TWI449122B - Fixture device, method for loading an object onto a support, lithography apparatus and machine readable medium - Google Patents

Description

Fixture device, method for loading an object onto a support, lithography apparatus and machine readable medium

The present invention relates to a clamp device and a method for clamping an article to a support. The invention further relates to a lithography apparatus and a method for loading a substrate onto a substrate support of a lithography apparatus. Finally, the invention relates to a machine readable medium.

A lithography apparatus is a machine that applies a desired pattern onto a substrate, typically applied to a target portion of the substrate. The lithography apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In this case, a patterned device (which may alternatively be referred to as a reticle or main reticle) may be used to create a circuit pattern to be formed on individual layers of the IC. This pattern can be transferred to a target portion (eg, including a portion of a die, a die, or a plurality of dies) on a substrate (eg, a germanium wafer). Transfer of the pattern is typically via imaging onto a layer of radiation-sensitive material (resist) provided on the substrate. In general, a single substrate will contain a network of sequentially patterned adjacent target portions. Conventional lithography apparatus includes a so-called stepper in which each target portion is illuminated by exposing the entire pattern to a target portion at a time; and a so-called scanner in which a direction is in a given direction ("scan" direction) Each of the target portions is illuminated by scanning the substrate simultaneously via the radiation beam while scanning the substrate in parallel or anti-parallel to this direction. It is also possible to transfer the pattern from the patterned device to the substrate by imprinting the pattern onto the substrate.

In known lithography apparatus, each substrate to be exposed is loaded on a substrate support that is supported on the substrate during exposure of the patterned radiation beam On the support. In order to clamp the substrate to the substrate support, a fixture device is provided. In known embodiments of the lithography apparatus, a vacuum clamp device is used. The vacuum clamp device provides a vacuum force to clamp the substrate to the support surface of the substrate support by vacuum force. In the case where the substrate is straight, the substrate will be clamped to the support surface without any substantial internal stress in the substrate.

However, the substrate may not be flat and, for example, warped in many shapes, such as a corrugated shape, a cylindrical shape, a dome shape, a saddle shape, or another shape. This may be caused by the manufacturing process used to fabricate the substrate or by the pre-exposure or post-exposure process experienced by the substrate during fabrication.

When a warpage substrate (eg, a dome shaped substrate) is held on a substrate support, for example, by a vacuum clamp, the substrate may first be at the outer circumference of the substrate and thereafter on the remainder of the surface of the substrate The substrate support is in contact. Due to the clamping force, the substrate is forced into a substantially flat form while the clamping begins at the outer circumference of the substrate. As a result, when the substrate is clamped on the support surface, stress may be induced in the substrate. In this application, a "warped" article will refer to any shape that does not require deformation, such as the shape of a cylinder, saddle, or object.

These stresses can have a negative impact on the quality of the final product. Also, since the substrate is held in another form different from the desired form, the coverage of the projection of the lithography apparatus may be lowered, which may have a negative impact on product quality.

The Applicant has determined that it is desirable to provide a substrate support having a holding configuration for the substrate in which the internal stress due to the clamping force is large in the substrate. Physically reduced. In addition, it is desirable to provide a clamping method for clamping a warped substrate to a substrate support by a clamping method, thereby potentially reducing the risk of stress and/or overlay errors in the substrate.

In accordance with an aspect of the present invention, a clamp device configured to clamp an article to a support member includes a first device configured to use a first force to force the article and the support member away from each other, and A second device configured to force the article and the support toward each other using a second force, wherein the first device and the second device are configured to simultaneously apply the first force separately prior to completing the clamping of the article on the support And a second force to shape the article into a desired shape.

According to an aspect of the present invention, there is provided a method for loading an article on a support member, comprising the steps of: forming an article in a desired shape, wherein forming comprises subjecting the article to the same time as forcing the article and the support member away from each other A force and a second force that forces the article and the support member toward each other; and completes the clamping of the article on the support member. Additionally, a machine readable medium encoded by machine executable instructions for performing the methods is provided.

In accordance with another aspect of the present invention, a method for loading a substrate onto a substrate support of a lithography apparatus is provided. The method comprises: forming a substrate in a desired shape while maintaining a spacing of the substrate from the substrate support, wherein forming comprises subjecting the substrate to the attraction of pulling the animal piece toward the support and pushing the substrate away from the support, and completing the shaped substrate Clamping on the substrate support.

Embodiments of the present invention will be described by way of example only with reference to the accompanying drawings, in which

FIG. 1 schematically depicts a lithography apparatus in accordance with an embodiment of the present invention. The apparatus includes an illumination system (illuminator) IL configured to condition a radiation beam B (eg, UV radiation or any other suitable radiation); a reticle support structure (eg, a reticle stage) MT configured to support A patterned device (eg, a reticle) MA is coupled to the first locating device PM, and the first locating device PM is configured to accurately position the patterned device in accordance with certain parameters. The device also includes a substrate table (eg, a wafer table) WT or a "substrate support" that is configured to hold a substrate (eg, a resist coated wafer) and is coupled to a second positioning device PW, The second positioning device PW is configured to accurately position the substrate according to certain parameters. The apparatus further includes a projection system (eg, a refractive projection lens system) PS configured to project a pattern imparted by the patterned device MA to the radiation beam B to a target portion C of the substrate W (eg, including one or more dies) )on.

The illumination system can include various types of optical components for guiding, shaping, or controlling radiation, such as refractive, reflective, magnetic, electromagnetic, electrostatic, or other types of optical components, or any combination thereof.

The reticle support structure supports (ie, carries) the patterned device. The reticle support structure holds the patterned device in a manner that depends on the orientation of the patterned device, the design of the lithographic device, and other conditions, such as whether the patterned device is held in a vacuum environment. The reticle support structure can hold the patterned device using mechanical, vacuum, electrostatic or other clamping techniques. The reticle support structure can be, for example, a frame or table that can be fixed or movable as desired. Light The cover support structure ensures that the patterned device, for example, is in a desired position relative to the projection system. Any use of the term "main reticle" or "reticle" herein is considered synonymous with the more general term "patterned device."

