and-repeat type projection exposure apparatus (a stepper) that collectively exposes the pattern of the mask M with the mask M and the substrate P being kept in a stopped state and sequentially moves the substrate P step by step, as well as a step-and-scan type scanning exposure apparatus (a scanning stepper) that scan-exposes the pattern of the mask M by synchronously moving the mask M and the substrate P.
Furthermore, as for the exposure apparatus EX-SYS, the present invention may be applied to an exposure apparatus of the type collectively exposing the reduced image of a first pattern on a substrate P by use of a projection optical system (e.g., a refraction type projection optical system with a reduction ratio of 118 but with no reflection element) in a state that the first pattern and the substrate P are kept nearly immovable. In this case and subsequent to the above process, the present invention may be applied to a stitching exposure apparatus by which the reduced image of a second pattern is partially overlapped with the first pattern and collectively exposed on the substrate P by use of the projection optical system in a state that the second pattern and the substrate P are kept nearly immovable. Moreover, as for the stitching exposure apparatus, the present invention may be applied to a step-and-stitch type exposure apparatus by which at least two patterns are transferred to the substrate P in a partially overlapped state and the substrate P is moved step by step.
The present invention may also be applied to a twin stage type exposure apparatus, as disclosed in Japanese Unexamined Patent Application, Publication No. H10-163099, Japanese Unexamined Patent Application, Publication No. H10-214783, Published Japanese Translation No. 2000-505958 of the PCT International Publication and so forth.
Furthermore, the present invention may be applied to an exposure apparatus that includes a substrate stage for holding a substrate and a measurement stage which carries a reference member with a reference mark and various kinds of photoelectric sensors, as disclosed in Japanese Unexamined Patent Application, Publication No. H11-135400.
Although the exposure apparatus employed in the foregoing embodiments is of the type locally filling the liquid between the projection optical system PL and the substrate P, the present invention may be applied to a liquid immersion exposure apparatus for performing exposure in a state that the entire surface of an exposure target substrate is soaked in the liquid, as disclosed in Japanese Unexamined Patent Application, Publication No. H06-124873, Japanese Unexamined Patent Application, Publication No. H10-303114, U.S. Pat. No. 5,825,043 and so forth.
As for the kind of exposure apparatus EX-SYS, the present invention is not limited to the exposure apparatus for the manufacture of semiconductor devices that exposes a semiconductor device pattern on the substrate P but may be extensively applied to an exposure apparatus for the manufacture of liquid crystal display devices or for the manufacture of displays, an exposure apparatus for the manufacture of thin film magnetic heads, image pickup devices (CCOD), reticles or masks, and other exposure apparatuses.
Furthermore, the present invention may be applied to an exposure apparatus using an electronic mask, as disclosed in, e.g., U.S. Pat. No. 6,778,257, by which a transmission pattern, a reflection pattern or a light emitting pattern is formed based on an electronic data of the pattern to be exposed.
As described above, the exposure apparatus EX-SYS in accordance with the embodiments of the present invention is manufactured by assembling various subsystems, including the respective elements recited in the claims of the subject application, so as to maintain specified mechanical, electrical and optical accuracy. In order to assure the various kinds of accuracy, calibration is conducted before and after the assembly process to accomplish optical accuracy for various optical systems, mechanical accuracy for various mechanical systems and electrical accuracy for various electric systems. The process for assembling the various subsystems into the exposure apparatus includes the tasks of mechanically interconnecting the various subsystems, connecting wire lines of an electric circuit and connecting pipelines of a pneumatic pressure circuit. It is a matter of course that individual processes for assembling each of the subsystems precede the process for assembling the various subsystems into the exposure apparatus. Once the process for assembling the various subsystems into the exposure apparatus comes to an end, general calibration is executed to assure various kinds of accuracy for the exposure apparatus as a whole. Moreover, it is desirable that the exposure apparatus be manufactured in a clean room whose temperature and degree of cleanliness are controlled.
As illustrated in
| Number | Date | Country | Kind |
|---|---|---|---|
| 2005-010093 | Jan 2005 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2006/300605 | 1/18/2006 | WO | 00 | 7/17/2007 |
