JP4549936B2 - Exposure apparatus and image observation apparatus - Google Patents

Description

  The present invention relates to an exposure apparatus and an image observation apparatus, and more particularly to an exposure apparatus and an image observation apparatus that can control the temperature of a member that moves in a vacuum vessel.

  FIG. 5 shows a schematic cross-sectional view of a positioning device with a cooling function disclosed in Patent Document 1 below. A top plate 102 is supported on the bottom plate 101 by a fine movement mechanism 103. The fine movement mechanism 103 performs positioning by slightly displacing the top plate 102 with respect to six degrees of freedom in the three-axis direction and the rotation direction around each axis. The bottom plate 101 is fixed to the coarse motion table 100. The bottom plate 101, the top plate 102, and the coarse motion table 100 are accommodated in a vacuum vessel.

  Between the bottom plate 101 and the top plate 102, the Peltier element 105 is arranged in such a posture that its heat absorption side surface faces the top plate 102. A cooling plate 104 is attached to the surface of the Peltier element 105 on the high temperature side, and the cooling plate 104 is supported on the bottom plate 101 by a support member 109. A radiation plate 106 is attached to the heat absorption side surface of the Peltier element 105. A black body 107 is attached to the bottom surface of the top plate 102. The black body 107 and the radiation plate 106 face each other with a certain gap therebetween.

  A refrigerant pipe 108 is coupled to the cooling plate 104. The cooling plate 104 is cooled by the refrigerant flowing in the refrigerant pipe 108. As a result, the surface on the heat generating side of the Peltier element 105 is cooled.

JP 2003-58258 A

  The bottom plate 101 of the apparatus disclosed in Patent Document 1 moves together with the coarse movement stage. For this reason, the refrigerant pipe 108 must be formed of a flexible material. Such materials cause contamination of the vacuum atmosphere.

  An object of the present invention is to provide an exposure apparatus and an image observation apparatus capable of controlling the temperature of a movable part without directly supplying a refrigerant to the movable part.

According to a first aspect of the invention,
A reference base disposed within the vacuum vessel and providing a reference for position;
A wafer stage attached to the reference base and holding a wafer to be exposed parallel to a first virtual plane (XY);
A mask stage for holding an exposure mask across a proximity gap from the wafer held on the wafer stage;
A beam source that irradiates the wafer held on the wafer stage with an energy beam for exposure via an exposure mask held on the mask stage;
An intermediate block supported by the reference base so as to be movable in a two-dimensional direction parallel to the first virtual plane;
A cooling means including an endothermic portion fixed to the reference base;
Optics for observing alignment marks on an exposure mask supported by the intermediate block and held on the mask stage so that the optical axis is inclined with respect to the first virtual plane and is movable in the optical axis direction Equipment,
A first heat transfer structure that constitutes a heat transfer path for transferring heat from the intermediate block to the heat absorption unit, and that allows the intermediate block to move in a two-dimensional direction parallel to the first virtual plane;
There is provided an exposure apparatus having a second heat transfer structure that forms a heat transfer path for transferring heat from the optical device to the intermediate block and allows the optical device to move in the optical axis direction.

According to a second aspect of the invention,
An intermediate block supported by the reference base so as to be movable in a two-dimensional direction parallel to the first virtual plane (XY);
An imaging device supported by the intermediate block so that the optical axis is inclined with respect to the first virtual plane and is movable in the optical axis direction;
A cooling means including an endothermic portion fixed to the reference base;
A first heat transfer having a flexibility that constitutes a heat transfer path for transferring heat from the intermediate block to the heat absorbing portion and allows the intermediate block to move in a two-dimensional direction parallel to the first virtual plane. Members,
An image observation apparatus comprising a heat transfer path that transfers heat from the image pickup apparatus to the intermediate block, and a flexible second heat transfer member that allows movement of the image pickup apparatus in the optical axis direction. Provided.

According to aspect 3 of the present invention,
An intermediate block supported by the reference base so as to be movable in a two-dimensional direction parallel to the first virtual plane (XY);
An imaging device supported by the intermediate block so that the optical axis is inclined with respect to the first virtual plane and is movable in the optical axis direction;
A cooling means including an endothermic portion fixed to the reference base;
A heat transfer mechanism that constitutes a heat transfer path for transferring heat from the intermediate block to the heat absorbing portion , and has a heat radiating surface, and is opposed to the heat radiating member attached to the intermediate block with a gap therebetween A heat receiving surface attached to the heat absorbing portion, and arranged so that the heat radiating surface and the heat receiving surface do not contact each other within a range in which the intermediate block moves in a two-dimensional direction. Heat transfer mechanism,
An image observation apparatus comprising a heat transfer path that transfers heat from the image pickup apparatus to the intermediate block, and a flexible second heat transfer member that allows movement of the image pickup apparatus in the optical axis direction. Provided.

