JP7385421B2 - Exposure device and article manufacturing method - Google Patents

Description

The present invention relates to an exposure apparatus and an article manufacturing method.

2. Description of the Related Art As one of the apparatuses used in the manufacturing process (lithography process) of liquid crystal panels and semiconductor devices, there is an exposure apparatus that projects a pattern of an original illuminated by an illumination optical system onto a substrate to expose the substrate. It is known that an original plate (mask, reticle) used in an exposure apparatus becomes cloudy due to reaction with, for example, acids, bases, or organic impurities in the atmosphere surrounding the original plate. It is also known that clouding of the original plate is accelerated by moisture in the atmosphere. When the original becomes cloudy, an insufficient amount of exposure occurs, which may make it difficult to accurately transfer the pattern of the original onto the substrate. Therefore, in the exposure apparatus, the space in which the original is placed is filled with a purge gas whose impurities and humidity have been adjusted (reduced). Patent Document 1 and Patent Document 2 propose a configuration in which a movable region of an original stage that holds an original is covered with a plate, and purge gas with reduced impurities and humidity is supplied to an internal space under the plate.

Japanese Patent Application Publication No. 2015-228519 JP2012-28531A

In order to accurately expose the pattern of the original at a targeted position on the substrate, accurate placement position information of the original is required. However, the placement position information of the original can be obtained by a position measuring device provided outside the purge space. Therefore, if the original is covered with a plate to form a purge space, it may be difficult to measure the position of the original using a position measuring device.

In the configuration of Patent Document 1, in order to measure the original with a position measuring device located outside the purge space, it is necessary to increase the movement range of the original stage and move the original stage to the outside of the purge space (that is, the plate). . If such a movement is performed, not only will the airtightness of the purge gas in the purge space deteriorate, but also the amount of movement of the original stage will increase, resulting in a reduction in throughput and an increase in the size of the exposure apparatus.

According to the configuration of Patent Document 2, by measuring the position of the original using an openable/closable shutter provided on the top plate, it is possible to suppress an increase in the amount of movement of the original stage. However, it is unavoidable that the airtightness of the purge gas in the purge space decreases due to the opening and closing of the shutter, and that the throughput decreases due to the opening and closing operation of the shutter.

An object of the present invention is, for example, to provide an exposure apparatus that is advantageous in maintaining airtightness of a purge gas in a purge space formed around an original and achieving high throughput.

According to one aspect of the present invention, there is provided an exposure apparatus that exposes the substrate while scanning the original and the substrate, the stage comprising a stage that holds and moves the original, and a stage formed on the stage to accommodate the original. a first member disposed so as to cover from above a movement range during the scanning exposure of the unit; and a supply unit that supplies gas for replacing air in a space around the original plate below the first member. , the first member is formed with a hole communicating between an upper surface and a lower surface through which measurement light from a measurement section disposed above the first member passes, A recessed portion is formed in a surface facing the first member to collect air flowing in from the hole , and the stage is moved to the end of a driving range by scanning driving the stage in a direction in which the original moves away from the hole. There is provided an exposure apparatus characterized in that the recess is located in the middle of an air flow path between the hole and the original plate.

According to the present invention, for example, it is possible to provide an exposure apparatus that is advantageous in maintaining airtightness of purge gas in a purge space formed around an original and achieving high throughput.

FIG. 1 is a diagram showing the configuration of an exposure apparatus in an embodiment. A diagram showing the detailed configuration around the original stage. FIG. 7 is a diagram illustrating that airtightness of purge gas in a purge space is maintained during scanning exposure. FIG. 6 is a diagram showing an example of a hole formed in the first member and a recess formed in the original stage. The figure which shows the example of the shape of the opening of the hole formed in a 1st member. FIG. 1 is a diagram showing the configuration of an exposure apparatus in an embodiment. FIG. 1 is a diagram showing the configuration of an exposure apparatus in an embodiment.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the claimed invention. Although a plurality of features are described in the embodiments, not all of these features are essential to the invention, and the plurality of features may be arbitrarily combined. Furthermore, in the accompanying drawings, the same or similar components are designated by the same reference numerals, and redundant description will be omitted.

