Low-Temperature Electrostatic Chuck

Abstract

The present disclosure relates to a low-temperature electrostatic chuck, and a technical problem to be solved is to provide a low-temperature electrostatic chuck that can be attached to equipment and prevents the formation of frost, ice, moisture, etc. on the equipment. To this end, the present disclosure provides a low-temperature electrostatic chuck including a base member and a support member including a first dielectric layer coated on the base member, an electrode layer provided on the first dielectric layer, and a second dielectric layer coated on the first dielectric layer and the electrode layer, the base member including a first flow path through which a first fluid at a first temperature provided to an upper region flows, and a second flow path through which a second fluid at a second temperature higher than the first temperature provided to a lower region flows.

Description

[Technical Field]

[0001] The present disclosure relates to low-temperature electrostatic chucks. [Background technology]

[0002] 2. Description of the Related Art Generally, semiconductor devices are manufactured through a number of unit processes, including a thin film deposition process and an etching process. The etching process is typically performed using a plasma etching apparatus in which a plasma reaction is induced.

[0003] In recent years, plasma etching has been required to be performed at low temperatures to form structures with high aspect ratios or to ensure high selectivity when etching wafers using photoresist films.

[0004] This low-temperature etching also reduces the electrostatic chuck temperature, which can cause various problems in the equipment to which the electrostatic chuck is attached. For example, because the electrostatic chuck is at a low temperature and the equipment is at room temperature, frost, ice, or water can form on the equipment. This moisture can affect various mechanical and electrical structures of the equipment, ultimately causing wafer defects.

[0005] The above-mentioned information disclosed in the background of the invention is intended to enhance understanding of the background of the invention only, and may therefore include information that does not constitute prior art. Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present disclosure is to provide a low-temperature electrostatic chuck that can be attached to equipment and that prevents frost, ice, moisture, etc. from forming on the equipment. [Means for solving the problem]

[0007] The low-temperature electrostatic chuck according to the present disclosure includes a base member; and a support member including a first dielectric layer coated on the base member, an electrode layer provided on the first dielectric layer, and a second dielectric layer coated on the first dielectric layer and the electrode layer; wherein the base member includes a first flow path through which a first fluid at a first temperature provided to an upper region flows, and a second flow path through which a second fluid at a second temperature higher than the first temperature provided to a lower region flows.

[0008] In some examples, the first temperature may be between -200°C and 0°C, and the second temperature may be between 0°C and 80°C. In some examples, the base member may further include a thermal isolation cavity provided between the first flow path and the second flow path.

[0009] In some examples, the thermal blocking cavity may include a first thermal blocking cavity provided between the first flow path and the second flow path, and a second thermal blocking cavity provided between the first flow paths and connected to the first thermal blocking cavity.

[0010] In some examples, the thermal blocking cavity may include a first thermal blocking cavity provided between the first flow path and the second flow path, and a second thermal blocking cavity provided between the second flow path and connected to the first thermal blocking cavity.

[0011] In some examples, the thermal blocking cavity may include a first thermal blocking cavity provided between the first flow path and the second flow path, a second thermal blocking cavity provided between the first flow paths and connected to the first thermal blocking cavity, and a third thermal blocking cavity provided between the second flow paths and connected to the first thermal blocking cavity.

[0012] In some examples, the interior of the heat blocking cavity may be filled with a thermal insulating material. In some examples, the heat-blocking cavity may have an upper or lower surface coated with YSZ (Yttria-stabilized zirconia), a YSZ plate bonded thereto, an Al2TiO5 coating thereon, or an Al2TiO5 plate bonded thereto.

[0013] In some examples, the base member may further include a thermal isolation heater provided between the first flow path and the second flow path. In some examples, the base member may further include a thermal blocking cavity provided between the first flow path and the second flow path; and a thermal blocking heater provided between the first flow path and the second flow path.

[0014] In some examples, the device may further include a bonding layer interposed between the base member and the support member. In some examples, the bonding layer may include a silicone polymer family or a metal family.

[0015] In some examples, the bonding layer may include at least one of one-part silicone, two-part silicone, one-part epoxy, two-part epoxy, and polyurethane, each having a thermal conductivity of 0.3 W / mK to 3 W / mK.

[0016] In some examples, the bonding layer may include at least one of a ceramic filler and a metallic filler. In some examples, the bonding layer may include a metallized brazing layer, an active metal brazing layer, a diffusion bonded layer, a friction welded layer, or a laser welded layer between the base member and the support member. [Effects of the Invention]

