Objective lens device

Abstract

The present invention provides an objective lens device (100) for projecting a light beam. The objective lens device includes an objective lens (110) comprising a plurality of optical components (112, 114a-f) supported by a plurality of component support structures (150, 152a-e) arranged within a housing (116). The plurality of optical components includes a final optical component (112) configured to focus the light beam onto a substrate (122). The final optical component is supported by the final component support structure (150). The objective lens device also includes a proximity sensor (130) and a processing unit (140). The proximity sensor (130) includes a sensor head (132) disposed between the objective lens and the substrate. The processing unit is configured to determine a first distance (d1) between the sensor head and the surface of the substrate based on input from the proximity sensor. The sensor head is mechanically attached to the final component support structure.

Description

Technical Field

[0001] This disclosure relates to an objective lens device for projecting a light beam onto a substrate. Background Technology

[0002] In optical microlithography, a projection optics device is used to focus a light beam onto a substrate, where a photoresist disposed on the substrate is exposed to the beam. Different areas of the substrate can be exposed to the beam, thus creating a pattern. Optical microlithography can produce extremely small patterns, down to the nanometer scale, and provides precise control over pattern design. Therefore, it is crucial that the beam is focused with high precision onto the correct plane. The performance achieved can be correlated with the accuracy of determining and compensating for deviations in the morphology of the photoresist to be exposed. For example, morphology variations can be compensated for by changing the spatial position of the projection optics of the exposure optical system relative to the photoresist.

[0003] A sensor can be provided to determine the distance between the projection optics and the surface of the substrate. Based on the determined distance, the spatial position of the projection optics, such as the height of the projection optics above the substrate or the distance between the projection optics and the substrate, can be dynamically adjusted, for example, via a feedback system. Thus, focusing can be maintained despite deviations in the morphology of the photoresist.

[0004] Furthermore, the achieved performance can also be affected by thermal instability. Various components within optical microlithography systems can generate heat and thus cause thermal instability. These thermal instabilities can affect components of projection optics, potentially leading to focal plane drift and performance degradation. To ensure performance and focusing accuracy, a reliable and effective method is needed to account for the impact of thermal instability on the components of projection optics. Summary of the Invention

[0005] A general objective of this disclosure is to provide a method for considering the effects of thermal instability or temperature variations on projection optics, such as those in a microlithography system. Specifically, it is desirable to provide an apparatus for detecting, measuring, and / or determining the effects of thermal variations on projection optics, such as changes in the spatial position of the projection optics. Furthermore, it is desirable to be able to adjust the spatial position of the projection optics to compensate for the effects of thermal variations, for example, by maintaining a certain distance between the projection optics and the photoresist.

[0006] Therefore, the object of the present invention is to satisfy at least some of the above-mentioned objectives and to provide improved focusing accuracy or focusing control and performance of the microlithography system. This and other objectives are achieved by the objective lens arrangement and the apparatus for projecting the light beam as defined in the appended independent claims. Other embodiments are defined by the dependent claims.

[0007] According to a first aspect of this disclosure, an objective lens device for projecting a light beam is provided. The objective lens device includes an objective lens comprising a plurality of optical components supported by a plurality of component support structures disposed within a housing. The plurality of optical components includes a final optical component. The final optical component is configured to focus the light beam onto a substrate and is supported by the final component support structure. The objective lens device also includes a proximity sensor comprising a sensor head. The sensor head is disposed between the objective lens and the substrate. The objective lens device further includes a processing unit configured to determine a first distance between the sensor head and a surface of the substrate based on input from the proximity sensor. The sensor head is mechanically attached to the final component support structure.

[0008] This disclosure relates to a concept for providing an objective lens device for projecting a light beam, which can improve quality and precision, for example, in optical microlithography. This disclosure also revolves around the idea of ​​providing a robust and efficient objective lens device that can improve focus control. The objective lens device can be used in devices employing optical microlithography technology. Optical microlithography is a process that uses a light beam (i.e., light) to create a pattern on a substrate. The substrate may have a thin coating of a suitable material, such as a photoresist. Thus, when different areas of the photoresist are exposed to the light beam, a pattern can be formed. Processes using microlithography can produce features in the micrometer range or smaller. The term nanolithography can be used for processes that can produce features in the nanometer range. Devices using this type of process may, for example, include a pattern generator and a mask writer. The term "lithography process" as used herein can, for example, refer to a process using microlithography or nanolithography.

[0009] The objective lens can be configured to project and / or focus a light beam onto a substrate. The light beam can include light of any suitable wavelength. The light beam can originate from a light source, such as a laser source. The substrate can include a flat surface, sheet, and / or plate. For example, the substrate can include a plate. The substrate can contain a material based on the chemical compound silica, such as glass, quartz, or soda-lime glass. The substrate can be at least partially transparent. At least one coating or layer can be provided on the surface of the substrate. The at least one coating or layer can include an opaque material, a photoresist, and / or a film. The at least one coating or layer can be a photoresist. The at least one coating or layer can be patterned.

[0010] The substrate can be arranged or placed on a movable or stationary substrate holder, platform or stand.

[0011] An objective lens may include one or more optical components, elements, or parts. One or more optical components may include lenses, mirrors, windows, optical planes, prisms, polarizers, beam splitters, waveplates, optical fibers, and / or filters. An objective lens may include a housing or cover. One or more optical components may be disposed within the housing. An objective lens may be configured to guide, transmit, modulate, and / or focus a light beam to a substrate or photoresist. An objective lens may be configured to focus light onto and / or collect light from a substrate. The light beam may be a laser beam. The light beam may enter the objective lens, pass through one or more optical components included in the objective lens, and then be projected or focused onto the substrate.

[0012] The final optical component can be the optical component closest to the substrate in the objective lens. The final optical component can be positioned adjacent to the substrate and / or at the front end of the objective lens. The front end of the objective lens can be the end facing the substrate and / or the end closest to the substrate. The final optical component can be a lens. Because the final optical component is configured to focus the light beam onto the substrate, it can at least partially determine the focusing plane, focal point, or focal point of the objective lens.

[0013] A proximity sensor can be configured to sense (or measure, detect, or determine) the presence of an object without any physical contact with it. The proximity sensor can be configured to perform measurements relating to the distance between a first object and a second object and / or the positions of the first and second objects. The proximity sensor can be configured to determine the presence of a substrate, for example, the proximity of the substrate surface to the sensor head. The proximity sensor can be configured to generate data relating to the proximity of the substrate surface to the sensor head. The proximity sensor can be configured to generate measurement data in real time during the projection process using the objective lens device.

