KR102580712B1 - Substrate holding device, method for manufacturing such a device, and apparatus and method for processing or imaging a sample - Google Patents

Abstract

The present invention relates to a substrate holding device comprising a holding plate, a base plate, an array of supports, and an array of droplets of heat absorbing material. The holding plate includes a first side for holding the substrate. The base plate is arranged at a certain distance from the holding plate and provides a gap between the base plate and the holding plate on the side of the holding plate opposite the first side. An array of supports is arranged between the holding plate and the base plate. An array of liquid and/or solid droplets is arranged 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 support, and adjacent to each other in the direction along the gap.

Description

Substrate holding device, method of manufacturing the substrate holding device, and apparatus and method for processing or imaging a sample {SUBSTRATE HOLDING DEVICE, METHOD FOR MANUFACTURING SUCH A DEVICE, AND APPARATUS AND METHOD FOR PROCESSING OR IMAGING A SAMPLE}

The present invention relates to a substrate holding device for use in, for example, lithography systems. The invention also relates to a method for manufacturing such a substrate holding device and the use of such a substrate holding device in a lithography system. The invention also relates to devices for exposing samples, in particular devices for processing or imaging samples, and more particularly to lithographic devices. The invention also relates to methods for processing or imaging samples.

In lithography systems, photons or charged particles, such as ions or electrons, are used to illuminate and pattern the surface of a substrate, for example a silicon wafer. Due to the energy load of these photons or charged particles, the substrate is heated, at least locally. In particular, in charged particle lithography systems, such as multi-beam charged particle lithography systems, the bombardment of charged particles results in significant heating of the substrate, especially in conjunction with localized imparting of charged particles on the substrate. It may cause

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

Many of these holding devices rely on thermal contact of the substrate with a coolant arranged to flow through the substrate holding device. One example of such a device is disclosed in US 5,685,363, which describes a substrate holding device comprising a heat absorbing fluid chamber beneath the wafer or target to be exposed. These known substrate holding devices comprise a heat absorbing fluid covered by a flexible sheet. In use, the substrate is pressed against the sheet by a substrate retainer, whereby the sheet, and therefore the heat absorbing fluid, is in intimate thermal contact with the back side of the substrate and stabilized in temperature.

When the substrate is heated only locally, as in charged particle beam lithography systems, while the heat absorbing fluid extends substantially along the entire backside of the substrate, the layer of heat absorbing fluid in this known design consists of a heat absorbing fluid. In addition to acting as a column buffer, it also acts as a column buffer and forms a column buffer.

Additionally, the temperature stabilization device as disclosed in US 5,685,363 includes a heat absorbing fluid passageway or a coolant passageway included in the stabilization base, wherein the heat absorbing fluid is used to cool the substrate holding device and away from the substrate holding device. To transfer heat, it flows through these passages. This allows stabilizing the temperature of the substrate holding device below the heat absorption chamber and provides better control of the temperature at which the substrate holding device and target must be stabilized.

In lithographic exposure systems, as they are often housed in a vacuum environment, such coolant passages are undesirable. One reason is that the coolant conduit involved interferes with or impedes accurate positioning of the substrate, either directly or through hysteresis.

Within the field of lithography, patent publication US 2005/0128449 teaches that phase change materials, so-called PCMs, can facilitate the removal of heat. PCMs 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 altering the temperature. PCM materials can be applied without coolant conduits while still tightly controlling the temperature at which the target or substrate and substrate holding device must be stabilized. Materials indicated for realizing this heat storage and stabilization system include paraffin wax and Rubitherm™ PX. PCM may be provided as PCM powder or as bound PCM.

This type of combined heat storage and temperature control is based on the generally known principle of exploiting the phase change of materials at constant temperature. In applying this principle, additional information will be taken from the vast amount of literature, inter alia, “A review of on phase change energy storage: materials and applications” by Mohamed M. Farid et al. (Energy Conversion and Management 45, 2004). As may be appreciated, suitable materials may generally be selected from handbooks. In order to provide storage of large amounts of thermal energy at a desired temperature, one skilled in the art will search for materials that have a relatively high heat of transition or latent heat at the desired temperature, in this case the temperature of stabilization. will be. One such handbook is the "Handbook of chemistry & Physics" which lists "thermodynamic properties of the elements" based on Report ANL-5750, a study published by the United States Atomic Energy Commission. The choice of paraffin (n-octadecane), gallium and tin to confirm the numerical simulation of PCM behavior in “Numerical simulation of solid-liquid phase change phenomena” by Costa et al., 1991, was very diverse. Indicates the popularity of a given material among PCMs.

Patent publication US 2008/0024743 in the name of the applicant provides an example of a lithography target exposure system representing this known temperature stabilization system, wherein the coolant conduit is of the form of, for example, hexadecane. is omitted by application of PCM. Hexadecane has a phase change temperature that matches the upper end of the typical temperature range for coolant fluids used in semiconductor manufacturing, thereby increasing the temperature of the substrate thermal buffer compared to other typical temperature ranges in industrial lithography systems. It was chosen because it prevents undesirable excursions from the liquid cooled part. In this regard, the PCM temperature of hexadecane is approximately 291 from, for example, "characterization of Alkanes and Paraffin Waxes for application as Phase Change Energy Storage Medium" by Himran and Suwono (Energy sources, vol.16, 1994). K may be considered as It may be considered within range.

Although hexadecane has the advantage of a phase change temperature that matches industrial operating temperatures, at least industrial coolant temperatures, it actually improves thermal conductivity between the target and the PCM, as taught in this known PCM-based substrate temperature stabilization system. Despite the use of means to achieve this, it was evident that it was suffering from poor performance due to poor conductivity of heat.

Moreover, US 7,528,349 discloses a temperature stabilization system comprising a heat absorbing material disposed in thermal contact with a substrate. Heat absorbing materials are characterized by a solid-liquid phase transition temperature that is in the desired temperature range for the material processing the substrate. According to US 7,528,349, the heat absorbing material may be provided as a flat layer disposed on the top of the carrier, or may be arranged to fill one or more depressions in the carrier surface or may be formed into a recess with the heat absorbing material. It can also be embedded within the carrier by filling the recess. The heat absorbing material is arranged in direct contact with the substrate or with a suitable thermally conductive layer in sufficient thermal contact with both sides of the substrate. If the substrate is only heated locally, as in charged particle beam lithography systems, the resulting heat is locally absorbed by the heat absorbing material. Due to the absorption of heat, the heat absorbing material will undergo a phase transition, at least partially, substantially at the location where the charged particle beam impacts the substrate. These local phase transitions appear as local expansion or contraction of the heat-absorbing material. These local expansions or contractions produce undesirable distortions or deformations of the substrate, which render the temperature stabilization system of US 7,528,349 unsuitable for high-resolution charged particle lithography.

Therefore, the present invention provides precise temperature control of a system, device and/or substrate holding device by using a phase change material, typically metallic, of sufficient thermal conductivity while still matching temperatures within the semiconductor standard range of the coolant liquid. Seeks to provide systems, devices and/or methods that provide the means for. Standard metallic materials have phase change temperatures that are far from the desired operating range. Gallium, with a transition temperature of 303 K, is closest to the temperature range of coolant liquids used in semiconductor manufacturing, but is still off by 12 degrees. Other metallic-like materials may be selected from metal-based compound materials. In cases where such liquid metal materials may exhibit gallium-like material behavior, the present invention optimizes the PCM stabilized substrate support in its combined function as a receptacle for such liquid metal compounds and substrate temperature stabilizers, thereby , further seeks to provide novel designs of such temperature-stabilized substrate supports.

Equally, although the substrate holding device according to US 2008/0024743 provides a very compact and sophisticated way to hold a substrate on top of the substrate holding device at a substantially constant temperature, it is difficult to manufacture such a substrate holding device and/ Alternatively, it has also proven difficult to obtain carriers or thermally conductive frames with highly accurate and reproducible dimensions suitable for use in lithographic systems.

Additionally or alternatively, it is an object of the present invention to provide a design adapted to, or at least addressing, the specific properties of metallic phase change materials, such as any of the various gallium compounds. In fact, these materials tend to exhibit ice- and water-like behavior in the solid-to-liquid transition, in that the volume in the solid form may be larger than in the liquid form, leading to the upper layer of the holding device and the underlying layer. It is clear that the phase change involved leads to poor thermal conductivity due to at least a potential loss of direct contact between the materials.

Additionally or alternatively, therefore, the exposure unit, in particular for projecting electromagnetic radiation or particles onto the substrate, has such close proximity to the substrate that the exposure unit may thermally influence the substrate. It is an object of the present invention to provide an exposure method and apparatus that provides accurate temperature control of the substrate in an arrayed apparatus.

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

According to a first aspect, the present invention provides a substrate holding device comprising:

Holding plate - The holding plate includes a first side for holding the substrate -,

a base plate arranged at a certain distance from the holding plate and providing a gap between the base plate and the holding plate on a second side of the holding plate facing away from the first side;

At least, an array of supports arranged within between the holding plate and the base plate, and

an array of droplets of heat absorbing material - the droplets are arranged in the gap between the holding plate and the base plate, the droplets are arranged spaced apart from the support and from other droplets of the array of droplets, the droplets are arranged in the base plate and the holding plate Arranged to contact both - .