<First embodiment>
FIG. 1 is a diagram showing the configuration of an exposure apparatus in an embodiment. In this specification and the drawings, directions are shown in an XYZ coordinate system in which the horizontal plane is the XY plane. Generally, a substrate W to be exposed is placed on the substrate stage 5 so that its surface is parallel to a horizontal plane (XY plane). Therefore, hereinafter, directions perpendicular to each other within a plane along the surface of the substrate W will be referred to as the X-axis and the Y-axis, and a direction perpendicular to the X-axis and the Y-axis will be referred to as the Z-axis. In this case, the direction of the optical axis of the light emitted from the illumination optical system 2 and incident on the original M is parallel to the Z-axis direction. Further, hereinafter, directions parallel to the X axis, Y axis, and Z axis in the XYZ coordinate system are referred to as the X direction, Y direction, and Z direction, respectively.

The exposure apparatus in the embodiment is a step-and-scan type exposure apparatus that transfers the pattern of the original onto the substrate by scanning and exposing the substrate while scanning the original and the substrate. Such an exposure device is also called a scanning exposure device or a scanner. In FIG. 1, the original M is, for example, a mask (reticle) made of quartz. On the original M, a circuit pattern to be transferred to each of a plurality of shot areas on the substrate W is formed. The substrate W is a wafer coated with photoresist. For example, a single crystal silicon substrate may be used as the substrate W.

The exposure apparatus includes an illumination optical system 2, an original stage 1 that is movable while holding an original M, a projection optical system 4, a substrate stage 5 that is movable while holding a substrate W, and a control unit 7. sell. The control unit 7 may be configured by, for example, a computer having a CPU and a memory. The control section 7 is electrically connected to each section within the exposure apparatus and centrally controls the operation of the entire apparatus.

The illumination optical system 2 shapes light emitted from a light source 6 such as a mercury lamp, an ArF excimer laser, or a KrF excimer laser into, for example, a band-shaped or arc-shaped slit light, and illuminates a part of the original M with the slit light. do. The light that has passed through a part of the original M enters the projection optical system 4 as pattern light reflecting the pattern of the part of the original M. The projection optical system 4 has a predetermined projection magnification and projects the pattern of the original M onto the substrate W (specifically, the resist on the substrate W) using pattern light. The original M and the substrate W are held by an original stage 1 and a substrate stage 5, respectively, and are placed at optically conjugate positions (object plane and image plane of the projection optical system 4) via the projection optical system 4. Ru.

The control unit 7 relatively scans the original stage 1 and the substrate stage 5 at a speed ratio according to the projection magnification of the projection optical system 4. In this embodiment, the scanning direction of the original M and the substrate W is the Y direction. The pattern of the original M is transferred onto the substrate W by scanning exposure.

A measuring section 3 for measuring the position of the original M and a reticle changer 8 for changing the original are provided above the original stage 1 and at a position outside the scanning drive range of the original stage 1. Therefore, the original stage 1 has a movable stroke capable of transporting the original beyond the scanning drive range to the measurement position by the measuring section 3 and the original delivery position by the reticle changer 8.

FIG. 2 is a diagram showing the configuration around the original stage 1 in detail. In FIG. 2, one or more gas supply sections 16 are formed around the illumination optical system 2 (the illumination light emission section thereof) and around the projection optical system 4, respectively. A purge gas supply device (not shown) is connected to the gas supply section 16 via piping. The purge gas supply device supplies purge gas 15 from the gas supply section 16 so that the space around the original M has a positive pressure. When the purge gas 15 is supplied, the air in the space around the original M below the first member 12, which will be described later, is replaced with the purge gas 15. The purge gas 15 is a gas in which impurities and humidity have been adjusted (reduced) to prevent clouding of the original. The purge gas 15 may be, for example, a gas containing at least any of clean air, clean dry air, nitrogen gas, and the like.

In order to improve the airtightness of the purge gas in the space around the original M, the first member 12 is disposed so as to cover from above the movement range of the original M accommodation portion P1 formed on the original stage 1 during scanning exposure. Ru. The first member 12 is attached to the illumination optical system 2, for example. In the example of FIG. 2, the first member 12 is arranged so as to surround the side surface of the illumination light emission part of the illumination optical system 2. In order to further improve the airtightness of the purge gas in the space around the original M, the opening P2, which is formed in the original stage 1 and through which the light transmitted through the original M passes, is covered from below the movement range during scanning exposure. , a second member 17 is also arranged. The second member 17 is attached to the projection optical system 4, for example. In the example of FIG. 2, the second member 17 is arranged so as to surround the side surface of the pattern light incident part of the projection optical system 4. A small gap is provided between the upper surface 1a of the original stage 1 and the first member 12. Similarly, a small gap is also provided between the lower surface 1b of the original stage and the second member 17. Therefore, the original stage 1 can move in the Y direction in a space in which the purge gas 15 is kept airtight by the first member 12 and the second member 17.