[0014] One or more components of the proximity sensor may be disposed at, on, or near one of the components of the objective lens assembly. At least some portions or components of the proximity sensor may be placed or arranged in a suitable position to perform the desired measurement. At least one component of the proximity sensor may be disposed on or integrated into the sensor head. The objective lens assembly may include at least one proximity sensor. The sensor head may form part of the proximity sensor. The sensor head may also be considered part of the objective lens assembly itself.

[0015] The sensor head can be configured to allow a light beam exiting the objective lens to pass through or approach the sensor head to at least partially reach the substrate. The sensor head may include at least one opening or aperture. For example, the sensor head may include at least one opening that extends from, crosses, or propagates from a first side of the sensor head to a second side. For example, the sensor head may include an opening extending through the sensor head such that a light beam exiting the objective lens can preferably pass through the sensor head undisturbed to reach the substrate. The opening may have dimensions that allow an optical (writing) light beam to pass through the opening but deflect or block stray light from the beam from reaching the substrate. The opening may, for example, be in the form of a conical cavity. The sensor head may include at least one inlet or outlet. An inlet or outlet disposed in or on the sensor head may form part of a proximity sensor or be associated with a measurement performed by the proximity sensor.

[0016] The processing unit can be connected to a proximity sensor. The processing unit can be configured to process any kind of data, such as data generated by the proximity sensor. During the photolithography process, the processing unit can receive measurement data from the proximity sensor in real time, thereby performing real-time calculations or processing of the measurement data. A first distance between the sensor head and the surface of the substrate is determined by the processing unit. The first distance is determined based on input generated by the proximity sensor; for example, the input can be data related to the proximity or distance between the sensor head and the substrate. The input from the proximity sensor can be any kind of data generated by the proximity sensor. A second distance between the final optical component of the objective lens and the surface of the substrate can be determined based on the first distance. For example, since the distance between the sensor head and the final optical component can be fixed and known, the second distance can be related to the first distance. The processing unit can also determine the second distance. For example, the second distance can be determined based on a known relationship between the second distance and the first distance. For example, a third distance between the final optical component and the sensor head can be known. The third distance can be at least substantially constant, such that a measurement change in the first distance implies a corresponding change in the second distance. Therefore, any deviation of the focal plane from its ideal or preferred position can be determined or inferred based on the measured or determined first distance.

[0017] The first, second, and third distances can be defined along the Z-direction, which can be defined as the direction from the objective lens assembly toward the substrate. The Z-direction can be orthogonal to the plane of the substrate. The Z-direction can be defined as the direction along the optical axis of the objective lens and / or the final optical component. The sensor head can be arranged (at least partially) along the Z-direction between the surfaces of the objective lens and the substrate.

[0018] It may be desirable to hold the objective lens (or final optical component) at a certain working distance from the surface of the substrate. This working distance can be a defined, suitable, or preferred distance that keeps the focal point of the objective lens within a certain range. Therefore, it may be desirable for a second distance to correspond to or be equal to the working distance. To achieve the desired quality in projection processes (such as photolithography), the beam can be focused in or on a plane, i.e., in this case, on the surface of the substrate, with an accuracy of up to 20-50 nm in the Z direction. This means that the second distance can be controlled with an accuracy of 20-50 nm.

[0019] The sensor head is mechanically attached to the final component support structure. In other words, the sensor head is mechanically attached to the final optical component. The sensor head may be mechanically attached to a portion that can contact the final optical component. The sensor head may be attached against or toward the final optical component of the objective lens, while being arranged between the objective lens and the substrate. The sensor head may be attached to the front end of the objective lens or the objective lens housing, attached to the front end of the objective lens or the objective lens housing, or attached against the front end of the objective lens or the objective lens housing. In one example, the sensor head may be mechanically attached to, for example, a structure (arrangement or portion) of the objective lens, which may be close to or adjacent to the final optical component.

[0020] The objective lens apparatus for projecting a beam according to a first aspect of this disclosure can provide an objective lens apparatus that can detect and / or consider changes in a second distance between the final optical element and the substrate based on the determination of a first distance. The change in the second distance can be caused, for example, by thermal instabilities affecting at least one component of the objective lens. For example, one or more components of the objective lens can expand or contract in response to temperature changes. The first distance between the sensor head and the substrate can be changed due to thermal instabilities affecting the objective lens. For example, the objective lens or at least one component of the objective lens may expand due to localized heating by a heat source. The thermal expansion of the objective lens or at least one component of the objective lens can, for example, cause the objective lens to elongate or laterally expand toward the substrate (i.e., in the Z direction). As a result, the focal plane or focus of the objective lens may deviate from its desired or nominal position. Even if the thermal instabilities are small, they can have a crucial effect on the focal plane of the objective lens, thus having a crucial effect on the quality and accuracy of the projection process. By mechanically attaching the sensor head to the final optical element (e.g., by attaching it to a final element support structure), a change in the position of the final optical element (corresponding to a deviation in the focal plane) can result in a corresponding change in the position of the sensor head. Therefore, determining the initial distance can capture or detect the effects of thermal instability on the objective lens. Consequently, the objective lens arrangement can provide the possibility of detecting the drift of the objective lens's focal plane or focus.

[0021] Conventionally, in existing systems, the sensor head can be attached to the upper part of the objective lens, at the end of the objective lens opposite the final optical component. Therefore, if components in the objective lens expand or contract due to thermal changes, the position of the final optical component may change, while the position of the sensor head remains unchanged. In other words, in existing systems, the third distance between the final optical component and the sensor head may be affected by thermal instability. If the third distance changes, the second distance between the final optical component of the objective lens and the surface of the substrate may not be accurately determined solely based on the measurement or determination of the first distance between the sensor head and the surface of the photoresist.

[0022] By attaching the sensor head to the final optical component, a change in the position of the final optical component can lead to a corresponding change in the position of the sensor head. Therefore, a change in the position of the final optical component can result in a change in the aforementioned first distance, but not a change in the third distance. Furthermore, the mechanical attachment device for mechanically attaching the sensor head to the final optical component can be smaller and requires fewer or even smaller components. Therefore, a mechanical attachment device for attaching the sensor head to the final optical component can be less sensitive to thermal instability than a mechanical attachment device for attaching the sensor head to the opposite side of the objective lens.

[0023] Attaching the sensor head to the final optical components provides stable mounting of the sensor head and thereby improves the accuracy of determining the first distance. Furthermore, detecting changes in the first distance provides the possibility of correcting, compensating for, or adjusting the spatial position of the objective lens to maintain a desired second distance or a specific working distance. Therefore, the objective lens arrangement according to the first aspect of this disclosure allows for the dynamic detection and compensation of changes in the second distance.

