Reticle pod with coated sensor zone

Abstract

The sensor zones are formed on the inner pod of the reticle container using a dry coating method. The sensor zones are discrete zones having specific spectral reflectances. The sensor zones are positioned so that they can be read by a tool to determine the distance of portions of the pod. The use of discrete zones and a dry coating method to apply these discrete zones overcomes the problems of inconsistency and difficulty in cleaning the inner pod of the reticle container or maintaining its reflectance compared to inner pods that are fully plated with a material or other wet-coated material.

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims the benefit and priority of U.S. Provisional Application No. 63 / 011,581, filed on April 17, 2020, and the above disclosure is hereby incorporated by reference in its entirety for all purposes.

[0002] This disclosure is directed to the formation of sensor zones on reticle pods, particularly reticle pods such as extreme ultraviolet (EUV) reticle pods.

Background Art

[0003] Reticle pods are used to house photolithography masks during semiconductor processing, such as during extreme ultraviolet (EUV) processing. A reticle pod can include a metal inner pod that is handled and manipulated by one or more tools during processing. Some tools can use reflectivity to determine the distance of the inner pod from one or more sensors within the tool. Reticle pods are typically cleaned using deionized (DI) water, which can cause oxidation of some materials.

[0004] The inner pod of a reticle pod can be wet - coated with chromium to improve reflectivity and appearance and resist loss of reflectivity due to oxidation caused by DI water cleaning. However, the shape of the reticle pod makes wet - coating difficult.

Summary of the Invention

[0005] This disclosure is directed to the formation of sensor zones on reticle pods, particularly reticle pods such as extreme ultraviolet (EUV) reticle pods.

[0006] By selectively applying a reflective coating to individual sensor zones on the reticle pod using a dry coating process, a reflective material for interfacing with the sensor on the process tool can be provided without requiring a wet coating of the entire reticle pod. In addition, the reflective coating can be provided to have the desired thickness and strength.

[0007] In one embodiment, the pod includes a base plate having a base plate surface. The base plate surface includes a base plate surface material and a reflective material. The reflective material of the base plate surface is arranged in one or more individual base plate sensor zones. The pod also includes a cover having a cover surface. The cover surface includes a cover surface material and a reflective material. The reflective material of the cover surface is arranged in one or more cover sensor zones.

[0008] In one embodiment, the pod is an EUV reticle pod. In one embodiment, the pod further includes an outer pod dome and an outer pod door, the pod dome and pod door being configured to house a base plate and cover within the pod dome when the door is attached to the pod dome.

[0009] In one embodiment, the reflective material has a spectral reflectance of approximately 50% to approximately 70% at a wavelength of 880 nm. In one embodiment, the reflective material contains chromium. In one embodiment, only the reflective material contains chromium.

[0010] In one embodiment, one or more baseplate sensor zones and one or more cover sensor zones are positioned such that the distance between the pod and the detector can be determined by reading one or more baseplate sensor zones and one or more cover sensor zones.

[0011] In one embodiment, the base plate surface is made of either aluminum or nickel, and the cover surface is made of either aluminum or nickel.

[0012] In one embodiment, a method for manufacturing a reticle pod includes applying a reflective material to each of one or more individual baseplate sensor zones of the baseplate of the reticle pod using a dry coating process, and applying a reflective material to each of one or more individual cover sensor zones of the cover of the reticle pod using a dry coating process.

[0013] In one embodiment, the reflective material has a spectral reflectance of approximately 50% to 70% at a wavelength of 880 nm.

[0014] In one embodiment, the dry coating process is selected from the group consisting of physical vapor deposition, sputter deposition, chemical vapor deposition, and plasma-enhanced chemical vapor deposition.

[0015] In one embodiment, one or more baseplate sensor zones and one or more cover sensor zones are positioned such that the distance between the pod and the detector can be determined by reading one or more baseplate sensor zones and one or more cover sensor zones.