The term "patterned device" as used herein shall be interpreted broadly to refer to any device that can be used to impart a pattern to a radiation beam in a cross-section of a radiation beam to form a pattern in a target portion of the substrate. It should be noted that, for example, if the pattern imparted to the radiation beam includes a phase shifting feature or a so-called auxiliary feature, the pattern may not exactly correspond to the desired pattern in the target portion of the substrate. Typically, the pattern imparted to the radiation beam will correspond to a particular functional layer in a device (such as an integrated circuit) formed in the target portion.

The patterned device can be transmissive or reflective. Examples of patterned devices include photomasks, programmable mirror arrays, and programmable LCD panels. Photomasks are well known in lithography and include reticle types such as binary alternating phase shift and attenuated phase shift, as well as various hybrid reticle types. One example of a programmable mirror array uses a matrix configuration of small mirrors, each of which can be individually tilted to reflect the incident radiation beam in different directions. The tilted mirror imparts a pattern to the radiation beam reflected by the mirror matrix.

The term "projection system" as used herein shall be interpreted broadly to encompass any type of projection system, including refractive, reflective, catadioptric, magnetic, electromagnetic, and electrostatic optical systems, or any combination thereof, suitable for the exposure radiation used. Or suitable for other factors such as the use of immersion liquids or the use of vacuum. Any use of the term "projection lens" herein is considered synonymous with the more general term "projection system."

As depicted herein, the device is of a transmissive type (eg, using transmitted light) cover). Alternatively, the device can be of the reflective type (eg, using a programmable mirror array of the type mentioned above, or using a reflective mask).

The lithography device can be of the type having two (dual platforms) or more than two substrate stages or "substrate supports" (and/or two or more reticle stages or "mask supports"). In such "multi-platform" machines, additional tables or supports may be used in parallel, or preparatory steps may be performed on one or more tables or supports while one or more other stations or supports are used for exposure .

The lithography apparatus can also be of the type wherein at least a portion of the substrate can be covered by a liquid (eg, water) having a relatively high refractive index to fill the space between the projection system and the substrate. The immersion liquid can also be applied to other spaces in the lithography apparatus, such as between the reticle and the projection system. Immersion techniques can be used to increase the numerical aperture of the projection system. The term "immersion" as used herein does not mean that a structure such as a substrate must be immersed in a liquid, but rather only means that the liquid is located between the projection system and the substrate during exposure.

Referring to Figure 1, illuminator IL receives a radiation beam from radiation source SO. For example, when the source of radiation is a quasi-molecular laser, the source of radiation and the lithography device can be separate entities. In such cases, the radiation source is not considered to form part of the lithography apparatus, and the radiation beam is transmitted from the radiation source SO to the illuminator IL by means of a beam delivery system BD comprising, for example, a suitable guiding mirror and/or beam amplifier. In other cases, for example, when the source of radiation is a mercury lamp, the source of radiation may be an integral part of the lithography apparatus. The radiation source SO and illuminator IL together with the beam delivery system BD (when needed) may be referred to as a radiation system.

The illuminator IL can include an adjuster AD configured to adjust the angular intensity distribution of the radiation beam. Generally, the intensity score in the pupil plane of the illuminator can be adjusted. At least the outer radial extent and/or the inner radial extent of the cloth (generally referred to as σ outer and σ inner, respectively). Further, the illuminator IL may include various other components such as the concentrator IN and the concentrator CO. The illuminator can be used to adjust the radiation beam to have a desired uniformity and intensity distribution in its cross section.

The radiation beam B is incident on a patterned device (e.g., reticle MA) that is held on a reticle support structure (e.g., reticle stage MT) and patterned by the patterned device. After traversing the reticle MA, the radiation beam B passes through the projection system PS, and the projection system PS focuses the beam onto the target portion C of the substrate W. By means of the second positioning means PW and the position sensor IF (for example an interference measuring device, a linear encoder, or a capacitive sensor), the substrate table WT can be moved precisely, for example, in the path of the radiation beam B Locate the different target parts C. Similarly, the first positioning device PM and another position sensor (which is not explicitly depicted in Figure 1) can be used, for example, with respect to the radiation beam after mechanical extraction from the reticle library or during scanning. The path of B to accurately position the mask MA. In general, the movement of the reticle stage MT can be achieved by means of a long stroke module (rough positioning) and a short stroke module (fine positioning) forming part of the first positioning means PM. Similarly, the movement of the substrate table WT or "substrate support" can be accomplished using a long stroke module and a short stroke module that form part of the second positioner PW. In the case of a stepper (as opposed to a scanner), the reticle stage MT can be connected only to a short-stroke actuator or can be fixed. The mask MA and the substrate W can be aligned using the mask alignment marks M1, M2 and the substrate alignment marks P1, P2. Although the substrate alignment marks occupy a dedicated target portion as illustrated, they may be located in the space between the target portions (this is referred to as a scribe line alignment mark). Similarly, in more than one die In the case of being provided on the reticle MA, the reticle alignment marks may be located between the dies.

The depicted device can be used in at least one of the following modes:

1. In the step mode, when the entire pattern to be given to the radiation beam is projected onto the target portion C at a time, the reticle stage MT or "mask support" and the substrate table WT or "substrate support" are made. It remains substantially stationary (ie, a single static exposure). Next, the substrate stage WT or "substrate support" is displaced in the X and/or Y direction so that different target portions C can be exposed. In step mode, the maximum size of the exposure field limits the size of the target portion C imaged in a single static exposure.

2. In the scan mode, when the pattern to be applied to the radiation beam is projected onto the target portion C, the mask table MT or "mask support" and the substrate table WT or "substrate support" are simultaneously scanned synchronously (also That is, a single dynamic exposure). The speed and direction of the substrate table WT or "substrate support" relative to the reticle stage MT or "mask support" can be determined by the magnification (reduction ratio) and image reversal characteristics of the projection system PS. In the scan mode, the maximum size of the exposure field limits the width of the target portion in a single dynamic exposure (in the non-scanning direction), and the length of the scanning motion determines the height of the target portion (in the scanning direction).

