TWI835063B - Substrate holding device, method for manufacturing such a device, and apparatus and method for processing or imaging a sample - Google Patents

Abstract

The invention relates to a substrate holding device comprising a holding plate, a base plate, an array of supports, and an array of droplets of a heat absorbing material. The holding plate comprises a first side for holding a substrate. The base plate is arranged at a distance from the holding plate and provides a gap between the base plate and the holding plate at a side of the holding plate opposite to the first side. The array of supports is arranged in between the holding plate and the base plate. The array of liquid and/or solid droplets is arranged in between the holding plate and the base plate, and the droplets are arranged to contact both the base plate and the holding plate. The droplets are arranged spaced apart from each other and from the supports, and are arranged adjacent to each other in a direction along the gap.

Description

Substrate holding devices, methods for fabricating such devices, and instruments and methods for processing or imaging samples

The present invention relates to substrate clamping devices, for example for use in lithography systems. The invention further relates to methods for manufacturing such substrate holding devices, and to the use of such substrate holding devices in lithography systems. The invention further relates to an apparatus for exposing a sample, in particular for processing or imaging a sample, more particularly a lithography apparatus. The invention further relates to methods for processing or imaging samples.

In lithography systems, for example, photons or charged particles such as ions or electrons are used to illuminate and pattern the surface of a substrate such as a silicon wafer. Due to the energy loading of such photons or charged particles, the substrate is at least locally heated. Particularly in charged particle lithography systems such as multi-beam charged particle lithography systems, the impact of charged particles can cause significant heating of the substrate, especially in combination with localized impact of charged particles on the substrate.

Various substrate clamping devices have been proposed that suppress the temperature rise of the substrate and thereby stabilize the temperature of the exposed substrate.

Many of these clamping devices rely on thermal contact of the substrate with a coolant that configured to flow through the substrate clamping device. An example of such a device is disclosed in US 5,685,363, which describes a substrate holding device containing a heat-absorbing fluid chamber beneath the wafer or target to be exposed. This known substrate holding device includes a heat absorbing fluid covered by a flexible sheet. In use, the substrate is pressed against the foil by the substrate holder whereby the foil and therefore the heat absorbing fluid comes into intimate thermal contact with the rear face of the substrate which is to be temperature stabilized.

In situations where the substrate is only heated locally, such as in a charged particle beam lithography system, the layer of heat-absorbing fluid in this known design acts in addition to In addition to the heat absorber, it acts as and forms a thermal buffer.

Additionally, a temperature stabilizing device as disclosed in US 5,685,363 includes a heat absorbing fluid channel or a coolant channel included in the stabilizing base, through which the heat absorbing fluid flows to cool the substrate holding device, and Transfer heat away from the substrate clamping device. This allows the temperature of the substrate holding device below the heat absorption chamber to be stabilized and provides better control of the temperature at which the substrate holding device and target will be stable.

Such coolant channels are not preferred in lithography exposure systems, which are typically adapted to vacuum environments. One reason is that associated coolant conduits impede or interfere with the precise positioning of the substrate, either directly or via hysteresis.

In the field of lithography, patent publication US 2005/0128449 teaches that phase change materials (so-called PCMs) can facilitate the removal of heat. PCM can store large amounts of energy as latent heat during the phase change from solid to liquid. Advantageously, large amounts of thermal energy can be stored at a relatively constant temperature. Therefore, the use of PCM can provide temperature stabilization by storing large amounts of thermal energy without significantly changing the temperature. The PCM material can be applied without coolant conduits while still safely controlling the temperature at which the target or substrate and substrate holding device will be stabilized. Materials indicated for achieving this thermal storage and stabilizing the system include paraffin wax and Rubitherm ^tm PX. PCM can be supplied as PCM powder or as bonded PCM.

This approach to combined thermal storage and temperature control is based on the commonly known principle of exploiting the phase change of materials at constant temperature. In applying this principle, as is further known from the extensive literature including "A review of on phase change energy storage: materials and applications" by Mohamed M. Farid et al. (Energy Conversion and Management 45, 2004), it is appropriate to Materials can usually be selected from the manual. To provide storage of large amounts of thermal energy at a desired temperature, one skilled in the art will look for materials that possess a relatively high heat of transformation or latent heat at the desired temperature, under stabilized temperature conditions. This handbook is "Handbook of chemistry & Physics", which is based on the published research list "thermodynamic properties of the elements" by the US Atomic Energy Commission, Report ANL-5750. An indication of the popularity of certain materials in bulk PCM is the selection of paraffin (n-octadecane), gallium and tin by Costa et al., "Numerical simulation of solid-liquid phase change phenomena", 1991. Numerical simulation used to verify PCM behavior.

Patent publication US 2008/0024743 in the name of the applicant provides an example of a lithography target exposure system showing this known temperature stabilization system, in which the coolant conduit is omitted by the use of PCM in the form of, for example, hexadecane. Hexadecane was selected for the following reasons: its phase change temperature matches the upper end of the typical temperature range for coolant fluids used in semiconductor manufacturing, thereby preventing the temperature of the substrate thermal buffer from increasing from the rest of the industrial lithography system. , often the liquid cooling section deviates to an undesirable degree. In this regard, the PCM temperature of hexadecane can be seen, for example, from Himran and Suwono's "Characterization of Alkanes and Paraffin Waxes for application as Phase Change Energy Storage Medium" (Energy sources, Vol. 16, 1994) as approximately 291K, The manufacturer's coolant liquid can be According to Chen, Gautam and Weig's "Bringing energy efficiency to the fab" (McKinsey on semiconductors, Autumn 2013), it is seen as being in the range from 286K to 291K (55F to 65F).

Although hexadecane has the advantage of having a phase transition temperature that matches industrial operating temperatures, at least industrial coolant temperatures, in practice it appears to suffer from poor performance due to poor thermal conductivity, regardless of whether used to modify the target as is known herein The use of thermal conductivity measures between PCMs taught in PCM-based substrate temperature stabilization systems.

Furthermore, US 7,528,349 discloses a temperature stabilization system comprising a heat absorbing material arranged in thermal contact with a substrate. The heat absorbing material is characterized by a solid-liquid phase transition temperature in the desired temperature range of the material used to process the substrate. According to US 7,528,349, the heat absorbing material may be provided as a flat layer arranged on top of the carrier, may be arranged to fill one or more depressions in the surface of the carrier, or may be embedded in the carrier by filling the depressions with the heat absorbing material . The heat absorbing material is configured to be in direct contact with the substrate or with a suitable thermally conductive layer that is in substantial thermal contact with both substrates. Where the substrate is heated only locally, such as in a charged particle beam lithography system, the resulting heat is locally absorbed by the heat absorbing material. Due to heat absorption, the heat absorbing material will generally undergo a phase transition at least partially at the location where the charged particle beam impacts the substrate. This local phase transition results in local expansion or contraction of the heat absorbing material. Such local expansion or contraction produces undesirable distortion or deformation of the substrate, making the temperature stabilization system of US 7,528,349 unsuitable for high-resolution charged particle lithography.

The present invention therefore seeks to provide systems, instruments and/or methods that provide precise temperatures for use in systems, instruments and/or substrate holding devices through the use of well thermally conductive, typically metallic phase change materials. control components while still matching the temperature of the coolant liquid within the semiconductor standard range. Standard metal materials have operating ranges far away from this desired Phase change temperature. Gallium, with a transition temperature of 303K, is closest to the temperature range used for coolant liquids used in semiconductor manufacturing, but is still off by 12 degrees. Other metal-like materials may be selected from metal-based compound materials. In the case where such liquid metal materials can exhibit gallium-like material behavior, the present invention further seeks to optimize the PCM stabilization in the combined function of the PCM stabilization substrate support as a container for the liquid metal compound and the substrate temperature stabilizer. Substrate support, thereby providing a new design of this temperature stable substrate support.

Likewise, while the substrate clamping device according to US 2008/0024743 provides an extremely compact and precise way of maintaining a substrate at a substantially constant temperature on top of the substrate clamping device, it has also proven difficult to manufacture such a substrate Clamp the device and/or obtain a carrier or thermally conductive frame with highly precise and visible dimensions suitable for use in lithography systems.

Additionally or alternatively, it is an object of the present invention to provide a design suitable for at least processing the specific properties of metal-like phase change materials such as any of the various gallium compounds. In practice, it appears that such materials tend to exhibit ice- and water-like behavior in the transition of ice and water from solid to liquid, since the volume in the solid form can generally be greater than in the liquid form, thus due to the clamping device At least potential loss of direct contact between the upper layer and the underlying phase change material causes poor thermal conductivity.

Additionally or alternatively, it is an object of the present invention to provide an exposure method and apparatus for such a device, which exposure method and apparatus provide precise temperature control of the substrate, in particular in an exposure unit for projecting electromagnetic radiation or particles onto the substrate. In an instrument disposed in close proximity to the substrate such that the exposure unit can thermally affect the substrate.

Additionally or alternatively, it is an object of the present invention to provide a substrate clamping device that at least partially avoids at least one of the above-mentioned disadvantages of prior art substrate clamping devices.

According to a first aspect, the present invention provides a substrate clamping device. The substrate clamping device includes: a clamping plate, wherein the clamping plate includes a first side for clamping the substrate; the base plate is arranged at a distance from The clamping plate provides a gap between the base plate and the clamping plate at a distance and at a second side of the clamping plate away from the first side, an array of support members, the support members are arranged at least on Between the clamping plate and the base plate, and an array of droplets of heat absorbing material, the droplets are arranged in the gap between the clamping plate and the base plate, wherein the droplets are configured to Spaced apart from the supports and spaced apart from other droplets in the array of droplets, and wherein the droplets are configured to contact both the base plate and the clamping plate.

The array of supports between the base plate and the clamping plate defines the width of the gap between the base plate and the clamping plate and provides a frame with highly accurate and reproducible dimensions. This novel design for containing droplets of phase change material in a manner suitable for successful, at least optimal thermal conduction, at least for successful temperature stable thermal buffering, utilizes the flexibility of using spheres or small droplets as part of the liquid material. The surface tension and cohesion of the drop shape at least make the container design suitable for the material properties. Therefore, the substrate holding device of the present invention is configured to receive and contain droplets of phase change material, particularly droplets spaced apart from the support and from other droplets in the array of droplets, rather than filling the PCM container, and also That is, a cavity configured for housing a PCM in a clamping device as described, for example, in US 7,528,349. The holder preferably has a plurality of well-spaced, relatively small and/or shallow indentations or cavities each adapted to accommodate droplets of PCM.

The droplets are configured with the support and with other droplets in the array of droplets Spaced apart to enable expansion of the droplets at least in a direction along the gap between the base plate and the clamping plate. The droplets in the array of droplets are configured to have sufficient lateral space so that the droplets are free to stand laterally at least in a direction along the gap between the clamping plate and the base plate. The substrate holding device according to this embodiment may be easier to manufacture because the position or positioning of the droplets does not interfere with the position or positioning of the support.

