JP2005079296A - Aligner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To give no influence of contamination of a master disk stage system to a mirror in a contraction projection optical system in an aligner using an EUV or the like as a light source in a vacuum environment. <P>SOLUTION: A pattern drawn on the surface of a master disk 4 in a vacuum environment is projected to a wafer by a projection optical system, and at least a substrate of the master disk and the substrate is relatively moved to the projection optical system by a stage device, thereby repeatedly exposing the pattern of the master disk 4 to the substrate. A positive pressure space area 30 where pressure is high is provided in a master disk stage space area and a projection optical system space area, concretely at least in either of the space areas and a peripheral vacuum environment area, and exhaust mechanisms 19-1 and 19-2 and an exhaust pump 20 are provided adjacent to the positive pressure space area, thereby recovering a part of air flowing out of the positive pressure space area in the vicinity of the positive pressure space area. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

    The present invention relates to an exposure apparatus used in a semiconductor manufacturing process, and relates to a projection exposure apparatus that projects and transfers a pattern of a master on a silicon wafer or the like, and in particular, EUV light (Extreme Ultraviolet ultra-ultraviolet). The present invention relates to an EUV exposure apparatus that uses, as a light source, exposure light having a wavelength of about 13 to 14 nm, which is light), and performs projection exposure in a vacuum from a mirror optical system.

  FIG. 7 shows a conventional example of an exposure apparatus. Reference numeral 101 denotes an EUV light source unit, which is installed inside a chamber 102 maintained in a vacuum. The exposure light emitted from the light source unit 101 passes through a plurality of illumination system mirrors 103, forms illumination necessary for exposure through a path schematically shown in the figure, and enters the master 104 on the master stage 105.

  Reference numeral 108 denotes a structure that supports the entire reduction projection optical system, and is installed on a vibration isolation table (not shown). Reference numeral 106 denotes a structure that supports the projection optical system mirror 107 with high accuracy at each mirror position. The projection optical system support structure 106 is configured with the projection optical system support structure 108 as a reference. The exposure light reflected by the exposure pattern surface on the master disk 104 travels according to the optical path schematically shown in the reduction projection optical system, is projected onto the silicon wafer 109 as a base, and the master disk pattern is transferred onto the wafer 109.

  Reference numeral 109 denotes a silicon wafer, which is chucked on the wafer stage 110. In the EUV exposure apparatus, generally, the master stage 105 and the wafer stage 110 are scanned in synchronization, or sequential exposure is performed with one of them stopped.

  Reference numeral 111 denotes a structure that supports the wafer stage 110 and is installed on a vibration isolation table (not shown). Reference numeral 112 denotes a structure for supporting the master stage 105, which is also installed on a vibration isolation table (not shown). The master stage support structure 112 may be installed on the reduction projection optical system support structure 108 or may be separated from the optical system support structure on the apparatus installation floor 115 as shown in the figure. May be configured.

  Reference numeral 113 denotes a main body vacuum chamber, which maintains the stage system and the projection optical system in a vacuum environment. Reference numeral 114 denotes a vacuum pump, which generally uses a plurality (not shown).

At the time of exposure, the EUV light is a gas in the atmosphere and the power is attenuated. Therefore, it is necessary to maintain the entire area where the EUV light passes in a high vacuum environment. In the illustrated EUV exposure apparatus, the entire body is covered with a vacuum chamber 113 to maintain a vacuum. In the conventional example, the main body vacuum chamber 113 and the illumination system vacuum chamber 102 are divided, and the occurrence of debris in the illumination system, particularly the light source unit, adversely affects a portion in the main body that requires a particularly high degree of vacuum. There is a known method for preventing this from occurring.
Japanese Patent No. 2691865

  It is difficult for a stage apparatus such as a master stage to avoid a resin member or the like, and it is necessary to install a component that is not preferable for maintaining a high vacuum in the vacuum chamber. On the other hand, in the projection optical system mirror, the mirror surface reflectance is deteriorated due to contamination with oxygen or water in particular, so that the mirror needs to be regenerated or replaced.

  It is an object of the present invention to prevent the influence of contamination of a master stage system from affecting a mirror in a reduction projection optical system in an exposure apparatus in a vacuum environment using EUV or the like as a light source.