[0024] A final component support structure can support, mount, hold, or arrange the final optical component. The final component support structure can be included within the objective lens, for example, disposed within the objective lens housing. The final component support structure can arrange the final optical component such that it is correctly positioned within the objective lens and / or correctly spaced from other components of the objective lens. For example, the final optical component can be partially framed by the final component support structure. The final component support structure can include, for example, rings, cylinders, collars, and / or shoulder mounts, which can have a shape suitable for supporting the final optical component. Depending on the nature of the final optical component, the design or shape of the final component support structure can vary. Different final component support structures can be adapted or suited to different final optical components and their corresponding functions or purposes. The sensor head can be attached, fastened, or fixed to the final component support structure, for example, using glue, screws, bolts, nails, or rivets. Thus, the sensor head can be attached to the final component support structure using, for example, screws, which in turn supports the final optical component of the objective lens disposed closest to the substrate. The final component support structure can include a metal-based material. The final component support structure may include a material with a similar coefficient of thermal expansion to the final optical component. For example, the final component support structure may include stainless steel or titanium. In one example, the final optical component may be a lens, and the final component support structure may include a metal cylinder that partially surrounds or frames the edge of the lens. The metal cylinder can partially surround the lens to allow light beams to pass through it, and it can also provide support for the lens so that it is properly positioned within the objective lens. The sensor head can be attached to the lens by using screws to fasten it to or against the metal cylinder that supports the lens.

[0025] Attaching the sensor head to the final component support structure provides increased stability for the sensor head attachment or mounting. Because the sensor head can be attached to the final component support structure that supports the final optical components, it can effectively and safely allow the detection of changes in the initial distance caused by thermal instability affecting the objective lens. For example, the sensor head can be mechanically attached to the final component support structure using screws. Objective lens devices with this type of sensor head attachment provide improved stability and, consequently, smaller variations in the accuracy of projection processes such as photolithography.

[0026] Multiple additional optical components, elements, or parts may include lenses, mirrors, windows, optical planes, prisms, polarizers, beam splitters, waveplates, optical fibers, and / or filters. The optical components of the objective lens can be arranged or positioned in various configurations and / or combinations depending on the application and purpose of the objective lens assembly. Multiple optical components of the objective lens may be arranged within the objective lens housing. Each of the multiple additional optical components may be supported by a component support structure. The component support structure can support, mount, hold, or arrange the optical components. The component support structure may be included in the objective lens, for example, arranged within the objective lens housing. The component support structure can arrange the optical components such that the optical components are correctly positioned within the objective lens and / or spaced apart from each other. For example, the optical components in the objective lens may be at least partially framed by the component support structure. The component support structure may include, for example, rings, cylinders, collars, and / or shoulder mounts, which may have a shape suitable for supporting a particular optical component. Depending on the characteristics of the optical component, the design or shape of the component support structure supporting that optical component can vary. Different component support structures can be adapted to or suited to different optical components and their corresponding functions or purposes. Component support structures can be configured to position, arrange, or space multiple additional optical components within the objective lens. The component support structures of the optical components within the objective lens can be interconnected, linked, or connected to each other. Therefore, optical components can be correctly positioned within the objective lens and / or correctly spaced apart from each other within the objective lens. Component support structures ensure the stability of the optical components within the objective lens.

[0027] According to some embodiments, the objective lens may be a microscope objective lens.

[0028] Objective lenses can be of the type that can be used in a microscope.

[0029] Therefore, objectives can have focal points in the micrometer or nanometer range. Objectives can be final lenses or field lenses, which are types found in microlithography systems or devices such as pattern generators or mask writers.

[0030] According to some embodiments, the proximity sensor may include a pneumatic proximity sensor.

[0031] A pneumatic proximity sensor can be configured to sense, measure, detect, or determine the pressure, flow rate, mass, and / or volume of a gas, and, for example, determine the presence of an object based on the gas's pressure, flow rate, mass, and / or volume. For example, gas can flow into or through a gap or space between the sensor head or objective lens and the surface of a photoresist, and the pneumatic proximity sensor can measure the flow rate of the gas in that gap or space. The gas flow rate can vary depending on the distance or proximity between the sensor head and the surface of the substrate. A pneumatic proximity sensor may include one or more components. A pneumatic proximity sensor can provide proximity measurements without affecting the surface of the substrate. For example, if the substrate includes a photoresist, an optical proximity sensor can interact with or partially develop the photoresist. A pneumatic proximity sensor can have reduced interaction with or influence on the surface of the substrate. Furthermore, compared to, for example, an optical proximity sensor, such a sensor can reduce the influence or interaction of a light beam projected onto the photoresist.

[0032] According to some embodiments, a pneumatic proximity sensor may include a gas source, a gas channel configured to guide gas from the gas source through a gas outlet in a sensor head, and a flow rate sensor configured to measure the gas flow rate. A processing unit may be configured to determine a first distance between the sensor head and the surface of a substrate based on the measured gas flow rate.

[0033] One or more components of a pneumatic proximity sensor may be arranged or placed in various locations within and / or on different components of the objective lens assembly. One or more components of a pneumatic proximity sensor may be arranged in locations other than the objective lens assembly, such as as part of a system or device in which the objective lens assembly is arranged.

[0034] A gas source can be, for example, a pressurized gas reservoir. The gas source may include pressurized or compressed gas, such as air. The gas in the gas source may have a known or constant pressure. A gas passage may be connected to the gas source. The gas passage may include one or more hollow lines or conduits to guide, direct, or direct gas from the gas source. The gas passage may supply or provide a gas flow to one or more gas outlets in the sensor head. The sensor head may include one or more outlets or openings, where one or more airflows may be provided. For example, a gas outlet may be a nozzle. The gas outlets in the sensor head may be arranged or positioned such that gas flowing out of the gas outlets flows toward the surface of the substrate. Pressurized gas in the gas source provides an airflow guided through the gas passage to the gas outlets in the sensor head. Gas may flow from the gas outlets into a space or gap formed between the gas outlets and the surface of the substrate, and ultimately diffuse around the objective lens and / or objective lens assembly.

[0035] Flow rate sensors may include mass flow rate sensors and / or volumetric flow rate sensors. Flow rate sensors can be configured to measure, detect, or determine the flow rate of a gas. Flow rate sensors can measure the gas flow rate in a gas channel and / or the gas flow rate in the space formed between the gas outlet and the substrate surface. The gas flow rate in the gas channel can correspond to the gas pressure in the gas channel. The gas flow rate in the space formed between the gas outlet and the substrate surface can correspond to the gas pressure in that space.