Preferably, the PCM exhibits greater cohesion than bonding to the gap-facing surfaces of the clamping plate and/or base plate. This enables the accommodation of flattened PCM droplets within the gap, particularly in the indentations or cavities of the gap, allowing the flattened droplet to shrink or expand as appropriate while maintaining optimal alignment with the clamping plate and base plate. optimal contact while providing the required functionality as a temperature-stable substrate clamping device. The latter functionality is achieved in particular without the disadvantages of the solutions described above.

Furthermore, the array droplets in a liquid phase, a solid phase, or a combination of liquid and solid phases are configured to bridge the gap between the clamping plate and the base plate. Therefore, the droplet is in contact with both the clamping plate and the base plate. This can be configured in particular by a suitable choice of the volume of the individual droplets and/or the width of the gap between the base plate and the clamping plate. The contact between the clamping plate and the droplet provides, on the one hand, a suitable heat conduction from the clamping plate to the droplet of the heat absorbing material, and the contact between the base plate and the droplet, on the other hand, provides a suitable heat conduction from the base plate to the heat absorbing material. Proper heat conduction of small droplets.

When the entire gap between the base plate and the clamping plate will be filled with heat-absorbing material, any expansion or contraction of the heat-absorbing material due to heat absorption will cause an increase or decrease in the pressure in the heat-absorbing material. This situation can cause Changes in dimensions of the substrate clamping device and/or deformation of the clamping plate. This problem has been identified in patent publication US 2014/0017613, which states that, taking into account expansion, it is desirable to advance the external dimensions of the heat storage structure in a state in which the heat I does not absorb compared to the clamping unit The inner diameter is small. However, making the thermal storage structure small The inner diameter of the clamping unit has a notable disadvantage: the thermal storage structure is not configured to be in direct contact with the substrate, as shown in US 2014/0017613. Additional means need to be provided to move the heat generated in the substrate to the thermal storage structure. US 2014/0017613 teaches the use of a liquid, such as water, that completely fills the gap between substrate and substrate. The present invention provides a completely different solution to this problem by using an array of droplets of heat absorbing material, the array droplets being configured to be spaced apart from the support and from other droplets in the array, and wherein the array droplets The droplets are configured to contact the base plate and the clamping plate, preferably wherein the droplets are squeezed, wedged or retained between the base plate and the clamping plate.

It should be noted that when filling a PCM container with a less heat absorbing material as proposed by US 2014/0017613, ie a cavity configured to accommodate PCM in a clamping device as described for example in US 7,528,349, the empty space The cavity will only be partially filled and will not be filled to the clamping plate. This provides room for expansion of the heat absorbing material in the cavity, but it will also deprive the heat absorbing material of direct contact with the clamping plate, contrary to the invention as defined in claim 1.

In one embodiment, the droplets are configured to enable substantial free expansion of the droplets in a direction along the gap between the base plate and the clamping plate. The assembly of substantially individual droplets allows each droplet to expand or contract in a direction along the gap, generally without providing an increase or decrease in the pressure of the droplets on the clamping plate or base plate.

In one embodiment, the array of supports is fixedly attached to the second side of the clamping plate. By attaching the array of supports to the second side of the clamping plate, the supports are configured in a generally fixed position on the clamping plate. This allows the supports to be configured in a suitable pattern to provide rigid support to the clamping plate that is generally uniform over the area of the clamping plate. Additionally, this allows to provide a gap between the base plate and the clamping plate with highly precise and reproducible dimensions.

Alternatively or additionally, in one embodiment, one of the array supports is fixedly attached to the base plate. In one embodiment, the base plate is provided with an array of holes, and wherein each support member of the array supports at least partially extends into one of the array holes, preferably wherein the support members are connected by The circumferential gap between the hole and the supporting member extending into the hole is provided with glue connection and is fixedly arranged in the holes. By providing glue between the inner wall of the hole and the circumferential outer wall of the support, any shrinkage or expansion of the glue during its hardening results in action in a direction generally perpendicular to the width of the gap between the base plate and the clamping plate. force. Therefore, these forces do not substantially affect or change the distance between the base plate and the clamping plate, especially during the hardening or setting of the glue. The substrate clamping device according to this embodiment can therefore be configured with respect to the width of the gap between the substrate plate and the clamping plate, and also with respect to the overall thickness of the substrate clamping device, especially in a direction perpendicular to the first side of the clamping plate. The thickness is manufactured with high precision.

In one embodiment, the substrate clamping device further includes an array ring disposed in a gap between the clamping plate and the substrate plate, and wherein each of the array rings is configured to surround the array droplet One of the droplets. Each of the rings may serve as a mold for a droplet of the array of droplets of heat absorbing material, with the droplets being disposed inside the ring.

In one embodiment, the thickness of the rings is less than the width of the gap between the clamping plate and the base plate. Preferably, the dimensions and/or materials of the rings are selected such that the thickness of the rings remains smaller than the width of the gap, regardless of any expansion of the rings due to temperature changes, particularly within the operating temperature range of the substrate holding device. shrink. The ring is not in contact between the base plate and the clamping plate, and therefore the ring exerts no substantial force to the clamping plate and the base plate. Therefore, the ring has no effect on the width of the gap.

When using such a ring as a mold for the droplets, the droplets are also made thinner than the width of the gap between the clamping plate and the base plate in the first case, and these droplets are subsequently "solidified" into solid. Such solid droplets of heat absorbing material can be easily handled and positioned between the substrate plate and the clamping plate during fabrication of the substrate clamping device. When the clamping plate is disposed on top of the base plate with the array of supports and the array of solid droplets in between, the droplets of heat absorbing material melt to create liquid droplets that contact both the base plate and the clamping plate. In addition, the droplets shrink in the direction along the gap, thereby providing space to enable expansion of the droplets in the direction along the gap between the base plate and the clamping plate. Subsequently, the droplet in contact with both the base plate and the clamping plate solidifies again. These solidified droplets provide a means for absorbing heat from the clamping plate and/or the base plate.

Preferably, the droplets comprise a material having a high surface tension relative to the surface of the clamping plate and/or the base plate facing the gap between the base plate and the clamping plate. The use of heat-absorbing materials with high surface tension advantageously promotes contact between the base plate and the clamping plate through liquid droplets.

Additionally or alternatively, the ring provides a means for fixing the position of the droplet in the gap between the base plate and the clamping plate.

Preferably, the ring is made of flexible or elastic material. The ring of this embodiment also promotes the expansion of the droplets in the direction along the gap between the base plate and the clamping plate.

In one embodiment, the base plate and/or the clamping plate is provided with an array of pockets, wherein the width of the gap between the clamping plate and the base plate at a pocket in the array of pockets is greater than the width of the pocket. The width of the surrounding gap between the clamping plate and the base plate, and wherein each pocket in the array pocket is configured to clamp one of the droplets in the array. It should be noted that each pocket portion may also be provided with an indentation or depression, especially a shallow indentation or depression. The pocket is disposed in a surface of the base plate facing the gap and/or a surface of the clamping plate facing the gap. Preferably, the depth of the pockets is smaller than the height of the droplets. The pocket provides a means for fixing the position of the droplet in the gap between the base plate and the clamping plate, especially if the use of a ring is not required. Because no rings or other members are required to substantially fix the position of the droplets, the droplets can be configured closer together, This provides better coverage of the heat absorbing material on the area at the second side of the clamping plate.

In one embodiment, at least one pocket in the array of pockets is generally shaped as a cone, a conical cone, a truncated sphere, or a spherical cone. Preferably, the bag is shaped such that the width of the gap at or near the circumferential edge of the bag is smaller than the width of the gap at or near the center of the bag. In this case, the shape of the pocket helps to generally keep the droplet in place, especially when the PCM exhibits greater cohesion than the bond to the gap-facing surfaces of the clamping plate and/or base plate. .

In one embodiment, a surface of the base plate facing the gap includes an array of pockets, wherein each pocket of the array of pockets includes an elastic member that spans the pocket and is configured to engage with the pocket. The bottom surface is spaced apart and wherein each pocket contains a droplet from the array of droplets, wherein the droplet is disposed between the elastic member and the clamping plate. The elastic member provides means for absorbing any residual expansion in a direction generally perpendicular to the gap by curvature of the elastic member towards the bottom surface of the bag. Additionally, the elastic member may help propel the droplet toward the cover plate to ensure and provide stable contact between the droplet and the cover plate. Preferably, the elasticity of the elastic member is selected so that the spring force provided by the curved elastic member does not substantially cause local deformation of the clamping plate.

In one embodiment, the distance between the elastic component and the clamping plate is greater than the distance between the clamping plate and a surface of the base plate adjacent to the pockets. Therefore, the elastic member is arranged inside the corresponding bag portion. In one aspect, the elastic member is configured to be spaced apart from the bottom surface of the bag to allow the elastic member to flex toward the bottom surface of the bag. On the other hand, the elastic member is arranged below the surface of the base plate surrounding the bag portion, which provides a means for fixing the position of the droplet in the gap between the base plate and the clamping plate.

In one embodiment, the elastic member includes a cover, preferably a cover plate. because Here, the covering or covering plate covers the bottom surface of the bag, and preferably separates the portion of the bag between the covering or covering plate and the bottom surface of the bag from the portion of the bag above the covering or covering plate. In one embodiment, the cover or cover plate is substantially flat. This flat cover or cover panel can be easily produced by cutting the cover or cover panel from a large piece of suitable material. In an alternative embodiment, the cover or cover plate is non-flat, and is preferably shaped as a cone, a conical cone, a truncated sphere, or a spherical cone. This non-flat cover panel provides the same benefits as described above with reference to the tapered pocket, in addition to taking advantage of any residual expansion in a direction generally perpendicular to the gap by the cover or curvature of the cover panel towards the bottom surface of the pocket. same advantages. In one embodiment, the cover or cover plate is shaped as a cup with a circumferential flange placed at least partially in contact with the base plate for supporting the cup-shaped cover or cover plate.

In one embodiment, each pocket includes a support element for supporting in the pocket at least part of the edge of the elastic member, preferably the circumferential edge of the covering or covering plate. Therefore, the support element is configured for supporting at least part of the edge of the elastic member, which allows the central portion of the elastic member to bend towards the bottom surface of the bag. Preferably, the droplet of PCM is disposed substantially centrally on top of the elastic member.