[0017] The present disclosure provides a low-temperature electrostatic chuck that can be attached to equipment and prevents frost, ice, moisture, or the like from forming on the equipment. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a cross-sectional view of an exemplary low-temperature electrostatic chuck according to the present disclosure. [Figure 2a] 1A-1C are cross-sectional views illustrating a method for manufacturing an exemplary low-temperature electrostatic chuck according to the present disclosure. [Figure 2b] 1A-1C are cross-sectional views illustrating a method for manufacturing an exemplary low-temperature electrostatic chuck according to the present disclosure. [Figure 2c] 1A-1C are cross-sectional views illustrating a method for manufacturing an exemplary low-temperature electrostatic chuck according to the present disclosure. [Figure 2d] 1A-1C are cross-sectional views illustrating a method for manufacturing an exemplary low-temperature electrostatic chuck according to the present disclosure. [Figure 3a] 1 is a cross-sectional view of an exemplary low-temperature electrostatic chuck according to the present disclosure. [Figure 3b] 1 is a cross-sectional view of an exemplary low-temperature electrostatic chuck according to the present disclosure. [Figure 4] 1 is a cross-sectional view of an exemplary low-temperature electrostatic chuck according to the present disclosure. [Figure 5a] 1 is a cross-sectional view of an exemplary low-temperature electrostatic chuck according to the present disclosure. [Figure 5b] 1 is a cross-sectional view of an exemplary low-temperature electrostatic chuck according to the present disclosure. [Figure 5c] 1 is a cross-sectional view of an exemplary low-temperature electrostatic chuck according to the present disclosure. [Figure 6] 1 is a cross-sectional view of an exemplary low-temperature electrostatic chuck according to the present disclosure. [Figure 7] 1 is a cross-sectional view of an exemplary low-temperature electrostatic chuck according to the present disclosure. [Figure 8a] 1A-1C are cross-sectional views illustrating a method for manufacturing an exemplary low-temperature electrostatic chuck according to the present disclosure. [Figure 8b] 1A-1C are cross-sectional views illustrating a method for manufacturing an exemplary low-temperature electrostatic chuck according to the present disclosure. [Figure 8c] 1A-1C are cross-sectional views illustrating a method for manufacturing an exemplary low-temperature electrostatic chuck according to the present disclosure. [Figure 9a] 1 is a cross-sectional view of an exemplary low-temperature electrostatic chuck according to the present disclosure. [Figure 9b] 1 is a cross-sectional view of an exemplary low-temperature electrostatic chuck according to the present disclosure. [Figure 10] 1 is a cross-sectional view of an exemplary low-temperature electrostatic chuck according to the present disclosure. [Figure 11a] 1 is a cross-sectional view of an exemplary low-temperature electrostatic chuck according to the present disclosure. [Figure 11b] 1 is a cross-sectional view of an exemplary low-temperature electrostatic chuck according to the present disclosure. [Figure 11c] 1 is a cross-sectional view of an exemplary low-temperature electrostatic chuck according to the present disclosure. [Figure 12] 1 is a cross-sectional view of an exemplary low-temperature electrostatic chuck according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0019] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The present disclosure is provided to more completely explain the present invention to those skilled in the art, and the following examples can be modified into many other forms, and the scope of the present invention is not limited to the following examples. Rather, these examples are provided to make the disclosure more complete and thorough, and to fully convey the concept of the present invention to those skilled in the art.

[0020] In the following drawings, the thickness and size of each layer have been exaggerated for convenience and clarity of explanation, and the same reference numerals in the drawings refer to the same elements. As used herein, the term "and / or" includes any one and all combinations of one or more of the listed items. In addition, in this specification, "connected" refers not only to a case where member A and member B are directly connected, but also to a case where member A and member B are indirectly connected through member C between them.

[0021] The terms used in this specification are for the purpose of describing particular embodiments and are not intended to limit the present invention. As used in this specification, the singular forms can include the plural forms unless the context clearly dictates otherwise. Furthermore, as used in this specification, the words "comprise," "include," and / or "comprising," "including," specify the presence of each stated shape, number, step, operation, member, element, and / or group thereof, but do not exclude the presence or addition of one or more other shapes, numbers, operations, members, elements, and / or groups thereof.

[0022] In this specification, terms such as "first" and "second" are used to describe various members, components, regions, layers, and / or portions, but it is clear that these members, components, regions, layers, and / or portions should not be limited by these terms. These terms are used only to distinguish one member, component, region, layer, or portion from another region, layer, or portion. Therefore, a "first" member, component, region, layer, or portion described in detail below can be referred to as a "second" member, component, region, layer, or portion without departing from the teachings of the present invention.

[0023] Terms related to space, such as "beneath," "below," "lower," "above," and "upper," may be used to facilitate understanding of one element or feature from another element or feature shown in the drawings. These terms related to space are used to facilitate understanding of the present invention in various process states or usage states of the present invention, and are not intended to limit the present invention. For example, if an element or feature in the drawings is turned over, an element or feature described as "beneath" or "below" becomes "upper" or "upper." Therefore, "beneath" is a concept that encompasses "upper" or "below."

[0024] First, the coating type low-temperature electrostatic chuck will be described. 1 is a cross-sectional view of an exemplary low-temperature electrostatic chuck 100A according to the present disclosure. In the example shown in FIG. 1, the exemplary low-temperature electrostatic chuck 100A according to the present disclosure can include a base member 110 and a support member 120.

[0025] The base member 110 may include a lower region 111 and an upper region 112 provided on the lower region 111. In some examples, the upper region 112 may be provided with a number of first flow paths 113 at a predetermined pitch through which a first fluid at a first temperature flows, and the lower region 111 may be provided with a number of second flow paths 114 at a predetermined pitch through which a second fluid at a second temperature higher than the first temperature flows.