[0016] This disclosure can be better understood by considering the following description of various exemplary embodiments relating to the attached drawings. [Brief explanation of the drawing]

[0017] [Figure 1A] This is a bottom view of the base plate of a reticle pod according to one embodiment. [Figure 1B] This is a bottom view of the reticle pod cover according to one embodiment. [Figure 1C] Figure 1B is a side view of the reticle pod cover. [Figure 2] This is a flowchart of a method for manufacturing a reticle pod according to one embodiment. [Figure 3] This figure shows a reticle pod including an outer pod and an inner pod according to one embodiment. [Figure 4] This is a schematic diagram of a reticle pod in an extreme ultraviolet (EUV) tool according to one embodiment. [Modes for carrying out the invention]

[0018] This disclosure is compliant with various forms of modification and alternatives, the details of which are shown in the drawings as examples and described in detail. However, it should be understood that the intent is not to limit the aspects of this disclosure to the specific exemplary embodiments described. Rather, the intent is to encompass all modifications, equivalents, and alternatives that fall within the spirit and scope of this disclosure.

[0019] This disclosure relates to the formation of sensor zones on reticle pods, particularly on reticle pods such as extreme ultraviolet (EUV) reticle pods.

[0020] Figure 1A shows a plan view of the bottom of the base plate of a reticle pod according to one embodiment. The base plate 100 forms part of the inner pod of the reticle pod. The base plate 100 includes one or more sensor zones 102.

[0021] The base plate 100 includes a base plate surface material that forms the surface of the base plate 100. The base plate surface material can be a material used to form the base plate, such as aluminum, or any other suitable material for the base plate 100 of the reticle pod. The base plate 100 may further include features, in particular, for operating the reticle pod or the base plate 100. The base plate surface material can be a coating applied to the base plate 100 to form the surface of the base plate 100, such as a nickel coating.

[0022] In one or more embodiments, at least one sensor zone 102 can be provided on the surface of the base plate 100. The sensor zone 102 is an individual zone made of a reflective material. The sensor zone 102 is a defined area of the reflective material formed on a segment of the surface of the base plate 100. The one or more sensor zones 102 cover an area smaller than the entire surface of the base plate 100. The sensor zone 102 can have any suitable shape for presenting a reflective material to be read by one or more sensors, such as sensors included in a tool for handling a reticle pod including the base plate 100. The sensor zone 102 can include a sensor zone material that can be a different material from the surrounding base plate material on the surface of the base plate 100. For example, the base plate 100 may be made of aluminum, and the sensor zone material is applied to the exposed aluminum material or nickel coating on the base plate 100 to form individual sensor zones 102. In one embodiment, the sensor zone material can be disposed in contact with a coating applied to the surface material of the base plate 100 to form individual sensor zones 102. In one embodiment, the sensor zone 102 can be applied to a coating made of a material different from the sensor zone material used in the sensor zone 102. In one embodiment, the sensor zone 102 can be applied to a coating provided by a method different from a dry coating although it includes at least some of the same material as the sensor zone 102. For example, a chrome coating can be applied to the chrome surface material for the base plate 100, and the sensor zones 102 are formed by applying additional chrome by a dry coating method, providing chrome with different density, thickness, and uniformity within those sensor zones 102 as compared to the base plate surface material that is a wet-coated chrome on nickel.

[0023] The sensor zone 102 can be located on any portion of the base plate 100 from which a sensor can attempt to detect the base plate 100. In one embodiment, the sensor zone 102 is located on the bottom surface of the base plate 100 and is visible from the bottom of the reticle pod when the base plate 100 is assembled with a cover such as the cover 150 shown in Figure 1B and described below. In one embodiment, one sensor zone 102 is included on the base plate 100. In one embodiment, multiple sensor zones 102 are included on the base plate. In one embodiment, the sensor zone 102 is located on the bottom surface of the base plate 100 so as not to be obscured by a cover such as the cover 150 shown in Figures 1B and 1C when the reticle pod including the base plate 100 is assembled. In the embodiment shown in Figure 1A, four sensor zones 102 are located on the base plate 100, and four sensor zones 102 are located on the bottom surface of the base plate 100.