The array of supports between the base plate and the holding plate defines the width of the gap between the base plate and the holding plate and provides a frame with highly accurate and reproducible dimensions. This novel design for containing droplets of phase change material in a way that is adapted to optimal thermal conductivity, at least for successful temperature-stabilized thermal buffering, makes smart use of the container design, at least for successful temperature-stabilized thermal buffering. In this case, it adapts the material properties, namely the properties of surface tension and cohesion, which cause a portion of the liquid material to adopt a ball or droplet shape. Therefore, instead of filling a PCM container, i.e. a cavity arranged to contain the PCM within a holding device as described for example in US 7,528,349, the substrate holding device of the present invention contains droplets of phase change material, In particular, it is arranged to receive and contain droplets spaced apart from the support and from other droplets of the array of droplets. The holder preferably has a plurality of well-distributed, relatively small and/or shallow indentations or cavities each adapted to contain droplets of PCM.

The droplets are arranged spaced apart from the support and from other droplets of the array of droplets, at least to enable expansion of the droplets in a direction along the gap between the base plate and the holding plate. The droplets in the array of droplets are arranged with sufficient lateral space so that the droplets are freely positioned laterally, at least in a direction along the gap between the holding plate and the base plate. The substrate holding device according to this embodiment can be manufactured more easily because the position or positioning of the droplet does not interfere with the position or positioning of the support.

Preferably, the PCM exhibits a cohesive force greater than adhesion to the surface of the holding plate and/or base plate opposing the gap. This makes it possible to contain droplets of the PCM that are flattened within the gap, especially in the recesses or cavities of the surface of the holding plate and/or base plate, with the result that the flattened droplets are connected to the holding plate and the base plate. It can contract or expand depending on conditions while holding optimal contact, while providing the desired function as a temperature-stabilized substrate holding device. The latter function is realized without disadvantages, especially as in the solution described above.

Furthermore, an array of liquid droplets, either a liquid phase, a solid phase, or a combination of liquid and solid phases, is arranged to bridge the gap between the holding plate and the base plate. Therefore, the droplet contacts both the holding plate and the base plate. This can be arranged, in particular, by appropriate selection of the volume of the individual droplets and/or the width of the gap between the base plate and the holding plate. The contact between the holding plate and the droplet, on the one hand, provides adequate heat conduction from the holding plate to the droplet of the heat-absorbing material, and on the other hand, the contact between the base plate and the droplet provides the transfer of heat from the base plate to the droplet. The droplets provide adequate heat conduction.

If the entire gap between the base plate and the holding plate is filled with heat-absorbing material, any expansion or contraction of the heat-absorbing material due to absorption of heat will appear as an increase or decrease in pressure in the heat-absorbing material, which is It may appear as a change in the dimensions of and/or deformation of the holding plate. This problem has already been identified in US 2014/0017613, which states that, taking thermal expansion into account, the external dimensions of the heat storage structure in a state where heat is not absorbed are of the holding unit, taking thermal expansion into account. It is mentioned that it is desirable to make it smaller in advance than the inner diameter. However, making the heat storage structure smaller than the inner diameter of the holding unit has a notable disadvantage: the heat storage structure is not arranged in direct contact with the substrate, as shown in US 2014/0017613. Additional means need to be provided to transfer heat generated from the substrate to the heat storage structure. US 2014/0017613 teaches using a liquid such as water to completely fill the gap between the substrate and the base. The present invention provides a completely different solution to this problem, by using an array of droplets of heat-absorbing material arranged spaced apart from the support and from the other droplets of the array, where the droplets are formed on a base plate and a holding plate. Arranged to contact both, preferably the droplet is squeezed, wedged or held between the base plate and the holding plate.

If the PCM container, i.e. a cavity arranged to contain the PCM in a holding device as for example described in US 7,528,349, is filled with less heat-absorbing material as suggested by US 2014/0017613, The cavity will only be partially filled and will not be filled up to the holding plate. This will provide space for expansion of the heat absorbing material within the cavity, but it will also eliminate direct contact between the heat absorbing material and the holding plate, contrary to the invention as defined in claim 1.

In one embodiment, the droplet is arranged to allow substantially free expansion of the droplet in a direction along the gap between the base plate and the holding plate. The assembly of the individual droplets substantially allows each droplet to expand or contract in a direction along the gap without substantially providing for an increase or decrease in the pressure of the droplet on the holding plate or base plate.

In one embodiment, the array of supports is fixedly attached to the second side of the holding plate. By attaching the array of supports to the second side of the holding plate, the supports are arranged on a substantially fixed position of the holding plate. This allows arranging the supports in a suitable pattern to provide a rigid support for the holding plate that is substantially uniform over the area of the holding plate. Additionally, this allows providing a gap between the base plate and the holding plate with highly accurate and reproducible dimensions.

Alternatively or additionally, in one embodiment, the supports of the array of supports are fixedly attached to the base plate. In one embodiment, the base plate has an array of holes, each support of the array of supports extending at least partially into one hole of the array of holes, preferably the support having a hole and It is fixedly arranged in the hole by providing a glue connection in the circumferential gap between the supports extending into the hole. By providing adhesive within the circumferential inner wall of the hole and the circumferential outer wall of the support, any shrinkage or expansion of the adhesive during curing is substantially perpendicular to the width of the gap between the base plate and the holding plate. Generates a force that acts in one direction. Accordingly, these forces do not substantially affect or change the distance between the base plate and the holding plate, especially during curing or solidification of the adhesive. Therefore, the substrate holding device according to the present embodiment has a high value with respect to the width of the gap between the base plate and the holding plate and also with respect to the overall thickness of the substrate holding device, especially the thickness in the direction perpendicular to the first side of the holding plate. Can be manufactured with precision.

In one embodiment, the substrate holding device further comprises an array of rings arranged in the gap between the holding plate and the base plate, such that each ring of the array of rings surrounds one droplet of the array of droplets. are arranged. Each of these rings can be used as a mold for one droplet of the array of droplets of heat absorbing material, the droplets being arranged inside the ring.

In one embodiment, the thickness of the ring is less than the width of the gap between the holding plate and the base plate. Preferably, the dimensions and/or material of the ring are such that the thickness of the ring is such that, regardless of any expansion or contraction of the ring due to changes in temperature, especially within the operating temperature range of the substrate holding device, the thickness of the ring is It is selected to be held in a state smaller than the width of . The ring does not contact both the base plate and the holding plate, and therefore the ring exerts no substantial force on the holding plate and the base plate. Therefore, the ring does not affect the width of the gap.

When using such a ring as a mold for the droplet, the droplet is first made thinner than the width of the gap between the holding plate and the base plate and then completely 'frozen'. These solid droplets of heat absorbing material can be easily handled and arranged within between the base plate and the holding plate during fabrication of the substrate holding device. When a holding plate is arranged on top of the base plate, sandwiching the array of supports and the array of solid droplets, the droplets of heat absorbing material melt, creating liquid droplets that contact both the base plate and the holding plate. . Additionally, the droplet contracts in the direction along the gap, providing space to allow expansion of the droplet in the direction along the gap between the base plate and the holding plate. Subsequently, the droplets that contact both the base plate and the holding plate are frozen again. These frozen droplets provide a means for absorbing heat from the holding plate and/or base plate.

Preferably, the droplet comprises a material that has a high surface tension with respect to the surface of the base plate and/or the holding plate, opposite the gap between the base plate and the holding plate. Using a heat absorbing material with high surface tension preferably facilitates contact of both the base plate and the holding plate by liquid droplets.

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

Preferably, the ring is made of flexible or elastic material. The ring of this embodiment also facilitates expansion of the droplet in a direction along the gap between the base plate and the holding plate.

In one embodiment, the base plate and/or holding plate has an array of pockets, wherein the width of the gap between the base plate and the holding plate at a pocket of the array of pockets is such that the width of the gap between the base plate and the holding plate around the pocket is greater than the width of the gap, and each pocket of the array of pockets is arranged to hold one droplet of the array of droplets. It is noted that each pocket may also be provided as a depression or depression, in particular a shallow depression or depression. The pockets are arranged on the surface of the base plate opposite the gap and/or on the surface of the holding plate opposite the gap. Preferably, the depth of the pocket is smaller than the height of the droplet. The pocket provides a means for fixing the position of the droplet within the gap between the base plate and the holding plate, in particular without the need to use a ring. Since no rings or other means are required to substantially fix the position of the droplets, the droplets can be arranged close together, which provides better coverage of the heat absorbing material over the area on the second side of the holding plate. .

In one embodiment, at least one pocket of the array of pockets is substantially shaped as a cone, conical frustum, truncated sphere, or spherical frustum. Preferably, the pocket is shaped so that the width of the gap at or near the circumferential edge of the pocket is smaller than the width of the gap at or near the center of the pocket. In this case, the shape of the pocket substantially helps to hold the droplet on the desired position, especially when the PCM exhibits greater cohesion than the adhesion with the surface of the holding plate and/or base plate opposing the gap.

In one embodiment, the surface of the base plate opposite the gap includes an array of pockets, each pocket of the array of pockets spanning the pocket and an elastic member arranged spaced apart from the bottom surface of the pocket. wherein each pocket contains a droplet from the array of droplets, the droplets being arranged between the elastic member and the holding plate. The elastic member provides a means for absorbing any residual expansion in a direction substantially perpendicular to the gap by bending the elastic member toward the bottom surface of the pocket. Additionally, the elastic member may help push 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 such that the spring force provided by the curved elastic member substantially results in a local deformation of the holding plate.