3. In another mode, the reticle stage MT or "mask support" is held substantially stationary while the pattern to be imparted to the radiation beam is projected onto the target portion C, thereby holding the programmable patterning device And move or scan the substrate table WT or "substrate support". In this mode, a pulsed radiation source is typically used and the program is updated as needed between each movement of the substrate table WT or "substrate support" or between successive pulses of radiation during the scan. Patterned device. This mode of operation can be readily applied to matte lithography utilizing a programmable patterning device such as a programmable mirror array of the type mentioned above.

Combinations and/or variations or completely different modes of use of the modes of use described above may also be used.

The substrate support 1 according to an embodiment of the present invention includes a mirrored block 2 on which the substrate stage 3 is placed. 2 and 3 respectively show a side view and a plan view of the substrate support 1 according to the embodiment.

The top side of the substrate support 1 includes a vacuum clamp 4 to clamp the substrate onto the substrate support 1. The substrate support 1 further comprises three collapsible pins 5 (also referred to as e-pins) which are extendable between the extended position of the pin 5 from the substrate support 1 and the contracted position of the pin 5 in the substrate support 1 Move relative to the substrate support. The collapsible pin 5 is movable in a substantially vertical direction, that is, in a direction substantially perpendicular to the major plane of the substrate to be supported by the pin. The shrinkable pin 5 is used to transfer the substrate between the substrate support 1 and the robot or any other type of substrate handler. The shrinkable pin 5 is provided such that the robot can be placed under the substrate for supporting the substrate. The collapsible pin 5 can be omitted when the robot is configured to hold the substrate at the side or top. In alternative embodiments, any other type of device capable of applying an attractive force to a substrate, such as an electrostatic chuck, a magnetic clamp, or an electromagnetic clamp, can be used.

In an embodiment, the robot places the substrate on the pin 5 in the extended position. Next, the pin 5 is moved to the retracted position such that the substrate rests on the support surface of the substrate support 1. After the substrate supported by the substrate support 1 is exposed to the patterned radiation beam, it is exchanged with another substrate. in order to The exchange substrate, which is moved from the self-retracting position to the extended position, is lifted from the substrate stage 3. When the pin 5 is in the extended position, the substrate is taken over by a robot or any other type of substrate handler.

The vacuum clamp 4 is formed by a recessed surface 6 which is surrounded by a sealing rim 7. The suction duct 8 is provided to create a low pressure in the vacuum space bounded by the recessed surface 6, the sealing rim 7, and the substrate placed or to be placed on the substrate support 1. The suction duct 8 is connected to a suction pump to draw air or another gas present in the treatment environment out of the vacuum space. The lower pressure provides a vacuum force that draws the substrate placed within a certain range toward the substrate support 1 above the support surface. Within this range or at least a portion thereof, the vacuum force applied to the substrate is substantially independent of the distance x between the substrate support and the substrate.

In the recessed surface 6, a plurality of nodules 9 are arranged. The top end of the knob 9 provides a support surface to the substrate to be placed on the substrate support 1. The tips of the sealing rim 7 and the knob 9 can be disposed in substantially the same plane to provide a generally planar surface for supporting the substrate. In an alternate embodiment, as shown in Figure 2, the sealing rim 7 can be disposed lower than the knob 9, or vice versa.

In the embodiment of the substrate support 1, two or more vacuum clamps are provided. In another embodiment, another means for providing an attractive force applied to the substrate (i.e., forcing the substrate toward the substrate support), such as an electrostatic chuck, a magnetic clamp, or an electromagnetic clamp, is provided. The force applied by the clamp is preferably in a range higher than the support surface of the substrate support 1, independent of the distance x between the substrate support and the substrate. In an embodiment, gravity is used as the clamping force. The gravity depending on the orientation of the fixture device can be a) attraction or repulsive force. In an embodiment, the pressure difference is used as an attractive or repulsive force. In an embodiment, the additional spring and the negative spring may be an option.

In many knobs 9, a nozzle 10 is provided. In the embodiment shown in Figures 2 and 3, the nozzles 10 are evenly distributed over the surface area bounded by the sealing rim 7. The nozzle 10 is coupled to the gas supply conduit 11 and is configured to provide ejection in a direction generally perpendicular to the recessed surface, i.e., substantially perpendicular to a major plane of the substrate to be disposed on the substrate support 1. In order to actually provide the injection, a pump (not shown) or another source of pressurized gas is connected to the supply conduit 11. In an alternative embodiment of the substrate support, the nozzles 10 are not integrated into the nodules but are provided separately. Notes, provides for the ejection, can be used any type of suitable gas, such as air or H _2.

The substrate placed within the range mentioned above in which the jig is active is subjected to the force applied by the ejection depending on the distance x between the substrate support 1 and the substrate.

In an alternate embodiment, other devices may be provided to force the substrate away from the substrate support, for example, using a repulsive force. Such devices may, for example, include linear or non-linear springs, or electrostatic, magnetic or electromagnetic devices. The repulsive force applied to the substrate preferably decreases as the distance x between the substrate support 1 and the substrate increases.

In general, it is noted that repulsive forces and attractive forces are preferably provided by means of a device capable of applying a force to the substrate without mechanical contact between the respective force application devices and the substrate.

In FIG. 4a, for the embodiment, the suction vacuum force plus gravity and the repulsive ejection force applied to the substrate are shown as the distance of the substrate from the substrate support x And set. On the x-axis, the distance x between the substrate support and the substrate is indicated for a range. On the y-axis, the attractive force (the combination of vacuum force and gravity) and the repulsive force (ejection force) are shown as the viewing distance x.

