Substrate fixing device, electrostatic chuck and method of manufacturing electrostatic chuck

Abstract

A substrate fixing device includes: a base plate; and an electrostatic chuck fixed to the base plate and configured to attract the substrate by electrostatic force. The electrostatic chuck includes: a ceramic layer formed of ceramic and configured to attract the substrate in a state where the ceramic layer contacts the substrate; a first heater pattern disposed on the ceramic layer and configured to generate heat; an insulating resin layer disposed on the first heater pattern to cover the first heater pattern; a second heater pattern disposed on the insulating resin layer and configured to generate heat; and a conductive member penetrating the insulating resin layer, such that one end of the conductive member contacts the surface of the first heater pattern and the other end of the conductive member contacts the surface of the second heater pattern.

Description

[Technical Field]

[0001] This disclosure relates to a substrate fixing device, an electrostatic chuck, and a method for manufacturing an electrostatic chuck. [Previous Technology]

[0002] Electrostatic chucks (ESCs) are typically incorporated into substrate holding devices to hold and hold wafers, for example, in the manufacture of semiconductor components. The ESC is constructed using a ceramic plate in which electrodes are disposed. The substrate holding device has a structure in which the ESC is fixed to a substrate. When a voltage is applied to the electrodes disposed in the ceramic plate, the wafer is attracted to the ESC by electrostatic force. Because the wafer is attracted to and held by the ESC, processes such as microfabrication and etching can be performed efficiently on the wafer.

[0003] This electrostatic chuck can have a temperature control function for regulating the temperature of the wafer. Specifically, for example, heater electrodes can be formed by screen printing a paste of a metal such as tungsten, so that the heater electrodes can be fired simultaneously with the formation of the ceramic plate. In addition, to obtain high thermal uniformity on the wafer device surface, a technique has been designed to form external heater electrodes by using photolithography to etch rolled metal foil on an insulating resin.

[0004] Regarding the electrostatic chuck using external heater electrodes, the electrostatic chuck has been examined as follows. In the electrostatic chuck, the heater electrodes are divided into two layers and deposited on a ceramic plate, and the two layers of heater electrodes are connected via through-holes. When the heater electrodes are divided into two layers, the freedom of designing heater wiring can be improved, and the thermal uniformity of the wafer device surface can be further improved by placing the heater electrodes in complementary positions in the respective layers (see, for example, JP-A-2016-100474, JP-A-2018-026427, and JP-A-2001-028036).

[0005] However, when two layers of external heater electrodes are mounted in an electrostatic chuck, a step is required to form through-holes to connect the heater electrode layers to each other. Therefore, there is a problem of reduced manufacturing efficiency of the electrostatic chuck. Specifically, to form through-holes, for example, a laser or similar device is used to form through-holes between the two layers of heater electrodes in an insulating resin, and the through-holes are filled with a metal paste. The aforementioned steps are performed to form one through-hole. Therefore, as the number of through-holes increases, it is necessary to repeatedly form through-holes and fill them with metal paste, thereby reducing the manufacturing efficiency of the electrostatic chuck. [Summary of the Invention]

[0006] A specific example provides a substrate fixing device. The substrate fixing device includes: a base plate; and an electrostatic chuck fixed to the base plate and configured to attract the substrate by electrostatic force. The electrostatic chuck includes: a ceramic layer formed of ceramic and configured to attract the substrate in a state where the ceramic layer contacts the substrate; a first heater pattern disposed on the ceramic layer and configured to generate heat; an insulating resin layer disposed on the first heater pattern to cover the first heater pattern; a second heater pattern disposed on the insulating resin layer and configured to generate heat; and a conductive member penetrating the insulating resin layer such that one end of the conductive member contacts the surface of the first heater pattern and the other end of the conductive member contacts the surface of the second heater pattern.