The measurement unit 3 includes a light projector 3a that emits measurement light, and a light receiver 3b that receives the measurement light from the light projector 3a. In the example of FIG. 2, the light projector 3a is arranged above the first member 12, and the light receiver 3b is arranged on the side of the projection optical system 4, directly below the projector 3a. The light receiver 3b may be supported by the second member 17.

A hole 13 is formed in the first member 12 to communicate the upper surface and the lower surface. The hole 13 is formed so that measurement light connecting the light emitter 3a and the light receiver 3b can pass therethrough. The shape of the hole 13 may be round or polygonal. The position of the original stage 1 shown in FIG. 2 is a position where the position of the original M can be measured by the measuring section 3. At this position, measurement light is emitted from the light projector 3a, passes through the hole 13, and is irradiated onto the original M and the original stage 1. Marks are arranged on the original M and the original stage 1, and the position of the original M is measured by projecting the marks illuminated by measurement light onto the light receiver 3b. However, the measurement method is not limited to this method. Further, the hole 13 may be used when a plate different from the original M is placed on the original stage 1 to obtain positional information of the original stage 1 and position information of the plate. Further, the positions of the light emitter 3a and the light receiver 3b may be switched.

When the original M is at rest while the position of the original M is being measured, or when the original M is moving at low speed, the purge space is established by maintaining positive pressure by the purge gas 15. In order to easily maintain positive pressure in the purge space, the hole 13 is preferably as small as possible as long as it is larger than the diameter of the measurement light of the measurement section 3.

A recess 14 is formed in the upper surface 1a of the original stage 1 facing the first member 12. This recess 14 serves to trap air flowing in from the hole 13 during scanning exposure and prevent the air from entering the purge space. Hereinafter, it will be explained with reference to FIG. 3 that the concave portion 14 maintains the airtightness of the purge gas in the purge space during scanning exposure.

FIG. 3A shows a state in which the original stage 1 moves at an acceleration A in a moving direction V (Y direction) from a state where the original stage 1 is at one end of the reciprocating drive. In the state shown in FIG. 3A, ambient air G, which would cause the purge space to collapse, tries to enter around the original M, but this is prevented by keeping the purge space at a positive pressure with the purge gas 15.

Subsequently, the original stage 1 moves to the position shown in FIG. 3(b). The movement at this time is generally uniform movement. At this time, the ambient air G passes through the hole 13 and is drawn into the space between the upper surface 1a of the original stage 1 and the first member 12, but in this state, the ambient air G does not reach around the original M. I can't.

Further, when the original stage 1 changes the direction of the acceleration A and decelerates and moves to the position shown in FIG. 3(c), the surrounding air G moves closer to the original M.

Then, as shown in FIG. 3(d), when the original stage 1 turns back at the end of the drive range by scanning drive, the surrounding air G moves closer to the original M. However, due to the presence of the recess 14, the ambient air G enters the recess 14. This prevents the ambient air G from reaching around the original M.

FIG. 3(d) shows the gas flow path between the hole 13 and the original M when the original stage 1 is at the end of the driving range due to scanning drive of the original stage 1 in a direction in which the original M moves away from the hole 13. It is shown that the recessed portion 14 is located in the middle. When the recesses 14 are formed in such a positional relationship, the recesses 14 can serve to trap air that has flowed in from the holes 13 during scanning exposure and prevent the air from entering the purge space. The recess 14 is positioned in the middle of the gas flow path between the hole 13 and the original M before the direction of the acceleration A changes as shown in FIG. If it is, it will be more effective.

The shapes of the hole 13 and the recess 14 will be described with reference to FIGS. 4 and 5. FIG. 4(a) shows the same state as FIG. 3(b). FIG. 4(b) is a diagram of the first member 12 in the state of FIG. 4(a) viewed from the Z direction. 4(c) and 4(d) are views of the upper surface 1a of the original stage 1 in the state of FIG. 4(a), viewed from the Z direction.

The hole 13 is formed with a diameter as small as possible relative to the first member 12, and a plurality of holes may be provided as shown in FIG. 4(b). For example, it is preferable that the holes 13 have a minimum diameter that allows the measurement light of the measurement section 3 to pass through, and that the number of holes 13 equal to the number of measurement sections 3 is provided. FIG. 4(b) shows a case where two holes 13 are formed corresponding to two measurement units 3. Moreover, instead of holes corresponding to the number of measurement units 3, one hole 13 having a size that allows measurement light from each of the plurality of measurement units 3 to pass may be formed. Even in that case, by providing the recess 14, it is possible to take measures such that the effect is not significantly reduced.