In an embodiment, the vacuum force is independent of the distance x. The horizontal line in Figure 4a shows the force that drives the substrate and the support towards each other. This force is the vacuum force corrected for the gravity component operating in the same direction as the vacuum force. Therefore, it can be claimed that the vacuum force cooperates with gravity. The repulsive force caused by the ejection decreases as the distance x is increased. Therefore, the attraction is less dependent on the distance x than the repulsive force. At the equilibrium distance x _b , the vacuum force corrected for gravity is equal to the repulsive force. The equilibrium distance x _b corresponds to the extremely stable distance. This is because when the substrate is present at this equilibrium distance, it will be held at this distance because of the equal force, which means that there is no resultant force to drive the substrate and the support to another distance. If the substrate and the support move in a manner away from each other to a distance greater than x _b , the attractive force will remain the same and the repulsive force will decrease. Accordingly, repulsive force will be less than attractive, so that the distance is smaller toward (i.e., toward the equilibrium distance x _b) drive substrate and the support member. If the substrate and the support move towards a distance x less than x _b , the attractive force will remain unchanged again, but the repulsive force will increase. Accordingly, repulsive force will be greater than attraction, and the substrate and the support member toward the equilibrium position x _b is forced away from each other. In this manner, the substrate may be holding and moving toward equilibrium position x _b, as indicated by the arrow in FIG. 4a.

In the above embodiment, the gravity is in the same direction as the attraction. In an alternate embodiment, there is an angle therebetween and correction will be made for the gravity component in the same direction as the attraction. Alternatively, in an embodiment of the gravitational component acting in the same direction of the repulsive force, repulsive force needs to be corrected for obtaining the equilibrium distance x _b, not attractive. In this embodiment, the repulsive force cooperates with gravity to force the substrate away from the support.

Furthermore, not only will the substrate generally move towards the equilibrium position. The balance between attractive and repulsive forces can also be used to shape the warped substrate into the desired shape. This can be advantageous in the case where the substrate to be loaded on the substrate support is warped. When the equilibrium distance x _b is equal to the entire surface area of the substrate supported on the substrate support, the attraction and rejection of the substrate support can be used before the warpage substrate is clamped on the support surface of the substrate support The force balances the warpage substrate at a distance x _{b for} a certain time and flattens the warpage substrate at this distance x _b .

In an embodiment, it is also possible to perform straightening or more generally performing forming while moving the substrate toward the substrate support. In this embodiment, the equilibrium distance x _b during molding shortened, therewith moving the substrate toward the substrate support member. The change in equilibrium distance can be obtained by varying the attractive and/or repulsive forces accordingly. For example, in Figure 4b, shown in dashed lines to the repulsive force decreases, resulting in a further equilibrium distance x _b -2, which is closer to the substrate support member.

In an embodiment, the ejection force or vacuum may be, for example, by a plurality of nozzles that are unevenly distributed or by using different supply conduits or two or more vacuum clamps, preferably having their own suction conduits. The difference in force provides an attractive distribution of attractive and/or repulsive forces. In this embodiment, the equilibrium distance x _b may vary along the surface area of the substrate, and as a result, the substrate may be formed in a desired shape. In an embodiment, the unevenly distributed force comprises a region missing force. The portion of the object to be clamped is free from the forces acting on it regionally.

In an embodiment, it is possible that both forces are dependent on the distance x between the substrate support 1 and the substrate 20. For example, in Figure 4c, the attractive force (i.e., vacuum force plus gravity) and repulsive force (i.e., ejection force) applied to the substrate are reduced as the distance between the substrate support and the substrate is increased. . However, less than x _b of the shorter distance, the greater the repulsive force, and is greater than a distance x _b, the more attractive. Therefore, the substrate holder at a distance x _b, the molded substrate is formed therewith (e.g., warping of the substrate prior to clamping the substrate support member so that the flat warp of the substrate) of possibilities.

With respect to the figures shown in Figures 4a and 4b and the other illustrated embodiments, it is noted that in these embodiments, gravity is a portion or an attractive force because the substrate is clamped on the top side of the support. In an alternative embodiment, it is possible to clamp the substrate to the underside of the support (in which case gravity will be part of the repulsive force or form a repulsive force), or the substrate can be clamped to the side of the support (In this case, gravity will not work in the balance between attraction and repulsive forces).

Figures 5a to 5c show certain steps of a clamping method for clamping a warping substrate 20 to a substrate support 1 in accordance with the present invention.

Figure 5a shows the substrate support of Figure 2 with the substrate 20 placed on the collapsible pin 5. The substrate 20 is warped, which may, for example, be caused by a pre-exposure process or a post-exposure process such as coating, baking, cooling or developing the substrate. In an embodiment, warping of the shape of the article, particularly the substrate, or any other kind of deformation may result from a channel in the substrate. The height difference in the substrate is typically in the range of 5 microns to 50 microns (especially for relatively new substrates that have not been processed (eg, coated, baked, cooled, and developed), but up to 450 Micrometers or even more differences are equally possible (especially after the substrate has been processed).

When the warped substrate is loaded on the substrate support without additional measurement, the stress may be introduced into the substrate 20 due to the clamping of the substrate 20 in a warped form. For example, when the substrate is in the shape of a dome, the outer circumference may be first clamped and thereafter sandwiched between the substrates 20. Since the circumference of the warpage substrate may be smaller than the circumference of the same flat substrate, the clamping may cause stress in the substrate.

In Figure 5b, by the contraction of the substrate support pin 1 5 is moved downward to the substrate 20 to the substrate close to the equilibrium position, i.e., close to the distance x x _B 1 between the substrate 20 and the substrate support member. It is noted that the equilibrium distance x _b can generally be in the range of 1 micrometer to 1000 micrometers (preferably, in the range of 1 micrometer to 100 micrometers). The preferred equilibrium distance may also depend on the height difference present in the respective substrate.

In order to form the warpage substrate, the attractive force and the repulsive force are simultaneously applied to the substrate. The magnitude of these forces can be altered to change the equilibrium position of the substrate.

Thereby, it is possible to shape the substrate during the movement of the substrate toward the substrate support. Also, the substrate can be shaped during the first proximity of the substrate support and then held at a distance (eg, between 1 micron and 100 microns) to be further shaped substantially flat before it is clamped onto the substrate support form.