In one embodiment, the support element includes a rim or step disposed in the circumferential side wall of the pocket. A rim or step preferably extending circumferentially around the pocket may be achieved by first fabricating a first pocket portion having a first diameter in the base plate to a first predetermined depth, and then placing the first pocket portion in the base plate. It is relatively easy to manufacture a second pocket portion having a second diameter less than the first diameter substantially centrally to a second predetermined depth. Alternatively, it may be achieved by first manufacturing a pocket portion with a second diameter to a predetermined depth of the pocket, and then inserting a rotary cutter into the first pocket portion up to the level of the rim or step, and surrounding the first pocket pocket portion and cyclically driving the rotary cutter in an outward direction up to a first diameter for cutting the base plate surrounding the first pocket portion The material is milled away while maintaining a constant level or depth to create the rim or step. This results in a rim or step arranged at the predetermined depth. By using an elastic member with a diameter smaller than the first diameter but larger than the second diameter, the edge of the elastic member rests on top of the rim or step.

In one embodiment, each pocket portion includes a ring or hoop disposed in the gap between the clamping plate and the elastic cover plate, and wherein the ring or hoop is configured to surround a droplet in the pocket. A ring or hoop is disposed in the pocket, preferably on top of the elastic cover plate, and acts as a confinement member for droplets of PCM in the pocket.

In one embodiment, the thickness of the ring or hoop is less than the distance between the clamping plate and the elastic cover plate. Preferably, the dimensions and/or material of the ring or hoop are selected such that the thickness of the ring or hoop remains smaller than the width between the elastic cover plate and the clamping plate, regardless of the thickness due to the substrate clamping device in particular. Any expansion or contraction of the ring or loops due to changes in temperature within the operating temperature range. The ring or hoop is in contact with only one of the cover plate and the clamping plate.

In one embodiment, the ring or hoop is made of a flexible or elastic material. The ring or hoop of this embodiment also promotes the expansion of the PCM droplets inside the ring or hoop, especially in the direction along the gap between the base plate and the clamping plate.

In one embodiment, the ring or hoop includes a generally rectangular cross-section. In particular, the ring or hoop includes a rectangular cross-section in a direction generally perpendicular to the first side of the clamping plate. Preferably, the ring or hoop includes a substantially planar upper surface, wherein the substantially planar upper surface is configured to face the second side of the clamping plate. This embodiment is particularly advantageous in situations where the density of the liquid PCM is higher than the density of the material of the ring or hoop. In this case, the ring or hoop will "float" in the PCM material while it is in the liquid state, which will push the ring or hoop towards the second side of the clamping plate and will allow for flattening of the ring or hoop. The upper surface abuts the second side of the clamping plate and provides restraint to the PCM.

In one embodiment, the base plate is provided with vents that flow out in the bottom surface of the pockets, and preferably generally in the center of the pockets. Due to the vents, the pressure inside the pocket portion between the bottom surface and the elastic cover panel is substantially unmodified by the bending of the elastic cover panel.

In one embodiment for use in a substrate processing instrument or a substrate imaging instrument, the droplets in the array of droplets comprise a temperature that is present in the substrate processing instrument at least during processing of the substrate, or the substrate imaging instrument at least Materials with a melting temperature or melting range at or near the temperature during imaging of the substrate. Preferably, the droplets in the array of droplets comprise material having a melting temperature or melting range at or near the operating temperature of the industrial coolant. Preferably, in use, the temperature of the substrate processing instrument is close to or slightly above the operating temperature of the industrial coolant, preferably at or slightly below room temperature, preferably at or slightly below room temperature. At or slightly below 18 degrees Celsius. Therefore, the machine part of the substrate processing apparatus or the substrate imaging apparatus does not need to rise in temperature, and the industrial coolant can be easily applied or used by the substrate processing apparatus or the substrate imaging apparatus including the substrate clamping device according to the present invention. in the substrate processing instrument or the substrate imaging instrument.

In one embodiment, the gap includes an open connection to the outside of the substrate holding device. The air pressure or vacuum pressure inside the gap is substantially equal to the air pressure or vacuum pressure outside the substrate holding device. In one embodiment, the gap is generally open along a peripheral side edge of the substrate clamping device, preferably the gap is generally open along a substantially complete peripheral side edge of the substrate clamping device.

According to a second aspect, the present invention provides a substrate clamping device. The substrate clamping device includes: a clamping plate, wherein the clamping plate includes a first side for clamping the substrate, a base plate disposed at a distance from the clamping plate and providing a gap between the base plate and the clamping plate at a second side of the clamping plate facing away from the first side, an array support, The supports are at least disposed between the clamping plate and the base plate, and an array of droplets of heat absorbing material is disposed between the clamping plate and the base plate, wherein the droplets constrained by the clamping plate and the base plate in a direction substantially perpendicular to the first side of the clamping plate, and wherein the droplets are configured to enable the droplets to move at least along the base plate and expansion in the direction of the gap between the clamping plates.

An array of droplets, preferably containing liquid and/or solid droplets, is generally confined between the clamping plate and the base plate. Therefore, the droplet is in contact with both the clamping plate and the base plate. This can be configured in particular by a suitable choice of the volume of the individual droplets and/or the width of the gap between the base plate and the clamping plate. The contact between the clamping plate and the droplet provides, on the one hand, a suitable heat conduction from the clamping plate to the droplet of the heat absorbing material, and the contact between the base plate and the droplet, on the other hand, provides a suitable heat conduction from the base plate to the heat absorbing material. Proper heat conduction of small droplets.

According to a third aspect, the invention provides an apparatus for processing or imaging a sample, wherein the apparatus includes a source for electromagnetic radiation or particles having energy, an exposure unit for exposing the sample to the Electromagnetic radiation or particles having energy, and a substrate holding device as described above, or embodiments thereof, for holding the sample at least during the exposure.

In one embodiment, the exposure unit comprises a component for at least partially and/or temporarily manipulating and/or blocking at least part of electromagnetic radiation or charged particles, wherein the component has Conduits for directing cooling fluid through the conduits, wherein the conduits are configured to be in thermal contact with the component. Accordingly, the cooling fluid in the conduit is configured for removing heat generated by at least part of the electromagnetic radiation or charged particles by the partial and/or temporary manipulation and/or blocking of the component. Such components include, for example, diaphragms, electrostatic beam deflectors, or electrostatic or magnetic lens systems.

Typically, the exposure unit is arranged at a side of the substrate facing away from the substrate clamping device. When the exposure unit contains one or more components for at least partially and/or temporarily manipulating and/or blocking at least part of electromagnetic radiation or charged particles, the components heat up in use. For example, when at least part of the electromagnetic radiation or charged particles impinges on the component. In addition to the heat generated by electromagnetic radiation or charged particles impinging in the substrate during exposure, radiant heat from one or more components of the exposure unit can further heat the substrate, especially when one or more components are configured in close proximity to on the surface of the substrate. This extra heat from the exposure unit will also be absorbed by the heat absorbing material in the substrate clamping device of the present invention, which results in a faster depletion of the heat absorbing material, especially when the heat absorbing material is PCM. Therefore, it is advantageous to reduce as much excess heat from the exposure unit as possible and to combine the substrate clamping device of the present invention with an exposure unit having a cooling arrangement for cooling the at least one component of the exposure unit.

In one embodiment, the projection lens system is configured for use in a multi-beam charged particle lithography system, wherein at least a first portion of the conduit is disposed in a region between two charged particle beams, and wherein the conduit The central axis of the first portion extends in a direction substantially perpendicular to the central axis or optical axis of the exposure unit. Therefore, the first portion of the conduit is configured close to the area where the charged particle beam travels through the projection lens system in use, which allows any heat generated to be effectively removed from this area.

In one embodiment, at least a second portion of the conduit is configured to extend such that a central axis of the second portion of the conduit is substantially parallel to a central axis of the exposure unit or light extends in the direction of the learning axis. Thus, the first portion of the conduit may be arranged at or near a first end of the exposure unit facing the substrate in use. The second portion of the conduit provides an extension of the conduit away from the first end of the exposure unit, which allows for provision of input connections and/or output connections for fluid suitably spaced apart from the first end, and configuring the first end of the exposure unit Very close to the substrate. In one embodiment, the assembly includes a projection lens system disposed at the first end of the exposure unit.

According to a fourth aspect, the invention relates to a projection lens system for use in an exposure unit for exposing a substrate with electromagnetic radiation or charged particles having energy, wherein the projection lens system includes means for at least partially and /or a component that temporarily manipulates and/or blocks at least part of electromagnetic radiation or charged particles, wherein the component is provided with conduits for directing cooling fluid therethrough, wherein the conduits are configured to be in thermal contact with the component In contact.

The projection lens system thus provides a temperature controlled exposure unit for use in, for example, a temperature stabilized lithography system. The projection lens is effectively cooled to a temperature range that is preferably within the normal manufacturing temperature range in order to have the lithography system in a stable and internally consistent, i.e., equilibrium thermal state, thereby on the one hand avoiding the need for instrument design complexity and energy saving, and on the other hand promote optimal exposure conditions, as is highly required for ultimate precision in exposure and within contemporary lithography.

In one embodiment, the projection lens system is configured for use in a multi-beam charged particle lithography system, wherein at least a first portion of the conduit is disposed in a region between two charged particle beams, wherein the conduit The central axis of the first portion extends in a direction generally perpendicular to the central axis or optical axis of the projection lens system.

In one embodiment, at least a second portion of the conduit is configured to extend such that a central axis of the second portion of the conduit is substantially parallel to a central axis of the projection lens system or extending in the direction of the optical axis.

According to a fifth aspect, the present invention provides a method for manufacturing a substrate clamping device. The substrate clamping device includes: a clamping plate, wherein the clamping plate includes a first side for clamping a substrate; a base plate , which is arranged at a distance from the clamping plate and provides a gap between the base plate and the clamping plate at the second side of the clamping plate away from the first side; an array support member, The support member is at least disposed between the clamping plate and the base plate; and an array droplet of heat absorbing material, wherein the method includes the following steps: spacing the support member and other droplets in the array droplet Separate droplets are disposed between the clamping plate and the base plate, wherein the droplets are configured, at least in their liquid phase, to contact both the clamping plate and the base plate, and/or wherein the droplets Droplets are restrained by the clamping plate and the base plate in a direction substantially perpendicular to the first side of the clamping plate, and wherein the droplets are configured such that the droplets can be directed along the base plate and expansion in the direction of the gap between the clamping plates.

According to a sixth aspect, the invention relates to a method for assembling a substrate clamping device, wherein the method includes the steps of: providing a clamping plate, wherein the clamping plate includes a first side for clamping a substrate, and an array of supports secured to a second side of the clamping plate facing away from the first side, wherein the supports are configured to extend generally perpendicular to the second side; a base plate is provided, the base The plate includes an array of holes for mounting the supports in the holes; an array of droplets of heat absorbing material spaced apart from the supports and from other droplets in the array of droplets is placed on the surface One side of the base plate is arranged on the clamping plate, or the side facing the clamping plate is arranged on the base plate; the clamping plate and the base plate having the supports are move towards each other until they have reached to a desired distance between the clamping plate and the base plate, wherein the supports are positioned in the holes and the array droplets are disposed in the gap between the clamping plate and the base plate; and One or more of the supporting members are fixed in the corresponding holes.