The recess 14 formed on the original stage 1 side has a larger opening area than the hole 13, for example, as shown in FIGS. 4(c) and 4(d). Since the opening area of the recess 14 is larger than the opening area of the hole 13, the area in which the surrounding air G entering through the hole 13 spreads and covers the path toward the original M increases.

Furthermore, as shown in FIGS. 4(c) and 4(d), the recesses 14 may be connected or divided. Further, in FIGS. 4(c) and 4(d), the recessed portion 14 is shown in a rectangular shape, but it may have a curvature shape.

Furthermore, when the hole 13 is viewed from the side, a protruding wall 12a that protrudes upward from the first member 12 may be formed at the opening of the hole 13, as shown in FIG. The formation of the protruding wall 12a can reduce the conductance and help reduce the amount of ambient air G entering the hole 13.

According to the first embodiment described above, the hole 13 for performing measurement by the measurement unit 3 is formed in the first member 12 for efficiently forming a purge space around the original M. Therefore, the amount of movement of the original stage 1 for measurement by the measuring section 3 can be made smaller than in the past. This suppresses a decrease in throughput.

In addition, since the recess 14 is formed in the surface of the original stage 1 facing the first member 12, the air flowing in from the hole 13 during scanning exposure passes through the recess 14 before entering the purge space around the original M. accepted. This maintains the airtightness of the purge gas in the purge space.

Therefore, according to the first embodiment described above, an exposure apparatus is provided that is advantageous in maintaining both the airtightness of the purge gas in the purge space formed around the original and achieving high throughput.

<Second embodiment>
FIG. 6 is a diagram showing the configuration of an exposure apparatus in the second embodiment. Note that parts not specifically mentioned in the following description are the same as those in the first embodiment. The second embodiment shows an effective method of arranging the holes 13 when air conditioning the atmosphere around the original stage 1.

In FIG. 6, a position measuring device 21 is arranged around the original stage 1 in order to control the position of the original stage 1. Furthermore, air conditioning is performed to stabilize the atmosphere in the measurement optical path 22 of the position measuring device 21. Air conditioning uses gas whose temperature and humidity are adjusted within a certain range. In air conditioning, as shown in FIG. 6, gas 10 is flowed in one direction from a gas supply section 9. The airflow caused by the gas 10 is in the same direction as the moving direction V of the original stage 1.

In this embodiment, the hole 13 is formed downstream of the illumination light emission part of the illumination optical system 2 with respect to the airflow between the first member formed by the gas 10 and the original stage 1 . When the original stage 1 is reciprocated in the presence of an airflow of gas 10, the amount of gas 10 that attempts to enter the purge space of the original M from between the upper surface 1a of the original stage 1 and the first member 12 is smaller than that on the downstream side. is smaller than that on the upstream side. Since the amount of gas 10 that enters is reduced, there is a margin for gas 10 that enters through the holes 13, which is advantageous in maintaining the purge space.

<Third embodiment>
FIG. 7 is a diagram showing the configuration of an exposure apparatus in the third embodiment. Note that parts not specifically mentioned in the following description are the same as those in the first embodiment and the second embodiment. In the third embodiment, as shown in FIG. 7B, the first member 12 is provided with a shutter 23 that opens and closes an opening for replacing the original. The shutter 23 is opened when the original is replaced by the reticle changer 8.

As shown in FIG. 7A, since the reticle changer 8 is located on the optical path of the measurement light of the measurement section 3, if the shutter 23 is on the optical path, the hole 13 can be formed in the shutter 23. By positioning the hole 13 at a position where the measuring section 3 becomes effective when the shutter 23 is closed, the position of the original M can be measured without opening the shutter 23. In the case of a mechanism that is driven at high speed, such as the shutter 23, it is difficult to use a fragile member such as glass therein. In contrast, according to the present embodiment, by forming the hole 13 in the shutter 23, it is possible to deal with this problem without causing it.

Although FIG. 7B shows the opening/closing direction SV of the shutter 23 as being in the X direction, the present invention is not limited thereto. For example, the opening/closing direction SV of the shutter 23 may be the Y direction or the rotation direction around the Z axis.

According to the third embodiment described above, since the hole 13 is formed in the shutter 23, the measuring unit 3 can perform measurement while keeping the shutter 23 in the closed state. Thereby, the airtightness of the purge gas in the purge space is maintained, and a decrease in throughput can be suppressed.