In one embodiment, the distance between the elastic member and the holding plate is greater than the distance between the holding plate and the surface of the base plate adjacent the pocket. Accordingly, the elastic member is arranged inside the corresponding pocket. On the one hand, the elastic member is arranged at a distance from the bottom surface of the pocket, in order to allow the elastic member to bend towards the bottom surface of the pocket. Meanwhile, an elastic member is arranged under the surface of the base plate surrounding the pocket, which provides a means of fixing the position of the droplet within the gap between the base plate and the holding plate.

In one embodiment, the elastic member comprises a cover, preferably a cover plate. Accordingly, the cover or cover plate covers the bottom surface of the pocket and preferably separates the portion of the pocket between the bottom surface of the pocket and the cover or cover plate from the portion of the pocket above the cover or cover plate. In one embodiment, the cover or cover plate is substantially flat. Such flat covers or cover plates can be easily manufactured by cutting the covers or cover plates from large pieces of suitable material. In alternative embodiments, the cover or cover plate is preferably not flat but is shaped as a cone, conical frustum, truncated sphere, or spherical frustum. Such non-planar cover plates are described above in relation to conical pockets in addition to the advantage of absorbing any residual expansion in a direction substantially perpendicular to the gap by bending the cover or cover plates towards the bottom surface of the pocket. It provides the same benefits as before. In one embodiment, the cover or cover plate is molded as a cup with a circumferential flange disposed to at least partially contact the base plate to support the cup-shaped cover or cover plate.

In one embodiment, each pocket comprises within the pocket a support element for supporting at least a portion of an edge of the elastic member, preferably a circumferential edge of the cover or cover plate. Accordingly, the support element is arranged to support at least a portion of an edge of the elastic member, which allows the central portion of the elastic member to bend towards the bottom surface of the pocket. Preferably, the droplets of PCM are arranged substantially centrally on top of the elastic member.

In one embodiment, the support element includes a rim or step arranged on a circumferential side wall of the pocket. The rim or step preferably extends circumferentially around the pocket, firstly producing a first pocket portion having a first diameter in the base plate to a first predetermined depth, and subsequently substantially It can be manufactured relatively easily by manufacturing a second pocket portion with a second diameter smaller than the first diameter at its center to a second predetermined depth. Alternatively, such a rim or step may include first manufacturing a pocket portion having a second diameter to a predetermined depth of the pocket, and subsequently rotating the cutter within the first pocket portion down to the level of the rim or step. inserting a cutter that rotates circularly around the first pocket portion and outward to a first diameter to cut away material of the base plate about the first pocket portion while holding a constant level or depth. It can be manufactured by driving. This yields a rim or step arranged at the predetermined depth. By using an elastic member having 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 includes a ring or loop arranged within the gap between the holding plate and the elastic cover plate, the ring or loop arranged to surround the droplet within the pocket. A ring or loop is arranged within the pocket, preferably on the top of the elastic cover plate, and acts as a confinement member for the PCM droplet within the pocket.

In one embodiment, the thickness of the ring or loop is less than the distance between the holding plate and the elastic cover plate. Preferably, the dimensions and/or material of the ring or loop are such that the ring or loop is independent of any expansion or contraction of the ring or loop due to changes in temperature, especially within the operating temperature range of the substrate holding device. Alternatively, the thickness of the loop is selected to be held smaller than the width between the elastic cover plate and the holding plate. The ring or loop only contacts any one of the cover plate and the holding plate.

In one embodiment, the ring or loop is made from a flexible or elastic material. The ring or loop of this embodiment also facilitates expansion of the droplet of PCM inside the ring or loop, especially in the direction along the gap between the base plate and the holding plate.

In one embodiment, the ring or loop comprises a substantially rectangular cross-section. In particular, the ring or loop comprises a rectangular cross-section in a direction substantially perpendicular to the first face of the holding plate. Preferably, the ring or loop comprises a substantially flat upper surface arranged opposite the second side of the holding plate. This embodiment is particularly advantageous if the density of the liquid PCM is higher than the density of the material of the ring or loop. In this case, the ring or loop will 'float' on the PCM material when it is in a liquid state, which will push the ring or loop towards the second side of the holding plate, with the flat upper surface of the ring or loop holding the holding plate. This will allow abutting the second side of the plate and providing restraint of the PCM.

In one embodiment, the base plate has a venting hole opening at the bottom surface of the pocket, preferably at a substantially central portion of the pocket. Due to the vent holes, the pressure inside the pocket portion between the bottom surface and the elastic cover plate is substantially unchanged by bending of the elastic cover plate.

In one embodiment for use in a substrate processing device or a substrate imaging device, the droplets of the array of droplets are at least at a temperature of the substrate processing device during processing of the substrate, or at least at a temperature of the substrate imaging device during imaging of the substrate. It includes materials having a melting temperature or melting range at or near a temperature of Preferably, the droplets of the array of droplets comprise a 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 device is close to or the operating temperature of the industrial coolant, preferably at or slightly below room temperature, preferably at or slightly below 18 degrees Celsius. It's slightly above. Accordingly, the mechanical components of the substrate processing device or substrate imaging device do not need to be elevated in temperature, and the industrial coolant is easily applied by or in the substrate processing device or substrate imaging device comprising the substrate holding device according to the invention. It can be.

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

According to a second aspect, the present invention provides a substrate holding device comprising:

Holding plate - the holding plate includes a first side for holding the substrate -

a base plate arranged at a certain distance from the holding plate and providing a gap between the base plate and the holding plate on a second side of the holding plate facing away from the first side;

At least, an array of supports arranged within between the holding plate and the base plate, and

an array of droplets of heat absorbing material, wherein the droplets are arranged between a holding plate and a base plate, the droplets being confined by the holding plate and the base plate in a direction substantially perpendicular to the first side of the holding plate, the droplets comprising: arranged to enable expansion of the droplet, at least in a direction along the gap between the base plate and the holding plate.

Preferably the array of droplets comprising liquid and/or solid droplets is substantially confined between the holding plate and the base plate. Therefore, the droplet contacts both the holding plate and the base plate. This can be arranged, in particular, by appropriate selection of the volume of the individual droplets and/or the width of the gap between the base plate and the holding plate. The contact between the holding plate and the droplet, on the one hand, provides adequate heat conduction from the holding plate to the droplet of the heat-absorbing material, and on the other hand, the contact between the base plate and the droplet provides the transfer of heat from the base plate to the droplet. The droplets provide adequate heat conduction.

According to a third aspect, the invention provides a device for processing or imaging a sample, the device comprising:

a source for electromagnetic radiation or energetic particles;

an exposure unit for exposing the sample to the electromagnetic radiation or energetic particles; and

At least a substrate holding device as described above for holding the sample during the exposure, or an embodiment thereof.

In one embodiment, the exposure unit comprises a component for manipulating and/or blocking at least partially and/or temporarily at least some of the electromagnetic radiation or charged particles, the component comprising: a conduit for guiding cooling fluid through the conduit; and the conduit is arranged in thermal contact with the component. Accordingly, the cooling fluid in the conduit is arranged to remove heat generated by said partially and/or temporarily manipulating and/or blocking at least a portion of electromagnetic radiation or charged particles by the component. These components include, for example, a diaphragm, an electrostatic beam deflector, or an electrostatic or magnetic lens system.

Generally, the exposure unit is arranged on the side of the substrate facing away from the substrate holding device. If the exposure unit comprises one or more components for manipulating and/or blocking at least partially and/or temporarily at least some of the electromagnetic radiation or charged particles, these components are heated in use. For example, when at least some of the electromagnetic radiation or charged particles impinge on a component. In addition to the heat generated by electromagnetic radiation or charged particles impinging on the substrate during exposure, radiant heat from one or more components of the exposure unit may affect the substrate, especially if one or more components are arranged in close proximity to the surface of the substrate. can be additionally heated. This additional heat from the exposure unit will also be absorbed by the heat absorbing material of the substrate holding device of the invention, which results in faster consumption of the heat absorbing material, especially if the heat absorbing material is PCM. Accordingly, reducing the additional heat from the exposure unit as much as possible, and combining the substrate holding device of the invention with an exposure unit having a cooling arrangement for cooling the at least one component of the exposure unit. It is advantageous.

In one embodiment, a projection lens system is arranged for use in a multi-beam charged particle lithography system, wherein at least a first portion of the conduit is arranged in a region between two charged particle beams, the conduit comprising: The central axis of the first portion extends in a direction substantially perpendicular to the central axis or optical axis of the exposure unit. Accordingly, the first portion of the conduit is, in use, arranged close to the area through which the charged particle beam travels through the projection lens system, which allows effective removal of any generated heat from this area.

In one embodiment, at least the second portion of the conduit is arranged to extend such that the central axis of the second portion of the conduit extends in a direction substantially parallel to the central axis or optical axis of the exposure unit. Accordingly, the first portion of the conduit may, in use, be arranged at or near the first end of the exposure unit opposite the substrate. The second portion of the conduit provides an extension of the conduit away from the first end of the exposure unit, which provides an input and/or output connection for fluid suitably spaced from the first end, and an exposure unit. allows the first end of the to be arranged very close to the substrate. In one embodiment, the component includes a projection lens system arranged 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 transmits at least a portion of the electromagnetic radiation or charged particles. It includes a component capable of being partially and/or temporarily manipulated and/or blocked, the component having a conduit for guiding cooling fluid therethrough, the conduit being arranged in thermal contact with the component.