In an embodiment, the support is fixed to the second side via a glue connection. In one embodiment, one or more supports are fixed in corresponding holes via glue connections provided in the circumferential gap between the holes and the supports extending into the holes.

According to a seventh aspect, the present invention relates to the substrate holding device as described above in an instrument for processing or imaging a sample, preferably a lithography system, more preferably a charged particle beam lithography system. , such as for use in multi-beam charged particle lithography systems.

In one embodiment, an apparatus for processing or imaging a sample includes a source for electromagnetic radiation or particles having energy, and an exposure unit for exposing the sample to the electromagnetic radiation or charged particles having energy, wherein the exposure unit includes a component for at least partially and/or temporarily manipulating and/or blocking at least part of electromagnetic radiation or charged particles, wherein the component is provided with a conduit for guiding cooling fluid through the conduit, wherein the component The conduit is configured to be in thermal contact with the component.

According to an eighth aspect, the present invention provides an apparatus for exposing a sample, wherein the apparatus includes a source for electromagnetic radiation or particles having energy, and an exposure unit for exposing the sample to the electromagnetic radiation. or particles, wherein the exposure unit includes a component for at least partially and/or temporarily manipulating and/or blocking at least part of the electromagnetic radiation or charged particles, wherein the component includes a cooling arrangement configured to for maintaining the assembly substantially at a predetermined first temperature, and a substrate clamping device for clamping the sample at least during the exposure, wherein the substrate The clamping device includes a temperature stabilizing configuration configured to substantially stabilize the temperature of a sample disposed on the substrate clamping device, wherein the temperature stabilizing configuration includes a phase change having a phase change at a second temperature Material, wherein the cooling arrangement includes a control device configured to adjust the first temperature to be near or equal to the second temperature.

Because the exposure unit is configured to expose the sample using electromagnetic radiation or particles having energy, the exposure unit and/or the sample will absorb at least a portion of the energy and will increase in temperature of the sample on the exposure unit and/or substrate holding device . It should be noted that typically, the sample is arranged at a distance from the exposure unit such that possible heating of the exposure unit has a negligible or substantially no effect on the sample, and any cooling of the exposure unit may be independent of cooling of the sample. In particular, the cooling configuration for the exposure unit as described in Applicant's WO 2013/171216 is optimized to provide an optimal temperature for the exposure unit without taking into account the impact of this optimal temperature on the sample.

The inventors have recognized that it would be advantageous to provide both the substrate holding device and the exposure unit with arrangements for controlling their temperatures, particularly for systems in which the exposure unit is configured close to the sample, and based on the stability of the temperature of the substrate holding device The temperature of the cooling arrangement of the exposure unit (the second temperature) is used to control the temperature of the cooling arrangement of the exposure unit (the first temperature). By providing both the exposure unit and the substrate holding device with their own cooling arrangements and temperature stabilization arrangements, precise temperature control of the substrate is obtained that allows exposure of the substrate by such electromagnetic radiation or particles During this period, the temperature of the substrate is at least substantially maintained at the second temperature.

The present invention proposes a concept for defining an exposure process and an instrument for this exposure process, which concept is adapted to the constraints of the practical environment. Specifically, in an instrument in which an exposure unit for projecting electromagnetic radiation or particles onto the substrate is disposed in close proximity to the substrate, the exposure unit The temperature of the element can thermally affect the substrate. By controlling the temperature of the exposure unit, for example using a cooling arrangement, negative effects of the temperature of the exposure unit on the substrate can be substantially prevented.

On further consideration, any such modulation should moreover be maintained with minimum effort for the method or process to be obtained in the most economical manner. On the one hand, in an economical exposure apparatus or method, the operating temperature should not be at such a level that in fact the entire surrounding of the wafer carrier should be maintained at an elevated temperature of 29,8°C, as will be recommended for gallium Condition of use. The melting temperature of the phase change material used in the substrate holding device should be at a relatively low level.

On the other hand, the operating temperature should not be substantially higher than 18°C for the following reasons: when depending on which coolant should be at a lower, preferably only slightly lower temperature compared to the operating temperature, at least during the exposure The temperature maintained at the target is a further consideration when integrating into the present invention. In this way, standard fab coolant can be used in the process directly or only with moderate conditioning. Considering that the manufacturer's coolant usually ranges from 12°C to 18°C, and the deviation should be the smallest, the manufacturer's ambient temperature can usually be the indoor temperature, that is, not exceeding 25°C, preferably not exceeding 22°C, equal to the second temperature The melting temperature of the phase change material will be defined according to one embodiment of the invention, and therefore the selected material will be defined according to the target exposure process to have a manufacturing coolant temperature above 18°C, preferably above 18,5 ℃, and below the maximum indoor temperature of 25℃, preferably below the operating temperature of 22,5℃.

It should be noted that operating temperatures as referred to in this application are the temperatures of the instrument used to expose the sample during operation.

In an embodiment, the cooling arrangement and the temperature stabilization arrangement are configured such that the difference between the first temperature and the second temperature does not exceed 4°C, preferably does not exceed 2°C. This provides a generally thermally stable environment for the sample. By actively controlling the cooling configuration and by selecting the correct phase change material, the components of the exposure unit and substrate holding device are configured to substantially maintain the first phase, respectively. a temperature and the second temperature, and thus maintain the thermally stable environment during exposure of the sample.

In one embodiment, the first temperature is lower than the second temperature. Thus, in use, the temperature of the exposure unit, at least its components, is lower than the temperature of the substrate holding device and the temperature of the sample on top of the holding device. This measure substantially prevents any heating of the sample by the components of the exposure unit, even when the components of the exposure unit for projecting electromagnetic radiation or particles onto the substrate are arranged in close proximity to the sample.

In a preferred embodiment, the first temperature is substantially equal to the second temperature. In one embodiment, the first temperature and the second temperature are substantially equal to the indoor temperature, specifically equal to the indoor temperature in the manufacturing plant (Fab).

In one embodiment, the phase change material includes a metal, alloy, or metal-based material. In a preferred embodiment, the phase change material includes a eutectic metal alloy. Metal-based phase change materials provide high thermal conductivity in both the solid and liquid phases, which ensures that the heat generated by exposure of the sample is directed to the phase even when a significant portion of the phase change material has liquefied. phase change material and absorbed by the phase change material.

In one embodiment, the cooling arrangement includes conduits for directing cooling fluid therethrough, wherein the conduits are configured to be in thermal contact with the component. Therefore, standard fab coolants such as cooling water can be used to cool at least the components of the exposure unit.

In one embodiment, the cooling arrangement is configured such that the difference between the temperature of the cooling fluid and the second temperature does not exceed 4°C, preferably does not exceed 2°C. In one embodiment, the cooling arrangement includes a temperature control system configured to control the temperature of the cooling fluid relative to the temperature of the substrate holding device. In one embodiment, the instrument includes a temperature sensor for measuring the temperature of the substrate clamping device and/or the exposure unit, specifically the temperature of a portion of the exposure unit disposed adjacent to the substrate clamping device. detector. In one embodiment, the cooling device The device includes cooling means for cooling the cooling fluid to a temperature lower than the first temperature, and heating means for heating the cooling fluid, wherein the heating means is arranged in the conduit at an upstream position relative to the assembly. Specifically, a temperature sensor for measuring the temperature of a portion of the exposure unit facing the substrate clamping device, a combined cooling device and a heating device for accurately controlling the temperature of the cooling fluid, and a temperature sensor based on the temperature of the cooling fluid. The combination of a temperature control system that controls the temperature of the cooling fluid using a signal from a temperature sensor allows controlling the temperature of the exposure device with high precision and aligning the substrate clamping device with the exposure unit, specifically the exposure unit facing the substrate clamping device The temperature difference between the parts is adjusted to less than 4°C, preferably less than 2°C, and more preferably less than 1°C.

In one embodiment, the component includes a projection lens for projecting electromagnetic radiation or particles onto the sample. In an embodiment in which the cooling arrangement includes conduits for directing cooling fluid therethrough and wherein the conduits are configured to be in thermal contact with the component, the conduits are configured for delivering cooling through or around the projection lens fluid. Specifically, in projection lenses for charged particles, the lens effect is established by the need to generate magnetic and/or electrostatic fields. In use, the magnetic and/or electrostatic lenses also generate heat that can be removed using cooling arrangements according to this embodiment.

In one embodiment, the assembly includes modulation means for modulating electromagnetic radiation or particles. In an embodiment in which the cooling arrangement includes conduits for directing cooling fluid therethrough and wherein the conduits are configured to be in thermal contact with the components, the conduits are configured for delivery through or around the modulation device cooling fluid. In use, the modulating device also generates heat that can be removed using a cooling arrangement according to this embodiment.

In one embodiment, the modulation device includes a beam quenching assembly including a beam deflector for deflecting the beam of electromagnetic radiation or particles and a beam terminator for blocking the beam of electromagnetic radiation or particles. , wherein the conduits are configured for passing through or around the bundle terminator Deliver this cooling fluid. When a beam of electromagnetic radiation or particles is directed to a beam terminator, the electromagnetic radiation or particles are absorbed to a great extent by the beam terminator. In use, absorption of electromagnetic radiation by particles also generates heat in the beam terminator that can be removed using a cooling arrangement according to this embodiment.

In one embodiment, the source is a source for charged particles and the exposure unit includes a charged particle optical system for projecting one or more charged particle beams onto the sample. In one embodiment, the source is configured to provide a plurality of charged particle beams, and wherein the charged particle optical system is configured for projecting one or more of the plurality of charged particle beams onto the sample, wherein at least a first portion of the conduits is disposed in a region between two charged particle beams.

In one embodiment, the exposure unit includes one or more temperature sensors, preferably one of the one or more temperature sensors is disposed on a side of the exposure unit facing the substrate clamping device .

According to a ninth aspect, the present invention provides a method for processing or imaging a sample using an instrument or embodiment as described above, wherein modulation of a temperature stable configuration is performed prior to the processing or imaging of the sample, wherein The modulation includes the step of curing at least a portion of the phase change material in the temperature stable configuration. When the phase change material absorbs heat, part of the phase change material liquefies or melts; the phase of the phase change material changes from solid to liquid. This absorbed heat may be removed from the phase change material during a modulation process in which the heat exchange material solidifies or solidifies; causing the phase change material to change its phase from a liquid back to a solid. After this modulation, the solid phase change material can again be used to absorb heat.