[0036] The gas source can be maintained at a constant pressure. When gas from the gas source flows through a gas outlet located in the sensor head via a gas channel, the gas pressure and / or flow rate can change according to a first distance. A flow rate sensor can detect changes in gas flow rate. Changes in the first distance can correspond to changes in the space (and, for example, the volume of that space) between the surface of the sensor head and the substrate, and thus to changes in the gas flow rate and / or pressure in that space or the gas channel.

[0037] The processing unit can be configured to receive data from a pneumatic proximity sensor and / or a flow rate sensor. The processing unit can be configured to calculate or determine a first distance based on the measured gas flow rate and / or the gas pressure corresponding to the measured gas flow rate.

[0038] A pneumatic proximity sensor may include one or more gas sources, one or more gas channels, and / or one or more flow rate sensors. A pneumatic proximity sensor may be of a type described in more detail in the same applicant's patent application published as WO2020126981A1.

[0039] The various flow velocities mentioned in this article can be, for example, pneumatic flow velocities. The various pressures mentioned in this article can be, for example, pneumatic pressures.

[0040] According to some embodiments, the sensor head may include a plate. The plate may include a gas outlet.

[0041] The sensor head may include a plate and / or a flat surface. The plate may be parallel to or aligned with the plane of a substrate. The surface of the plate may face the substrate. The plate included in the sensor head may be referred to as a focusing plate, foot plate, or base. Such a plate may be found in microlithography equipment such as a pattern generator or mask writer. The sensor head may include one or more portions or components of a pneumatic proximity sensor. One or more gas outlets of the pneumatic proximity sensor may be arranged or placed in the plate of the sensor head. A sensor head including a plate with gas outlets can help and improve the accuracy of measurements associated with the determination of a first distance. A plate including gas outlets can improve the detection of changes in the first distance.

[0042] According to some embodiments, the final optical component can be configured to focus a light beam onto a photoresist (120) disposed on a substrate. The surface of the substrate can be the surface of the photoresist.

[0043] As described above, in the photolithography process, a photoresist layer can be formed on the substrate. The light beam (such as a laser beam) can be a writing beam. A projection optics device can focus the beam onto the photoresist. The beam can locally develop the photoresist, that is, locally change the properties of the photoresist. The projection optics device can move relative to the substrate, so that different portions of the photoresist are exposed to the beam.

[0044] The intensity of the laser beam can be modulated based on pattern data, exposing different portions of the photoresist to laser beams of varying intensities. By exposing different portions of the photoresist, a pattern can be generated within the photoresist. The pattern can then be transferred to other layers of the substrate or onto other layers of the substrate after processing.

[0045] According to a second aspect of this disclosure, an apparatus for projecting a light beam is provided. The apparatus includes a light beam source configured to generate a light beam, an objective lens assembly according to a first aspect of this disclosure, and a substrate holder configured to hold a substrate. The objective lens assembly is configured to project the light beam onto the substrate held by the substrate holder.

[0046] The beam source may be a laser source configured to generate a laser beam. The apparatus may include another optical device for guiding the beam to the objective lens assembly and / or modulating the beam. A substrate holder may be configured to arrange, place, hold, mount, or support a substrate. The substrate holder may be configured to receive a substrate onto which the beam can be projected. The substrate holder may be movable or static. The substrate holder may be configured to move relative to the objective lens assembly and / or the final optical components. The objective lens assembly and / or the final optical components may be configured to move relative to the substrate holder, thereby moving relative to a substrate disposed in or on the substrate holder. The substrate holder may include a platform or stage. The substrate may be disposed directly on or indirectly on the substrate holder. The objective lens assembly and the substrate holder may cooperate to move relative to each other during the projection process.

[0047] According to some embodiments, the device may also include a control system configured to focus a light beam relative to the substrate by adjusting a second distance between the final optical component and the surface of the substrate based on a first distance determined by the processing unit.

[0048] The control system can be connected to one or more components of the objective lens assembly. The processing unit of the objective lens assembly can be integrated with or communicate with the control system. During projection processes such as photolithography, where a light beam is projected onto a substrate through the objective lens assembly, the control system can receive data from the processing unit in real time. This data may include real-time, continuous feedback of a first distance between the sensor head and the surface of the substrate. The control system can indirectly control a second distance by controlling the first distance. Since the first distance can vary or change, the control system can be configured to dynamically adjust the second distance between the final optical component and the surface of the substrate. The control system can be configured to perform this adjustment based on a known relationship between the second and first distances. In an example, a third distance between the final optical component and the sensor head may be known. Because the control system can be configured to adjust the second distance, a certain working distance can be maintained and / or the focal plane of the objective lens can be prevented from drifting to its target position. A target first distance can be determined or known, corresponding to the objective lens being in its target or preferred working position, i.e., at a target second distance. Therefore, the second distance can be adjusted based on controlling the first distance toward the target first distance.

[0049] A control system configured to adjust a second distance based on a first distance can provide real-time focusing functionality for a device projecting a light beam onto a substrate. Therefore, changes in the first distance, such as those caused by heat sources affecting components of the objective lens, can be compensated for in real time during the projection process. This allows for dynamic correction or adjustment of the focal plane of the objective lens that deviates from its nominal or target position. This, in turn, provides improved focusing accuracy and projection process performance.

[0050] According to some embodiments, the control system may include an actuator connected to the objective lens holding structure and configured to move the objective lens via the objective lens holding structure to adjust the second distance.

[0051] An objective lens holding structure can be configured to connect, mount, or attach an objective lens to, as part of a device. The objective lens holding structure can be connected to the rear end of the objective lens, which is opposite to the front end of the objective lens. In an example, the objective lens holding structure may include a flange and / or one or more threads. The objective lens can be connected, mounted, or attached to the device via the flange and / or one or more threads. The objective lens can be interlocked with the objective lens holding structure, and vice versa. An actuator can be configured to dynamically move the objective lens via the objective lens holding structure. The actuator can be configured to adjust or change the spatial position of the objective lens, thereby adjusting or changing the spatial position of the final optical components included in the objective lens and the sensor head attached to the final optical components. Thus, a second distance and therefore a first distance can be controlled or adjusted by the actuator. The actuator can be configured to continuously receive signals indicating the position, movement, and / or displacement of the objective lens, for example, from a control system.

[0052] In this example, the objective lens can be exposed to a localized heat source, causing the lens components to expand and the lens to elongate toward the substrate surface (i.e., in the Z direction). As a result, a first distance can be reduced, which is detected by a proximity sensor of the objective lens assembly. The control system can then adjust a second distance using an actuator. This adjustment of the second distance can be based on a change in the first distance determined by the processing unit. As the first distance decreases, the actuator can move the objective lens (including the final optical components) away from the substrate surface (i.e., in the negative Z direction) to maintain a certain second distance, or working distance. Thus, the focal plane of the objective lens can be maintained at its nominal / target position during the photolithography process. The control system and objective lens arrangement can provide real-time feedback, thereby providing effective and improved focus control during the photolithography process.