[0026] In some examples, the first temperature can be between about −200° C. and about 0° C., and the second temperature can be between about 0° C. and about 80° C. In some examples, the first fluid and the second fluid can include He, Ne, Ar, Kr, or Xe in a liquid or gas state. The first and second fluids can differ only in temperature and be the same material, or they can differ in temperature and material.

[0027] Although the cross-sectional view of FIG. 1 shows multiple first and second flow channels 113 and 114, they may be provided in the form of one or multiple spirals or helices in a substantially planar state. In some examples, the base member 110 can further include an elongated thermal blocking cavity 115 provided between the first flow path 113 and the second flow path 114 .

[0028] In some examples, the heat blocking cavity 115 is hollow, which allows the first flow path 113 and the second flow path 114 to be blocked from heat exchange with each other. This allows the upper region 112 of the base member 110 to maintain a first temperature (e.g., about -200°C to about 0°C) in the first flow path 113, and the lower region 111 of the base member 110 to maintain a second temperature (e.g., about 0°C to about 80°C) in the second flow path 114.

[0029] In some examples, the thickness of the thermal blocking cavity 115 may be about 1% to about 30% of the thickness of the base member 110. If the thickness of the thermal blocking cavity 115 is less than about 1% of the thickness of the base member 110, the thermal blocking effect between the upper region 112 and the lower region 111 of the base member 110 may be small, while if the thickness of the thermal blocking cavity 115 is about 30% greater than the thickness of the base member 110, the thickness of the base member 110 may be relatively (unnecessarily) large. In some examples, the thermal blocking cavity 115 may be filled with a heat insulating material (e.g., aerogel, perlite, foam glass, mineral wool, glass wool, etc.). In some examples, the upper and / or lower surfaces of the thermal blocking cavity 115 may be coated with YSZ (Yttria-stabilized zirconia) or Al2TiO5, which have low thermal conductivity, or may be bonded with a YSZ plate or an Al2TiO5 plate.

[0030] In some examples, the lower region 111 of the base member 110 may be directly or indirectly coupled to the equipment. As described above, even if the upper region 112 of the base member 110 is maintained at a low temperature of about −200° C. to about 0° C., the lower region 111 of the base member 110 may be maintained at a temperature of about 0° C. to about 80° C. (preferably, at room temperature of about 1° C. to 35° C.), so that frost, ice, or moisture does not form in the attachment region of the etching equipment to which the low-temperature electrostatic chuck 100A is coupled. Therefore, defects in semiconductor wafers due to moisture during the semiconductor manufacturing process may be prevented.

[0031] In some examples, the base member 110 may be made of pure titanium, a titanium alloy, pure aluminum, or an aluminum alloy. For reference, pure titanium and / or titanium alloys have a thermal expansion coefficient (unit: m / m°C) of approximately 7×10 -6 to approximately 11×10 -6 while pure aluminum and / or aluminum alloys have a thermal expansion coefficient of 23×10 -6 It could be.

[0032] The support member 120 may be provided directly on the base member 110 without a bonding layer. In some examples, the support member 120 may include a first dielectric layer 121, an electrode layer 123, and a second dielectric layer 122. The first dielectric layer 121 may be provided by being coated directly on the base member 110 without a bonding layer. The electrode layer 123 may be provided on the first dielectric layer 121. The second dielectric layer 122 may be provided by being coated directly on the first dielectric layer 121 and the electrode layer 123.

[0033] In some examples, the first dielectric layer 121 may be provided by being directly coated on the base member 110 using atmospheric plasma spraying. In some examples, the second dielectric layer 122 may be provided by being directly coated on the electrode layer 123 and the first dielectric layer 121 using atmospheric plasma spraying. In some examples, aerosol deposition, arc spraying, high-velocity oxygen-fuel spraying, cold spraying, or flame spraying may be used in addition to atmospheric plasma spraying.

[0034] In some examples, at least one of the first and second dielectric layers 121, 122 may be provided as a ceramic. In some examples, at least one of the first and second dielectric layers 121, 122 may include zirconia (ZrO), beryllium oxide (BeO), aluminum oxide (AlO), aluminum nitride (AlN), silicon carbide (SiC), silicon nitride (SiN), or aluminum titanate (AlTiO). In some examples, at least one of the first and second dielectric layers 121, 122 may include yttrium oxide (YO), yttrium oxyfluoride (YOF), or yttrium fluoride (YF). For reference, the thermal expansion coefficient of zirconia is approximately 11×10 -6 The thermal expansion coefficient of beryllium oxide is approximately 8 x 10 -6 The thermal expansion coefficient of aluminum oxide is approximately 7.3 x 10 -6 The thermal expansion coefficient of aluminum nitride is approximately 4.4 x 10 -6 The thermal expansion coefficient of silicon carbide is approximately 3.7 x 10 -6The thermal expansion coefficient of silicon nitride is approximately 3.4 x 10 -6 The thermal expansion coefficient of aluminum titanate is approximately 1 x 10 -6 The thermal expansion coefficients of yttrium oxide, yttrium oxyfluoride, and yttrium fluoride are about 10 to about 10.5×10 -6 is.

[0035] Therefore, by appropriately selecting materials for the base member 110 and the support member 120 that have a small difference in thermal expansion coefficient between them, it is possible to minimize the warpage of the low-temperature electrostatic chuck 100A caused by the difference in thermal expansion coefficient between them.