[0007] A specific example provides an electrostatic chuck. The electrostatic chuck includes: a ceramic layer formed of ceramic and configured to adsorb an object; a first heater pattern disposed on the ceramic layer and configured to generate heat; an insulating resin layer disposed on the first heater pattern to cover the first heater pattern; a second heater pattern disposed on the insulating resin layer and configured to generate heat; and a conductive member penetrating the insulating resin layer such that one end of the conductive member contacts the surface of the first heater pattern and the other end of the conductive member contacts the surface of the second heater pattern.

[0008] A specific example provides a method for manufacturing an electrostatic chuck. The method includes the steps of: forming a ceramic layer comprising electrodes and ceramic surrounding the electrodes; forming a first heater pattern on the ceramic layer, wherein the first heater pattern is configured to generate heat; placing a conductive component on the surface of the first heater pattern; providing an insulating resin layer on the ceramic layer to cover the conductive component and the first heater pattern, wherein a metal layer is formed on one side of the insulating resin layer; and patterning the metal layer to form a second heater pattern, wherein in the step of providing the insulating resin layer, the conductive component penetrates the insulating resin layer to contact the metal layer.

Implementation Method

[0010] A specific example of the substrate fixing device, electrostatic chuck, and method for manufacturing the electrostatic chuck disclosed in this application will be described in detail below with reference to the drawings. Incidentally, this disclosure is not limited to this specific example.

[0011] FIG1 is a perspective view showing the configuration of a substrate fixing device 100 according to a specific example. The substrate fixing device 100 shown in FIG1 has a structure in which an electrostatic chuck 120 is adhered to a substrate 110.

[0012] The substrate 110 is a circular component made of a metal such as aluminum. The substrate 110 is the base material for the electrostatic chuck 120. The substrate 110 is attached, for example, to a semiconductor manufacturing apparatus or the like to obtain a substrate holding device 100 for use as a semiconductor holding device for holding a wafer.

[0013] The electrostatic chuck 120 regulates the temperature of an object, such as a wafer, while using electrostatic force to attract it. That is, a ceramic layer for attracting the object and a heater layer for heating the object are provided to form the electrostatic chuck 120. The electrostatic chuck 120, with a diameter smaller than that of the substrate 110, is fixed to the center of the substrate 110. In this case, the heater layer of the electrostatic chuck 120 is adhesively bonded to the substrate 110, thus fixing the electrostatic chuck 120 to the substrate 110. The ceramic layer is provided on the surface above the heater layer, thereby exposing the attraction surface of the ceramic layer of the attracting object.

[0014] Figure 2 is a schematic diagram showing a cross section along line II of Figure 1. As shown in Figure 2, the substrate fixing device 100 has a configuration in which the electrostatic chuck 120 is adhered to the substrate 110.

[0015] The substrate 110 is a metal component, and a cooling water channel 111 is provided inside it as a flow channel for cooling water. For example, the substrate 110 is about 20 mm to 50 mm thick. The substrate 110 is configured to cool the electrostatic chuck 120 by means of cooling water flowing from the outside of the substrate holder 100 into the cooling water channel 111. As a result of cooling the electrostatic chuck 120, objects (such as wafers) adsorbed onto the electrostatic chuck 120 are cooled.

[0016] Incidentally, the substrate 110 may have a cooling gas passage provided as a flow passage for cooling gas instead of the cooling water passage 111. In short, the substrate 110 has a refrigerant passage through which a refrigerant, such as cooling water or cooling gas, passes.

[0017] The electrostatic chuck 120 has a ceramic layer 130, a first insulating resin layer 140, a second insulating resin layer 150, and a third insulating resin layer 160, wherein the third insulating resin layer 160 is bonded to the substrate 110.