Since the substrate 20 floats on the bed formed by the ejection, it is necessary to provide some kind of fixing for the substrate. For this reason, the substrate 20 is still held by the shrinkable pin 5 for fixing in the x, y, and Rz directions. However, in order to make the pin 5 There is a small impact on the straightness, the pin having a low hardness in the vertical z direction at least during the straight phase. Any other device for maintaining the substrate in substantially the same position in the x, y, and Rz directions can also be used. In some embodiments, there are elements such as pins 5 to increase the shape of the article to subsequently shape the article in accordance with the present invention. In some embodiments, certain deformations may be preferred because the deformation is more or less predictable.

When the flatness of the substrate 20 has been completed, the substrate 20 is clamped by generating an attraction force greater than the repulsive force (for example, by increasing the vacuum force of the vacuum chuck 4 or by reducing the velocity of the ejection from the nozzle 10). On the substrate support 1. Therefore, the substrate 20 is stopped on the support surface of the substrate support 1. When the vacuum force is maintained, the substrate 20 is clamped on the substrate support 1 while still being substantially straight. This situation is referred to as full clamping when the loading process for clamping the substrate to the substrate support is completed.

In Figure 5c, the substrate 20 is shown clamped onto the substrate support 1 using a vacuum clamp 4. Because the substrate 20 is flat during clamping on the substrate support, the risk of internal stress in the substrate 20 is substantially reduced and the coverage efficiency increases. The shrinkable pin 5 is moved to the retracted position.

It is noted that the flat phase can also be used to thermally condition the substrate 20 by temperature control of the gas used for ejection.

Figures 6a to 6c show side views of an alternative embodiment of a substrate support 1a in accordance with the present invention. Each of Figs. 6a to 6c shows the steps during the forming and clamping of the warpage substrate 20 on the substrate support 1a. Features of the substrate support 1a having the same or substantially the same functions as those in the embodiments of Figs. 2, 3 and 5a to 5c are given the same reference numerals.

The top side of the substrate support 1a includes a first vacuum chuck 4a and a second vacuum chuck 4b to clamp the substrate on the substrate support 1a. The first vacuum clamp 4a is configured to clamp a central portion of the substrate and is bounded by a circular inner sealing rim 7a. A gas suction conduit 8a is provided to draw the gas out of the vacuum space defined by the recessed surface 6a and the sealing rim 7a.

The second vacuum chuck 6b is annular and concentrically surrounds the first vacuum chuck 6a. The second vacuum clamp 6b is configured to clamp a circumferential area of the substrate around a central portion of the substrate. The second vacuum clamp 4b is bounded by an inner sealing rim 7a and a circular outer sealing rim 7b. A gas suction conduit 8b is provided to draw the gas out of the vacuum space defined by the recessed surface 6b between the inner seal rim 7a and the outer seal rim 7b.

In the recessed surface 6b, a plurality of nodules 9 are arranged. The top end of the knob 9 combines the top ends of the inner sealing rim 7a and the outer sealing rim 7b to provide a support surface to the substrate to be placed on the substrate support 1a.

In many knobs 9, a nozzle 10 is provided. The nozzle 10 is disposed in the knob 9 in the recessed portion 6b such that a repulsive force can be applied to another portion of the substrate that is different from the central portion of the substrate. The nozzle 10 is coupled to the gas supply conduit 11 and is configured to provide injection substantially perpendicular to a major plane of the substrate supported or to be supported on the substrate support 1a.

Figures 6a through 6c show certain steps of an alternative clamping method for clamping a substrate 20 to a substrate support 1a in accordance with the present invention.

Figure 6a shows the substrate support 1a by which the substrate 20 is placed on the collapsible pin 5. The substrate 20 is warped, which may, for example, be caused by a pre-exposure process or a post-exposure process such as coating, baking, cooling or developing the substrate. In this In the method, the pin 5 is lowered until the support is at least partially supported on the substrate support 1a. Next, the first vacuum chuck 6a holds the central portion of the substrate 20 on the support. Thereafter, the substrate 20 is brought into a desired cup shape or a concave shape by ejecting air or another suitable gas out of the nozzle 10.

In Figure 6b, the substrate 20 is shown in a cupped or concave shape. During this state, the second jig device 4b can apply an attractive force to the substrate 20, but the ejection force exerted by the gas ejection from the nozzle 10 is larger, so that the circumferential portion of the substrate is bent upward from the substrate support to form A cup or concave shape as shown in Figure 6b.

Since the substrate 20 is held by the first vacuum chuck at the central portion of the substrate 20 in this state, the fixing for the substrate is provided in the x, y, and Rz directions. The substrate 20 is generally prevented from floating improperly in these directions, while the pin 5 can be completely shrunk into the substrate support without mechanical impact on the substrate 20.

When the attraction force of the second vacuum jig is gradually increased and/or the repulsive force of the ejection is gradually lowered, the substrate will be clamped to the substrate support in a radial direction starting from the central portion. As a result, the substrate 20 will be clamped to the substrate support 1a without or with substantially reduced internal stress, as the substrate 20 is gradually "spread" over the substrate support 1a. As a result, coverage errors can be avoided.

In an alternate embodiment, it is possible that the first clamp device 4a is not configured to clamp the central portion of the substrate 20 in the first instance, but to sandwich another portion of the substrate 20 (eg, the edge of the substrate). In this embodiment, after the substrate is formed in one form, the substrate can be clamped to the substrate support 1a, in which form the substrate is only clamped at the portion, starting from this portion of the substrate.

In the embodiment shown in Figures 6a to 6c, the first vacuum clamp 4a and the second vacuum clamp 4b combine to apply an attractive force to the entire surface area of the substrate 20. In another embodiment, a first clamp device can be provided to apply a clamping force to only a portion of the substrate, and a second clamp device can be provided to apply a clamping force to the entire surface area of the substrate. In this embodiment, the first clamp device can be used as a pre-clamp device configured to hold only a portion of the substrate during forming, and the second clamp device can be used as a clamp device during the actual lithography process. Any suitable fixture device, such as a vacuum clamp device, an electrostatic device, a magnetic device, or an electromagnetic device, can be used as the fixture device.