[0053] According to some embodiments, the device can be a photolithography device.

[0054] Note that other embodiments using all possible combinations of the features described in the above embodiments are conceivable. Therefore, this disclosure also relates to all possible combinations of the features mentioned herein. Attached Figure Description

[0055] Exemplary embodiments will now be described in more detail with reference to the following figures:

[0056] Figure 1 An objective lens device for projecting a light beam according to a first aspect of this disclosure is schematically shown;

[0057] Figure 2A and 2B Cross sections of objective lens devices for projecting light beams according to some embodiments of the present disclosure are shown schematically.

[0058] Figure 3 A cross-section of an objective lens device for projecting a light beam according to some embodiments of the present disclosure is schematically shown;

[0059] Figure 4 An apparatus for projecting a light beam according to some embodiments of the present disclosure is schematically illustrated; and

[0060] Figure 5 An apparatus for projecting a light beam according to some embodiments of the present disclosure is illustrated schematically.

[0061] As shown in the figures, for illustrative purposes, the dimensions of elements and regions may be exaggerated and are therefore provided to illustrate the general structure of the embodiments. The same reference numerals always denote the same elements. Detailed Implementation

[0062] Exemplary embodiments will now be described more fully below with reference to the accompanying drawings, in which presently preferred embodiments are illustrated. However, the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness and to fully convey the scope of the invention to those skilled in the art.

[0063] exist Figure 1 The diagram shows a schematic cross-sectional view of an objective lens assembly 100 for projecting a light beam L according to a first aspect of the present disclosure. The objective lens assembly 100 includes an objective lens 110. The objective lens 110 includes a final optical component 112 configured to focus the light beam L onto a substrate 122. Figure 1 In the diagram, the light beam L is shown as a dashed line extending from the final optical component 112 to the surface of the photoresist 120. The substrate 122 may be provided with at least one coating or layer of photoresist. For example... Figure 1 (as well as Figure 3 , 4 As shown in Figures 5 and 6), the substrate 122 is provided with a layer of photoresist 120. In addition to at least one photoresist coating or layer, the substrate 122 may be provided with one or more coatings or layers.

[0064] The final optical component 112 is positioned at the front end of the objective lens 110. The front end of the objective lens 110 is the end closest to the surface of the photoresist 120 (i.e., the shortest distance to the surface of the photoresist 120). The front end of the objective lens 110 faces the photoresist 120. Figure 1 As shown, the final optical component 112 is the optical element in the objective lens 110 that is closest to the photoresist 120 (i.e., has the shortest distance from the photoresist 120). It is conceivable that the objective lens 110 may include additional optical components required to project a light beam onto the photoresist 120.

[0065] exist Figure 1 In the illustration, objective lens 110 is shown as a mechanically stable housing 116 or cover, and final optical component 112 is arranged within the housing 116 or cover. Final optical component 112 is... Figure 1 The objective lens is shown as a lens; however, the final optical component can be any other suitable optical element. Objective lens 110 can be a microscope objective configured to focus a beam of light onto photoresist 120 in the micrometer or nanometer range. Objective lens 110 can be a final lens or a field lens.

[0066] In the Z direction Figure 1 The Z-direction is defined as the direction from the objective lens assembly 100 toward the substrate 122. The Z-direction is orthogonal to the plane of the substrate 122. The Z-direction is defined as the direction along the optical axis A of the objective lens 110 and / or the final optical component 112.

[0067] Objective lens assembly 100 includes a proximity sensor 130. The proximity sensor includes a sensor head 132. The proximity sensor 130 may include one or more parts or components, which may be arranged or integrated, for example, within the sensor head 132. Figure 1 In this configuration, sensor head 132 is arranged along the Z-direction between objective lens 110 and photoresist 120. Sensor head 132 is mechanically attached to final optical component 112 via attachment means or attachment arrangement 118. For example, sensor head 132 may be attached to or near the front end of objective lens 110, such as to housing 116, a component or portion of objective lens 110. Sensor head 132 may be attached to the portion that contacts final optical component 112.

[0068] As in Figure 1 As seen in the cross-sectional view, the sensor head 132 includes an opening that allows a beam of light exiting the final optical component 112 and thus also the objective lens 110 to pass through the sensor head 132 to reach the surface of the photoresist 120. Figure 1 In the diagram, the opening in sensor head 132 is shown as a cavity having a conical or tapered shape. It is conceivable that the opening in sensor head 132 can have shapes other than conical, and sensor head 132 can include one or more openings with different shapes. The opening in sensor head 132 can be sized to accommodate a light beam L. In an example, sensor head 132 can include a circular plate with a circular opening. The circular opening can be centered in the circular plate and have a diameter smaller than the diameter of the circular plate.

[0069] exist Figure 1 In the diagram, sensor head 132 is shown as a plate; however, sensor head 132 may have different shapes and designs suitable for different applications of proximity sensor 130 and / or objective lens assembly 100. Proximity sensor 130 may be configured to measure or determine the proximity of sensor head 132 to the surface of photoresist 120. Proximity sensor 130 may be configured to generate data indicating a first distance d1 between sensor head 132 and the surface of photoresist 120, or data related to the first distance d1. The first distance d1 between sensor head 132 and the surface of photoresist 120 is defined along the Z direction, and... Figure 1 It is indicated by a double arrow.

[0070] Objective lens assembly 100 includes processing unit 140. In Figure 1In the diagram, processing unit 140 is schematically shown on one side of objective lens 110 and sensor head 132. However, processing unit 140 may be integrated into or disposed on sensor head 132, for example. The processing unit may be disposed as part of a device (not shown) in which the objective lens assembly is disposed and used. Processing unit 140 may be connected to proximity sensor 130 via cable or wirelessly and is configured to receive input or data from proximity sensor 130. Processing unit 140 is configured to determine a first distance d1 based on input from proximity sensor 130. Input from proximity sensor 130 may be, for example, measurement data relating to or indicating the distance d1 or space between sensor head 132 and photoresist 120. Processing unit 140 may be further configured to determine a second distance d2 between final optical component 112 and the surface of photoresist layer 120 based on the first distance d1. The second distance d2 between final optical component 112 and the surface of photoresist 120 is defined along the Z direction and... Figure 1 The image is shown with double arrows. The processing unit 140 can determine the second distance d2 based on a known relationship between the first distance d1 and the first and second distances (e.g., a known third distance d3 between the final optical component 112 and the sensor head 132). The third distance can be defined along the Z direction.