The projection lens system correspondingly provides a temperature-controlled exposure unit for use, for example, in temperature-stabilized lithographic systems. The projection lens is actively well cooled to a temperature range within the range of typical fab temperatures to ensure that the lithography system is in a stable and internally suitable, i.e. balanced, thermal state, thereby ensuring ultimate accuracy and stability in exposure. It eliminates complexity in device design, saves energy on the one hand, and promotes optimal exposure conditions on the other, as is excessively demanded within modern lithography.

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

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

According to a fifth aspect, the present invention provides a holding plate, the holding plate comprising a first side for holding a substrate, a second side of the holding plate arranged at a certain distance from the holding plate and facing away from the first side. A method for manufacturing a substrate holding device comprising a base plate providing a gap between the base plate and the holding plate in plane, an array of supports arranged at least within between the holding plate and the base plate, and an array of droplets of heat absorbing material. This method is:

Arranging droplets spaced from a support and from other droplets of the array of droplets within between a holding plate and a base plate, wherein the droplets are arranged to contact both the holding plate and the base plate, at least in their liquid phase, and /or the droplet is constrained by the holding plate and the base plate in a direction substantially perpendicular to the first side of the holding plate, and the droplet is arranged to enable expansion of the droplet in a direction along the gap between the base plate and the holding plate. do.

According to a sixth aspect, the invention relates to a method for assembling a substrate holding device, the method comprising the following steps:

a holding plate, the holding plate comprising a first side for holding a substrate, and a support fixed to a second side of the holding plate facing away from the first side, the support being substantially perpendicular to the second side. arranged to extend - providing an array of;

providing a base plate including therein an array of holes for mounting a support;

arranging the array of droplets of heat absorbing material spaced apart from a support and from other droplets of the array of droplets on a holding plate on a side opposite the base plate, or on a side opposite the base plate and the holding plate;

The holding plate and the base plate with the support - the support is positioned in the hole and the array of droplets are arranged in the gap between the holding plate and the base plate - are directed towards each other until the desired distance between the holding plate and the base plate is reached. moving; and

Fixing one or more of the supports into corresponding holes.

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

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

In one embodiment, an apparatus for processing or imaging a sample includes a source for electromagnetic radiation or energetic particles, and an exposure unit for exposing the sample to the electromagnetic radiation or energetic charged particles, the exposure unit comprising a component for manipulating and/or blocking at least partially and/or temporarily at least some of the electromagnetic radiation or charged particles, the component having a conduit for guiding a cooling fluid through the conduit, the conduit comprising the component comes into thermal contact with

According to an eighth aspect, the invention provides an apparatus for exposing a sample, said apparatus comprising:

a source for electromagnetic radiation or energetic particles;

an exposure unit for exposing the sample to the electromagnetic radiation or particles, the exposure unit comprising components for manipulating and/or blocking at least partially and/or temporarily at least a portion of the electromagnetic radiation or charged particles, the components comprising: a cooling device arranged to substantially hold the component at a first predetermined temperature, and

a substrate holding device for holding the sample at least during the exposure, the substrate holding device comprising a temperature stabilization device arranged to substantially stabilize the temperature of the sample arranged on the substrate holding device, the temperature stabilization device comprising a second Including a phase change material having a phase change at temperature,

The cooling device includes a control device configured to adjust the first temperature to be close to or equal to the second temperature.

Since the exposure unit is arranged to expose the sample using electromagnetic radiation or energetic particles, the exposure unit and/or the sample will absorb at least part of the energy and the temperature of the sample on the exposure unit and/or the substrate holding device will rise. something to do. Generally the sample is removed from the exposure unit in such a way that possible heating of the exposure unit has negligible or substantially no effect on the sample, and any cooling of the exposure unit can be independent of cooling of the sample. Note that they are arranged in distance. In particular, the cooling device for the exposure unit as described in the applicant's WO 2013/171216 is optimized to provide an optimum temperature for the exposure unit, and no consideration is taken about the effect of this optimum temperature on the sample. no need.

The present inventor has, particularly in the case of systems where the exposure unit is arranged in close proximity to the sample, provided both the substrate holding device and the exposure unit with a device for controlling its temperature, and the temperature of the temperature stabilization device of the substrate holding device. It has been recognized that it is advantageous to control the temperature (first temperature) of the cooling device of the exposure unit based on the (second temperature). By providing both the exposure unit and the substrate holding device with their own cooling and temperature stabilization devices, accurate temperature control of the substrate can be obtained, which temperature control depends on the exposure of the substrate by the electromagnetic radiation or particles. while allowing the temperature of the substrate to be held at least substantially at a second temperature.

The present invention describes concepts for defining exposure processes and apparatus, adapted to the constraints of practical environments. In particular, in devices where an exposure unit for projecting electromagnetic radiation or particles onto the substrate is arranged in close proximity to the substrate, the temperature of the exposure unit may thermally affect the substrate. For example, by controlling the temperature of the exposure unit using a cooling device, the negative influence of the temperature of the exposure unit on the substrate can be substantially prevented.

In order to achieve such method or process in the most economical manner, it is further considered that any such conditioning should be maintained with minimal effort thereon. On the other hand, in an economical exposure apparatus or method, as is the case with the proposed use of gallium, the operating temperature should not be at a level such that virtually the entire perimeter of the wafer carrier must be held at an elevated temperature of 29.8°C. The melting temperature of the phase change material used in the substrate holding device must be at a fairly low level.

On the other hand, since in such a way a standard Fabrication Plant (Fab) coolant may be used in the process, either directly or only through appropriate conditioning, applying additional considerations as incorporated herein: The operating temperature should not be substantially higher than 18° C., but a further consideration is that the coolant should be kept at a lower temperature, preferably only slightly lower than the operating temperature, at least during exposure, taking into account the cooling capacity required. It must be at a holding temperature. Considering that fab coolants typically range from 12 to 18°C, and that the fab ambient temperature at which variation should be minimal may often be room temperature, i.e., 25°C or lower, preferably 22°C or lower, According to an embodiment of the invention, a phase change material melting temperature equal to the second temperature should be defined, and thus the material to be selected, higher than the fab coolant temperature of 18°C, preferably 18.5°C, depending on the target exposure process. It is defined as having an operating temperature higher than and preferably lower than 22.5°C, and lower than the maximum room temperature of 25°C.

Note that the operating temperature referred to in this application is the temperature of the device for exposing the sample during operation.

In one embodiment, the cooling device and the temperature stabilizing device are arranged such that the difference between the first temperature and the second temperature is not more than 4°C, preferably not more than 2°C. This provides a substantially thermally stable environment for the sample. By actively controlling the cooling device and by carefully selecting the correct phase change material, the components of the exposure unit and the substrate holding device are adapted to substantially hold said first and second temperatures respectively, thus during exposure of the sample. It is arranged to hold the thermally stable environment.

In one embodiment, the first temperature is lower than the second temperature. Therefore, 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 if 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 room temperature, especially room temperature within a 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 comprises a eutectic metal alloy. Metal-based phase change materials provide high thermal conductivity in both the solid and liquid phases, which means that the heat generated by exposure of the sample is absorbed by the phase change material, even when a significant portion of the phase change material is already liquefied. Guaranteed to be guided and absorbed.

In one embodiment, the cooling device includes a conduit for guiding cooling fluid through the conduit, which is arranged in thermal contact with the component. Accordingly, standard fab coolants, such as coolants, may be used to cool at least the components of the exposure unit.

In one embodiment, the cooling device is arranged such that the difference between the temperature of the cooling fluid and the second temperature is not more than 4°C, preferably not more than 2°C. In one embodiment, the cooling device includes a temperature control system arranged to control the temperature of the cooling fluid in relation to the temperature of the substrate holding device. In one embodiment, the device comprises a temperature sensor for measuring the temperature of the substrate holding device and/or the temperature of an exposure unit, in particular a part of the exposure unit arranged adjacent to the substrate holding device. In one embodiment, the cooling device includes a cooling device for cooling the cooling fluid to a temperature below the first temperature, and a heating device for heating the cooling fluid, the heating device comprising a component arranged within the conduit at an upstream position in relation to In particular, a temperature sensor for measuring the temperature of the part of the exposure unit opposite the substrate holding device, a combined cooling device and a heating device for accurately controlling the temperature of the cooling fluid, and a heating device for accurately controlling the temperature of the cooling fluid based on the signal from the temperature sensor. The combination of a temperature control system for controlling the temperature controls the temperature of the exposure device with high precision and the temperature difference between the substrate holding device and the exposure unit, especially the part of said exposure unit opposite the substrate holding device, 4 Control is allowed to be below ℃, preferably below 2℃, more preferably below 1℃.

In one embodiment, the component includes a projection lens for projecting electromagnetic radiation or particles onto the sample. In embodiments where the cooling device comprises a conduit for guiding cooling fluid through the conduit and the conduit is arranged in thermal contact with the component, the conduit is arranged to convey the cooling fluid through or around the projection lens. In particular, in projection lenses for charged particles, the lens effect is established by magnetic and/or electrostatic fields that need to be created. In use, magnets and/or electrostatic lenses also generate amounts of heat that can be removed using cooling devices according to this embodiment.