In the embodiment shown in Figures 6a to 6c, the nozzle 10 is provided in the recessed surface 6b. In an alternative embodiment, the nozzle 10 may also be provided in the recessed area 6a as long as the attraction force of the first vacuum chuck during forming is greater than the ejection force of the jet discharged from the nozzle in the inner recessed area 6b. In another embodiment, the nozzle may be provided only at the rounded edge of the substrate support and thus configured to apply a repulsive force to only the circumferential edge of the substrate to be placed on the substrate support.

In one embodiment of the substrate support, different groups of nozzles can be provided, each group being connected to a separate gas supply conduit. This embodiment makes it possible to use each nozzle group to provide different ejection forces, with which a more precise control of the force applied to the substrate is made possible.

In this embodiment, it is preferred to configure the nozzle groups in concentric circles around a first clamp device configured to clamp a portion of the substrate during formation of the substrate. Also, the second vacuum clamp or more generally the second clamp device can be Subdivided into a number of preferably concentrically configured clamp devices to enable more precise control of the attractive force applied to different portions of the substrate.

Figures 7a and 7b show another embodiment of a substrate support 101 in accordance with the present invention. The substrate support 101 includes three substantially concentric annular vacuum clamps 102, 103, 104, each containing a plurality of vacuum apertures 105 configured in a circular configuration.

The vacuum holes 105 of each of the annular vacuum clamps 102, 103, 104 are connected to a common vacuum source 106 via vacuum lines 107, 108, 109, respectively. In each of the vacuum lines 107, 108, 109, a flow restriction 112 is provided. The flow restriction 112 provides a certain flow resistance against the flow through the respective vacuum lines 107, 108, 109. The flow resistance of the vacuum line 109 of the outer annular vacuum clamp 104 is greater than the flow resistance of the vacuum line 108 of the intermediate annular vacuum clamp 103, and the flow resistance of the vacuum line 108 of the intermediate annular vacuum clamp 103 is greater than that of the vacuum line 107 of the inner annular vacuum clamp 102. Flow resistance.

Around the outer annular vacuum clamp 104, the annular repulsive force device 110 is configured to provide a repulsive force on or near the edge of the substrate to be loaded. The repulsive force device 110 is concentrically disposed with the annular vacuum clamps 102, 103, 104 and includes, for example, a plurality of nozzles configured in a circle configured to eject air or another gas in the direction of the substrate to be loaded.

The substrate support 101 of Figures 7a and 7b is particularly suitable for warping substrates wherein the edges will contact the substrate support 101 prior to the center of the substrate during loading, when no additional measures are taken. As a result, the roll-off of the substrate during the accumulation of the clamping force can cause stress and deformation in the substrate (especially in the substrate) Center). The difference in the coefficient of friction between the substrate and the substrate support and the difference in the shape of the substrate can strongly influence the position of the deformation.

In order to avoid the above stress and deformation, it is proposed to clamp or pre-clamp the warped substrate by the annular vacuum clamps 102, 103, 104 of the substrate support 1 as shown in FIGS. 7a and 7b, while the substrate 120 to be loaded is mounted. The repulsive force is simultaneously applied by the repulsive force device 110 on or near the outer edge (shown in phantom) to avoid the outer edge contacting the substrate support when the substrate is lowered toward the substrate support, for example, by the e-pin 111. Vacuum is applied to the annular vacuum clamps 102, 103, 104 such that an attractive force is applied to the substrate 120.

Because the flow resistance of the vacuum line 107 of the inner annular vacuum clamp 102 is relatively low, the inner annular vacuum clamp 102 will be supported by application of vacuum until the substrate 120 is clamped to the inner annular vacuum clamp 102. Due to the grip, the flow resistance of the vacuum line 107 of the inner annular vacuum clamp 102 is rapidly increased and the vacuum will support the intermediate annular vacuum clamp 103. When the substrate is also clamped to the intermediate annular vacuum clamp 103, the outer annular clamp 104 will be supported.

The clamping force and repulsive force applied to the substrate 120 are shown by dashed arrows in Fig. 7b. The thickness of the arrows of the ring clamps 102, 103, 104 indicates that the applied vacuum will be supported by the ring clamp in the first case because the flow resistance in the vacuum line 107 of the inner annular vacuum clamp 102 is relatively small.

In this manner, the substrate is held on the substrate starting at a central portion of the substrate and then amplifying the surface of the substrate held in the radial direction.

When the wafer is held by all three annular vacuum clamps 102, 103, 104, the repulsive force can be eliminated or reduced and the edge of the substrate can be bonded to the substrate support 101 makes contact. Since the edge of the substrate is the last portion for making contact with the substrate support 101, stress and deformation of the substrate are avoided. Then, the substrate is completely clamped on the substrate support.

In an alternate embodiment, the inner ring clamp device 102 can be circular in shape. In view of the application of the invention, the circular shape is considered to be annular. Further, it is noted that the flow resistance as shown in Fig. 7b is obtained by providing a flow resistance. It is also possible to obtain different flow resistances by the shape and length of the vacuum line of different annular vacuum clamps or by any other means.

Depending on the size of the substrate and the need for internal stresses and deformations after clamping, more or less annular vacuum clamps may be provided. In addition, any other type of clamp device can be used as the ring fixture device. Preferably, the clamping force of each of the annular clamp devices is adapted or adjustable such that the clamping will begin at the innermost annular clamp device and extend radially to the edge of the substrate. Any other suitable roll-off of the grip can also be applied (eg, starting from the edge of the substrate).

Any suitable type of device for applying a repulsive force to the substrate, such as a nozzle, an electrostatic device, a magnetic device, or an electromagnetic device, can be used.

In the above, it has been explained how the substrate can be formed before clamping (i.e., ending the complete clamping) on the substrate support by simultaneously applying the attractive force and the repulsive force to the same portion or different portions of the substrate. In this way, the shape of the substrate is controlled during the loading process. It is noted that the term full clamping refers to a substrate that is clamped to the substrate support at the end of the substrate loading process and is therefore ready for further processing, for example, in a lithography process. Full clamping therefore does not necessarily mean that a clamping force is applied to the full surface of the substrate.