  In the invention according to the first aspect, the heat generated in the optical device is transmitted to the heat absorption part via the second heat transfer structure, the intermediate block, and the first heat transfer structure. The temperature rise of the optical device can be suppressed without directly cooling the optical device movable in the vacuum vessel with the refrigerant.

  In the invention according to the second aspect, the heat generated by the imaging device can be transmitted to the heat absorption part via the second heat transfer member, the intermediate block, and the first heat transfer member. The temperature rise of the image pickup apparatus can be suppressed without directly cooling the image pickup apparatus movable in the vacuum vessel with the refrigerant.

  In the invention according to the third aspect, the heat generated in the imaging device can be transmitted to the heat absorption part via the second heat transfer member, the intermediate block, the heat radiating member, and the heat receiving member. The temperature rise of the image pickup apparatus can be suppressed without directly cooling the image pickup apparatus movable in the vacuum vessel with the refrigerant.

  Since it is not necessary to arrange a flexible tube for flowing the refrigerant in the vacuum vessel, contamination of the vacuum atmosphere can be prevented.

  FIG. 1 is a schematic diagram of a low energy electron beam proximity exposure (LEEEPL) apparatus according to an embodiment. A wafer movable stage 5 is mounted on the lower reference base 1. The upper reference base 2 is fixed to the lower reference base 1, and the mask movable stage 6 is supported above the wafer movable stage 5. The lower reference base 1 and the upper reference base 2 constitute a reference base 3. An XYZ orthogonal coordinate system is defined which is fixed to the reference base 3 and has a horizontal plane as an XY plane. An electron beam source 7 is disposed above the mask movable stage 6. The electron beam source 7 includes a low-speed electron gun, an aperture, an electron beam lens, a deflector, and the like. The reference base 3, the wafer movable stage 5, the mask movable stage 6, and the electron beam source 7 are accommodated in a vacuum vessel 8.

  The wafer to be exposed is held on the wafer movable stage 5, and the mask is held on the mask movable stage 6. The wafer movable stage 5 can move the held wafer in the X and Y directions and can be displaced by a minute distance in the Z direction. Further, it can be displaced by a small angle in the rotational direction around each of the three axes parallel to the X, Y, and Z axes.

A low energy electron beam emitted from the electron beam source 7 enters the wafer through the mask.
FIG. 2 shows a schematic diagram of an imaging device for detecting the position of the alignment mark formed on the mask and the wafer, and a support mechanism of the imaging device.

  The mask movable stage 6 shown in FIG. 1 is supported on the upper reference base 2 by a rotary bearing 10. The mask movable stage 6 is rotatable around an axis parallel to the Z direction. An exposure mask 15 is held on the lower surface of the movable mask stage 6.

  The intermediate block 21 is supported by the upper reference base 2 so as to be movable in the X direction and the Y direction by the XY drive mechanism 22. The intermediate block 21 is made of, for example, aluminum. The imaging device 20 is supported on the intermediate block 21 by the F-axis drive mechanism 23. The F-axis drive mechanism 23 can move the imaging device 20 in a direction parallel to the optical axis 20a. The optical axis 20a is disposed obliquely with respect to the XY plane.

  The imaging device 20 includes, for example, a microscope and a CCD image receiving element. The alignment marks formed on the mask and the wafer are imaged on the image receiving surface of the CCD image receiving element, and image information is obtained.

  A support column 30 is attached to the upper reference base 2. The support column 30 is formed of a heat insulating member. A cooling jacket (cooling unit) 35 is fixed to the support column 30 by a refrigerant supply pipe 37 and a refrigerant discharge pipe 38. A coolant channel 35 a is formed in the cooling jacket 35. The refrigerant is supplied to the flow path 35 a in the cooling jacket 35 through the refrigerant supply pipe 37. The refrigerant that has flowed through the flow path 35 a is discharged through the refrigerant discharge pipe 38. The cooling jacket 35 is cooled by the refrigerant flowing in the flow path 35a.

  The first heat transfer member 36 connects the intermediate block 21 and the cooling jacket 35 to thermally couple them together. The first heat transfer member 36 has flexibility that allows the intermediate block 21 to move in a two-dimensional direction parallel to the XY plane. The second heat transfer member 39 connects the intermediate block 21 and the imaging device 20 and thermally couples them. The second heat transfer member 39 has flexibility to allow the imaging device 20 to move in a direction parallel to the optical axis 20a. The first heat transfer member 36 and the second heat transfer member 39 are, for example, copper plates.