In one embodiment, the conditioning further comprises the step of setting the temperature of the temperature stabilizing arrangement at the second temperature prior to the processing or imaging of the sample. The second temperature is the melting temperature of the phase change material, and thus the temperature at which the phase of the phase change material changes from solid to liquid. The phase change material will be at this second temperature when both the solid and liquid phases of the phase change material are present and in thermal equilibrium. Therefore, to ensure that at least a small amount of the phase change material is in the liquid phase and the majority of the phase change material is in the solid phase, the temperature stabilizing arrangement is at the second temperature and is ready to absorb any heat induced by the exposure process.

In one embodiment, the heating device and/or the cooling device are controlled to establish a temperature difference between the substrate clamping device and the exposure unit, in particular the exposed portion facing the substrate clamping device, the temperature difference being less than 4 °C, preferably less than 2°C, more preferably less than 1°C.

In one embodiment, the temperature of the instrument during operation is within a temperature range from 19°C to 22°C, preferably wherein the first temperature and the second temperature are also configured within a temperature range from 19°C to 22°C.

According to a tenth aspect, the present invention provides the use of an apparatus or embodiment as described above for processing or imaging a sample.

According to an eleventh aspect, the present invention provides a method of manufacturing a semiconductor device by means of an apparatus as described above, the method comprising the following steps: - placing a wafer on the substrate holding device and placing the wafer positioned downstream of the exposure unit; - processing the wafer, including projecting an image or pattern onto the wafer by means of the electromagnetic radiation or particles having energy from the source; and - performing subsequent steps in order to use the wafer by means of the electromagnetic radiation or particles having energy from the source The wafers are processed to produce semiconductor devices.

According to a twelfth aspect, the invention provides a method for inspecting a target by means of an instrument as hereinbefore described, the method comprising the steps of: - placing the target on the substrate holding device and placing the wafer positioned downstream of the exposure unit; - projecting the electromagnetic radiation or particles with energy from the source onto the target; - when the electromagnetic radiation or particles with energy from the source are incident on the target detect electromagnetic radiation or charged particles transmitted, emitted and/or reflected by the target; and - performing subsequent steps for examining the target with the aid of data from the step of detecting charged particles.

The embodiments mentioned above with respect to the first aspect may also be suitably applied to the present invention according to other aspects.

Whenever possible, the various aspects and features described and illustrated in the specification can be applied individually. Such individual aspects, in particular the aspects and features described in the attached dependent claims, may be the subject of separate patent applications.

1:Substrate clamping device

1’:Substrate clamping device

1”:Substrate clamping device

2: Clamping plate

2’: Clamping plate

2”: Clamping plate

3: First side

4: Base plate

4’: base plate

4”: base plate

5: Gap

5’: Gap

5”: Gap

6: Second side

7:Support

8:Drip

9: Bag part

9’: Bag part

11: Substrate clamping device

12: Clamping plate

14: Base plate

17:Support

18: Xiaodi

19: Bag Department

21:Substrate clamping device

22: Clamping plate

23: Clamping plate

24: Base plate

25: Gap

27:Support

28:little drop

29: Bag Department

31: Substrate clamping device

31’:Substrate clamping device

32: Clamping plate

32’: clamping plate

33: First side

34: Base plate

34’: base plate

35: Gap

35’: Gap

36: Second side

36’: Second side

37:Support

37’: Support piece

38: Xiaodi

38’: small drop

39:O ring

39’:O ring

41:hole

51:Substrate clamping device

52: Clamping plate

53: First side

54: Base plate

55: Gap

56: Second side

57:Support

58:little drop

59: Bag Department

60: Elastic covering board

61:Stairs

62: Circle

63:Surface

71:Glue connection

91: Conical edge

92: Bag part

101: Charged particle beam source

102: Beam collimation system

103:Aperture array

104: Condenser lens array

105: Beam extinguishing device array

108: Beam terminator array

109: Beam deflector array

110: Projection lens array

130:wafer

141:hole

142:Exhaust hole

150: Schematic flow chart

151: Steps

152: Steps

153: Steps

160: Schematic flow chart

161: Steps

162: Steps

163: Steps

164:Step

200: Lithography equipment

201:Lighting optical module

202: Condenser lens module

203:Beam conversion module

204:Projection optical module

205: Align the inner subframe

206: Align the outer subframe

207:Vibration damping frame

208:Frame

209:Substrate clamping device

209’: first side

210:Chuck

211:Short stroke stage

212: Long stroke stage

215: Amcor iron (μ metal) shielding layer

220: Base plate

221:Frame parts

230: Vacuum chamber

250: Measuring device

251:Mirror

252:Beam

300:Improved projection lens assembly

301: first electrode

302: Second electrode

303:First end

304: Input connection

305: Output connection

306: The second part of the catheter

307: The first part of the catheter

308: Beam terminator array

309:Catheter

310: Surrounding side edges

313: Through opening

330: Electrically conductive circumferential wall

340:Support element

341:hole

341’:hole

370:Target

400: Projection lens assembly

401: first electrode

402: Second electrode

403:First end

404:Catheter

405:Catheter

406:Catheter

406’:Conduit

408: Beam terminator array

409:Catheter

410: Covering components

413: Through opening

430: Electrically conductive circumferential wall

440:Support element

450: Cooling device

451:Heat exchange circuit

470:Heating device

480:Substrate clamping device

481: Clamping plate

482: Base plate

483: Phase change materials

490: Temperature control system

541:hole

542:Exhaust hole

591: Bottom surface

592: Upper pocket part

593:Lower pocket part

A-A: Line

OA: central axis/optical axis

d:Thickness

d1:Thickness

d2:Thickness

h: same degree

w:width

w’:width

s: distance

T1: first temperature sensor

T2: Second temperature sensor

T3: first temperature sensor

T4: The fourth temperature sensor

The invention will be described based on an exemplary embodiment shown in the accompanying drawings, in which: Figure 1 is a schematic top view of a substrate clamping device; Figure 2 is a schematic partial cross-section along line A-A in Figure 1 Cross-section; Figures 3A, 3B and 3C schematically illustrate steps of a method for manufacturing a substrate clamping device; Figures 4A and 4B are second and third exemplary embodiments of the substrate clamping device FIG. 5 is a schematic partial cross-section of the fourth exemplary embodiment of the substrate clamping device; FIG. 6 is a schematic partial top view of the substrate plate of the substrate clamping device of FIG. 5 ; FIG. 7 is a schematic partial cross-section of the fourth exemplary embodiment of the substrate clamping device; A schematic partial cross-section of the fifth exemplary embodiment of the substrate clamping device; Figure 8 is a schematic partial cross-section of the sixth exemplary embodiment of the substrate clamping device; Figures 9A, 9B and 9C schematically Showing the steps of an alternative method for manufacturing a substrate clamping device according to the sixth embodiment as shown in Figure 8; Figure 10 is a schematic partial cross-section of a seventh exemplary embodiment of a substrate holding device; Figure 11 schematically shows an instrument for processing or imaging a sample, wherein the instrument includes a substrate holding device of the present invention; Figure 12 schematically shows a cross-section of an embodiment of a projection lens system assembly for use in an apparatus as schematically shown in FIG. 11 ; FIG. 13 schematically shows a projection lens system assembly as schematically shown in FIG. The cooling device used in the projection lens system in Figure 12; Figure 14 schematically shows a part of the apparatus including: the projection lens system including a cooling arrangement; and a substrate clamping device including a temperature stabilizing arrangement, Figure 15 An exemplary process for manufacturing a semiconductor device is illustrated, and FIG. 16 illustrates an exemplary process for inspecting a target.

FIG. 1 shows a top view of a first example of a substrate clamping device according to the invention, and FIG. 2 shows a partial cross-section of the first example along line A-A in FIG. 1 . The substrate clamping device 1 includes a clamping plate 2 having a first side 3 for clamping a substrate (not shown). The substrate clamping device 1 further includes a base plate 4 arranged at a distance from the clamping plate 2 and at a second side 6 of the clamping plate 2 facing away from the first side 3 . Between the base plate 4 and the clamping plate 2 a gap 5 is provided, which gap extends in a direction substantially parallel to the first side 3 of the clamping plate 2 . An array of supports 7 is arranged between the clamping plate 2 and the base plate 4 , these supports define the distance between the clamping plate 2 and the base plate 4 and therefore define the width w of the gap 5 . The clamping plate 2 , the base plate 4 and the support 7 provide a framework for providing heat absorbing material in the gap 5 which in use is configured for self-arrangement on the first side of the substrate clamping device 1 3 on the substrate to remove heat.

The clamping plate 2 includes, for example, a Si plate. The base plate 4 includes, for example, a silicon carbide plate, which carbon The silicone plate has an expansion coefficient that is substantially the same as that of silicon. Additionally, silicon carbide is generally inert and allows the use of a wide range of heat absorbing materials. Furthermore, silicon carbide has a high thermal conductivity that allows cooling of the substrate holding device 1 via the base plate 4 and provides a substantially constant temperature along the base plate 4 .

The supports 7 comprise, for example, titanium supports, which are non-magnetic. Non-magnetic supports are advantageous when the substrate holding device 1 is used in charged particle processing or imaging instruments. Although the support 7 can be clamped between the clamping plate 2 and the base plate 4, it is preferred that the support 7 is fixedly attached to the second side 6 of the clamping plate 2 and/or to the base plate. 4, as will be explained in more detail below with reference to Figures 2, 3A, 3B and 3C.

According to the invention, an array of droplets 8 of heat absorbing material is arranged between the clamping plate 2 and the base plate 4 . Liquid and/or solid droplets 8 are configured to bridge the gap 5 between the base plate 4 and the clamping plate 2 ; thus the droplets 8 are configured to contact both the base plate 4 and the clamping plate 2 . The droplets 8 are arranged to be spaced apart from each other, arranged to be adjacent to each other in the direction along the gap 5 , and arranged to be generally spaced apart from the support 7 . The droplet 8 is limited by the clamping plate 2 and the base plate 4 in a direction substantially perpendicular to the first side 3 of the clamping plate 2 . In addition, the droplets 8 are arranged so as to enable expansion of the droplets 8 in the direction along the gap 5 between the base plate 4 and the clamping plate 2 . As shown schematically in Figure 2, the droplet 8 is arranged in (thermal) contact with the clamping plate 2 and the base plate 4. Preferably, the droplets 8 comprise materials having a melting temperature or melting range at or near the temperature of a substrate processing instrument at least during processing of the substrate, or at or near the temperature of a substrate imaging instrument at least during imaging of the substrate. Material. Heat removal is provided by using phase transformation, especially melting, of droplets 8 . Since the droplets 8 are configured to enable expansion of the droplets 8 in the direction along the gap 5 , the contraction or expansion of the droplets 8 when changing from solid to liquid and vice versa is generally of concern to the clamping plate 2 , the The size of the components of base plate 4 and support 7 has no effect.