[0024] The reflective material used in the sensor zone 102 has a known spectral reflectivity selected for use in a detection system of a tool that uses a pod including a base plate 100. In some embodiments, the reflective material can have a reflectivity different from that of the base plate surface material, such as greater or less than the reflectivity of the base plate surface material. The sensor zone 102 can provide a spectral reflectivity within a known predetermined range at one or more predetermined wavelengths such that the light reflected by the sensor zone 102 is associated with a specific distance of the inner pod base plate 100 from a reference using a tool using a reticle, for example, an extreme ultraviolet (EUV) tool for processing a wafer. As a non-limiting example, the range for each spectral reflectivity of the sensor zone 102 is from about 57% to about 63% for at least one of one or more predetermined wavelengths. In one embodiment, each of the sensor zones 102 has a spectral reflectivity of from about 57% to about 63% at a wavelength of 880 nm. The sensor zone can include any suitable reflective material having the desired spectral reflectivity properties and can be applied by a dry coating method. The reflective material can be an inert material selected so as not to react during processing by the tool. The reflective material can include, as a non-limiting example, chromium. In one embodiment, only one or more of the sensor zones 102 and 152 included in the reticle pod include chromium.

[0025] The reflective material can be provided to the sensor zone 102 by a dry coating method such as physical vapor deposition (PVD), sputter deposition, chemical vapor deposition (CVD), and plasma enhanced chemical vapor deposition (PE-CVD). The resulting sensor zones 102 can have a more durable and uniform coating within those sensor zones 102 as compared to a wet coating method such as plating the entire base plate 100. The improved durability can, in turn, improve the appearance and maintenance of the appropriate reflectivity for the sensor zones 102.

[0026] Figure 1B shows a plan view of the bottom surface of the cover 150 of the reticle pod according to one embodiment, and Figure 1C shows a side view of the cover 150 of the reticle pod shown in Figure 1B. The cover 150 includes a sensor zone 152.

[0027] The cover 150 is configured to be joined to a base plate, such as the base plate 100 shown in Figure 1A, and to form a reticle pod configured to house a reticle. The cover 150 can be configured such that the reticle housing portion 158 is surrounded by the base plate 100. The cover 150 may further include features, in particular, for operating the reticle pod or the cover 150. The cover 150 can be made of any suitable material, such as aluminum. The surface of the cover 150 is the cover surface material, which can be the material forming the body of the cover 150 or a coating such as nickel formed on that material.

[0028] In addition to, or instead of, the sensor zone 152 provided on the base plate 100, one or more sensor zones 102 can be provided on the cover 150. The one or more sensor zones 152 are individual zones containing reflective material. The one or more sensor zones 152 cover an area smaller than the entire surface of the cover 150. The reflective material can be applied by a dry coating process. The sensor zone 152 can have any suitable shape to present reflective material that can be read by one or more sensors, such as sensors included in a tool that handles the reticle pod, including the cover 150. The sensor zone 152 can use the same or different reflective material from the sensor zones on the base plate used with the cover 150, such as the reflective material of the sensor zone 102 on the base plate 100 shown in Figure 1A. When the cover 150 is combined with a base plate, such as the base plate 100, to form the inner pod of the reticle pod, one or more sensor zones can be provided on the cover 150 so that one or more sensor zones can be read by a tool. In one embodiment, the sensor zone 152 is positioned so as not to be obscured by a base plate, such as the base plate 100 shown in Figure 1A, when the reticle pod, including the base plate and cover 150, is assembled. In the embodiments shown in Figures 1B and 1C, four sensor zones 152 are provided, two of which are located on the bottom surface of the extension 154 from the side 156 of the cover, as seen in Figure 1B, and the other two sensor zones are located on the outward-facing side surface of the cover 150, as seen in Figure 1C.