[0036] In some examples, the base member 110 and / or the support member 120 may be provided in the form of a generally circular plate when viewed from above if they are intended for semiconductor wafers, and in some examples, the base member 110 and / or the support member 120 may be provided in the form of a generally rectangular plate when viewed from above if they are intended for display glass.

[0037] In some examples, when the low-temperature electrostatic chuck 100A is used for semiconductor manufacturing, the diameter of the support member 120 may be about 100 mm to about 400 mm. In some examples, when the low-temperature electrostatic chuck 100A is used for display manufacturing, the length of one side of the support member 120 may be about 400 mm to about 3500 mm.

[0038] In this manner, the present disclosure provides a low-temperature electrostatic chuck 100A that can be directly or indirectly mounted on etching equipment, and further includes a heat-shielding cavity 115 between the upper and lower regions to prevent heat from being transferred from the upper region to the lower region and prevent frost, ice, moisture, etc. from forming on the etching equipment.

[0039] 2a-2d are schematic diagrams illustrating a method for fabricating an exemplary low-temperature electrostatic chuck 100A according to the present disclosure. 2a illustrates an exemplary low-temperature electrostatic chuck 100A according to the present disclosure at an early stage in its manufacture. A base member 110 may be provided, having an upper region 112 with multiple first flow passages 113 through which a first fluid at a first temperature flows, a lower region 111 with multiple second flow passages 114 through which a second fluid at a second temperature higher than the first temperature flows, and a thermal isolation cavity 115 between the first flow passages 113 and the second flow passages 114. In some examples, the base member 110 may be made of pure titanium, a titanium alloy, pure aluminum, or an aluminum alloy.

[0040] 2b illustrates a later stage in the manufacture of an exemplary low-temperature electrostatic chuck 100A according to the present disclosure. A first dielectric layer 121 may be coated directly onto the base member 110. In some examples, aluminum oxide powder may be coated directly onto the base member 110 using atmospheric plasma spraying. This allows the first dielectric layer 121 to be provided directly on the base member 110 without a bonding layer between the base member 110 and the first dielectric layer 121. Reference numeral 150 in the figure denotes a powder spray nozzle.

[0041] 2c illustrates a later stage in the manufacture of an exemplary low-temperature electrostatic chuck 100A according to the present disclosure. An electrode layer 123 may be provided on the first dielectric layer 121. The electrode layer 123 may also be provided by plating or by one of the various spraying methods described above. The electrode layer 123 may include tungsten (W) and / or titanium (Ti).

[0042] 2d illustrates a later stage in the manufacture of an exemplary low-temperature electrostatic chuck 100A according to the present disclosure. The second dielectric layer 122 may be directly coated on the first dielectric layer 121 and the electrode layer 123. In some examples, aluminum oxide powder may be coated on the first dielectric layer 121 and the electrode layer 123 using atmospheric plasma spraying. Here, the first dielectric layer 121, the electrode layer 123, and the second dielectric layer 122 may be defined or referred to as the support member 120.

[0043] 3a and 3b are cross-sectional views of other exemplary low-temperature electrostatic chucks 200A, 200B according to the present disclosure. In the example shown in FIGS. 3a and 3b, another exemplary low-temperature electrostatic chuck 200A according to the present disclosure may include a thermal rejection heater 215. In some examples, the thermal rejection heater 215 may be provided substantially parallel between the first flow path 113 and the second flow path 114. In some examples, the thermal rejection heater 215 may include a nickel-chromium hot wire and an insulator covering the hot wire. Although multiple thermal rejection heaters 215 are shown in the cross-sectional views of FIGS. 3a and 3b, in a substantially planar state, the heaters may be provided in the form of one or multiple spirals or swirls. The thermal rejection heater 215 prevents heat from being transferred from the first flow path 113 to the second flow path 114, thereby allowing the temperature of the second flow path 114 to be adjusted to a temperature similar to the temperature of the equipment (e.g., room temperature).

[0044] In some examples, the thermal blocking heater 215 may be provided at a position that does not correspond to (vertically offset from) the first flow path 113 and the second flow path 114 (see FIG. 3a), or at a position that corresponds to (vertically identical to) the first flow path 113 and the second flow path 114 (see FIG. 3b).

[0045] On the other hand, the low-temperature electrostatic chucks 200A and 200B according to the present disclosure can stop the operation of the first flow passage 113 after the etching process of the semiconductor wafer is completed at a cryogenic temperature, and instead can further increase the temperature of the thermal isolation heater 215.

[0046] For example, by increasing the temperature of the thermal isolation heater 215 to 50°C to about 100°C, the temperature of the semiconductor wafer also reaches the above temperature range, thereby preventing moisture from remaining on the surface of the semiconductor wafer when it is removed from the process chamber.