In addition, in the above embodiment, although the example of a structure in which the hole 13 is formed in the 1st member 12 was shown, the structure in which the hole 13 is formed in the 2nd member 17 is also possible. In this case, specifically, the measuring section 3 (the projector 3 a ) is arranged below the second member 17 . A hole 13 is formed in the second member 17, through which the measurement light from the measurement section 3 passes, and which connects the upper surface and the lower surface. Furthermore, in this case, a recess 14 is formed on the surface of the original stage 1 that faces the second member 17 . Then, when the original stage 1 is at the end of the driving range by scanning drive of the original stage 1 in a direction in which the original M moves away from the hole 13, a recess 14 is formed in the middle of the air flow path between the hole 13 and the original M. The recess 14 is formed such that the .

According to the various embodiments described above, for example, it is possible to provide an exposure apparatus that is advantageous in maintaining the airtightness of the purge gas in the purge space formed around the original and achieving both high throughput.

<Embodiment of article manufacturing method>
The article manufacturing method according to the embodiment of the present invention is suitable for manufacturing articles such as micro devices such as semiconductor devices and elements having fine structures. The article manufacturing method of the present embodiment includes a step of forming a latent image pattern on a photosensitive agent applied to a substrate using the above exposure device (a step of exposing the substrate), and a step of forming a latent image pattern in this step. and developing the substrate. Additionally, such manufacturing methods include other well-known steps (oxidation, deposition, deposition, doping, planarization, etching, resist stripping, dicing, bonding, packaging, etc.). The article manufacturing method of this embodiment is advantageous in at least one of article performance, quality, productivity, and production cost compared to conventional methods.

The invention is not limited to the embodiments described above, and various changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, the following claims are hereby appended to disclose the scope of the invention.

1: Original stage, 2: Illumination optical system, 3: Measurement section, 12: First member, 14: Recess, 17: Second member

Claims (9)

An exposure device that scans and exposes the substrate while scanning the original and the substrate,
a stage that holds and moves the original;
a first member disposed so as to cover from above a movement range during the scanning exposure of the original housing part formed on the stage;
a supply unit that supplies gas to replace air in a space around the original below the first member;
has
The first member is formed with a hole that communicates between an upper surface and a lower surface, through which measurement light from a measurement section disposed above the first member passes;
A recessed portion for storing air flowing in from the hole is formed on a surface of the stage facing the first member ,
When the stage is at the end of a driving range due to scanning drive of the stage in a direction in which the original moves away from the hole, the recess is located in the middle of an air flow path between the hole and the original. An exposure device characterized by: 2. The method according to claim 1, further comprising a second member disposed so as to cover from below a movement range during the scanning exposure of an opening formed on the stage through which light passes through the original. The exposure apparatus described. an illumination optical system that illuminates the original plate held by the stage;
a projection optical system that projects the pattern of the original plate illuminated by the illumination optical system onto the substrate;
It further has
3. The exposure apparatus according to claim 2, wherein the first member is attached to the illumination optical system, and the second member is attached to the projection optical system. 4. The exposure apparatus according to claim 1, wherein the opening area of the recess is larger than the opening area of the hole. 5. The exposure apparatus according to claim 1, wherein the opening of the hole is formed with a protruding wall that protrudes upward from the first member. With respect to the airflow of the gas supplied between the first member and the stage from a gas supply unit that supplies gas in one direction parallel to the direction of the scanning drive of the stage , the hole is connected to the first member. 4. The exposure apparatus according to claim 3, wherein the exposure apparatus is formed at a position downstream from the illumination optical system. 7. The apparatus according to claim 1, further comprising a shutter for opening and closing an opening for original plate replacement formed in the first member, and the hole is formed in the shutter. Exposure equipment. An exposure device that scans and exposes the substrate while scanning the original and the substrate,
a stage that holds and moves the original;
a second member disposed to cover from below a movement range during the scanning exposure of an opening through which light transmitted through the original formed on the stage passes;
a supply unit that supplies gas to replace air in a space around the original above the second member;
has
A hole is formed in the second member, through which measurement light from a measurement unit disposed below the second member passes, and communicates between an upper surface and a lower surface;
A recess for storing air flowing in from the hole is formed on a surface of the stage facing the second member ,
When the stage is at the end of a driving range due to scanning drive of the stage in a direction in which the original moves away from the hole, the recess is located in the middle of an air flow path between the hole and the original. An exposure device characterized by: A step of exposing a substrate using the exposure apparatus according to any one of claims 1 to 8;
Developing the exposed substrate;
A method for manufacturing an article, comprising: manufacturing an article from the developed substrate.

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