In one embodiment, the component includes a modulation device for modulating electromagnetic radiation or particles. In embodiments where the cooling device comprises a conduit for guiding cooling fluid through the conduit and the conduit is arranged in thermal contact with the component, the conduit is arranged to convey the cooling fluid through or around the modulation device. In use, the modulation device also generates an amount of heat that can be removed using a cooling device according to the present embodiment.

In one embodiment, the modulation device comprises a beam blanking assembly comprising a beam deflector for deflecting a beam of electromagnetic radiation or particles and a beam stop for blocking the beam of electromagnetic radiation or particles. ), wherein the conduit is arranged to convey cooling fluid through or around the beam stop. When a beam of electromagnetic radiation or particles is directed to a beam stop, the electromagnetic radiation or particles are significantly absorbed by the beam stop. In use, the absorption of electromagnetic radiation by the particles also creates an amount of heat within the beam stop that can be removed using a cooling device 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 arranged to provide a plurality of charged particle beams, the charged particle optical system is arranged to project one or more of the plurality of charged particle beams onto the sample, and at least the first portion of the conduit has two Two charged particles are arranged in the area between the beams.

In one embodiment, the exposure unit comprises one or more temperature sensors, preferably one of the one or more temperature sensors is arranged on the side of the exposure unit opposite the substrate holding device.

According to a ninth aspect, the invention provides a method for processing or imaging a sample using a device or embodiment as described above, wherein conditioning of the temperature stabilization device is performed prior to processing or imaging of the sample, Conditioning includes solidifying at least a portion of the phase change material of the temperature stabilization device. When the phase change material absorbs heat, a portion of the phase change material liquefies or melts; The phase of a phase change material changes from solid to liquid. This absorbed heat can be removed from the phase change material in a condition process causing the thermal change material to solidify or freeze; The phase of a phase change material changes from liquid to solid again. After this conditioning, the solid phase change material can be used again to absorb heat.

In one embodiment, conditioning further includes setting the temperature of the temperature stabilization device at the second temperature prior to 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 stabilizer is at the second temperature and ready to absorb any heat caused by the exposure process. It has become.

In one embodiment, the heating device and/or the cooling device is controlled to establish a temperature difference between the substrate holding device and the exposure unit, in particular the part of said exposure unit opposite the substrate holding device, wherein the temperature difference is less than 4° C. Preferably it is less than 2°C, more preferably less than 1°C.

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

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

According to an eleventh aspect, the present invention provides a method for manufacturing a semiconductor device by an apparatus as described above herein, the method comprising the following steps:

- placing a wafer on a substrate holding device and positioning the wafer downstream of the exposure unit;

- processing the wafer comprising projecting an image or pattern onto the wafer by electromagnetic radiation or energetic particles from the source; and

- Performing subsequent steps to create a semiconductor device with the processed wafer.

According to a twelfth aspect, the invention provides a method for inspecting a target by a device as described above herein, the method comprising the following steps:

- placing the target on a substrate holding device and positioning the wafer downstream of the exposure unit;

- Projecting the electromagnetic radiation or energetic particles from the source onto a target;

- detecting electromagnetic radiation or charged particles transmitted, emitted and/or reflected by the target when the electromagnetic radiation or energetic particles from the source are incident on the target; and

- carrying out subsequent steps to inspect said target by means of data from the step of detecting charged particles.

The embodiments mentioned above in relation to the first aspect can also be appropriately applied to the invention according to other aspects.

The various aspects and features described and shown herein may be applied individually wherever possible. These individual aspects, particularly the aspects and features described in the appended dependent claims, may be the subject of a divisional patent application.

The invention will be described on the basis of exemplary embodiments shown in the accompanying drawings, in which:
Figure 1 is a schematic top view of a substrate holding device;
Figure 2 is a schematic partial cross-sectional view along line AA in Figure 1;
3A, 3B and 3C schematically show steps of a method for manufacturing a substrate holding device;
4A and 4B are schematic partial cross-sectional views of second and third exemplary embodiments of a substrate holding device;
Figure 5 is a schematic partial cross-sectional view of a fourth exemplary embodiment of a substrate holding device;
Figure 6 is a schematic partial top view of the base plate of the substrate holding device of Figure 5;
Figure 7 is a schematic partial cross-sectional view of a fifth exemplary embodiment of a substrate holding device;
Figure 8 is a schematic partial cross-sectional view of a sixth exemplary embodiment of a substrate holding device;
Figures 9a, 9b and 9c schematically show steps of an alternative method for manufacturing a substrate holding device according to the sixth embodiment as shown in Figure 8;
Figure 10 is a schematic partial cross-sectional view of a seventh exemplary embodiment of a substrate holding device;
Figure 11 schematically shows an apparatus for processing or imaging a sample, said apparatus comprising a substrate holding device of the invention;
Figure 12 schematically shows a cross-section of an embodiment of a projection lens system assembly for use in a device as shown schematically in Figure 11, for example;
Figure 13 schematically shows a cooling device for use in a projection lens system as schematically shown in Figure 12;
Figure 14 schematically shows part of the apparatus comprising a projection lens system including a cooling device and a substrate holding device including a temperature stabilization device.
15 illustrates an example process for manufacturing a semiconductor device, and
Figure 16 illustrates an example process for inspecting a target.

Figure 1 shows a top view of a first example of a substrate holding device according to the invention, and Figure 2 shows a partial cross-section of a first example along line A-A in Figure 1. The substrate holding device 1 comprises a holding plate 2 with a first side 3 for holding a substrate (not shown). The substrate holding device 1 comprises a base plate 4 arranged at a distance from the holding plate 2 and on the second side 6 of the holding plate 2 facing away from the first side 3. ) further includes. Between the base plate (4) and the holding plate (2), a gap (5) extending in a direction substantially parallel to the first face (3) of the holding plate (2) is provided. An array of supports (7) defining the distance between the holding plate (2) and the base plate (4) and thus the width (w) of the gap (5) is provided between the holding plate (2) and the base plate (4). are arranged in The holding plate (2), base plate (4) and support (7) provide a heat absorbing material arranged to remove heat from the substrate arranged on the first side (3) of the substrate holding device (1) when in use. A frame for this is provided within the gap (5).

The holding plate 2 includes, for example, a Si plate. The base plate 4 includes, for example, a plate of Si-Carbide, which has an expansion coefficient substantially equal to that of Si. Additionally, Si carbide is virtually inert and allows the use of a large range of heat-absorbing materials. Furthermore, Si carbide has a high thermal conductivity that allows cooling of the substrate holding device 1 through the base plate 4, providing a substantially constant temperature along the base plate 4.

The support 7 includes, for example, a titanium support that is non-magnetic. A non-magnetic support is advantageous when using the substrate holding device 1 in a charged particle processing device or an imaging device. Although the support 7 may be fixed between the holding plate 2 and the base plate 4, as explained in more detail below with reference to FIGS. 2, 3A, 3B and 3C, the support (7) may be fixed between the holding plate 2 and the base plate 4. 7) is preferably fixedly attached to the second side 6 of the holding plate 2 and/or to the base plate 4.

According to the invention, an array of droplets (8) of heat-absorbing material is arranged between the holding plate (2) and the base plate (4). Liquid and/or solid droplets (8) are arranged to fill the gap (5) between the base plate (4) and the holding plate (2); The droplet 8 is thus arranged to contact both the base plate 4 and the holding plate 2. The droplets 8 are arranged spaced apart from each other, adjacent to each other in the direction along the gap 5, and arranged substantially spaced apart from the support 7. The droplet 8 is restrained by the holding plate 2 and the base plate 4 in a direction substantially perpendicular to the first face 3 of the holding plate 2. Additionally, the droplet 8 is arranged to enable expansion of the droplet 8 in a direction along the gap 5 between the base plate 4 and the holding plate 2. As schematically shown in Figure 2, the droplet 8 is arranged in (thermal) contact with the holding plate 2 and the base plate 4. Preferably, the droplet 8 has a melting temperature at or near the temperature of the substrate processing device, at least during processing of said substrate, or at least at or near the temperature of the substrate imaging device during imaging of said substrate. Includes materials with a melting range. Heat removal is provided by the use of phase transition, especially melting, of the droplets 8. Since the droplet 8 is arranged to enable expansion of the droplet 8 in the direction along the gap 5, the contraction or expansion of the droplet 8 when proceeding from solid to liquid and vice versa is caused by the holding plate ( 2), there is virtually no effect on the dimensions of the assembly comprising the base plate 4 and support 7.

The heat absorbing material is preferably arranged in an array of flat droplets 7 with a diameter of approximately 15 mm and a thickness of approximately 0.8 mm. Using droplets 7 with a diameter of approximately 15 mm allows providing an array of supports 7 between the droplets, the supports 7 being positioned on the highly flat first side of the holding plate 2. arranged sufficiently close together to provide (3). In this particular example, the support 7 is arranged to provide a gap 5 with a width w of approximately 0.8 mm.