  In order to achieve the above object, the present invention projects a pattern drawn on a master surface onto a substrate through a projection optical system in a vacuum environment, and at least the substrate of the master and the substrate is projected to the projection optical system. In an exposure apparatus that repeatedly exposes a pattern of a master on a substrate by relatively moving by a stage device, at least the space area and the surrounding vacuum environment area are between the master stage space area and the projection optical system space area. A positive pressure space region having a high pressure is provided for any region. In short, the present invention is characterized in that a portion that is positive pressure with respect to at least one of the two spaces or the surrounding space is provided between the master stage space region and the projection optical system space region.

  In the present invention, an exhaust path and exhaust means are provided in the vicinity of the positive pressure space region, and at least a part of the gas flowing out from the positive pressure space region can be recovered in the vicinity of the positive pressure space region. Preferably, the positive pressure space region and at least one of the both space regions have shielding means for substantially shielding between these space regions.

  In the exposure apparatus according to the present invention, between the positive pressure space region and at least one of the two space regions, the space region is substantially shielded, and the exposure light is partially shielded. A shielding and shading molding means that also serves as a shading molding for the space between the positive pressure space area and at least one of the two space areas, and substantially shielding between these space areas, Shielding and radiating means may be provided which also serves as temperature control radiation of any one of the stage member of the master and the projection optical system.

  Further, in the exposure apparatus according to the present invention, a pattern surface of the master and a flat plate member that is close to and spaced apart from the pattern surface are configured in the vicinity of the boundary between the positive pressure space region and the stage space region of the master. It is preferable that a means for exhausting gas is provided on the positive pressure space region side substantially partitioned by the flat plate member.

  In the exposure apparatus according to the present invention, a member that forms a boundary that substantially divides the positive pressure space region may be provided with a light transmission means for a measurement light optical path for either measurement of a stage position or the like and master disk position measurement. Preferably, for example, in the positive pressure space region, gas is sent to a positive pressure portion between the stage space region and the projection optical system space region of the master, and the positive pressure space region is made positive pressure with respect to the surrounding vacuum space region. It is good. A device manufacturing method according to the present invention is characterized in that a device is manufactured using any one of the above exposure apparatuses.

  According to the present invention, a spatial region that becomes positive pressure is configured between the master stage space region and the projection optical system space region, so that contaminants released from the master stage can flow into the projection optical system space region. Therefore, it is possible to prevent deterioration in accuracy such as a decrease in reflectance of the projection optical system mirror, and it is possible to provide an exposure apparatus with higher accuracy and efficiency.

  Embodiments according to the best mode for carrying out the present invention will be described below. 1 to 4 show an exposure apparatus according to an embodiment of the present invention.

  1 to 4, reference numeral 1 denotes an EUV light source unit, which is installed inside a chamber 2 maintained in a vacuum. The exposure light emitted from the light source unit 1 passes through a plurality of illumination system mirrors 3, forms illumination necessary for exposure along an approximate path in the figure, and enters the master 4 on the master stage 5.

  Reference numeral 8 denotes a projection optical system support structure that supports the entire reduction projection optical system, and is installed on a vibration isolation table (not shown). Reference numeral 6 denotes a projection optical system mirror support structure that supports the projection optical system mirror 7 with high accuracy at each mirror position. The projection optical system support structure 6 is configured with reference to the projection optical system support structure 8. The exposure light reflected by the exposure pattern surface on the master 4 is projected onto the base silicon wafer through the optical path schematically shown in the reduction projection optical system, and the master surface pattern is transferred onto the wafer 9.

  The silicon wafer 9 is chucked on the wafer stage 10. In an EUV exposure apparatus, generally, the master stage 5 and the wafer stage 10 are scanned in synchronization, or sequential exposure is performed with one of them stopped.

  Reference numeral 11 denotes a wafer stage support structure that supports the wafer stage 10 and is installed on a vibration isolation table (not shown).

  Reference numeral 12 denotes a master stage support structure for supporting the master stage, which is also installed on a vibration isolation table (not shown). The master stage support structure 12 may be installed on the reduction projection optical system support structure 8 or may be separated from the optical system support structure on the apparatus installation floor 15 as shown in the figure. Sometimes configured.

  Reference numeral 13 denotes a main body vacuum chamber, which maintains the stage system and the projection optical system in a vacuum environment. Reference numeral 14 denotes a vacuum pump, which generally uses a plurality (not shown).

  FIG. 2 shows an enlarged view of the projection optical system space area and the master stage space area in the exposure apparatus having the above configuration. 2, the same reference numerals as those in FIG. 1 denote the same components. The projection optical system mirror 7 is supported from the support structure by a support mechanism (not shown).