[0029] The reflective material used in the sensor zone 152 has a known spectral reflectance selected for use in a detection system of a tool that uses a pod including the cover 150. The reflective material can be an inert material selected not to react during processing by the tool. The sensor zone 152 can provide spectral reflectance at one or more predetermined wavelengths within a known predetermined range so that the light reflected by the sensor zone 152 is associated with a specific distance of the inner pod cover 150 from a reference using a tool such as an extreme ultraviolet (EUV) tool for processing wafers using a reticle. As a non-limiting example, the range for the spectral reflectance of each sensor zone 152 is about 57% to about 63% for at least one of one or more predetermined wavelengths. In one embodiment, each sensor zone 152 has a spectral reflectance of about 57% to about 63% at a wavelength of 880 nm. The sensor zone 152 can include any suitable reflective material having the desired spectral reflectance properties and which can be applied by a dry coating method. The reflective material can be an inert material selected not to react during processing by the tool. The reflective material may include chromium, as an example of a non-limiting model. In one embodiment, only one or more sensor zones 102 and 152 included in the reticle pod contain chromium.

[0030] Reflective materials can be applied to the sensor zone 152 by dry coating methods such as physical vapor deposition (PVD), sputter deposition, chemical vapor deposition (CVD), and plasma-enhanced chemical vapor deposition (PE-CVD). The resulting sensor zones 152 can have a more durable and uniform coating within the sensor zones 152 compared to wet coating methods such as plating the entire cover 150. This improved durability, in turn, can improve the appearance and maintenance of appropriate reflectivity for the sensor zones 152.

[0031] The cover 150 may include further features for the function of the reticle pod it contains. For example, the cover 150 may include a reticle housing portion 154 oaming portion of an internal space configured to house a reticle such as a photolithography mask.

[0032] Figure 2 shows a flowchart of a method for manufacturing a reticle pod according to one embodiment. Method 200 includes providing a base plate 202, optionally coating the base plate 204, applying a reflective material to one or more sensor zones on the base plate using a dry coating method 206, providing a cover 208, optionally coating the cover 210, and applying a reflective material to one or more sensor zones on the cover using a dry coating method 212. Some embodiments of the method may also include a polishing step in which one or more sensor zones are polished to achieve a desired spectral reflectance.

[0033] In 202, a base plate may be provided. The base plate is a formed base plate for use in the reticle pod. The base plate can be made of any material suitable for a reticle pod base plate, such as aluminum, as a non-limiting example. The base plate provided in 202 may include all the features of a finished base plate at the time the base plate is provided in 202, such as walls defining the reticle housing portion, reticle supports, features for engaging with a cover, and features for engaging with automation in a tool that uses or operates the reticle.

[0034] In 204, the base plate may be optionally coated. The coating may be any suitable coating applied to the base plate, for example, a coating that improves appearance, provides wear resistance, provides an inert surface suitable for use with processing tools, or any other desired function of such a coating. The coating applied in 204 may be a wet coating process such as plating, or any other coating method including immersion of the base plate in a liquid. In 204, one or more such coatings may be applied to the base plate. One of the coatings applied to the base plate in 204 may be nickel.

[0035] In some embodiments, in 206, a dry coating method can be used to apply a reflective material to one or more separate locations on the base plate to form sensor zones. The dry coating method can be any method that does not involve applying a liquid to the base plate during coating. Examples of dry coating methods that are not limited to this include physical vapor deposition (PVD), sputter deposition, chemical vapor deposition (CVD), and plasma-enhanced chemical vapor deposition (PE-CVD). The one or more sensor zones to which the reflective material is applied in 206 are separate zones, and these separate zones constitute a portion less than the entire surface of the base plate. The one or more sensor zones can be defined, for example, through a mask applied during deposition by the dry coating method, which allows deposition only on one or more sensor zones.