[0071] In this example, objective lens assembly 100 may be arranged within a microlithography apparatus (not shown). Objective lens 110 may be exposed to a heat source (not shown) that locally heats one or more components of objective lens 110. The heat source may be part or a component of the microlithography apparatus, such as any kind of motor, or a component of objective lens assembly 100 that can generate heat. Due to the thermal expansion of the components of objective lens 110, objective lens 110 may elongate and / or laterally expand, for example, in the Z direction. Even if the thermal expansion may be small, it may have a crucial effect on the focal plane of objective lens 110, thereby having a crucial effect on the quality and accuracy of the photolithography process on the substrate. If objective lens 110 elongates in the Z direction in any way, the second distance d2 may decrease, and the focal plane of objective lens 110 may deviate from its nominal position. Since sensor head 132 is attached to the final optical component 112, i.e., attached to the front end of objective lens 110, the first distance d1 may also decrease as sensor head 132 moves along with the elongation or extension of objective lens 110. Processing unit 140 can receive input related to the change in the first distance d1 from proximity sensor 130 and determine the first distance d1. Therefore, changes in the second distance d2, and consequently the shift of the focal plane of objective lens 110, can be detected and determined by processing unit 140. Thus, objective lens assembly 100 allows for the possibility of dynamically detecting and compensating for changes in the second distance d2, thereby improving focus control.

[0072] exist Figure 2Aand Figure 2B The diagram shows, in cross-section, a schematic representation of two corresponding objective lens devices 100 for projecting a light beam according to some embodiments of the present disclosure. It should be noted that... Figure 2A and Figure 2B The objective lens assembly 100 shown has a similar design to Figure 1 Several common features of the objective lens assembly 100 shown. Therefore, further reference is made. Figure 1 And related text to enhance understanding of these features of the objective lens assembly 100. However, for simplicity, in Figure 2A and 2B The middle part is omitted Figure 1 Some components of the objective lens apparatus 100 are shown in order to highlight certain features according to some embodiments of the present disclosure.

[0073] like Figure 2A As shown, the objective lens assembly 100 includes a final component support structure 150 that supports the final optical component 112. The final component support structure 150 is included in the objective lens 110 and arranged to support the final optical component 112. The final component support structure 150 may partially surround the final optical component 112. For example, the final component support structure 150 may be a metal ring or shoulder mount arranged around the final optical component 112. Because... Figure 2A A cross-section of the objective lens assembly 100 is shown, thus the final component support structure 150 is illustrated on the left and right sides of the final optical component 112; however, the final component support structure 150 may surround the edge of the final optical component 112. The final component support structure 150 may be configured to mate with the final optical component 112 and to correctly position the final optical component 112 within the objective lens 110 according to the application of the objective lens assembly 100.

[0074] like Figure 2A As shown, the final component support structure 150 only partially covers the final optical component 112, thereby ensuring that the light beam can pass through the final optical component 112. In this way, the final optical component 112 can be adequately supported, and the light beam can pass through the objective lens 110 and reach the photoresist 120. Furthermore, as... Figure 2A As shown, the sensor head 132 is mechanically attached to the final component support structure 150. The sensor head 132 can be fastened to the final component support structure 150 using, for example, glue, screws, or rivets. Figure 2AIn the diagram, sensor head 132 is shown spaced apart from objective lens 110. However, this may not always be the case. Sensor head 132 may be attached, for example, to final component support structure 150, or otherwise to the final optical component, such that sensor head 132 is adjacent to, touches, or contacts objective lens 110, the housing 116 of objective lens 110, and / or final component support structure 150. Thus, sensor head 132 may be attached against or toward objective lens 110 and / or final component support structure 150. By attaching sensor head 132 to final component support structure 150, increased stability of the attachment or mounting of sensor head 132 can be provided. With increased stability of sensor head 132, the efficiency or accuracy of measurements performed with respect to sensor head 132, such as measurements performed by proximity sensors (not shown), can be improved.

[0075] like Figure 2B As shown, the objective lens assembly 100 includes an objective lens 110, which includes a plurality of additional optical components 114a, 114b, 114c, 114d, 114e, and 114f supported by additional component support structures 152a, 152b, 152c, 152d, and 152e. Figure 2B It also shows, for example Figure 2A The final component support structure 150 supports the final optical component 112 as described above. Figure 2A and Figure 2B As shown in both, the sensor head 132 is attached to the final component support structure 150. Figure 2B A simplified example of an objective lens 110, comprising several optical components and several component support structures, is illustrated, along with how they can be arranged. Optical components 114a, 114b, 114c, 114d, 114e, and 114f can be lenses, mirrors, windows, optical planes, prisms, polarizers, beam splitters, waveplates, optical fibers, and / or filters. A single optical component 114 can be supported by a single component support structure 152. Alternatively, two or more optical components 114 can be supported by the same component support structure 152. Figure 2BAs seen, optical component 114a is supported by component support structure 152a, and optical components 114b and 114c are supported by component support structure 152b. Component support structures 152a, 152b, 152c, 152d, and 152e can be metal rings, cylinders, or brackets, and each component support structure can be configured to support a specific optical component. Component support structures 152a, 152b, 152c, 152d, and 152e can arrange optical components 114a, 114b, 114c, 114d, 114e, and 114f such that they are correctly positioned within objective lens 110 and / or spaced apart from each other. Component support structures 152a, 152b, 152c, 152d, and 152e can be associated with, interconnected with, or connected to each other, and / or attached to objective lens 110.

[0076] exist Figure 3 The diagram shows a schematic cross-sectional view of an objective lens device 100 for projecting a light beam according to some embodiments of the present disclosure. Note that... Figure 3 The objective lens assembly 100 shown in the figure has a similar design to... Figure 1 Several common features of the objective lens assembly 100 shown. Therefore, further reference is made. Figure 1 And related text to enhance understanding of these features. However, for simplicity, in Figure 3 The middle part is omitted Figure 1 Some components of the objective lens apparatus 100 are shown in order to highlight certain features that can be implemented according to some embodiments of the present disclosure.

[0077] like Figure 3 As shown, the proximity sensor 130 includes a pneumatic proximity sensor, which comprises a gas source 131, a gas channel 134, and a flow rate sensor 138. The proximity sensor 130 also includes a sensor head 132 with a gas outlet 136. Figure 3 As shown, the sensor head 132, gas source 131, gas channel 134, gas outlet 136 and flow rate sensor 138 can all form part of the proximity sensor 130.

[0078] exist Figure 3 In this sensor, the proximity sensor includes two gas channels 134, each with a flow rate sensor 138 and a gas outlet 136. The gas channels 134 can be connected to the same gas source 131. Alternatively, each gas channel can be connected to a separate gas source 131.