The heat absorbing material is preferably arranged in an array of flat droplets 8 with a diameter of approximately 15 mm and a thickness of approximately 0,8 mm. The use of droplets 8 having a diameter of approximately 15 mm allows an array of supports 7 to be provided between the droplets, which supports 7 are arranged close enough to each other to provide a first flat height of the clamping plate 2 Side 3. In this particular example, the support 7 is configured so as to provide a gap 5 with a width w of approximately 0,8 mm.

In this first example, the base plate 4 is provided with an array of pockets 9 configured as shallow indentations or cavities in the surface of the base plate 4 facing the gap 5 . The pocket 9 of this first example is generally shaped as a conical hammer base. For example, the descending slope 91 of the cone may be approximately 15 degrees, and at the center of the pocket 9 a generally flat area is configured. Droplet 8 is configured to contact both base plate 4 and clamping plate 2 . The conical edge 91 of the pocket 9 will generally fix the position of the droplet 8 of heat absorbing material. Additionally, the conical edge 91 of the pocket 9 and the surface tension in the liquid phase of the droplet 8 provide positioning forces to substantially retain the liquid droplet 8 within the pocket 9 . No other parts are needed to fix the position of droplet 8. This allows the droplets 8 in the substrate clamping device 1 of this first example to be arranged closer to each other, which provides suitable coverage of the areas of the substrate plate 4 and the clamping plate 2 with heat absorbing material. The pocket 9 in the substrate clamping device 1 of the first example is shallow due to the substantially flat area in the center of the pocket 9, which reduces the amount of heat absorbing material required.

As shown in FIG. 2 , the base plate 4 is provided with an array of holes 41 , and the first end of each support member 7 in a series of support members is disposed in one of the holes 41 and is fixed to the hole 41 via a glue connection. middle. The second end of each support member 7 opposite the first end is fixed to the clamping plate 2 by means of glue connection.

Figures 3A, 3B and 3C schematically show the steps for assembling the substrate clamping device 1, in particular the substrate clamping device according to the embodiment of Figure 2. And the substrate clamping device according to the embodiment described below with reference to FIGS. 4A, 4B, 5, 7 and 10 can Assemble this way.

First, as shown in Figure 3A, a base plate 4 is provided, which base plate contains an array of pockets 9. Adjacent to the pockets 9, holes 41 are provided for mounting the supports 7 in these holes. In addition, the clamping plate 2 is provided with a series of supports 7 fixed to a second side 6 of the clamping plate 2 facing away from the first side 3 for clamping the substrate at least during use. The support 7 is configured to extend substantially perpendicularly to the second side 6 and is fixed thereto via a glue connection 71 .

Subsequently, droplets 8 of liquid heat absorbing material are arranged in the pocket 9 as shown schematically in Figure 3B. In each pocket 9 of substantially the same size, substantially the same volume of heat absorbing material is dispensed. Preferably, the heat absorbing material exhibits greater cohesion than the adhesion to the surfaces of the clamping plate 2 and/or the base plate 4 facing the gap 5 . Due to surface tension, the liquid droplets 8 assume an almost spherical shape.

Next, the clamping plate 2 with the support 7 is moved towards the base plate 4 and the support 7 is positioned in the hole 41 . The clamping plate 2 moves downward until the desired distance w between the clamping plate 2 and the base plate 4 has been reached. In this position, the droplet 8 is flat between the base plate 4 and the clamping plate 2, as shown in Figure 3C. The surface tension of the heat absorbing material provides and maintains the droplet 8 in contact with both the clamping plate 2 and the base plate 4 .

Subsequently, one or more of the supports 7 is fixed in the corresponding hole 41 via a glue connection provided in the circumferential gap between the hole 41 and the support 7 extending into the hole 41 .

Prior to use, the assembled substrate holding device 1 is configured in a "cold" environment at a temperature below the solidification temperature of the heat-absorbing phase change material, and the liquid droplets 8 will be positioned substantially as shown in Figure 3C The shape solidifies. The solid droplets 8 thus bridge the gap 5 between the base plate 4 and the clamping plate 2 . Now, the substrate holding device 1 is ready for use.

In the previous first example, pockets 9 for holding solid and/or liquid droplets 8 are arranged in the base plate 4, as described above. However, in a second example of the substrate clamping device 1', the pocket 9' is arranged in the clamping plate 2', in conjunction with the substrate plate 4' having a substantially flat surface facing the gap 5', as shown in Figure 4A shown schematically in .

Alternatively, in a third example of the substrate clamping device 1 ″, both surfaces of the substrate plate 4 ″ and the clamping plate 2 ″ facing the gap 5 ″ are provided with pockets 92 , 93 , as schematically shown in FIG. 4B shown. In this embodiment, compared with the pocket portions 9, 9' of the substrate clamping device 1, 1' according to the first and second examples, the facing gap 5" of the substrate plate 4" and the clamping plate 2" The indentations or cavities in the surface forming pockets 92, 93 may be shallower and less deep.

FIG. 5 is a schematic partial cross-section of a fourth exemplary embodiment of the substrate clamping device 11 . FIG. 6 is a schematic partial top view of the substrate plate 14 of the substrate clamping device of FIG. 5 . In this fourth example, the base plate 14 is provided with an array of pockets 19 that are generally conically shaped. For example, the descending slope of the cone may be approximately 15 degrees. Droplets 18 are disposed in the pockets 19 and are configured to bridge the gap between the base plate 14 and the clamping plate 12 . The conical shape of the pocket 19 will generally fix the position of the liquid and/or solid droplets 18 of the heat absorbing material. Additionally, the conical shape of pocket 19 and the surface tension of the heat absorbing material in the liquid phase provide forces to generally retain liquid droplets 18 in the center of pocket 19 . No other parts are needed to fix the position of droplet 18.

In addition, in this fourth example, the base plate 14 is provided with an array of holes 141, and each support member 17 of a series of support members is disposed on one side in one of the holes 141 and is fixed to the hole via a glue connection. 141 in. The other side of the support member 17 is fixed to the clamping plate 12 .

In addition, the base plate 14 may be provided with vents 142 that flow out generally in the center of the pocket 19 . Vent 142 is configured to prevent air from being trapped beneath droplet 18 .

FIG. 7 is a schematic partial cross-section of a fifth exemplary embodiment of the substrate clamping device 21 . In this fifth example, the base plate 24 is provided with an array of pockets 29 generally shaped as right cylinders with a generally circular bottom area. The droplet 28 is arranged in the pocket 29 and contacts both the circular bottom area of the pocket 29 and the clamping plate 22 in the base plate 24 . To allow expansion of the droplet 28 at least in the direction along the gap 25 , the volume of the droplet 28 is configured such that the diameter of the droplet 28 in a direction parallel to the bottom region of the pocket 29 is smaller than the diameter of the cylindrical pocket 29 . The cylindrical pocket 29 will generally establish the position of the droplets 28 of heat absorbing material in the solid and in the liquid phase. No other parts are needed to substantially fix the position of droplet 28. An advantage of this example is that the configured surface of the pocket-free portion 29 of the base plate 24 can be configured close to the clamping plate 22 . Therefore, the clamping plate 22 can be connected to the substrate plate 24 with very short supports 27, or even without supports at all, which results in an extremely rigid substrate clamping device 21.

In a sixth example of the substrate holding device 31, as schematically shown in Figure 8, the droplet 38 is arranged inside an O-ring 39 made of a flexible or elastic material such as rubber, such as ^Viton® . Each of the droplets 38 is disposed inside an O-ring 39 , which provides lateral containment of the droplets 38 and allows the droplets 38 to move along the O-ring 39 due to its flexible or elastic material. Contraction and expansion in the direction of gap 35.

Preferably, the thickness of the O-ring 39 is smaller than the width w’ of the gap 35 between the clamping plate 32 and the base plate 34. This allows the assembly of the substrate clamping device 31 comprising the clamping plate 32, the base plate 34 and the support 37 and obtaining a gap 35 with the required width w' without interference from the O-ring 39. O-ring 39 is avoided from contacting or compressing between clamping plate 32 and base plate 34 , as this may have a negative impact on the flatness of first side 33 of clamping plate 32 .

As indicated in FIG. 8 , the gap 35 is generally open at the peripheral side edge 310 of the substrate clamping device 31 . The gap 35 may even be substantially along the entire circumference of the substrate clamping device 31 The side edges 310 are generally open. The gap 35 therefore contains an open connection to the outside of the substrate clamping device 31 . The air pressure or vacuum pressure inside the gap 35 is substantially equal to the air pressure or vacuum pressure outside the substrate holding device 31 .

The steps of a method for constructing a substrate clamping device 31' according to the embodiment of Figure 8 are schematically shown in Figures 9A, 9B and 9C, with a support 37' arranged in this example on a substrate plate 34' This difference occurs in one of the array holes 341'.

First, a base plate 34' containing an array of holes 341' is provided. A series of supports 37' is provided, and each support 37' of the series is configured in one of the holes 341' and is preferably secured in the hole 341' via a glue connection.

Subsequently, the assembly of O-rings 39' with solid pellets or droplets 38' of heat absorbing material on the inside is arranged between the supports 37', as shown schematically in Figure 9A. It should be noted that the thickness d of the assembly of the droplet 38' and the O-ring 39' is less than the height h of the support member 37' protruding from the base plate 34'.

Next, the clamping plate 32' is arranged on top of the supports 37' and is fixed to these supports 37', preferably via glue connections. As indicated schematically in Figure 9B, the clamping plate 32' is arranged on top of the support 37' with a gap above the assembly of O-ring 39' and solid droplet of heat absorbing material 38'.

The solid droplets 38' of heat absorbing material are then melted, for example by arranging the assembly in a furnace at a temperature above the melting temperature. Due to the surface tension in the liquid droplet 38' of the heat absorbing material, the liquid droplet 38' will assume a more spherical shape, as indicated schematically in Figure 9C, and contact the second side 36' of the clamping plate 32'. Droplet 38' is now configured to bridge gap 35 between base plate 34' and clamping plate 32'.

Next, the assembled substrate holding device 31' is configured in a "cold" environment at a temperature below the solidification temperature of the heat absorbing material, and the liquid droplet 38' will solidify generally in the shape shown in Figure 9C . Thus, the solid droplet 38' fills the gap 35' and contacts both the base plate 34' and the clamping plate 32'. Now, the substrate holding device 31' is ready for use.

FIG. 10 is a schematic partial cross-section of a seventh exemplary embodiment of a substrate clamping device 51 . In this seventh example, the base plate 54 is provided with an array of pockets 59 that are generally shaped as right cylinders with a generally circular bottom surface 591 . Pocket 59 includes a first or upper pocket portion 592 having a first diameter, and a second or lower pocket portion 593 having a second diameter that is less than the first diameter. The second pocket portion 593 is generally centrally disposed within the first pocket portion 592 . This results in a rim or step 61 arranged inside the pocket 59 and extending along the circumferential side walls of the pocket 59 .