In this first example, the base plate 4 has an array of pockets 9 arranged as shallow depressions or cavities in the surface of the base plate 4 opposite the gap 5 . The pocket 9 in this first example is substantially shaped as a conical frustum. For example, the downward slope 91 of the cone may be approximately 15 degrees and, at the center of the pocket 9, a substantially flat area is arranged. The droplet 8 is arranged to contact both the base plate 4 and the holding plate 23. The cone-shaped edge 91 of the pocket 9 will substantially 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 liquid droplet 8 provide a positioning force that substantially holds the liquid droplet 8 within the pocket 9. No other parts are required to fix the position of the droplet 8. This allows to arrange the droplets 8 closer to each other within the substrate holding device 1 of this first example, which provides adequate coverage of the area of the holding plate 2 and the base plate 4 to absorb heat. Provides materials. Due to the substantially flat area at the center of the pocket 9, the pocket 9 of the first example substrate holding device 1 is shallow, which reduces the required amount of heat-absorbing material.

As shown in Figure 2, the base plate 4 is provided with an array of holes 41 and the first end of each support 7 of the series of supports is arranged within one of the holes 41 and is adhesively connected. It is fixed in the hole 41 through. The second end of each support 7, opposite the first end, is fixed to the holding plate 2 by an adhesive connection.

3A , 3B and 3C schematically show steps of a method for assembling a substrate holding device 1 , in particular for assembling a substrate holding device according to the embodiment of FIG. 2 . However, the substrate holding device according to the embodiment as described below with reference to FIGS. 4A, 4B, 5, 7 and 10 can also be assembled in this way.

First, a base plate 4 is provided comprising an array of pockets 9, as shown in Figure 3a. Adjacent to these pockets 9, holes 41 are provided on the inside for mounting the support 7 therein. Furthermore, the holding plate 2 comprises, at least in use, a series of supports 7 fixed to a second side 6 of the holding plate 2 facing away from the first side 3 for holding a substrate. is provided. The support 7 is arranged to extend substantially perpendicular to the second face 6 and is fixed to the second face 6 via an adhesive connection 71 .

Subsequently, droplets 8 of liquid heat-absorbing material are arranged within pockets 9, as schematically shown in FIG. 3B. In each pocket 9 of substantially equal size, substantially the same volume of heat absorbing material is distributed. Preferably, the heat-absorbing material exhibits a greater cohesive force than the adhesion with the surface of the holding plate 2 and/or base plate 2 facing the gap 5 . Due to surface tension, the liquid droplet 8 takes on a somewhat spherical shape.

Next, the holding plate 2 with the support 7 is moved towards the base plate 4, and the support 7 is placed in the hole 41. The holding plate 2 is moved downward until the desired distance w between the holding plate 2 and the base plate 4 is reached. In this position, the droplet 8 becomes flat within between the base plate 4 and the holding plate 2, as shown in Figure 3c. The surface tension of the heat absorbing material provides for and holds the droplet 8 in contact with both the holding plate 2 and the base plate 4.

Subsequently, at least one of the supports 7 is fixed in the corresponding hole 41 via an adhesive connection, the adhesive connection being formed in a circumferential direction between the hole 41 and the support 7 extending into the hole 41. provided within the gap.

Prior to use, the assembled substrate holding device 1 is arranged in a 'cold' environment at a temperature below the freezing temperature of the heat-absorbing phase change material, and the liquid droplet 8 is substantially as shown in Figure 3c. It will solidify into the same shape. Accordingly, the solid droplet 8 fills the gap 5 between the base plate 4 and the holding plate 2. Now, the substrate holding device 1 is ready for use.

In the first previous example, the pockets 9 for holding solid and/or liquid droplets 8 are arranged in the base plate 4, as explained above. However, in a second example of the substrate holding device 1', the pocket 9' is connected to the base plate 4 with a substantially flat surface opposite the gap 5', as schematically shown in FIG. 4A. It is arranged in the holding plate (2') in combination with ').

Alternatively, in a third example of the substrate holding device 1 ", a holding plate 2'' and a base plate 4'' opposite the gap 5'', as schematically shown in FIG. 4B ) have pockets 92, 93. In this embodiment, a holding plate 2" and a base plate 4" face the gap 5" forming the pockets 92, 93. ) may be shallower and less deep compared to the pockets 9, 9' of the substrate holding device 1, 1' according to the first and second examples.

Figure 5 is a schematic partial cross-sectional view of a fourth exemplary embodiment of the substrate holding device 11. Figure 6 is a schematic partial top view of the base plate 14 of the substrate holding device of Figure 5. In this fourth example, the base plate 14 has an array of pockets 19 that are substantially shaped as cones. For example, the downward slope of the cone may be approximately 15 degrees. Droplets 18 are arranged within the pockets 19 and are arranged to fill the gap between the base plate 14 and the holding plate 12. The conical shape of the pocket 91 will substantially fix the position of the liquid and/or solid droplet 18 of the heat absorbing material. Additionally, the conical shape of the pocket 19 and the surface tension of the liquid heat absorbing material provide a force holding the liquid droplet 18 substantially at the center of the pocket 19. No other parts are required to fix the position of the droplet 18.

Also in this fourth example, the base plate 14 is provided with an array of holes 141, each support 17 of the series of supports being arranged on one side within one of said holes 141 and having an adhesive connection. It is fixed within the hole 141 through. The other side of the support 17 is fixed to the holding plate 12.

Additionally, the base plate 14 may be provided with a ventilation hole 142 that opens substantially at the center of the pocket 19. The vent hole 142 is arranged to prevent entrapment of air beneath the droplet 18.

Figure 7 is a schematic partial cross-sectional view of a fifth exemplary embodiment of the substrate holding device 21. In this fifth example, the base plate 24 has an array of pockets 29 that are substantially shaped as straight cylinders with a substantially circular bottom area. The droplet 28 is arranged within the pocket 29 and contacts both the circular bottom region of the pocket 29 in the base plate 24 and the holding plate 22 . To allow the droplet 28 to expand at least in the direction along the gap 25 , the volume of the droplet 28 is determined by the diameter of the droplet 28 in the direction parallel to the bottom region of the pocket 29 It is arranged to be smaller than the diameter of the cylindrical pocket (29). The cylindrical pockets 29 will substantially establish the position of the droplets 28 of heat absorbing material, both in the solid and liquid phases. No other parts are required to substantially fix the position of the droplet 28. The advantage of this example is that the surface of the base plate 24 on which the pockets 29 are not arranged can be arranged close to the holding plate 22 . Accordingly, the holding plate 22 can be connected to the base plate 24 using very short supports 27 or even without supports at all, which results in a very robust substrate holding device 21 .

In a sixth example of the substrate holding device 31 , as schematically shown in FIG. 8 , the droplet 38 is connected to an O-ring 39 made of a flexible or elastic material such as rubber, for example Viton®. arranged inside. Each of the droplets 38 is arranged inside an O-ring 39, which provides transverse confinement of the droplet 38 and provides a gap due to the flexible or elastic material of the O. Allows contraction and expansion of the droplet 38 in the direction along 35).

The thickness of the O-ring 39 is preferably smaller than the width w' of the gap 35 between the holding plate 32 and the base plate 34. This involves assembling the substrate holding device 31 comprising the holding plate 32, the base plate 34 and the support 37 and the gap having the required width w' without the interference of the O-ring 39. Allows obtaining (35). O-ring 39 contacts both holding plate 32 and base plate 34 or is compressed within between holding plate 32 and base plate 34, which means that it This is avoided, as it may have a negative effect on the flatness of the surface 33.

As shown in FIG. 8 , gap 35 is substantially open at the peripheral side edge 310 of substrate holding device 31 . Gap 35 may even be substantially open along substantially the entire peripheral side edge 310 of substrate holding device 31 . Accordingly, gap 35 comprises an open connection to the outside of substrate holding device 31 . The air or vacuum pressure inside the gap 35 is substantially equal to the air or vacuum pressure outside the substrate holding device 31 .

9A, 9B and 9C schematically illustrate steps in a method for building a substrate holding device 31' according to the embodiment of Figure 8, in this example where the support 37' is a base plate ( 34') with this difference being that they are arranged within an array of holes 341'.

First, a base plate 34' is provided which includes an array of holes 341'. A series of supports 37' is provided and each support 37' of the series is arranged in one of the holes 341', preferably within the hole 341' via an adhesive connection. It is fixed in

Subsequently, as schematically shown in Figure 9a, an assembly of O-rings 39' with solid pills or droplets 38' of heat-absorbing material is arranged within between the supports 37'. The thickness d of the assemblies 38', 39' is smaller than the height h at which the support 37' protrudes out of the base plate 34'.

Next, a holding plate 32' is arranged on top of the support 37' and is preferably fixed to the support 37' via an adhesive connection. As schematically shown in Figure 9b, a holding plate 32' is arranged on top of the support 37' with a gap over the assembly of O-rings 39' and a solid droplet 38' of heat absorbing material. do.

Subsequently, the solid droplet 38' of heat absorbing material is melted, for example by placing the assembly in an oven at a temperature above the melting temperature. Due to the surface tension of the liquid droplet 38' of the heat absorbing material, the liquid droplet 38' will take on a more spherical shape, as schematically shown in Figure 9C, and will form a more spherical shape than that of the holding plate 32'. It contacts the second side 36'. The droplet 38' is now arranged to fill the gap 35 between the base plate 34' and the holding plate 32'.

The assembled substrate holding device 31' is then arranged in a 'cold' environment at a temperature below the freezing temperature of the heat absorbing material, and the liquid droplet 38' is formed substantially as shown in Figure 9C. will solidify into Accordingly, solid droplet 38' fills gap 35' and contacts both base plate 34' and holding plate 32'. Now, the substrate holding device 31' is ready for use.