[0079] The gas source 131 may be a pressurized gas reservoir and is located at a distance from the objective lens 110 and the substrate 122. The gas source 131 may be external to the objective lens assembly 100. The gas source 131 may include pressurized gas, such as air.

[0080] exist Figure 3 In the diagram, the sensor head is shown as a plate. The sensor head 132 forms part of the proximity sensor 130 and includes at least a portion of a gas passage 134. The gas passage 134 is connected to a gas source 131. The gas passage 134 can direct gas from the gas source through a gas outlet 136 in the sensor head 132. The gas outlet 136 may include an opening, nozzle, and / or orifice in the sensor head 132. Figure 3 In this configuration, a gas outlet 136 is formed in the bottom surface of the sensor head 132 plate (i.e., the surface facing the substrate 122). However, the gas outlet 136 may be formed and / or positioned at other locations on the sensor head 132 to emit gas into the space formed between the sensor head 132, optionally the objective lens 110, and the substrate 122. For example, the gas outlet 136 may be partially formed by a cavity or tapered opening 133 centered in the sensor head 132. For example, the gas outlet 136 may be one of a plurality of gas outlets. Pressurized gas from a gas source can generate an airflow that passes through the gas channel 134 and the gas outlet 136, enters the space formed between the sensor head 132 and the surface of the photoresist 120, and ultimately enters the free space surrounding the objective lens 110.

[0081] exist Figure 3 In this embodiment, a flow rate sensor 138 is positioned within a gas channel 134 and configured to measure the gas flow rate. For example, the flow rate sensor 138 can be configured to measure the flow rate of gas flowing within the gas channel 134, or the flow rate of gas flowing through a gas outlet 136 into the space formed between the gas outlet 136 and the surface of the photoresist 120. Since the gas source can be maintained at a constant pressure, the gas flow rate can vary depending on the proximity d1 between the surface of the photoresist 120 and the sensor head 132. The processing unit (e.g., Figure 1 The processing unit 140 can receive data related to the measured flow rate of the gas from the flow rate sensor 138 and determine a first distance d1 based on the data. For example, the flow rate sensor 138 can continuously or repeatedly provide a signal indicating the measured flow rate to the processing unit. The processing unit can determine a second distance d2 based on the first distance d1.

[0082] For example, components of objective lens 110 (e.g., housing 116 or component support structures 152a-e) may expand, causing objective lens 110 to elongate in the Z direction, for example, due to thermal instability. This reduces the space formed between the sensor head 132 and the surface of photoresist 120. This results in a change in the flow rate of the gas flowing through gas outlet 136. The change in flow rate is detected by flow rate sensor 138, and the processing unit can determine a first distance d1 based on the measured change in gas flow rate. Since flow rate sensor 138 can be configured to measure gas flow rate in real time, the first distance d1 can be determined in real time, for example during the projection process, i.e., during the projection of the light beam onto photoresist 120 or substrate 122.

[0083] As described above, the configuration of the components of the proximity sensor 130 is not limited to... Figure 3 The example shown. For instance, the gas outlet 136 and / or flow rate sensor 138 in the sensor head may be positioned differently in the objective lens assembly 100, but still appropriately positioned so that the proximity sensor 130 can perform the necessary measurements related to the first distance d1. In another example, the proximity sensor 130 (i.e., a pneumatic proximity sensor) may include one or more gas outlets, one or more gas channels, and / or one or more flow rate sensors.

[0084] exist Figure 4 The diagram shows a schematic of a device 200 for projecting a light beam according to some embodiments of the present disclosure.

[0085] The apparatus 200 includes a beam source 360 ​​configured to generate a beam. The apparatus 200 also includes an objective lens assembly 100 for projecting the beam L, as described above with reference to the preceding figures, and a substrate holder 210. A substrate 122 is disposed or placed on the substrate holder 210. The substrate holder 210 can hold or arrange the substrate 122 such that the beam L can be projected onto the substrate 122.

[0086] exist Figure 4 In this diagram, the substrate holder 210 is shown as a solid object or plate, and the substrate 122 is placed on top of the substrate holder 210. The substrate holder 210 can be coupled with... Figure 4 The implementation may differ from that seen in the previous example. For instance, the substrate holder 210 may be configured to hold only the edge of the substrate 122, or the substrate holder 210 may include a frame in which the substrate 122 is disposed.

[0087] One or more components of the substrate holder 210 and the objective lens assembly 100 may be movable relative to each other. The substrate holder 210 may be movable and configured to position the substrate 122 during the projection process.

[0088] Figure 4 The illustrated device 200 further includes a control system 220, which is configured to operate via a process unit 140 (in... Figure 1 The first distance d1 determined (as shown in the figure) is d1. Figure 1 and 3 (As shown in the image) Adjust the final optical component 112 (in Figure 1-3 The second distance d2 between (shown in) and the surface of substrate 122 (in) Figure 1 and 3 (As shown in the diagram) to focus the light beam relative to the photoresist 120. The control system 220 can allow the final optical components (including...) Figure 4 The relative movement between the objective lens (not shown) and the surface of the substrate 122 and the sensor head. In other words, the control system 220 can allow control of a second distance d2 (e.g., ...) via a first distance d1. Figure 1 and 3 (As shown).

[0089] The control system 220 can be connected to the objective lens assembly 100 and / or the substrate holder 210 via cable or wirelessly, such as Figure 4 As shown. The control system 220 can receive data from the processing unit of the objective lens assembly 100, such as data related to a first distance determined by the processing unit. Based on the data from the processing unit, the control system 220 can adjust or control a second distance, for example, to maintain a desired working distance. In one example, the control system 220 can adjust the second distance by adjusting the spatial position of the objective lens and the sensor head of the objective lens assembly 100. In another example, the control system 220 can adjust the second distance by adjusting the spatial position of the substrate holder 210 relative to the objective lens assembly 100.

[0090] exist Figure 5 The diagram shows a schematic of a device 200 for projecting a light beam according to some embodiments of the present disclosure.

[0091] Figure 5 The device 200 shown has a similar Figure 4 The device 200 shown and Figure 1 Several common features of the objective lens assembly 100 shown. Therefore, further reference is made. Figure 1 and Figure 4 And related texts to enhance understanding of these features of the device 200 and the objective lens assembly 100.

[0092] exist Figure 5 In the device 200, there is an objective lens assembly 100, which includes an objective lens 110, a proximity sensor 130, and a processing unit 140.