[0036] The reflective material applied to the baseplate in 206 has a known spectral reflectance selected for use in a detection system of a tool that uses a pod containing the baseplate. The reflective material can be an inert material selected so as not to react during use of the reticle pod in the tool. The reflective material may include chromium as a non-limiting example. The reflective material can be applied to the sensor zone so that the sensor zone provides spectral reflectance at one or more predetermined wavelengths within a known predetermined range, so that the light reflected by the sensor zone is associated with a specific distance of the inner pod baseplate from a reference using a tool such as an extreme ultraviolet (EUV) tool for processing using the reticle. As a non-limiting example, the range for the spectral reflectance of each sensor zone is about 50% to about 70% for at least one of one or more predetermined wavelengths. In one embodiment, each sensor zone has a spectral reflectance of about 50% to about 70% at a wavelength of 880 nm.

[0037] In 208, a cover is provided. The cover is a cover formed for the reticle pod. The cover can be made of any material suitable for a reticle pod cover, such as aluminum, as a non-limiting example. The cover provided in 208 may include all the features of the finished cover at the time the cover is provided in 208, such as walls defining the reticle housing portion, features for engaging with the base plate, and features for engaging with automation in the tool that uses the reticle.

[0038] Optionally, in 210, the cover is coated. The coating may be any suitable coating applied to the cover, e.g., a coating that improves appearance, provides wear resistance, provides an inert surface suitable for use in processing with a reticle, or any other desired function of such a coating. The coating applied in 210 may be a wet coating process such as plating, or any other coating method including immersion of the cover in a liquid. One or more such coatings may be applied to the cover in 210. One or more coatings applied to the cover in 210 may be the same coating as the coating applied to the base plate in 204. One or more coatings applied to the cover in 210 may include one or more coatings different from the one or more coatings applied to the base plate in 204. One of the coatings applied in 210 may be nickel.

[0039] In some embodiments, in 212, a dry coating method can be used to apply reflective material to one or more separate locations on the cover to form sensor zones. The dry coating method can be any method that does not involve applying a liquid to the cover during coating. Examples of dry coating methods that are not limited to this include physical vapor deposition (PVD), sputter deposition, chemical vapor deposition (CVD), and plasma-enhanced chemical vapor deposition (PE-CVD). The one or more sensor zones to which the reflective material is applied in 212 are separate zones, and these separate zones constitute a portion less than the entire surface of the cover. The one or more sensor zones can be defined, for example, through a mask applied during deposition by the dry coating method, which allows deposition only on one or more sensor zones.

[0040] The reflective material applied to the cover in 212 has a known spectral reflectance selected for use in a detection system of a tool that uses the pod, including the cover. The reflective material can be an inert material selected so as not to react when the reticle is being used. The reflective material may include chromium as a non-limiting example. The reflective material can be applied to the sensor zone so that the sensor zone provides spectral reflectance at one or more predetermined wavelengths within a known predetermined range, enabling the light reflected by the sensor zone to be associated with a specific distance of the inner pod baseplate from a reference using a tool such as an extreme ultraviolet (EUV) tool for processing using the reticle. As a non-limiting example, the range for the spectral reflectance of each sensor zone is about 50% to about 70% for at least one of one or more predetermined wavelengths. In one embodiment, each sensor zone has a spectral reflectance of about 50% to about 70% at a wavelength of 880 nm. In some cases, the sensor zone may be polished to achieve the desired spectral reflectance.

[0041] The base plate and cover processed during method 200 can be used, for example, as an inner pod of a reticle pod for housing a reticle to house a photolithography mask used for extreme ultraviolet (EUV) processing of a wafer.

[0042] Figure 3 shows a reticle pod including an outer pod and an inner pod according to one embodiment. The reticle pod 300 includes an inner pod 302, which includes a cover 304 and a base plate 306. The reticle pod 300 further includes an outer pod 308, which includes an outer pod dome 310 and an outer pod door 312. The reticle pod 300 can be used to surround a reticle 316. The reticle 316 may be any suitable reticle, such as a photolithography mask used when processing wafers using extreme ultraviolet (EUV), as a non-limiting example.