The use of the device and method for controlling the shape of the article prior to reaching the fully clamped state is explained above in terms of the substrate support 1 and the substrate 20 to be clamped to the support. The device and method can be used to clamp another object (especially a warped planar shaped object, such as a warpage plate or a sheet) to a support member to control the shape of the object on the support member, particularly to avoid the clip. The internal stress in the object after holding. These examples are considered to be within the scope of the invention.

The invention, which uses both repulsive force and attractive force, can also be used for other items to be held in a position and/or to reduce stress in the held item. An example article to be held in a similar manner can be a master reticle/reticle or patterned device. Any of the embodiments are suitable for holding a patterned device, and/or those skilled in the art can adapt the embodiment to hold the patterned device.

According to an embodiment, the apparatus and method include shaping the article into all shapes, preferably reducing internal stresses in the article, potentially resulting in a reduction in overlay error. In an embodiment, the forming is performed prior to full clamping of the article on the support. In one embodiment, the formation of the attraction and repulsive forces is performed in the loading station of the article to the table. In one embodiment, the full clamping in one embodiment includes positioning the article in a position relative to the table, which will generally maintain the position during further operation. If another subsequent clamping action is performed in a later step, the item may have been completely clamped. In an embodiment, full clamping is equivalent to cutting the repulsive force or at least reducing the repulsive force. This may be a complete cut of the repulsive force or only a partial cut of only a portion of the area of the object that is subject to repulsive forces.

In one embodiment, an external source external to the article table is used for attraction or repulsive forces or both. Here, the external source is the source that is not directly connected to the fixture device (and is not directly connected to the object table in one embodiment). One embodiment includes an air jet that is positioned above the article table and secured to different portions of the device, such as a lithography device.

In an embodiment, the flexible element is provided as part of a clamp device or as part of an object table. A flexible element, such as a spring or flexible wall element, can extend upward from the clamp device or article table. It provides repulsive force away from the fixture device.

In the foregoing, repulsive forces and attractive forces are forces as defined by the fixture device. The repulsive force is the force away from the fixture device. Attraction is the force toward the fixture device. Forces can be provided using units that each provide only attractive or repulsive forces. It will be apparent to those skilled in the art that the present invention encompasses embodiments in which the force is a force that forces the substrate and the support toward each other and the repulsive force is an embodiment that forces the substrate and the support away from each other. In an alternate embodiment, a vacuum force is applied to the surface of the article facing away from the substrate support 1 to force the substrate away from the support.

In yet another embodiment, the method includes the step of reducing stress in the substrate by applying a vibratory action to the substrate during loading and/or upon loading. By vibrating, the internal stress in the substrate can be released. The vibration action can be applied by using a spring or a flexible element. The vibration tool can be actuated. A suitable actuator can be used. In one embodiment, a vibratory action is applied to the substrate that begins in the central portion of the wafer. The vibration action can be applied to the substrate/object by the center gripper. In another step, the subsequent vibration action can be Applied to more externally positioned parts of the object. In this way, the stress in the article is preferably "moved" (preferably "released") to the outer portion of the article. In an embodiment, the E pin is used as a vibrating device to vibrate the object.

The vibration action can be a very short action, for example, only one or even a half cycle. The vibratory action is characterized by at least one action, preferably a movement relative to the equilibrium position. It can be shifted for offset. It is believed that this vibrational action will have a stress reduction effect in the object, as the vibrating action can cause movement through the wave stress relief projections such as the material of the article. It is believed that this type of wave motion is more effective in reducing the regional stress area in the object.

In another embodiment, a striking device can be used to apply vibration to the object. By striking the object, a one-time interference, in this case excessive interference, is transferred to the object, which can be used to dissipate or release other internal stresses on the object. The striking device can also initiate wave motions such as in objects.

Although reference may be made herein specifically to the use of lithographic apparatus in IC fabrication, it should be understood that the lithographic apparatus described herein may have other applications, such as fabrication of integrated optical systems, for magnetic domain memory. Guide and detection patterns, flat panel displays, liquid crystal displays (LCDs), thin film heads, and more. Those skilled in the art will appreciate that any use of the terms "wafer" or "grain" herein is considered synonymous with the more general term "substrate" or "target portion", respectively, in the context of such alternative applications. The substrates referred to herein may be processed before or after exposure, for example, in a track (a tool that typically applies a layer of resist to the substrate and develops the exposed resist), a metrology tool, and/or a test tool. Where applicable, the disclosure herein can be applied to such and other substrate processing tools. In addition, the substrate can be processed more than once, for example, so that The multilayer IC is formed such that the term substrate as used herein may also refer to a substrate that already contains multiple processed layers.

Although the above may be specifically referenced to the use of embodiments of the invention in the context of optical lithography, it will be appreciated that the invention may be used in other applications (eg, embossing lithography) and is not limited where context permits Optical lithography. In imprint lithography, the configuration in the patterned device defines a pattern formed on the substrate. The patterning device can be configured to be pressed into a resist layer that is supplied to the substrate where the resist is cured by application of electromagnetic radiation, heat, pressure, or a combination thereof. After the resist is cured, the patterned device is removed from the resist to leave a pattern therein.

The terms "radiation" and "beam" as used herein encompass all types of electromagnetic radiation, including ultraviolet (UV) radiation (eg, having a wavelength of about 365 nm, 248 nm, 193 nm, 157 nm, or 126 nm). And far ultraviolet (EUV) radiation (eg, having a wavelength in the range of 5 nm to 20 nm); and a particle beam (such as an ion beam or an electron beam).

The term "lens", when the context permits, may refer to any or a combination of various types of optical components, including refractive, reflective, magnetic, electromagnetic, and electrostatic optical components.

Although the specific embodiments of the invention have been described hereinabove, it is understood that the invention may be practiced otherwise than as described. For example, the invention can take the form of a computer program containing one or more sequences of machine readable instructions for describing a method as disclosed above; or a data storage medium (eg, a semiconductor memory, disk or optical disk) ), which has the computer program stored therein.