Each pocket 59 in the array of pockets includes an elastic member, particularly an elastic cover plate 60 , that spans the pocket 59 and is configured to be spaced apart from the bottom surface 591 of the pocket 59 . The elastic cover plate 60 has a diameter smaller than the first diameter but larger than the second diameter. Therefore, the circumferential edge of the elastic cover plate 60 rests on the top of this rim or step 61 . The resilient cover panel 60 provides a means for absorbing any residual expansion in a direction generally perpendicular to the gap 55 by bending or flexing of at least a central portion of the cover panel 60 toward the bottom surface 591 of the pocket 59 . Preferably, the elastic covering plate 60 is a titanium plate.

Each pocket 59 contains a droplet 58 from the array of droplets disposed between the elastic cover plate 60 and the second side 56 of the clamping plate 52 . A droplet 58 of PCM is disposed generally centrally on top of the elastic cover plate 60 .

As schematically shown in FIG. 10 , the cover plate 60 is disposed inside the corresponding pocket 59 and below the surface 63 of the base plate 54 surrounding the pocket. This provides for fixing between the base plate 54 and the clamping plate 52 The component of the position of the droplet 58 in the gap 55. To increase the elastic clamping plate 60 and the base plate 54, the heat conductive paste is preferably disposed between the circumferential edge of the elastic clamping plate 60 and the rim or step 61.

Additionally, each pocket 59 includes a ring or hoop 62 configured to surround a droplet 58 in the pocket 59 . Preferably, the ring is made of synthetic or rubber material such as ^Viton® . A ring or hoop 62 is disposed in the pocket 59 , preferably on top of the elastic cover plate 60 , and acts as a confinement member for the droplets 58 of PCM in the pocket 59 . The thickness of the ring or hoop 62 is less than the distance between the clamping plate 52 and the elastic cover plate 60 . Therefore, the ring or hoop 62 is not in direct contact with both the cover plate 60 and the clamping plate 52 . The ring or hoop 62 includes a generally rectangular cross-section in a direction generally perpendicular to the first side 53 of the clamping plate 52 . The generally planar upper surface of the ring or hoop 62 is configured to face the second side 56 of the clamping plate 52 . When using PCM with high density, such as a metal-like material with gallium-like behavior, the ring or hoop 62 is pushed upward by the PCM, which pushes the ring or hoop 62 toward the second side 56 of the clamping plate 52 . The flat upper surface of the ring or hoop 62 is pushed against the second side 56 of the clamping plate 52 and provides a seal for receiving the PCM inside the ring or hoop 62 .

In the example shown in FIG. 10 , the base plate 54 is provided with vents 542 that exit in the bottom surface 591 of the pockets 59 , preferably in the center of the pockets 59 . Due to the vents 591 , the pressure inside the lower portion 593 of the pocket 59 between the bottom surface 591 and the elastic cover plate 60 is substantially equal to the pressure surrounding the substrate clamping device 51 .

In addition, in this seventh example, the base plate 54 is provided with an array hole 541 , and the clamping plate 52 is provided with an array support 57 . Each support member 57 is disposed in a corresponding one of the holes 541 and is fixed in the hole 541 via glue connection.

It should be noted that the examples presented above all describe substrate clamping devices suitable for clamping array droplets of one of the heat absorbing materials, preferably phase change materials (PCM), more preferably metalloid PCM, according to the invention. Examples of such materials are presented in the table below:

Figure 11 shows a schematic diagram of an instrument used to process or image sample 130. The instrument includes: a module 201 that includes a source for electromagnetic radiation or particles having energy; a module 204 that includes a source for exposing the sample 130 to the electromagnetic radiation or particles having energy; and according to the present invention The substrate clamping device 209.

Specifically, Figure 11 schematically represents a multi-beam charged particle lithography system, which includes: - an illumination optical module 201, which includes a charged particle beam source 101 and a beam collimation system 102, - an aperture array and a condenser lens module 202, which includes an aperture array 103 and a condenser lens array 104, - a beam conversion module 203, which includes an array of beam quenching devices 105, and - a projection optics module 204, which includes a beam terminator array 108, beam deflectors Array 109, and projection lens array 110.

In the example shown in FIG. 11 , modules are configured in aligned inner subframes 205 and aligned outer subframes 206 . The frame 208 supports aligned subframes 205 and 206 via a vibration damping frame 207 .

Modules 201 , 202 , 203 , 204 are collectively formed for generating a plurality of charged particle beams, modulating the charged particle beams, and directing the charged particles of the charged particle beams toward the first side 209 ′ of the substrate clamping device 209 Optical unit.

The substrate clamping device 209 is disposed on the top of the chuck 210 . On the first side 209' of the substrate holding device 209, a target, such as a wafer 130, may be disposed.

The substrate clamping device 209 and the chuck 210 are arranged on a short stroke stage 211 configured to drive the chuck 210 over a small distance along all six degrees of freedom. A short-stroke stage 211 is mounted on top of a long-stroke stage 212 configured for driving the short-stroke stage 211 in two orthogonal directions (X and Y) in at least a substantially horizontal plane of soil. and chuck 210.

Lithography instrument 200 is disposed inside a vacuum chamber 230 that includes one or more Amcor (mu metal) shields 215 . Shield 215 is conveniently configured to line vacuum chamber 230. The machine rests on a base plate 220 supported by frame members 221 .

The positions of the wafer 130 and the substrate holding device 209 relative to the charged particle optical units 201, 202, 203, 204 are measured by a measurement device 250 attached to the alignment subframe 205. The measurement device 250 The position of the chuck 210 relative to the measurement device 250 is monitored. The measurement device 250 includes, for example, an interferometer system, and the chuck 210 is then provided with a mirror 251 for reflecting the light beam 252 from the interferometer system.

12 shows a cross-sectional view of an embodiment of a modified projection lens assembly 300, such as for use in the projection optical module 204 of the multi-beam charged particle lithography system of FIG. 11. Projection lens assembly 300 includes a housing with an electrically conductive circumferential wall 330 preferably made of metal. The projection lens assembly 300 further includes a cover element 310, and a support element 340 at the downstream end of the housing. The channel for the charged particle beam extends from the through opening 313 in the cover element 310 , through the interior of the projection lens assembly towards the first electrode 301 , through the support element 340 , and finally out in the second electrode 302 . A large amount of charged particle beam can pass through the through opening before impacting the target 370 disposed on top of a substrate clamping device, which is preferably, but not necessarily, a substrate clamp as described in Examples One to Six above. Holding device 1. In the embodiment shown, the support element 340 extends generally parallel to both the first electrode 301 and the second electrode 302 . Preferably, the supporting element 340 extends radially away from the lens hole arrays in the first electrode 301 and the second electrode 302 .

To avoid the formation of an electric field between target 370 and projection lens assembly 300, the two may be grounded and/or conductively connected to each other. Structurally Robust Projection Lens Assembly According to the Invention Can be placed integrally in known lithography systems, or can be swapped out or removed for maintenance purposes.

A large amount of charged particle beams first pass through the through channel 313 in the covering element 310 . Once the charged particle beam has passed through through opening 313, it reaches beam terminator array 308. The beam terminator array 308 is configured to block the charged particle beam that has been deflected by the beam quenching device array 105 of the beam conversion module 203 . The charged particle beam deflected by beam quenching device array 105 (see, eg, FIG. 11 ) is blocked by beam terminator array 308 and does not reach target 370 . Accordingly, the charged particle beams can be individually modulated by the array of beam quenching devices to allow individual charged particle beams to impinge on target 370 or not. The beam that is not deflected by the array of non-quenching devices travels through the beam terminator array 308 and is projected onto the surface of the target 370 by electrostatic lenses provided by the first electrode 301 and the second electrode 302 . The use of this modulation and relative movement of target 370 with respect to the exposure unit containing projection lens assembly 300 allows patterns to be written onto the surface of target 370 .

In some projection lens systems, a deflector unit is disposed between the beam stop array 308 and the first and second electrodes 301 and 302 , the deflector unit being configured to provide a beam stop array over the surface of the sample 307 308 beam scanning deflection. Preferably, the deflector unit includes an X deflector and a Y deflector to deflect the beam in an orthogonal direction perpendicular to the optical axis OA of the projection lens system 300 .

As indicated above, the beam terminator array 308 is a component for at least partially and/or temporarily blocking at least a portion of the charged particles in a plurality of charged particle beams. To remove heat generated by blocking of the charged particle beam, the beam terminator array 308 assembly is provided with conduits 309. In use, cooling fluid is directed via conduits 309 , wherein conduits 309 are configured to be in thermal contact with beam terminator array 308 . At least a first portion 307 of the conduit is arranged in the region between the two charged particle beams, as schematically indicated in Figure 13. The central axis of the first portion 307 of the conduit extends in a direction generally perpendicular to the central axis or optical axis OA of the projection lens system 300. stretch.

As indicated in FIGS. 12 and 13 , at least a second portion 306 of the conduit is configured to extend such that the central axis of the second portion 306 of the conduit is substantially parallel to the central axis or optical axis OA of the projection lens system 300 extending in the direction. Accordingly, the first portion 307 of the conduit may be disposed at or near the first end 303 of the projection lens system 300, which in use is disposed proximate the target 370. The second portion of the conduit provides an extension of the conduit away from the first end 303 of the projection lens system 300, which allows for the provision of input connections 304 and/or output connections 305 for fluid suitably spaced apart from the first end 303, and will The first end 303 of the projection lens system 300 is configured in close proximity to the target 370 .

It should be noted that the cooling unit as shown in Figure 13 can also be used to cool active components used to at least partially or temporarily steer the charged particle beam, such as but not limited to electrostatic deflectors or lenses, to move by being configured in such Heat generated by electronic components on or in active components. Active components such as first electrode 301 and second electrode 302 may be disposed between conduits 307 .

14 shows a cross-sectional view showing an embodiment of a portion of an assembly including an exposure unit for exposing a sample 470 and a substrate holding device 480 for holding the sample 470 at least during the exposure. The assembly shown in FIG. 14 is suitable for use, for example, in the projection optical module 204 of the multi-beam charged particle lithography system of FIG. 11 .

The exposure unit contains a projection lens assembly 400 containing a housing with an electrically conductive circumferential wall 430 preferably made of metal. As shown in the projection lens assembly 300 in FIG. 12 , the projection lens assembly 400 includes a cover element 410 , a through opening 413 in the cover element 410 , a beam terminator array 408 , a support element 440 , a first electrode 401 , and a second electrode. 402.