[0047] FIG. 4 is a cross-sectional view of an exemplary low-temperature electrostatic chuck 300A according to the present disclosure. In the example shown in FIG. 4 , another exemplary low-temperature electrostatic chuck 300A according to the present disclosure may further include a thermal blocking cavity 115 and a thermal blocking heater 215. In some examples, the thermal blocking cavity 115 and the thermal blocking heater 215 may be provided approximately parallel between the first flow path 113 and the second flow path 114. In some examples, the thermal blocking cavity 115 may be located at the top and the thermal blocking heater 215 may be located at the bottom, although the reverse is also possible. The thermal blocking cavity 115 and the thermal blocking heater 215 prevent heat from being transferred from the first flow path 113 to the second flow path 114, thereby allowing the temperature of the second flow path 114 to be adjusted to a temperature similar to that of the equipment. Furthermore, after the etching process is completed, the thermal blocking heater 215 can be used to quickly increase the temperature of the semiconductor wafer to room temperature.

[0048] TIFF0007808373000001.tif107170

[0049] TIFF0007808373000002.tif81170

[0050] 5c, the thermal blocking cavity 415 may include a first thermal blocking cavity 4151 provided between the first flow path 113 and the second flow path 114, a second thermal blocking cavity 4152 provided between the first flow path 113 and connected to the first thermal blocking cavity 4151, and a third thermal blocking cavity 4153 provided between the second flow path 114 and connected to the first thermal blocking cavity 4151. In some examples, the width of the first thermal blocking cavity 4151 may be greater than the widths of the second and third thermal blocking cavities 4152, 4153. In some examples, the thermal blocking cavity 415 may have a generally "+" cross-sectional shape.

[0051] FIG. 6 is a cross-sectional view of an exemplary low-temperature electrostatic chuck 500A according to the present disclosure. As shown in FIG. 6 , in another exemplary low-temperature electrostatic chuck 500A according to the present disclosure, in particular, the base member 110 may include a thermal isolation cavity 415 provided between the first flow path 113 and the second flow path 114, and may further include an insulating material 510 provided in the thermal isolation cavity 415 and having a thermal conductivity of less than about 10.

[0052] In some examples, the thermal insulation material 510 may include YSZ (Yttria-stabilized zirconia) coated on the thermal insulation cavity 415, coated Al2TiO5, or a YSZ plate or Al2TiO5 plate bonded to the thermal insulation cavity 415. In some examples, the thermal insulation material 510 can mostly be used if it has a thermal conductivity of about 0.1 W / mK to about 0.35 W / mK. In some examples, the height (thickness) of the thermal insulation material 510 may be smaller than the height (thickness) of the thermal insulation cavity 415, so that a substantial upper region and / or lower region of the thermal insulation cavity 415 may remain in the form of a cavity.

[0053] In some examples, the thermal blocking cavity 415 may include a first thermal blocking cavity 4151 extending between the first flow path 113 and the second flow path 114, a second thermal blocking cavity 4152 extending from the first thermal blocking cavity 4151 to the first flow path 113, and a third thermal blocking cavity 4153 extending from the first thermal blocking cavity 4151 to the second flow path 114. In some examples, the insulating material 510 may be located in the first thermal blocking cavity 4151 extending between the first flow path 113 and the second flow path 114.

[0054] In this way, the present disclosure provides a structure in which the lower region 111 (relatively high temperature region) and the upper region 112 (relatively low temperature region) of the base member 110 are unlikely to exchange heat with each other, thereby preventing the formation of frost, ice, moisture, etc. on the equipment and providing a variety of low-temperature electrostatic chucks that can be attached to the equipment.

[0055] Next, a description will be given of the bonding-type low-temperature electrostatic chuck, in which the description of the structure, material, and / or function that overlap with the coating-type low-temperature electrostatic chuck will be minimized.

[0056] 7 is a cross-sectional view of an exemplary low-temperature electrostatic chuck 100B according to the present disclosure. In the example shown in FIG. 7, the exemplary low-temperature electrostatic chuck 100B according to the present disclosure may include a base member 110, a support member 120, and a bonding layer 130.

[0057] The bonding layer 130 may be interposed between the base member 110 and the support member 120. In some examples, the bonding layer 130 may comprise a silicone polymer-based or a metal-based bonding layer. In some examples, the silicone polymer-based bonding layer may enable the electrostatic chuck to be used in a temperature range of about −200° C. to about 0° C., and the metal-based bonding layer may enable the electrostatic chuck to be used in a temperature range of about 0° C. to about 80° C.

[0058] In some examples, the silicone polymer based bonding layer can include at least one of a one-part silicone, a two-part silicone, a one-part epoxy, a two-part epoxy, and a polyurethane having a thermal conductivity of about 0.3 W / mK to about 3 W / mK.

[0059] In some examples, one-component silicone (or one-component epoxy) begins to harden when it reacts with moisture in the air, so when it is stored in a container that prevents contact with air and applied to the base member 110, hardening gradually spreads from the surface to the interior. In some examples, two-component silicone (or two-component epoxy) hardens as the two components (hardener and base) are mixed on the base member 110, regardless of moisture in the air. In some examples, the polyurethane adhesive may also include one-component polyurethane or two-component polyurethane.