The above description is intended to be illustrative, and not restrictive. It will be apparent to those skilled in the art that the present invention may be modified as described without departing from the scope of the appended claims.

1‧‧‧Substrate support

1a‧‧‧Substrate support

2‧‧‧Mirror block

3‧‧‧ substrate table

4‧‧‧vacuum fixture

4a‧‧‧First vacuum fixture

4b‧‧‧Second vacuum fixture

5‧‧‧Compensable pin

6‧‧‧ recessed surface

6a‧‧‧First vacuum clamp/recessed surface

6b‧‧‧Second vacuum clamp/recessed surface

7‧‧‧ Sealing rim

7a‧‧‧round internal sealing rim

7b‧‧‧round outer sealing rim

8‧‧‧Sucking pipe

8a‧‧‧ gas suction pipe

8b‧‧‧ gas suction pipe

9‧‧‧noma

10‧‧‧ nozzle

11‧‧‧ gas supply pipeline

20‧‧‧Substrate

101‧‧‧Substrate support

102‧‧‧Substantially concentric annular vacuum clamp

103‧‧‧Substantially concentric annular vacuum clamp

104‧‧‧Substantially concentric annular vacuum clamp

105‧‧‧vacuum hole

106‧‧‧Common vacuum source

107‧‧‧vacuum pipeline

108‧‧‧vacuum pipeline

109‧‧‧vacuum pipeline

110‧‧‧Ring Repulsive Force Devices

111‧‧‧e sales

112‧‧‧Flow restrictions

120‧‧‧Substrate

AD‧‧‧ adjuster

B‧‧‧radiation beam

BD‧‧‧beam transmission system

C‧‧‧Target section

CO‧‧‧ concentrator

IF‧‧‧ position sensor

IL‧‧‧ illuminator

IN‧‧‧ concentrator

M1‧‧‧mask alignment mark

M2‧‧‧Photomask alignment mark

MA‧‧‧Photo Mask

MT‧‧‧mask table

P1‧‧‧ substrate alignment mark

P2‧‧‧ substrate alignment mark

PM‧‧‧First Positioning Device

PS‧‧‧Projection System

PW‧‧‧Second positioning device

SO‧‧‧radiation source

W‧‧‧Substrate

WT‧‧‧ substrate table

x‧‧‧Distance/Axis/Direction

x _b ‧‧‧balance distance

x _b -2‧‧‧Equilibrium distance

Y‧‧‧Direction/axis

Z‧‧‧ direction

1 depicts a lithography apparatus in accordance with an embodiment of the present invention; FIG. 2 depicts a side view of a substrate support in accordance with the present invention; FIG. 3 depicts a top view of the substrate support of FIG. 2; FIGS. 4a, 4b, and 4c are A simplified diagram showing an example of the dependence of the attraction and repulsive force on the distance between the substrate and the substrate support; Figures 5a to 5c depict three steps of the method according to the invention; Figures 6a to 6c depict the invention according to the invention A side view of an alternative embodiment of a substrate support, and three steps of a clamping method in accordance with the present invention; and Figures 7a and 7b depict a top view and cross section of another embodiment of a substrate support in accordance with the present invention.

1‧‧‧Substrate support

2‧‧‧Mirror block

3‧‧‧ substrate table

4‧‧‧vacuum fixture

5‧‧‧Compensable pin

6‧‧‧ recessed surface

7‧‧‧ Sealing rim

8‧‧‧Sucking pipe

9‧‧‧noma

10‧‧‧ nozzle

11‧‧‧ gas supply pipeline

x‧‧‧Distance/Axis/Direction

Claims (11)

A clamp device configured to clamp an object to a support member, the clamp device comprising: a first device configured to use a first force to force the object and the support Far from each other, and a second device configured to use a second force to force the article and the support toward each other, wherein the first device and the second device are The first force and the second force are respectively applied to the support member prior to the clamping to shape the article into a desired shape, wherein the first device and the second device are configured to be simultaneously and with gravity Cooperatingly operating to maintain the article and the support at an equilibrium distance from each other, wherein after correcting the gravity, the first force is greater than the second force at a distance less than the equilibrium distance, and greater than the balance The first force is less than the second force at a distance from the distance. The jig device of claim 1, wherein at least one of the group of the first device and the second device is configured to apply a vibratory action to the object. A fixture device of claim 1 or 2, wherein the first device is configured to apply the first force to a portion of the object, and wherein the second device is configured to apply the second force to the At least another part of the object. The jig device of claim 1 or 2, wherein at least one of the group comprising the first device and the second device is configured to apply stress thereto to the object, and at least one component There is no mechanical connection between the objects touch. A jig device of claim 1 or 2, wherein the jig device further comprises a striking unit for striking the object. The jig device of claim 1 or 2, wherein the support member is a substrate support member of a lithography device and the object member is a substrate. A lithography apparatus comprising the fixture device of claim 6. A method for loading an article onto a support member, the method comprising the steps of: shaping the article in a desired shape, wherein the forming comprises subjecting the article to a condition that forces the article away from the support member a force and a second force forcing the article and the support member toward each other; and completing the clamping of the article on the support member; wherein in the forming step, the object member and the support member maintain a balanced distance from each other, And wherein, after correcting the gravity, the first force is greater than the second force at a distance less than the equilibrium distance, and the first force is less than the second force at a distance greater than the equilibrium distance. The method of claim 8 further comprising applying a vibrating action to the object. A method for loading a substrate onto a substrate support of a lithography apparatus, the method comprising the steps of: shaping the substrate in a desired shape while maintaining the substrate spaced from the substrate support, wherein the forming Including causing the substrate to simultaneously withstand the attraction of pulling the substrate toward the substrate support and pushing the substrate far Repulsive force from the substrate support; and clamping of the substrate on the substrate support, wherein in the forming step, the substrate and the substrate support maintain a balanced distance from each other, and after correcting gravity, The repulsive force is greater than the attractive force at a distance less than the equilibrium distance, and the repulsive force is less than the attractive force at a distance greater than the equilibrium distance. The method of claim 10, further comprising applying a vibrating action to the substrate.