Additionally, projection lens assembly 400 includes means for at least partially and/or temporarily A component that manipulates and/or blocks at least part of a charged particle beam. One such component is a beam terminator array 408 configured to block a charged particle beam that has been deflected by the beam quenching device array 105 of the beam conversion module 203 shown in FIG. 11 . The beam terminator array 408 includes a cooling arrangement configured to maintain the beam terminator array 408 generally at a predetermined first temperature. In the example shown in Figure 14, the cooling arrangement also cools other parts of the projection lens assembly, and in use, substantially the entire projection lens assembly is at the first temperature. The projection lens assembly includes a first temperature sensor T1, which is disposed at, for example, the support element 440. The first temperature sensor T1 is configured to measure the projection lens assembly, especially the The temperature of the portion of the projection lens assembly facing the substrate clamping device 480.

The cooling arrangement includes a generally closed circuit of conduits or pipes for a cooling fluid, in particular a cooling liquid, such as high purity water. The cooling arrangement further includes cooling means 450 for cooling the cooling fluid to a temperature lower than the first temperature. The cooling device 450 is comprised of a heat exchange circuit 451 coupled to the manufacturing plant coolant circuit.

Downstream of the cooling device 450, a heating device 470 is arranged in a closed circuit. Heating device 470 is configured for heating the cooling liquid. The combination of cooling device 450 and heating device 470 provides means for accurately controlling the temperature of the cooling fluid. The heating device is disposed in the conduit at an upstream position relative to the projection lens assembly 400 .

As indicated above, beam terminator array 408 is a component for at least partially and/or temporarily blocking at least a portion of the charged particles in a plurality of charged particle beams. To remove heat generated by blocking of the charged particle beam, the beam terminator array 408 assembly has conduits 409 that are part of the cooling arrangement. In use, cooling fluid from cooling device 450 and from heating device 470 is configured to flow via conduit 406 toward conduit 409 , wherein conduit 409 is configured to be in thermal contact with beam terminator array 408 . The cooling fluid then flows back through conduits 406', 405 to cooling device 450. As indicated in Figure 14, conduit 409 is configured inside projection lens system 400 at or near first end 403 of projection lens system 400, which in use is configured close to substrate 470.

Additionally, the closed loop includes one or more temperature sensors for measuring the temperature of the cooling fluid in the conduits 404, 406, 409, 406', 405. In the specific example shown in Figure 14: the second temperature sensor T2 is disposed in the conduit between the cooling device 450 and the heating device 470; the third temperature sensor T3 is disposed between the heating device 470 and the beam terminator array 408 in the conduit; and the fourth temperature sensor T4 is configured in the conduit downstream of the beam terminator array 408 .

Temperature sensors T1, T2, T3, and T4 provide inputs to a temperature control system 490 configured to control the flow of manufacturing cooling liquid through the heat exchange loop 451 in the cooling device 450 and/or The heating of the cooling fluid by the heating device 470 is controlled. The temperature control system 490 is configured to control the heating device 470 and/or the cooling device 450 between the substrate clamping device 480 and the projection lens system 400 , particularly the first end 403 of the projection lens system 400 facing the substrate clamping device 480 A temperature difference is established between them, and the temperature difference is preferably in the range of 1°C to 1,5°C.

Sample 470 is disposed on top of a substrate holding device 480 for holding the sample 470 at least during exposure. The substrate clamping device 480 includes a clamping plate 481 , which includes a first side for clamping the substrate 470 , and a base plate 482 . Between clamping plate 481 and base plate 482, the configuration includes a temperature stable configuration of phase change material 483 having a phase change at a second temperature. The substrate clamping device 480 is preferably, but not necessarily, as in Example 1 above. to the substrate clamping device described in Section 6.

In the example shown in Figure 14, both substrate clamping device 480 and projection lens system 400 each have configurations for controlling their temperatures. Specifically, because projection lens system 400 is configured to expose sample 470 using an energetic charged particle beam, projection lens system 400, particularly beam stop array 408 and/or sample 470, will absorb at least a portion of the energy. By providing both the projection lens system 400 and the substrate clamping device 480 with their own cooling and temperature stabilization configurations, precise temperature control of the substrate 470 is achieved that allows for optimal use of readily available factory cooling. The agent at least generally maintains the temperature of the projection lens system 400, and in particular the beam terminator array 408 of the projection lens system, at a first temperature, and maintains the temperature of the substrate 470 using a phase change material having a phase change at a second temperature. Maintain at the second temperature.

It should be noted that schematic diagrams 12 and 14 are not drawn to scale, particularly for charged particle beam exposure systems using low kiloelectronvolt charged particles, for example having energies substantially below 10 keV, preferably about 5 keV. of charged particles. In such charged particle beam exposure systems using low kiloelectronvolt charged particles, the distance s between the first end 403 of the projection lens system 400 and the top surface of the substrate 470 is extremely small. The distance s is preferably less than the thickness d2 of the sample 470. In the case where sample 470 is a silicon wafer, thickness d2 is typically 330 microns. Preferably, the distance s is less than the thickness d1 of the second electrode 402 defining the first end 403 of the projection lens system 400 . In particular, the distance s is less than 100 microns, preferably 50 microns.

As shown in the examples of FIGS. 12 and 14 , both the substrate clamping device 480 and the exposure unit, particularly the projection lens system 400 of the exposure unit, are configured to control their temperatures. In addition, as schematically shown in FIG. 14 , the temperature of the cooling arrangement of the exposure unit is controlled based on the temperature of the temperature stabilizing arrangement of the substrate clamping device 480 . Therefore, the cooling configuration includes controlled A control device 490 configured to adjust the first temperature, in particular the temperature as measured by the first temperature sensor T1, to a second temperature at which the phase change material 483 exhibits a phase change, near or equal to the second temperature. 2. Temperature.

Preferably, the cooling arrangement and the temperature stabilizing arrangement are configured such that the second temperature is at or near the first temperature at least during exposure of the substrate by the charged particle beam.

Figure 15 shows a schematic flow diagram 150 of an example of a method for fabricating a semiconductor device by means of an apparatus according to as described above. The method includes the following steps: 151: placing the wafer on the substrate holding device and positioning the wafer downstream of the exposure unit; 152: processing the wafer, including by means of electromagnetic radiation with energy from the source or particles project images or patterns onto the wafer; and 153: perform subsequent steps to produce a semiconductor device using the processed wafer.

Figure 16 shows a schematic flow chart 160 of an example of a method for inspecting a target by means of an instrument as described above, the method comprising the steps of: 161: placing the target on a substrate holding device and placing the wafer Positioned downstream of the exposure unit; 162: Project the electromagnetic radiation or particles with energy from the source onto the target; 163: The electromagnetic radiation or particles with energy from the source are incident on the target detecting electromagnetic radiation or charged particles transmitted, emitted and/or reflected by the target; and 164: performing subsequent steps to examine the target with the aid of data from the step of detecting charged particles.

It should be understood that the above description is included to illustrate the operation of the preferred embodiments and is not meant to limit the scope of the invention. From the above discussion, it will be apparent to those skilled in the art that the present invention The spirit and scope will still cover many changes.

For example, although the shape and diameter of the pockets in the examples described above are generally the same for all pockets shown, the base plate may also have pockets of different sizes and/or different shapes. In particular, the pockets along the edges of the substrate clamping device may be smaller than the pockets to obtain better coverage of the heat absorbing material along the edges of the substrate clamping device.

In addition, a large number of heat absorbing materials can be used. As indicated, the heat absorbing material is preferably selected so as to have a melting temperature or melting range at or near the operating temperature of the substrate processing instrument using the substrate clamping device. Such heat-absorbing materials are also known under the name phase change materials, or PCM for short.

In summary, the present invention is directed to a substrate clamping device that includes a clamping plate, a substrate plate, an array of supports, and an array of droplets of heat absorbing material. The clamping plate includes a first side for clamping the substrate. The base plate is disposed at a distance from the clamping plate and provides a gap between the base plate and the clamping plate at a side of the clamping plate opposite the first side. The array support member is arranged between the clamping plate and the base plate. The array of liquid and/or solid droplets is disposed between the clamping plate and the base plate, and the droplets are configured to contact both the base plate and the clamping plate. The droplets are configured to be spaced apart from each other and the support, and are configured to be adjacent to each other in a direction along the gap.

Additionally or alternatively, the present invention relates to apparatus and methods for exposing samples. The apparatus includes a source of electromagnetic radiation or particles having energy, an exposure unit for exposing the sample to the electromagnetic radiation or particles, and a substrate holding device for holding the sample at least during the exposure. The exposure unit includes components for manipulating and/or blocking at least part of electromagnetic radiation or charged particles. The wire includes a cooling arrangement configured for maintaining the component generally at a predetermined first temperature. The substrate holding device includes a temperature stabilizing arrangement configured to substantially stabilize the temperature of a sample disposed on the substrate holding device. Spend. The temperature stable configuration includes a phase change material having a phase change at a second temperature at or near the first temperature.

1:Substrate clamping device

2: Clamping plate

3: First side

4: Base plate

5: Gap

6: Second side

7:Support

8:Drip

9: Bag part

41:hole

91: Conical edge

w:width

Claims (12)

A substrate holding device, which includes: a clamping plate having a first side for clamping a substrate; a base plate arranged at a distance from the clamping plate and A gap is provided between the base plate and the clamping plate at a second side of the clamping plate that faces away from the first side; an array of supports is provided at least on the Between the clamping plate and the base plate; wherein the base plate and/or the clamping plate is provided with an array of pockets, and the clamping plate at one of the pockets in the array of pockets and the The width of the gap between the base plates is greater than the width of the gap between the clamping plate and the base plate around the pockets, and wherein each pocket is provided as an indentation or an Depression. The substrate clamping device of claim 1, wherein the support array is fixedly attached to the second side of the clamping plate and/or to the substrate plate. The substrate clamping device according to claim 1 or 2, wherein the substrate plate is provided with a plurality of holes for mounting the support array therein. The substrate clamping device according to claim 1 or 2, wherein the substrate plate is provided with an exhaust hole debouche in a bottom surface of the pockets. The substrate clamping device according to claim 4, wherein the exhaust holes substantially flow out from the center of the pockets. The substrate clamping device according to claim 1 or 2, wherein the substrate plate contains silicon carbide (SiC). The substrate clamping device according to claim 1 or 2, wherein the gap includes an open connection to an outer side of the substrate clamping device. The substrate clamping device according to claim 1 or 2, wherein the gap is substantially open at a peripheral side edge of the substrate clamping device. The substrate clamping device according to claim 1 or 2, wherein the gap between the clamping plate and the base plate has a heat absorbing material, and the heat absorbing material is configured to remove heat from the substrate configured on the first side. The substrate clamping device according to claim 9, wherein the heat absorbing material includes a phase change material. The substrate clamping device according to claim 1 or 2, further comprising a ring array arranged in the gap between the clamping plate and the substrate plate. A multi-beam charged particle lithography system, which includes the substrate clamping device according to any one of claims 1 to 11.