[0060] In some examples, the bonding layer 130 may further include nanofillers, such as ceramic fillers or metal fillers, to improve thermal conductivity. In some examples, the average size of the nanofillers may be about 1 nm to about 10 μm. In some examples, the weight (wt%) of the nanofillers may be about 5 wt% to about 95 wt%. If the weight of the nanofillers is less than about 5 wt%, the thermal conductivity may be lower than the target value. If the weight of the nanofillers is more than about 95%, the viscosity may be relatively high, making the adhesive difficult to spray / apply. In some examples, the thickness of the bonding layer 130 may be about 1 μm to about 100 μm. If the thickness of the bonding layer 130 is less than about 1 μm, the thermal conductivity is excellent, but the thermal diffusion performance is reduced, which may result in poor thermal uniformity of the support member 120. If the thickness of the bonding layer 130 is greater than about 100 mm, the thermal uniformity of the support member 120 may be improved due to its excellent thermal diffusion performance, but the thermal conductivity may be reduced.

[0061] In some examples, the nano-fillers can include pure titanium (CTE: 8.6), beryllium oxide (CTE: 8), and / or aluminum oxide (CTE: 7.3). In some examples, the nano-fillers can include a material (metal or ceramic) similar to or the same as the base member 110 and / or support member 120.

[0062] In some examples, the metallurgical bonding layer 130 may include a metallized brazing layer, an active metal brazing layer, a diffusion bonded layer, a friction welded layer, and / or a laser welded layer between the base member (i.e., metal) 110 and the support member (i.e., ceramic) 120. Alternatively, glass frit bonding, metal brazing bonding, diffusion bonding, and / or diffusion brazing bonding may also be used.

[0063] For example, a metallized brazing layer can be formed by forming a metal layer on the ceramic surface and then bonding it using a brazing alloy. Methods for forming the metal layer include applying an intermetallic compound and then reacting it with the ceramic by thermal decomposition to precipitate the metal, depositing the metal in the gas phase, and plating it using physical methods such as vapor deposition and sputtering. One example is the Mo-Mn method. In this method, Mo or Mo-Mn powder is mixed with an organic solvent and a binder to form a paste, which is then applied to the ceramic, metallized, and brazed. For example, Ti can be metallized to bond stabilized zirconia (PSZ) and Ti-6Al-4V at approximately 820°C. For example, a zirconia surface can be metallized with Ti and then bonded using an Ag-28Cu brazing alloy. In some cases, a black reaction layer consisting of Ti-O compounds (TiO, Ti2O3, Ti3O5, TiO2, etc.) is formed on the surface of the metallized zirconia, improving the wettability of the ceramic surface and achieving good bonding.

[0064] For example, active metal brazing layers are not only highly reliable and economical for manufacturing small products, but also suitable for mass production processes where complex-shaped products must be joined in a single operation. A brazing alloy, consisting of a soft metal such as Ni, Cu, or Ag with an appropriate amount of a Group IV active metal such as Ti or Zr, is used to directly bond the components in a vacuum or inert atmosphere. The active metals, such as Ti and Zr, contained in the brazing alloy react with the ceramic to form oxides, nitrides, or carbides at the interface, achieving bonding. Furthermore, Ag, Cu, and other elements segregate to the center, forming a soft layer that relieves stress and improves bonding strength.

[0065] In some cases, a diffusion-bonded layer is formed by bonding two materials together and utilizing atomic diffusion between the bonding surfaces. It is characterized by minimal thermal stress and deformation after bonding, and minimal material degradation due to structural changes. It is possible to bond not only similar materials but also dissimilar materials with different properties and complex shapes. There are two methods for joining metals: one that applies pressure and heat below a stress that barely deforms the metal, and another that applies pressure and heat to deform the metal. Bonding occurs through a three-step process: plastic deformation due to high-temperature creep, void elimination due to atomic diffusion, and grain boundary migration. Key factors in diffusion bonding include vacuum atmosphere control, heating and maintaining the temperature of the bonding materials, and reducing thermal stresses that occur during temperature rise and fall.

[0066] In some examples, the friction-welded layer can be obtained by rotating the metal and ceramic while applying pressure, heating them with the friction heat, and then applying pressure to bond them together once they reach a certain temperature. In some cases, the laser beam welding layer is a layer obtained by using high-density energy as a heat source, and high-power lasers include CO2 lasers and Nd:YAG lasers. Although lasers are thermal processes, they have a small beam and high energy density (10 6 W / cm 2 As a result, the influence of heat is small, welding can be performed within a small deformation range, and fine welding is possible due to the good controllability of the input energy.

[0067] In this way, the present disclosure can provide a low-temperature electrostatic chuck 100B in which the distance between the first flow path 113 in the base member 110 and the support member 120 is relatively increased by interposing a bonding layer 130 with high thermal conductivity between the base member 110 and the support member 120, thereby achieving high temperature uniformity on the support member 120.

[0068] In some examples, the electrostatic chuck may be used in a temperature range of about −200° C. to about 0° C. In some examples, the standard deviation of the thermal expansion coefficients among the base member 110, the support member 120, and the bonding layer 130 may be about 0.01% to about 10%. Therefore, in the operating temperature range of the electrostatic chuck, about −200° C. to about 0° C., warping due to the difference in the thermal expansion coefficients among the base member 110, the support member 120, and the bonding layer 130 may be minimized, and as a result, the flatness of the electrostatic chuck may be maintained excellently in a low-temperature environment.