An image signal transmission cable 32 connected to the imaging device 32 is temporarily fixed to the top of the support column 30 and led out of the vacuum vessel.
FIG. 3 shows a plan view of the first heat transfer member 36. The first heat transfer member 36 is arranged in a race track shape. Both the intermediate block 21 and the cooling jacket 35 are provided with surfaces parallel to the ZY plane and facing each other. One straight portion of the racetrack-type first heat transfer member 36 is in close contact with the surface of the intermediate block 21, and the other straight portion is in close contact with the surface of the cooling jacket 35. The first heat transfer member 36 is in close contact with the surfaces of the intermediate block 21 and the cooling jacket 35 by being pressed against the intermediate block 21 and the cooling jacket 35 by the pressing members 21A and 35A, respectively. When the intermediate block 21 moves in the X direction and the Y direction, the race track shape of the first heat transfer member 36 changes.

  In the LEEPL device according to the above embodiment, heat is generated from the power portion of the XY drive mechanism 22 and the CCD image receiving element of the imaging device 20. The heat generated from the XY drive mechanism 22 is discharged to the cooling jacket 35 via the intermediate block 21 and the first heat transfer member 36. The heat generated in the imaging device 20 is discharged to the cooling jacket 35 via the second heat transfer member 39, the intermediate block 21, and the first heat transfer member 36.

  The imaging device 20 and the intermediate block 21 are not attached with a refrigerant flow path. The refrigerant flows only in the cooling jacket 35 fixed to the upper reference base 2. For this reason, a movable part can be cooled, without using a flexible tube. Since a flexible tube that causes contamination of the vacuum atmosphere is not used, contamination in the vacuum vessel 8 shown in FIG. 1 can be prevented.

  The surface where the imaging device 20 and the second heat transfer member 39 are in close contact, the surface where the second heat transfer member 39 and the intermediate block 21 are in close contact, and the surface where the intermediate block 21 and the first heat transfer member 36 are in close contact If there are small irregularities on the surface where the first heat transfer member 36 and the cooling jacket 35 are in close contact with each other, a minute cavity is formed between the two members in contact with each other, and the thermal conductivity is lowered. It is preferable to insert a foil made of a metal that is softer than the members forming the two surfaces between the two surfaces to be brought into close contact with each other. By deforming the foil so as to follow the unevenness of the two surfaces facing each other, the degree of adhesion can be increased and the decrease in thermal conductivity can be prevented.

  FIG. 4 shows another configuration example of the heat transfer mechanism that thermally couples the intermediate block 21 and the cooling jacket 35. Both the intermediate block 21 and the cooling jacket 35 are formed with surfaces that are parallel to the YZ plane and that face each other. A heat radiating member 40 is attached to the surface of the intermediate block 21, and a heat receiving member 41 is attached to the surface of the cooling jacket 35. The heat radiating member 40 and the heat receiving member 41 are made of copper.

  The heat radiating member 40 includes three heat radiating plates 40a arranged in the X direction. Both surfaces of each heat radiating plate 40a are heat radiating surfaces parallel to the YZ plane. One heat radiating plate 40 a is in close contact with the surface of the intermediate block 21 and is thermally coupled to the intermediate block 21. The remaining two heat radiating plates 40 a are also thermally coupled to the intermediate block 21. The heat receiving member 41 includes three heat receiving plates 41a arranged in the X direction. Both surfaces of each heat receiving plate 41a are heat receiving surfaces parallel to the YZ plane. One heat receiving plate 41 a is in close contact with the surface of the cooling jacket 35 and is thermally coupled to the cooling jacket 35. The remaining two heat receiving plates 41 a are also thermally coupled to the cooling jacket 35.

  The three heat radiating plates 40a and the three heat receiving plates 41a are alternately arranged in the X direction. For this reason, the heat radiation surface and the heat receiving surface face each other. Even if the intermediate block 21 is moved in the Y direction within the movable range, the distance between the heat dissipation surface and the heat receiving surface is set so as not to contact. The heat radiating surface and the heat receiving surface are parallel to the YZ plane. For this reason, even if the intermediate block 21 moves in the Y direction, the distance between them does not change.

  Black chrome plating or a diamond-like carbon (DLC) film is formed on the heat radiating surface and the heat receiving surface. As heat radiated from the heat radiating surface is absorbed by the heat receiving surface, heat is transmitted from the intermediate block 21 to the cooling jacket 35. In particular, when a DLC film is formed, high heat transfer efficiency by heat radiation can be obtained.