[0018] The ceramic layer 130 is made of ceramic 132, and a conductive electrode 131 is disposed therein. For example, the ceramic layer 130 is about 4.5 mm thick. The ceramic 132 is obtained by firing (for example) a green sheet made of alumina. By the electrostatic force generated by the voltage applied to the electrode 131 of the ceramic layer 130, the ceramic layer 130 contacts and adsorbs an object such as a substrate. In other words, in FIG. 2, the upper surface of the ceramic layer 130 serves as the adsorption surface for contacting the object, and when a voltage is applied to the electrode 131, the object is adsorbed onto the adsorption surface.

[0019] The first insulating resin layer 140 is formed on the ceramic layer 130 and is made of an insulating resin (such as epoxy resin or dicis-diimide-trimethylamine resin) with high thermal conductivity and high heat resistance. The first insulating resin layer 140 is, for example, about 40 μm to 100 μm thick. The first heater pattern 141 is formed on the side of the first insulating resin layer 140 opposite to the ceramic layer 130 (the lower side in FIG2).

[0020] The first heater pattern 141 is an electrode made of an alloy such as CN49 (constantan) (Cu-Ni-Mn-Fe alloy), Zeranin (Cu-Mn-Sn alloy), or Manganin (Cu-Mn-Ni alloy). The first heater pattern 141 generates heat when a voltage is applied to it. The thickness of each of the first heater patterns 141 is, for example, about 25 μm to 50 μm, including the range of 15 μm to 200 μm.

[0021] The second insulating resin layer 150 is formed on the first insulating resin layer 140 to cover the first heater pattern 141. Like the first insulating resin layer 140, the second insulating resin layer 150 is a layer made of an insulating resin with high thermal conductivity and high heat resistance (such as epoxy resin or dicis-diimide-trimethylamine resin). The second insulating resin layer 150 is, for example, about 40 μm to 300 μm thick, thicker than the first insulating resin layer 140. The second heater pattern 151 is formed on the side of the second insulating resin layer 150 opposite to the first insulating resin layer 140 (the lower side in FIG2).

[0022] The second heater pattern 151 is an electrode made of an alloy such as CN49 (constantan) (Cu-Ni-Mn-Fe alloy), Zeranin (Cu-Mn-Sn alloy), or manganese-nickel copper (Cu-Mn-Ni alloy). The second heater pattern 151 generates heat when a voltage is applied to it. The thickness of each of the second heater patterns 151 is, for example, about 25 μm to 50 μm, including the range of 15 μm to 200 μm. The second heater pattern 151 is electrically connected to the first heater pattern 141 via a conductive component 170, which will be described later.

[0023] The third insulating resin layer 160 is formed on the second insulating resin layer 150 to cover the second heater pattern 151. Like the first insulating resin layer 140 and the second insulating resin layer 150, the third insulating resin layer 160 is a layer made of an insulating resin with high thermal conductivity and high heat resistance (such as epoxy resin or dicis-diimide-trimethylamine resin). The thickness of the third insulating resin layer 160 is, for example, about 40 μm to 300 μm. A power feeding portion 161 for feeding electrical power from the substrate 110 to the second heater pattern 151 is formed inside the third insulating resin layer 160.

[0024] The power supply section 161 is a conductive component that electrically connects the substrate 110 to the second heater pattern 151. The power supply section 161 applies the voltage supplied from the substrate 110 to the second heater pattern 151.

[0025] The conductive component 170 is embedded in the second insulating resin layer 150. Each conductive component 170 is a conductive component with one end adjacent to the surface of the corresponding first heater pattern 141 and the other end adjacent to the surface of the corresponding second heater pattern 151. The conductive component 170 has an upper surface 172 and an upper lower surface 173 located on the opposite side of the upper surface 172. The conductive adhesive sheet is formed, for example, by including conductive fillers in a resin such as an acrylic resin or a urethane resin. The conductive component 170 is cut from the conductive adhesive sheet to form, for example, a circular cylinder or a rectangular cylinder. The bottom diameter of the conductive component 170 adjacent to the corresponding first heater pattern 141 and the corresponding second heater pattern 151 is, for example, about 0.1 mm to 3 mm. Furthermore, the height of the conductive component 170 is equal to the distance between the opposite surfaces of the corresponding first heater pattern 141 and the corresponding second heater pattern 151. The height of the conductive component 170 is, for example, about 60 μm to 70 μm.