[0069] In some examples, when the base member 110 is made of pure titanium (CTE: 8.6), the first and second dielectric layers 121, 122 constituting the support member 120 are made of beryllium oxide (CTE: 8), and the bonding layer 130 is made of pure titanium (CTE: 8.6) or beryllium oxide (CTE: 8), the standard deviation of the CTE may be about 0.4%. In some examples, when the base member 110 is made of pure titanium (CTE: 8.6), the first and second dielectric layers 121, 122 constituting the support member 120 are made of aluminum oxide (CTE: 7.3), and the bonding layer 130 is made of aluminum oxide (CTE: 7.3), the standard deviation of the CTE may be about 0.9%.

[0070] 8a-8c are schematic diagrams illustrating a method for fabricating an exemplary low-temperature electrostatic chuck 100B in accordance with the present disclosure. 8a illustrates an example low-temperature electrostatic chuck 100B according to the present disclosure at an early stage in its manufacture. A base member 110 may be provided, having an upper region 112 with multiple first flow passages 113 through which a first fluid at a first temperature flows, a lower region 111 with multiple second flow passages 114 through which a second fluid at a second temperature higher than the first temperature flows, and a thermal isolation cavity 115 between the first flow passages 113 and the second flow passages 114. In some examples, the base member 110 may be made of pure titanium, a titanium alloy, or aluminum.

[0071] 8b illustrates a later stage in the manufacture of an exemplary low-temperature electrostatic chuck 100B according to the present disclosure. A bonding layer 130 may be provided on the base member 110. In some examples, the bonding layer 130 may be provided on the base member 110 via a dispenser, a sprayer, a jetting device, a 3D printer, or the like. The bonding layer 130 may be provided on the entire top surface of the base member 110 or may be provided in a dot array pattern on the entire top surface.

[0072] FIG. 8c illustrates a later stage in the manufacturing process of an exemplary low-temperature electrostatic chuck 100B according to the present disclosure. A support member 120 including a first dielectric layer 121, a second dielectric layer 122, and an electrode layer 123 may be attached to the bonding layer 130. In some examples, the first dielectric layer 121 may be formed of aluminum oxide. In some examples, the first dielectric layer 121 may be formed in a plate shape through a sintering process. In some examples, the electrode layer 123 may be formed on the first dielectric layer 121. The electrode layer 123 may be formed by plating or various spraying methods. The electrode layer 123 may include tungsten (W) and / or titanium (Ti). In some examples, the second dielectric layer 122 may be directly coated on the first dielectric layer 121 and the electrode layer 123. In some examples, aluminum oxide powder may be coated on the first dielectric layer 121 and the electrode layer 123 using atmospheric plasma spraying.

[0073] As described above, since the base member 110 contains titanium and the support member 120 and bonding layer 130 contain aluminum oxide, the standard deviation of the thermal expansion coefficients of the base member 110, support member 120, and bonding layer 130 is less than about 2%. As a result, even when the electrostatic chuck is used in a low-temperature environment of about -200°C to about 0°C, the base member 110, support member 120, and bonding layer 130 are hardly warped and maintain excellent flatness. Therefore, the holding force of the glass or wafer by the electrostatic chuck can be maintained excellently.

[0074] 9a and 9b are cross-sectional views of other exemplary low-temperature electrostatic chucks 200C and 200D according to the present disclosure. 9a and 9b, other exemplary low-temperature electrostatic chucks 200C, 200D according to the present disclosure may include a thermal rejection heater 215. In some examples, the thermal rejection heater 215 may be provided substantially parallel between the first flow path 113 and the second flow path 114. In some examples, the thermal rejection heater 215 may be made of a nickel-chromium hot wire and an insulator covering the wire. The thermal rejection heater 215 prevents heat from being transferred from the first flow path 113 to the second flow path 114, thereby allowing the temperature of the second flow path 114 to be adjusted to a temperature similar to the temperature of the equipment (e.g., room temperature).

[0075] In some examples, the thermal blocking heater 215 may be provided at a position not corresponding to the first flow path 113 and the second flow path 114 (see FIG. 9a), or at a position corresponding to the first flow path 113 and the second flow path 114 (see FIG. 9b).

[0076] FIG. 10 is a cross-sectional view of an exemplary low-temperature electrostatic chuck 300B according to the present disclosure. 10 , another exemplary low-temperature electrostatic chuck 300B according to the present disclosure may further include a thermal blocking cavity 115 and a thermal blocking heater 215. In some examples, the thermal blocking cavity 115 and the thermal blocking heater 215 may be provided in parallel between the first flow path 113 and the second flow path 114. In some examples, the thermal blocking cavity 115 may be located at the top and the thermal blocking heater 215 may be located at the bottom, although the reverse is also possible.

[0077] 11a-11c are cross-sectional views of exemplary low-temperature electrostatic chucks 400D, 400E, and 400F according to the present disclosure. In some examples, such as the electrostatic chuck 400D shown in FIG. 11a, the thermal blocking cavity 415 may include a first thermal blocking cavity 4151 provided between the first flow path 113 and the second flow path 114, and a second thermal blocking cavity 4152 provided between the first flow path 113 and connected to the first thermal blocking cavity 4151.

[0078] In some examples, such as the electrostatic chuck 400E shown in FIG. 11b, the thermal blocking cavity 415 may include a first thermal blocking cavity 4151 provided between the first flow path 113 and the second flow path 114, and a second thermal blocking cavity 4152 provided between the second flow path 114 and connected to the first thermal blocking cavity 4151.