In the configuration shown in FIG. 4 as well, the movable part can be cooled without using a flexible tube, as in the case of the embodiment shown in FIGS.
Although the present invention has been described with reference to the embodiments, the present invention is not limited thereto. It will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

It is the schematic of the LEEPL apparatus by an Example. It is the schematic of the imaging device used for the LEEPL apparatus of an Example, and its drive part. It is a top view of the 1st heat transfer member which connects an intermediate block, a cooling jacket, and both. It is sectional drawing which shows the other structural example of the heat-transfer mechanism between an intermediate | middle block and a cooling jacket. It is the schematic which shows the conventional temperature control apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lower reference base 2 Upper reference base 3 Reference base 5 Wafer movable stage 6 Mask movable stage 7 Electron beam source 8 Vacuum vessel 10 Rotating bearing 15 Exposure mask 20 Imaging device 21 Intermediate block 22 XY drive mechanism 23 F axis drive mechanism 30 Strut 32 Cable 35 Cooling jacket 36 First heat transfer member 37 Refrigerant supply line 38 Refrigerant discharge line 39 Second heat transfer member 40 Heat dissipation member 41 Heat receiving member

Claims (8)

A reference base disposed within the vacuum vessel and providing a reference for position;
A wafer stage attached to the reference base and holding a wafer to be exposed parallel to a first virtual plane (XY);
A mask stage for holding an exposure mask across a proximity gap from the wafer held on the wafer stage;
A beam source that irradiates the wafer held on the wafer stage with an energy beam for exposure via an exposure mask held on the mask stage;
An intermediate block supported by the reference base so as to be movable in a two-dimensional direction parallel to the first virtual plane;
A cooling means including an endothermic portion fixed to the reference base;
Optics for observing alignment marks on an exposure mask supported by the intermediate block and held on the mask stage so that the optical axis is inclined with respect to the first virtual plane and is movable in the optical axis direction Equipment,
A first heat transfer structure that constitutes a heat transfer path for transferring heat from the intermediate block to the heat absorption unit, and that allows the intermediate block to move in a two-dimensional direction parallel to the first virtual plane;
An exposure apparatus comprising: a second heat transfer structure that constitutes a heat transfer path for transferring heat from the optical device to the intermediate block and allows the optical device to move in the optical axis direction. The first heat transfer structure is
A first flexible member that is connected to the intermediate block and the heat absorbing portion to thermally couple them and allows the intermediate block to move in a two-dimensional direction parallel to the first virtual plane. The exposure apparatus according to claim 1, comprising a heat transfer member. The first heat transfer structure is
A heat dissipating member including a heat dissipating surface and attached to the intermediate block;
Including a heat receiving surface facing the heat radiating surface with a gap, and a heat receiving member attached to the heat absorbing portion, and within a range in which the intermediate block moves in a two-dimensional direction, the heat radiating surface and the heat receiving surface are The exposure apparatus according to claim 1, wherein the exposure apparatus is disposed so as not to contact each other.   The second heat transfer structure is connected to the intermediate block and the optical device, thermally couples them, and has a flexibility that allows the optical device to move in the optical axis direction. The exposure apparatus according to claim 1, comprising a heat transfer member. An intermediate block supported by the reference base so as to be movable in a two-dimensional direction parallel to the first virtual plane (XY);
An imaging device supported by the intermediate block so that the optical axis is inclined with respect to the first virtual plane and is movable in the optical axis direction;
A cooling means including an endothermic portion fixed to the reference base;
A first heat transfer having a flexibility that constitutes a heat transfer path for transferring heat from the intermediate block to the heat absorbing portion and allows the intermediate block to move in a two-dimensional direction parallel to the first virtual plane. Members,
An image observation apparatus comprising: a heat transfer path configured to transfer heat from the image pickup apparatus to the intermediate block, and a flexible second heat transfer member that allows movement of the image pickup apparatus in the optical axis direction.   The image according to claim 5, further comprising a vacuum container that accommodates the reference base, the intermediate block, the imaging device, the cooling unit, the first heat transfer member, and the second heat transfer member and is capable of evacuating the inside. Observation device. An intermediate block supported by the reference base so as to be movable in a two-dimensional direction parallel to the first virtual plane (XY);
An imaging device supported by the intermediate block so that the optical axis is inclined with respect to the first virtual plane and is movable in the optical axis direction;
A cooling means including an endothermic portion fixed to the reference base;
A heat transfer mechanism that constitutes a heat transfer path for transferring heat from the intermediate block to the heat absorbing portion , and has a heat radiating surface, and is opposed to the heat radiating member attached to the intermediate block with a gap therebetween A heat receiving surface attached to the heat absorbing portion, and arranged so that the heat radiating surface and the heat receiving surface do not contact each other within a range in which the intermediate block moves in a two-dimensional direction. Heat transfer mechanism,
An image observation apparatus comprising: a heat transfer path configured to transfer heat from the image pickup apparatus to the intermediate block, and a flexible second heat transfer member that allows movement of the image pickup apparatus in the optical axis direction.   The image according to claim 7, further comprising a vacuum container that accommodates the reference base, the intermediate block, the imaging device, the cooling unit, the first heat transfer member, and the second heat transfer member and is capable of evacuating the inside. Observation device.

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