[0043] The inner pod 302 includes a cover 304 and a base plate 306. The cover 304 and the base plate 306 are configured to be joined to each other. Together, the cover 304 and the base plate 306 define an internal space of a size and shape that houses a reticle, such as a photolithography mask used for extreme ultraviolet (EUV) processing of a wafer. In some embodiments, at least one of the cover 304 and the base plate 306 may each include one or more sensor zones 314, which are separate zones containing reflective material. In some embodiments, both the cover 304 and the base plate 306 may each include one or more sensor zones 314. The sensor zones 314 can be sensor zones 102 and 152 as described above. In the diagram shown in Figure 3, the sensor zones 314 are visible along the side of the cover 304, and from the viewpoint of Figure 3, the other zones are hidden by other components. Other sensor zones 304 can be located on the sides or bottom, which are not visible in the perspective view of Figure 3, for example, at the locations of sensor zones 102 and 152 shown in Figures 1A and 1B. Reflective material can be applied to the sensor zones of the cover 304 and base plate 306 by a dry coating process. The cover 304 can be, for example, the cover 150 described above and shown in Figure 1B. The base plate 306 can be, for example, the base plate 100 described above and shown in Figure 1A.

[0044] The outer pod 308 is configured to house the inner pod 302 within an internal space defined by the outer pod dome 310 and the outer pod door 312. The outer pod dome can enclose the internal space and be secured to the outer pod door 312 to house the inner pod 302, for example, during the transport and handling of the reticle pod 300. The outer pod dome 310 and the outer pod door 312 can each contain one or more polymer materials or be fabricated entirely from them.

[0045] Figure 4 shows a schematic diagram of a reticle pod in an extreme ultraviolet (EUV) tool according to one embodiment. In the embodiment shown in Figure 4, the inner pod 400 is placed inside the tool 402.

[0046] The inner pod 400 can be any suitable inner pod, such as the inner pod 302 or an inner pod including the base plate 100 and cover 150. The inner pod 400 includes multiple sensor zones 404.

[0047] Tool 402 can be any suitable tool that is handled or operates on the inner pod 400. As a non-limiting example, tool 402 can be an extreme ultraviolet (EUV) tool that uses a reticle such as a photolithography mask. Tool 402 may be located in a vacuum chamber, and the inner pod 400 is removed from the outer pod (not shown) and placed inside tool 402 in the vacuum chamber. During use of the reticle in tool 402, the cover can be removed from the base plate of the inner pod 400 to expose the reticle housed inside the inner pod 400. Tool 402 includes a light source 406 and a detector 408. The light source 406 and detector 408 are positioned so that light provided by the light source 406 can be reflected by the sensor zone 404 toward the detector 408, and the light detected by the detector 408 can determine the distance to the inner pod 400. As a non-limiting example, the light source can provide light at one or more predetermined wavelengths, including 880 nm. The sensor zones 404 of the inner pod 400 can provide spectral reflectance at one or more predetermined wavelengths within a known predetermined range, enabling the light detected by the detector 408 to be associated with a specific distance from the inner pod 400. As a non-limiting example, the range for the spectral reflectance of each sensor zone 404 is about 50% to about 70% for at least one of one or more predetermined wavelengths. In one embodiment, each sensor zone 404 has a spectral reflectance of about 50% to about 70% at 880 nm.

[0048] Pattern: It is understood that any of embodiments 1 to 9 can be combined with any of embodiments 10 to 16.

[0049] Embodiment 1. A base plate having a base plate surface, wherein the base plate surface includes a base plate surface material, A cover having a cover surface, wherein the cover surface includes a cover surface material, One or more individual sensor zones, each of which includes a reflective material, and the one or more individual sensor zones are located on one or both of the base plate surface and the cover surface. A pod equipped with this.

[0050] Embodiment 2. The pod according to Embodiment 1, wherein the pod is an EUV reticle pod.