  Reference numeral 16 denotes, for example, nitrogen or helium as a purge gas in order to realize a space region (positive pressure space region 30) having a higher pressure than at least one of these two space regions between the master stage space region and the projection optical system region. , A positive pressure piping section for feeding inert gas and the like, and 17 is a positive pressure feeding mechanism for controlling and feeding the positive pressure gas. Reference numerals 18-1 and 18-2 are shielding plates for substantially partitioning and shielding between the two space regions. In the present embodiment, two plates are formed on the top and bottom, but one plate may be used, or a plurality of plates. You may partition the space with Exhaust mechanisms 19-1 and 19-2 and an exhaust pump 20 are provided in the vicinity of the positive pressure space region 30, and the gas flowing out from the positive pressure space region 30 adversely affects the degree of vacuum in other regions. It is structured to collect gas so that there is no gas. By providing the positive pressure portion between the two space regions, the contaminant released from the master stage space region does not adhere to the projection optical system mirror.

  FIG. 3 shows a second embodiment of the present invention. FIG. 4 is a partial isometric view of FIG. 3, the same reference numerals as those in FIGS. 1 and 2 denote the same components. In the embodiment of FIG. 3, the shielding plate / light shielding member 21 serves as a member that substantially partitions and shields the master stage space area and the projection optical system space area, and the exposure light 22 along the substantially optical path indicated by the broken line. It also serves as a molding port 25 for shading molding.

  Reference numeral 26 denotes a position measuring means such as an interferometer, and 23 schematically shows a stage position measuring or master disk measuring optical path. Reference numeral 24 denotes a transmission window for the measurement optical path or an optical path hole, which is configured as a shielding plate. As shown in the partial isometric view of the shielding plate in FIG. 4, the measurement light emitted by the measuring means 26 can be introduced from the projection optical system space region into the master stage space region.

FIG. 5 shows a third embodiment of the present invention. 5, the same reference numerals as those in FIGS. 1 to 4 denote the same components.
The shield plate / temperature control radiation plate 28 serves as a shield plate between the two space areas of the master stage space area and the projection optical system space area, and any one or all of the master disk, the master disk stage, and the projection optical system. It also serves as a radiation plate that adjusts the radiation temperature. Reference numeral 27 denotes a radiation plate temperature control mechanism. The temperature control mechanism 27 may directly measure the solid temperature of the portion where temperature control is desired, apply temperature control feedback, or perform table control.

  FIG. 6 shows a fourth embodiment of the present invention. In FIG. 6, the same reference numerals as those in FIGS. 1 to 5 denote the same components. Reference numeral 29 denotes a plate surface adjacent to and separated from the pattern surface of the master plate, which constitutes a member facing the pattern surface of the master plate with a certain gap, and an exhaust mechanism 19-1 is provided in the projection optical system space region. Even when the pressure in the positive pressure space region is maintained at one or two orders of magnitude higher than the surrounding high vacuum region, the positive pressure space region belongs to the low vacuum classification, so that the gas molecules are in a dilute state. . Therefore, the probability that the molecules pass through the closely spaced portions is low, and further, since the exhaust mechanism is provided on the positive pressure space region side of the gap, the two space regions are compared with the embodiment described in FIGS. The fluid space separation degree is high.

  Each of the embodiments can be used alone, or can have a plurality of functions.

(Example of device production method)
Next, an embodiment of a device production method using the above-described exposure apparatus will be described.
FIG. 8 shows a flow of manufacturing a microdevice (a semiconductor chip such as an IC or LSI, a liquid crystal panel, a CCD, a thin film magnetic head, a micromachine, etc.). In step 1 (circuit design), a device pattern is designed. In step 2 (mask production), a mask on which the designed pattern is formed is produced. On the other hand, in step 3 (wafer manufacture), a wafer is manufactured using a material such as silicon or glass. Step 4 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer by lithography using the prepared mask and wafer. The next step 5 (assembly) is referred to as a post-process, and is a process for forming a semiconductor chip using the wafer produced in step 4, such as an assembly process (dicing, bonding), a packaging process (chip encapsulation), and the like. including. In step 6 (inspection), inspections such as an operation confirmation test and a durability test of the semiconductor device manufactured in step 5 are performed. Through these steps, the semiconductor device is completed and shipped (step 7).

  FIG. 9 shows a detailed flow of the wafer process. In step 11 (oxidation), the wafer surface is oxidized. In step 12 (CVD), an insulating film is formed on the wafer surface. In step 13 (electrode formation), an electrode is formed on the wafer by vapor deposition. In step 14 (ion implantation), ions are implanted into the wafer. In step 15 (resist process), a photosensitive agent is applied to the wafer. In step 16 (exposure), the circuit pattern of the mask is printed onto the wafer by exposure using the exposure apparatus described above. In step 17 (development), the exposed wafer is developed. In step 18 (etching), portions other than the developed resist image are removed. In step 19 (resist stripping), unnecessary resist after etching is removed. By repeating these steps, multiple circuit patterns are formed on the wafer.