[0093] like Figure 5As shown, the device 200 also includes a control system 220, which includes an actuator 222. The actuator 222 is connected to an objective lens holding structure 230. The objective lens holding structure 230 is connected to the objective lens 110. The objective lens holding structure 230 can be connected to the rear end of the objective lens 110, such as... Figure 5 As shown. The rear end of objective lens 110 is opposite to the front end of objective lens 110. Objective lens holding structure 230 can connect or attach objective lens 110 to another structure (not shown) of device 200. Objective lens holding structure 230 may, for example, include a flange or one or more threads formed to engage objective lens 110. Similarly, the rear end of objective lens 110 may include a flange or one or more threads formed to engage objective lens holding structure 230. Thus, objective lens holding structure 230 can be interlocked or interconnected with objective lens 110, and vice versa.

[0094] exist Figure 5 In the illustration, the objective lens holding structure 230 is shown as a solid structure or object; however, the objective lens holding structure 230 can be formed differently. The actuator 222 can be configured to move the objective lens 110 (including the final optical component 112 and the sensor head 132) via the objective lens holding structure 230. The actuator 222 can change or adjust the spatial position of the objective lens 110 (including the final optical component 112 and the sensor head 132), for example, in the Z direction. Thus, when the objective lens 110 can be moved via the objective lens holding structure 230, a first distance d1 and a second distance d2 can be changed by the actuator 222.

[0095] The processing unit 140 of the objective lens assembly can be connected to the control system 220 via cable or wirelessly, such as Figure 5 As shown. The processing unit 140 can be integrated into the control system 220. The processing unit 140 is connected to ( Figure 5 (Not explicitly shown) to proximity sensor 130 and configured to receive data from proximity sensor 130. Therefore, data related to a first distance d1 can be generated by proximity sensor 130 and transmitted to processing unit 140, which can determine the first distance d1 and optionally determine a second distance d2 based on the first distance d1.

[0096] The control system 220 can receive data including a determined first distance d1 and / or a second distance d2 from the processing unit 140. The control system 220 can use the actuator 222 to control the second distance d2 based on the determined first distance d1 and / or second distance d2.

[0097] In this example, objective lens 110 may be exposed to a localized heat source, causing it to elongate towards the surface of photoresist 120 (i.e., in the Z direction) due to thermal expansion of its components. A first distance d1 and a second distance d2 may decrease as objective lens 110 elongates. This may cause the focal plane of objective lens 110 to deviate from its nominal position. Proximity sensor 130 may detect changes in the first distance d1, generate data associated with the first distance d1, and continuously or repeatedly feed the data to processing unit 140. Control system 220 may continuously or repeatedly feed control signals to actuator 222 to move objective lens 110 via objective lens holding structure 230. In this example, objective lens 110 may move away from the surface of photoresist 120, i.e., in the negative Z direction. Thus, the focal plane of objective lens 110 can be brought back to its nominal position. Therefore, the light beam projected onto the surface of the photoresist 120 via the objective lens 110 can be correctly focused onto the photoresist 120 or the substrate 122.

[0098] Figure 4 and Figure 5 The apparatus 200 shown can be a microlithography apparatus or a photolithography apparatus. The components of apparatus 200 can cooperate to project a light beam L onto a photoresist 120 disposed on a substrate 122 during the photolithography process and provide focusing control of the light beam L. The photolithography process in a microlithography apparatus can write, draw, or create features in a photoresist at the micrometer scale or smaller. A process or apparatus capable of producing nanoscale features can be referred to as a nanolithography process or apparatus.

[0099] The control system 220 of device 200 can control the focusing of the light beam relative to the photoresist 120 within the micrometer range. Figure 5 In this configuration, actuator 222 can be configured to allow objective lens 110 to be moved, displaced, or positioned within a micrometer range via objective lens holding structure 230. Microlithography or nanolithography equipment can be, for example, a mask writer or pattern generator.

[0100] Those skilled in the art will recognize that the present invention is by no means limited to the preferred embodiments described above. Rather, many modifications and variations are possible within the scope of the appended claims.

[0101] Although the features and elements have been described above in specific combinations, each feature or element may be used alone without other features and elements, or in various combinations with or without other features and elements.

[0102] Furthermore, by studying the accompanying drawings, the disclosure, and the appended claims, those skilled in the art can understand and implement variations of the disclosed embodiments in practicing the claimed invention. In the claims, the word "comprising" does not exclude other elements, and the indefinite articles "a" or "an" do not exclude a plurality. The mere fact that certain features are recited in mutually different dependent claims does not imply that combinations of these features cannot be advantageously used.

Claims

1. An objective lens device (100) for projecting a light beam, the objective lens device comprising: Objective lens (110), the objective lens (110) includes a plurality of optical components (112, 114a-f) supported by a plurality of component support structures (150, 152a-e) arranged inside a housing (116), the plurality of optical components including a final optical component (112) configured to focus the light beam onto a substrate (122), the final optical component being supported by a final component support structure (150); A proximity sensor (130) includes a sensor head (132) disposed between the objective lens and the substrate; as well as A processing unit (140) is configured to determine a first distance (d1) between the sensor head and the surface of the substrate based on input from the proximity sensor. The sensor head is mechanically attached to the final component support structure.

2. The objective lens apparatus according to claim 1, wherein, The objective lens is a microscope objective lens.

3. The objective lens apparatus according to any one of the preceding claims, wherein, The proximity sensor includes a pneumatic proximity sensor.

4. The objective lens apparatus according to claim 3, wherein, The pneumatic proximity sensor includes: Gas source; Gas channel (134), the gas channel being configured to guide gas from the gas source through gas outlet (136) in the sensor head; and A flow rate sensor (138) is configured to measure the flow rate of the gas; wherein The processing unit is configured to determine a first distance between the sensor head and the surface of the substrate based on the measured gas flow rate.

5. The objective lens apparatus according to claim 4, wherein, The sensor head includes a plate, and the plate includes the gas outlet.

6. The objective lens apparatus according to any one of the preceding claims, wherein: The final optical component is configured to focus the light beam onto a photosensitive resist (120) disposed on the substrate; and The surface of the substrate is the surface of a photoresist.

7. A device (200) for projecting a light beam, said device comprising: A beam source (360) is configured to generate a beam (L); Objective lens device (100) according to any one of the preceding claims; and A substrate holder (210) is configured to hold a substrate; The objective lens is configured to project the light beam onto a substrate held by the substrate holder.

8. The device according to claim 7, characterized in that, Further includes: A control system (220) is configured to focus the light beam relative to the substrate by adjusting a second distance (d2) between the final optical component and the surface of the substrate based on a first distance determined by the processing unit.

9. The device according to claim 8, wherein, The control system includes an actuator (222) connected to an objective lens holding structure (230) and configured to move the objective lens via the objective lens holding structure to adjust the second distance.

10. The apparatus according to any one of claims 7-9, wherein the apparatus is a microlithography apparatus.

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