Figure 10 is a schematic partial cross-sectional view of a seventh embodiment of the substrate holding device 51. In this seventh example, the base plate 54 has an array of pockets 59 that are substantially shaped as straight cylinders with a substantially 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 smaller than the first diameter. The second pocket portion 593 is arranged substantially in the center of the first pocket portion 592. This yields a rim or step 61 arranged inside the pocket 59, extending along the circumferential side wall of the pocket 59.

Each pocket 59 of the array of pockets comprises an elastic member, in particular an elastic cover plate 60, spanning the pocket 59 and arranged at a distance from the bottom surface 591 of the pocket 59. . The elastic cover plate 60 has a diameter that is smaller than the first diameter, but larger than the second diameter. Accordingly, the circumferential edge of the elastic cover plate 60 lies on top of the rim or step 61. The elastic cover plate 60 is positioned in any direction substantially perpendicular to the gap 55 by flexing or bending at least a central portion of the cover plate 60 toward the bottom surface 591 of the pocket 59. Provides a means for absorbing residual expansion. Preferably, the elastic cover plate 60 is a titanium plate.

Each pocket 59 contains a droplet 58 from the array of droplets, the droplets 58 being arranged between the elastic cover plate 60 and the second side 56 of the holding plate 52. . The droplet 58 of the PCM is arranged substantially centrally on top of the elastic cover plate 60 .

As schematically shown in FIG. 10 , a cover plate 60 is arranged inside a corresponding pocket 59, below the surface 63 of the base plate 54 surrounding the pocket. ) provides means for fixing the position of the droplet 58 in the gap 55 between the base plate 54 and the holding plate 52. In order to increase heat transfer between the elastic holding plate 60 and the base plate 54, a thermally conductive paste is preferably arranged between the circumferential edge of the elastic holding plate 60 and the rim or step 61.

Additionally, each pocket 59 includes a ring or loop 62 arranged to surround the droplet 58 within the pocket 59. Preferably, the ring is made from a synthetic material such as Viton® or a rubber material. A ring or loop 62 is arranged within the pocket 59, preferably on the top of the elastic cover plate 60, and acts as a restraining member for the droplet 58 of PCM within the pocket 59. do. The thickness of the ring or loop 62 is smaller than the distance between the holding plate 52 and the elastic cover plate 60. Accordingly, the ring or loop 62 is not in direct contact with both the cover plate 60 and the holding plate 52. The ring or loop 62 comprises a substantially rectangular cross-section in a direction substantially perpendicular to the first face 53 of the holding plate 52 . The substantially flat upper surface of the ring or loop 62 is arranged opposite the second face 56 of the holding plate 52 . When using a PCM with a high density, such as a metallic material with gallium-like material behavior, the ring or loop 62 is pushed upward by the PCM, which holds the ring or loop 62 against the holding plate 52. It will push towards the second side 56. The flat upper surface of the ring or loop 62 is pushed against the second side 56 of the holding plate 52 and provides a seal for containing the PCM inside the ring or loop 62.

In the example shown in FIG. 10 , the base plate 54 opens a ventilation hole 542 opening at the bottom surface 591 of the pocket 59, preferably at the center of the pocket 59. Due to the vent hole 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 holding device 51. is the same as

Additionally, in this seventh example, the base plate 54 has an array of holes 541 and the holding plate 52 has an array of supports 57 . Each support 57 is arranged in a corresponding one of the holes 541 and is fixed in the hole 541 through an adhesive connection.

All of the examples given above illustrate, according to the invention, a substrate holding device suitable for holding an array of droplets of a heat absorbing material, preferably a phase change material (PCM), more preferably a metallic PCM. . Examples of these materials are presented in the table below:

11 shows a simplified diagram of an apparatus for processing or imaging sample 130. The apparatus comprises a module 201 comprising a source for electromagnetic radiation or energetic particles, a module 204 comprising an exposure unit for exposing the sample 103 to electromagnetic radiation or energetic particles, and It includes a substrate holding device 209 according to the present invention.

In particular, Figure 11 schematically represents a multi-beam charged particle lithography system comprising:

- an illumination optics module (201) comprising a charged particle beam source (101) and a beam collimating system (102),

- an aperture array and converging lens module (202) comprising an aperture array (103) and converging lens array (104),

- a beam switching module (203) comprising a beam blanker array (105), and

- a projection optics module 204 comprising a beam stop array 108, a beam deflector array 109, and a projection lens array 110.

In the example shown in Figure 11, the modules are arranged within an alignment inner subframe 205 and an alignment outer subframe 206. Frame 208 supports alignment subframes 205 and 206 via vibration damping mounts 207.

Modules 201, 202, 203, 204 are configured to generate a plurality of charged particle beams, to modulate the charged particle beam, and to direct the charged particle beam to the first side 209' of the substrate holding device 209. ) together to form a charged particle optical unit for directing towards.

A substrate holding device 209 is arranged on the top of a chuck 201 . On the first side 209' of the substrate holding device 209, a target, for example a wafer 130, may be arranged.

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

The lithographic apparatus 200 is arranged inside a vacuum chamber 400 containing a mu metal (μ metal) shielding layer or layers 215 . The shield 215 is arranged in a convenient manner as a lining of the vacuum chamber 400. 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 with a measurement device 250 attached to the alignment subframe 205, 250 monitors the position of chuck 210 relative to measurement device 250. The measurement device 250 comprises, for example, an interferometric system, with the chuck 210 now having a mirror 251 for reflecting the light beam 252 from the interferometric system.

FIG. 12 shows a cross-sectional view of an embodiment of an improved projection lens assembly 300 for use in, for example, projection optics 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. Projection lens assembly 300 further includes a cover element 310 and a support element 340 at the downstream end of the housing. The passage 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 to the second electrode. It opens at (302). The plurality of charged particle beams impact a target 370 arranged on top of a substrate holding device, preferably but not necessarily, the substrate holding device 1 as described in Examples 1 to 6 above. It is also possible to previously penetrate the through opening. In the depicted embodiment, support element 340 extends substantially parallel to both first and second electrodes 301, 302. Preferably, the support element 340 extends radially away from the lens aperture array in the first and second electrodes 301, 302.

To prevent the formation of an electric field between target 370 and projection lens assembly 300, both may be connected to ground and/or conductively connected to each other. The structurally sound projection lens assembly according to the present invention may be placed integrally in a known lithography system or may be exchanged or removed for holding maintenance purposes.

The plurality of charged particle beams first pass through a through passage 313 within the cover element 310. Once the charged particle beam passes through the through opening 313 they reach the beam stop array 308. The beam stop array 308 is arranged to block the charged particle beam deflected by the beam blanker array 105 of the beam switching module 203. A charged particle beam deflected by beam blanker array 105 (see, e.g., Figure 11) is blocked by beam stop array 308 and does not reach target 370. Accordingly, the charged particle beams may be individually modulated by the beam blanker array to allow or not allow the individual charged particle beams to impinge on the target 370. The beam that is not deflected by the beam blanker array travels through the beam stop array 308 and is projected onto the surface of the target 370 by an electrostatic lens provided by the first and second electrodes 301 and 302. . Using this modulation and movement of the target 370 relative to the exposure unit comprising the projection lens assembly 300 allows writing of a pattern onto the surface of the target 370.

In some projection lens systems, a deflector unit is arranged between the beam stop array 308 and the first and second electrodes 301, 302, where the deflector unit directs the beam stop array over the surface of the sample 307. is arranged to provide scanning deflection of the beam passing through 308). Preferably, the deflector unit comprises X and Y deflectors for deflecting the beam in an orthogonal direction perpendicular to the optical axis (OA) of the projection lens system 300.

As indicated above, beam stop array 308 is a component for at least partially and/or temporarily blocking at least some of the charged particles of a plurality of charged particle beams. To remove heat generated by blocking the charged particle beam, the beam stop array 308 component is provided with a conduit 309. In use, cooling fluid is conducted through conduits 309, which are arranged in thermal contact with the beam stop array 308. At least the first portion 307 of the conduit is arranged in the region between the two charged particle beams, as schematically shown in FIG. 13 . The central axis of the first portion 307 of the conduit extends in a direction substantially perpendicular to the central axis or optical axis OA of the projection lens system 300.

12 and 13, at least the second portion 306 of the conduit is configured such that the central axis of the second portion 306 of the conduit is the central axis or optical axis (OA) of the projection lens system 300. It is arranged to extend, so as to extend in a direction substantially parallel to. Accordingly, the first portion 307 of the conduit may be arranged at or near the first end 303 of the projection lens system 300, which, in use, is arranged close to the substrate 370. The second portion 306 of the conduit provides an extension of the conduit away from the first end 303 of the projection lens system 300, which provides an input connection for fluid suitably spaced from the first end 303. 304) and/or output connections 305 and arranged at the first end 303 of the projection lens system 300 very close to the substrate 370.

The cooling unit as shown in FIG. 13 cools active components for manipulating the charged particle beam, such as but not limited to electrostatic deflectors or lenses, at least partially or temporarily on these active components. Note that it can also be used to displace heat generated by electronic components arranged within. Active components, for example first and second electrodes 301 and 302, may be arranged within between conduits 307.

FIG. 14 shows a cross-sectional view of 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 during at least the exposure. The assembly shown in Figure 14 is suitable for use, for example, in the projection optics module 204 of the multi-beam charged particle lithography system of Figure 11.