  By using the production method of this embodiment, a highly integrated device that has been difficult to manufacture can be manufactured at low cost.

1 is an overall view of an exposure apparatus shown in the present embodiment. It is an enlarged view of a master stage and a projection optical system area shown in the present embodiment. It is an enlarged view of a master stage and a projection optical system area shown in another embodiment. 3 is a schematic isometric view of the measuring means. It is an enlarged view of a master stage and a projection optical system area shown in another embodiment. It is an enlarged view of a master stage and a projection optical system area shown in another embodiment. It is a whole exposure apparatus shown in a conventional example. It is a figure which shows the flow of manufacture of a microdevice. It is a figure which shows the detailed flow of the wafer process in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 EUV light source 2 Light source chamber 3 Illumination system mirror 4 Master disk 5 Master disk stage 6 Projection system mirror support structure 7 Projection system mirror 8 Projection optical system support structure 9 Wafer 10 Wafer stage 11 Wafer stage support structure 12 Master disk stage support structure 13 Main body vacuum chamber 14 Vacuum pump 15 Equipment installation reference floor 16 Positive pressure section piping 17 Positive pressure feed mechanism 18-1 Shield plate 18-2 Shield plate 19-1 Exhaust mechanism 19-2 Exhaust mechanism 20 Exhaust pump 21 Exhaust pump 21 Light shielding member 22 Exposure light 23 Stage measurement or master disk measurement optical path 24 Measurement light optical path window or hole 25 Molding port 26 Measuring means 27 Radiation plate temperature adjustment mechanism 28 Shielding plate / temperature adjustment radiation plate 29 Pair pattern proximity spaced flat plate 30 Positive pressure space Area 101 EUV light source 102 Light source chamber 103 Illumination system mirror 104 Master disc 105 Master disc stage 1 06 Projection system mirror support structure 107 Projection system mirror 108 Projection optical system support structure 109 Wafer 110 Wafer stage 111 Wafer stage support structure 112 Master disk stage support structure 113 Main body vacuum chamber 114 Vacuum pump 115 Equipment installation reference floor

Claims (10)

  By projecting a pattern drawn on the surface of the master on a substrate through a projection optical system in a vacuum environment and moving the master and at least one of the substrates relative to the projection optical system by a stage device, In an exposure apparatus that repeatedly exposes the substrate pattern to the substrate, a positive pressure is high between the master stage space area and the projection optical system space area with respect to at least one of the space area and the surrounding vacuum environment area. An exposure apparatus provided with a spatial region.   The exhaust path and exhaust means are provided in the vicinity of the positive pressure space region, and at least a part of the gas flowing out from the positive pressure space region is recovered in the vicinity of the positive pressure space region. Exposure device.   The exposure apparatus according to claim 1, further comprising a shielding unit that substantially shields between the positive pressure space region and at least one of the two space regions.   Between the positive pressure space area and at least one of the both space areas, the space area is substantially shielded, and the shielding and light shielding functioning as a light shielding molding for partially shielding the exposure light. The exposure apparatus according to claim 1, further comprising a forming unit.   Between the positive pressure space region and at least one of the two space regions, the space region is substantially shielded, and any one of the master, the stage member of the master, and the member of the projection optical system 4. An exposure apparatus according to claim 1, further comprising a shielding and radiation means that also serves as a temperature control radiation.   The pattern surface of the master disk and a flat plate member that is close to and spaced apart from the pattern surface are formed near the boundary between the positive pressure space area and the stage space area of the master disk. The exposure apparatus according to any one of 1 to 5.   7. An exposure apparatus according to claim 6, wherein means for exhausting gas is provided on the positive pressure space region side substantially partitioned by the flat plate member.   8. A light transmission means for a measurement light optical path for either a stage position measurement or a master disk position measurement is provided on a member that forms a boundary that substantially partitions the positive pressure space region. An exposure apparatus according to claim 1.   The positive pressure space region is characterized in that a gas is fed into a positive pressure portion between a stage space region and a projection optical system space region of the master, and the positive pressure space region is positively pressurized. 2. The exposure apparatus according to 1.   A device manufacturing method comprising manufacturing a device using the exposure apparatus according to claim 1.