[0079] In some examples, such as the electrostatic chuck 400F shown in FIG. 11c, the thermal blocking cavity 415 may include a first thermal blocking cavity 4151 provided between the first flow path 113 and the second flow path 114, a second thermal blocking cavity 4152 provided between the first flow path 113 and connected to the first thermal blocking cavity 4151, and a third thermal blocking cavity 4153 provided between the second flow path 114 and connected to the first thermal blocking cavity 4151.

[0080] FIG. 12 is a cross-sectional view of an exemplary low-temperature electrostatic chuck 500B according to the present disclosure. As shown in FIG. 12 , in another exemplary low-temperature electrostatic chuck 500B according to the present disclosure, in particular, the base member 110 may include a thermal isolation cavity 415 provided between the first flow path 113 and the second flow path 114, and may include an insulating material 510 provided in the thermal isolation cavity 415, the insulating material having a thermal conductivity of less than about 10.

[0081] In some examples, the thermal insulation material 510 can include YSZ (Yttria-stabilized zirconia) coated on the thermal break cavity 415 or coated Al2TiO5, or a YSZ plate or Al2TiO5 plate bonded to the thermal break cavity 415.

[0082] In some examples, the insulation material 510 may be located in a first thermal blocking cavity 4151 extending between the first flow path 113 and the second flow path 114, and additionally, the thermal blocking cavity 415 may further include a second thermal blocking cavity 4152 extending from the first thermal blocking cavity 4151 to the first flow path 113, and a third thermal blocking cavity 4153 extending from the first thermal blocking cavity 4151 to the second flow path 114.

[0083] The above description is merely one example for implementing an exemplary low-temperature electrostatic chuck according to the present disclosure, and the present invention is not limited to the above example. As claimed in the following claims, it can be said that anyone having ordinary skill in the art to which the invention pertains can make various modifications without departing from the gist of the present invention, and that they encompass the technical spirit of the present invention to the extent that such modifications are possible.

Claims

1. a base member; and a support member comprising a first dielectric layer coated on the base member, an electrode layer provided on the first dielectric layer, and a second dielectric layer coated on the first dielectric layer and the electrode layer; The base member includes a first flow path through which a first fluid having a first temperature provided to an upper region flows, and a second flow path through which a second fluid having a second temperature higher than the first temperature provided to a lower region flows, the base member further includes a thermal isolation cavity provided between the first flow path and the second flow path; The low-temperature electrostatic chuck has an upper or lower surface of the heat insulating cavity coated with YSZ (Yttrium-stabilized zirconia) or bonded to a YSZ plate, or coated with Al 2 TiO 5 or bonded to an Al 2 TiO 5 plate.

2. 2. The low-temperature electrostatic chuck of claim 1, wherein the first temperature is between -200°C and 0°C, and the second temperature is between 0°C and 80°C.

3. 2. The low-temperature electrostatic chuck of claim 1, wherein the thermal blocking cavity includes a first thermal blocking cavity provided between the first flow path and the second flow path, and a second thermal blocking cavity provided between the first flow paths and connected to the first thermal blocking cavity.

4. 2. The low-temperature electrostatic chuck of claim 1, wherein the thermal blocking cavity includes a first thermal blocking cavity provided between the first flow path and the second flow path, and a second thermal blocking cavity provided between the second flow path and connected to the first thermal blocking cavity.

5. 2. The low-temperature electrostatic chuck of claim 1, wherein the thermal blocking cavities include: a first thermal blocking cavity provided between the first flow path and the second flow path; a second thermal blocking cavity provided between the first flow paths and connected to the first thermal blocking cavity; and a third thermal blocking cavity provided between the second flow paths and connected to the first thermal blocking cavity.

6. 2. The low-temperature electrostatic chuck of claim 1, wherein the interior of said heat-shielding cavity is filled with a heat insulating material.

7. 2. The low-temperature electrostatic chuck of claim 1, wherein the base member further comprises a thermal barrier heater provided between the first and second flow paths.

8. The base member is a thermal isolation cavity provided between the first flow path and the second flow path; and 10. The low-temperature electrostatic chuck of claim 1, further comprising: a thermal barrier heater provided between said first flow path and said second flow path.

9. 10. The low-temperature electrostatic chuck of claim 1, further comprising a bonding layer interposed between said base member and said support member.

10. 10. The low-temperature electrostatic chuck of claim 9, wherein the bonding layer comprises a silicone polymer family or a metal family.

11. 10. The low-temperature electrostatic chuck of claim 9, wherein the bonding layer comprises at least one of one-part silicone, two-part silicone, one-part epoxy, two-part epoxy, and polyurethane, each having a thermal conductivity of 0.3 W / mK to 3 W / mK.

12. 10. The low-temperature electrostatic chuck of claim 9, wherein the bonding layer includes at least one of a ceramic filler and a metallic filler.

13. 10. The low-temperature electrostatic chuck of claim 9, wherein the bonding layer comprises a metallized brazing layer, an active metal brazing layer, a diffusion bonded layer, a friction welded layer, or a laser welded layer between the base member and the support member.

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