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

Projection lens assembly 400 also includes components for manipulating and/or blocking at least partially and/or temporarily at least a portion of the charged particle beam. One such component is a beam stop array 408 arranged to block a charged particle beam deflected by the beam blanker array 105 of the beam switching module 203 shown in FIG. 11 . The beam stop array 408 includes a cooling device arranged to substantially hold the beam stop array 408 at a first predetermined temperature. In the example shown in Figure 14, the cooling device also cools other portions of the projection lens assembly and, in use, substantially the entire projection lens assembly is at the first temperature. The projection lens assembly comprises a first temperature sensor T1 arranged on a support element 440 , for example the first temperature sensor T1 is positioned opposite the projection lens assembly, in particular the substrate holding device 480 . arranged to measure the temperature of a portion of the projection lens assembly.

The cooling device comprises a substantially closed circuit of conduits or ducts for a cooling fluid, particularly a cooling liquid such as high purity water. The cooling device further includes a cooling device 450 for cooling the cooling fluid to a temperature lower than the first temperature. Cooling device 450 includes a heat exchange circuit 451 that, when in use, is coupled to a fab coolant circuit.

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

As indicated above, beam stop array 408 is a component for at least partially and/or temporarily blocking at least some of the charged particles of a plurality of charged particle beams. To remove the heat generated by blocking the charged particle beam, the beam stop array 408 component is provided with a conduit 409 that is part of a cooling device. In use, cooling fluid from the cooling device 450 and from the heating device 470 is arranged to flow through the conduit 406 toward the conduit 409, which is connected to the beam stop array 408. Arranged in thermal contact. Subsequently, the cooling fluid flows back to the cooling device 450 through conduits 406', 405. As shown in FIG. 14 , the conduit 409 is within the projection lens system 400 and, in use, at or near the first end 403 of the projection lens system 400, which is arranged close to the substrate 470. are arranged in

Moreover, the closed circuit 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:

A second temperature sensor T2 is arranged in the conduit between the cooling device 450 and the heating device 470;

A third temperature sensor T3 is arranged in the conduit between the heating device 470 and the beam stop array 408; and

A fourth temperature sensor T4 is arranged in the conduit downstream of the beam stop array 408.

Temperature sensors T1, T2, T3 and T4 are configured to control the flow of fab cooling liquid through heat exchange circuit 451 within cooling device 450 and/or control the flow of cooling fluid by heating device 470. Provides input to a temperature control system 490 arranged to control heating. The temperature control system 490 maintains a temperature difference between the substrate holding device 480 and the projection lens system 400, particularly the first end 403 of the projection lens system 400 opposite the substrate holding device 480. It is arranged to control the heating device 470 and/or the cooling device 450 to establish, preferably, a temperature difference in the range of 1° C. to 1.5° C.

Sample 470 is arranged on top of a substrate holding device 480 for holding the sample 470 at least during exposure. The substrate holding device 480 includes a holding plate 481 , where the holding plate includes a first side for holding a substrate 470 , and a base plate 482 . Between the holding plate 481 and the base plate 482, a temperature stabilizing device comprising a phase change material 483 having a phase change at a second temperature is arranged. The substrate holding device 480 is preferably, but not required, a substrate holding device as described in Examples 1 to 6 above.

In the example shown in Figure 14, both substrate holding device 480 and projection lens system 400 each have provisions for controlling their temperature. In particular, since the projection lens system 400 is arranged to expose the sample 470 using an energetic charged particle beam, the projection lens system 400, in particular the beam stop array 408 and/or the sample 470 will absorb at least some of the energy. By providing both the projection lens system 400 and the substrate holding device 480 with their own cooling and temperature stabilization devices, precise temperature control of the substrate 470 can be achieved, comprising:

holding the temperature of the projection lens system 400, particularly its beam stop array 408, at least substantially at a first temperature, preferably using a readily available fab coolant, and

Use of a phase change material that has a phase change at the second temperature allows the temperature of the substrate 470 to be held at the second temperature.

Figures 12 and 14 schematically show, in particular, a charged particle beam exposure system using low keV charged particles, for example charged particles having an energy of substantially less than 10 keV, preferably about 5 keV, Please note that this is not a constant ratio. In this charged particle beam exposure system using low keV 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 very small. The distance s is preferably smaller than the thickness d2 of the sample 470. If the sample 470 is a silicon wafer, the thickness d2 is typically 330 micrometers. The distance s is preferably smaller 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 smaller than 100 micrometers, preferably 50 micrometers.

As shown in the examples of Figures 12 and 14, both the substrate holding device 480 and the exposure unit, especially its projection lens system 400, are equipped with arrangements for controlling their temperature. Additionally, as schematically shown in FIG. 14 , the temperature of the cooling device of the exposure unit is controlled based on the temperature of the temperature stabilizing device of the substrate holding device 480. Accordingly, the cooling device adjusts the first temperature, in particular the temperature as measured by the first temperature sensor T1, to be close to or equal to the second temperature at which the phase change material 483 exhibits a phase change. It includes a configured control device 490.

The cooling device and the temperature stabilizing device are preferably arranged so that, at least during exposure of the substrate by the charged particle beam, the second temperature is at or near the first temperature.

Figure 15 shows a schematic flowchart 150 of an example of a method for manufacturing a semiconductor device by an apparatus according to the above-described description herein. The method includes the following steps:

151: Placing a wafer on a substrate holding device and positioning the wafer downstream of the exposure unit;

152: Processing the wafer including projecting an image or pattern onto the wafer by electromagnetic radiation or energized particles from the source; and

153: Performing subsequent steps to create a semiconductor device with the processed wafer.

16 shows a schematic flowchart 160 of an example of a method for inspecting a target by a device as described above herein, the method comprising the following steps:

161: Placing the target on a substrate holding device and positioning the wafer downstream of the exposure unit;

162: Projecting the electromagnetic radiation or particles with energy from the source onto a target;

163: When the electromagnetic radiation or energetic particles 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 inspect the target by 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 intended to limit the scope of the invention. From the above discussion, it will be apparent to those skilled in the art that there are many variations that will still be encompassed by the spirit and scope of the invention.

For example, although the shape and diameter of the pockets in the examples described above are substantially 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 holding device may be smaller than the pockets to obtain good coverage of the heat absorbing material along the edges of the substrate holding device.

Moreover, a large number of heat absorbing materials can be used. As already indicated, the heat absorbing material is preferably selected to have a melting temperature or melting range at or near the operating temperature of the substrate processing apparatus in which the substrate holding device is used. These heat-absorbing materials are also known under the name of phase change materials, or simply PCM.

In summary, the present invention relates to a substrate holding device comprising a holding plate, a base plate, an array of supports, and an array of droplets of heat absorbing material. The holding plate includes a first side for holding the substrate. The base plate is arranged at a certain distance from the holding plate and provides a gap between the base plate and the holding plate on the side of the holding plate opposite the first side. An array of supports is arranged between the holding plate and the base plate. An array of liquid and/or solid droplets is arranged 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 support, and adjacent to each other in the direction along the gap.

Additionally or alternatively, the present invention relates to devices and methods for exposing samples. The apparatus includes a source for electromagnetic radiation or energetic particles, 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 some of the electromagnetic radiation or charged particles. The component includes a cooling device arranged to substantially hold the component at a first predetermined temperature. The substrate holding device includes a temperature stabilization device arranged to substantially stabilize the temperature of the sample arranged on the substrate holding device. The temperature stabilizing device includes a phase change material having a phase change at a second temperature that is at or near the first temperature.

Claims (12)

As a substrate holding device,
A holding plate including a first side for holding the substrate;
a base plate arranged at a predetermined distance from the holding plate and providing a gap between the base plate and the holding plate on a second side of the holding plate facing away from the first side; and
At least comprising a support array arranged between the holding plate and the base plate,
A pocket array is located on the base plate and/or the holding plate, and the width of the gap between the holding plate and the base plate in one pocket of the pocket array is the gap between the holding plate and the base plate around the pocket. greater than the width of, each pocket being provided with an indentation or depression,
Substrate holding device. According to claim 1,
wherein the support array is fixedly attached to the second side of the holding plate and/or to the base plate,
Substrate holding device. According to claim 1,
The base plate has a plurality of holes for mounting the support array,
Substrate holding device. According to claim 1,
The base plate has a venting hole opening at the bottom surface of the pocket,
Substrate holding device. According to claim 4,
wherein the ventilation hole opens substantially in the center of the pocket,
Substrate holding device. According to claim 1,
The base plate includes Si-Carbide,
Substrate holding device. The method according to any one of claims 1 to 6,
The gap comprises an open connection to the outside of the substrate holding device.
Substrate holding device. The method according to any one of claims 1 to 6,
the gap is substantially open at a surrounding side edge of the substrate holding device,
Substrate holding device. The method according to any one of claims 1 to 6,
In the gap between the holding plate and the base plate, a heat absorbing material disposed to remove heat from the substrate disposed on the first side is located.
Substrate holding device. According to clause 9,
The heat absorbing material includes a phase change material,
Substrate holding device. The method according to any one of claims 1 to 6,
Further comprising a ring array arranged in the gap between the holding plate and the base plate,
Substrate holding device. Comprising a substrate holding device according to any one of claims 1 to 6,
Multi-beam charged particle lithography system.