[0051] Embodiment 3. The pod according to Embodiment 2, further comprising an outer pod dome and an outer pod door, wherein the pod dome and the pod door are configured to house the base plate and the cover within the pod dome when the door is attached to the pod dome.

[0052] Embodiment 4. The pod according to any one of Embodiments 1 to 3, wherein the reflective material has a spectral reflectance of about 50% to about 70% at a wavelength of 880 nm.

[0053] Embodiment 5. The pod according to any one of Embodiments 1 to 4, wherein the reflective material has a reflectance different from that of the base plate surface material.

[0054] Embodiment 6. The pod according to any one of Embodiments 1 to 5, wherein the reflective material comprises chromium.

[0055] Embodiment 7. The pod according to Embodiment 6, wherein only the reflective material contains the chromium.

[0056] Embodiment 8. The pod according to any one of Embodiments 1 to 7, wherein the one or more sensor zones are positioned such that the distance between the pod and the detector can be determined by reading the one or more sensor zones.

[0057] Embodiment 9. The pod according to any one of Embodiments 1 to 8, wherein the base plate surface comprises one of aluminum or nickel, and the cover surface comprises one of aluminum or nickel.

[0058] Embodiment 10. The pod according to any one of Embodiments 1 to 9, wherein each of the base plate surface and the cover surface includes one or more of the individual sensor zones.

[0059] Embodiment 11. A method for manufacturing a reticle pod, Applying reflective material to each of one or more individual sensor zones on either the base plate of the reticle pod or the cover of the reticle pod using a dry coating process. Methods that include...

[0060] Embodiment 12. The method according to Embodiment 11, wherein the reflective material has a spectral reflectance different from that of the base plate and the cover.

[0061] Embodiment 13. The method according to any one of Embodiments 11 to 12, wherein the reflective material has a spectral reflectance of about 50% to about 70% at a wavelength of 880 nm.

[0062] Embodiment 14. The method according to any one of Embodiments 11 to 13, wherein the base plate or the cover includes a surface material, and the reflective material has a reflectance different from that of the surface material.

[0063] Embodiment 15. The method according to any one of embodiments 11 to 14, further comprising applying the coating to the base plate and the cover.

[0064] Embodiment 16. The method according to any one of Embodiments 11 to 15, wherein the dry coating process is selected from the group consisting of physical vapor deposition, sputter deposition, chemical vapor deposition, and plasma-enhanced chemical vapor deposition.

[0065] Embodiment 17. The method according to any one of embodiments 11 to 16, wherein the one or more baseplate sensor zones and the one or more cover sensor zones are positioned such that the distance between the pod and the detector can be determined by reading the one or more baseplate sensor zones and the one or more cover sensor zones.

[0066] Embodiment 18. The method according to any one of embodiments 11 to 17, further comprising applying the reflective material to each of one or more individual sensor zones on the base plate of the reticle pod or on the cover of the reticle pod using the dry coating process.

[0067] The examples disclosed in this application should be considered in all respects illustrative and not limiting. The scope of this disclosure is indicated by the appended claims rather than the foregoing description, and all modifications that fall within the meaning and scope of equivalence to the claims are intended to be incorporated into the claims.

Claims

1. A base plate having a base plate surface, wherein the base plate surface includes a base plate surface material, A cover having a cover surface, wherein the cover surface includes a cover surface material, A plurality of individual sensor zones, each of which includes a reflective material, and the plurality of individual sensor zones are arranged on one or both of the base plate surface and the cover surface. Equipped with, The reflective material is an inert material selected so as not to react during use of the pod. The plurality of individual sensor zones are located on the bottom surface of an extension extending from the side of the cover and on the outward-facing side of the cover, forming a pod.

2. The pod according to claim 1, wherein the reflective material has a spectral reflectance of 50% to 70% at a wavelength of 880 nm.

3. The pod according to claim 1, wherein only the reflective material contains chromium.

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