[0026] The conductive component 170 is bonded to the corresponding first heater pattern 141 in a semi-cured state, and is formed from a material having a higher hardness than the insulating resin forming the second insulating resin layer 150 in the semi-cured state. Therefore, when the second insulating resin layer 150 is formed on the first insulating resin layer 140 and pressure is applied to the conductive component 170 against the insulating resin layer 140 while one end of the conductive component 170 is bonded to the corresponding first heater pattern 141, the other end of the conductive component 170 penetrates the second insulating resin layer 150. As a result, the other end of the conductive component 170 reaches the surface of the corresponding second heater pattern 151, such that the upper surface 172 of the conductive component 170 contacts the surface of the corresponding first heater pattern 141 and the lower surface 173 of the conductive component 170 contacts the surface of the corresponding second heater pattern 151. Furthermore, the upper surface 172 of the conductive component 170 is flush with the surface of the corresponding first heater pattern 141, and the lower surface 173 of the conductive component 170 is flush with the surface of the corresponding second heater pattern 151.

[0027] In the substrate fixing device 100 having this configuration, when electrical power is fed from the substrate 110 to the second heater pattern 151 through the power feeding section 161, electrical power is also fed to the first heater pattern 141 through the conductive member 170. When voltage is applied to the first heater pattern 141 and the second heater pattern 151, the first heater pattern 141 and the second heater pattern 151 generate heat to heat the ceramic layer 130 and the object adsorbed onto the ceramic layer 130.

[0028] In the substrate fixing device 100, the temperature of the ceramic layer 130 is adjusted by heating by the first heater pattern 141 and the second heater pattern 151 and cooling by the substrate 110, so that the temperature of the object adsorbed onto the ceramic layer 130 can be adjusted to the desired temperature. Incidentally, instead of the heater electrodes that generate heat, the second heater pattern 151 can function to electrically connect the electrodes of the first heater pattern 141 to each other or to electrically connect the first heater pattern 141 to the bypass electrode of the power feed section 161.

[0029] Incidentally, in the case where the second heater pattern 151 functions as a bypass electrode, the second heater pattern 151 can be formed using an electrical conductor with low resistance (such as copper or a copper alloy). Furthermore, in the aforementioned substrate fixing device 100, a filler such as aluminum oxide, aluminum nitride, or the like can be incorporated into the first insulating resin layer 140, the second insulating resin layer 150, and the third insulating resin layer 160 to improve the thermal conductivity of the insulating resin layers.

[0030] Next, the manufacturing method of the substrate fixing device 100 having the above configuration will be described with reference to the flowchart shown in FIG3.

[0031] First, a ceramic layer 130 for adsorbing objects is formed (step S101). Specifically, for example, a plurality of green sheets containing alumina as the main material are manufactured, and an electrode 131 is appropriately formed on one surface of the green sheet. The electrode 131 can be formed, for example, by screen printing a metal paste onto the surface of the green sheet. Next, the plurality of green sheets are laminated and fired. As a result, a ceramic layer 130 is formed. The interior of the ceramic layer 130 has a layer of electrode 131, for example, as shown in FIG4.

[0032] When the ceramic layer 130 has been formed, a first insulating resin layer 140 is provided on the surface of the ceramic layer 130 (step S102). A metal foil layer is formed on the side of the first insulating resin layer 140 opposite to the ceramic layer 130. That is, a first insulating resin layer 140 with a thickness of, for example, about 40 μm to 100 μm is formed on the surface of the ceramic layer 130, which includes a metal foil layer 141a formed on one side of the first insulating resin layer 140 with a thickness of, for example, about 25 μm to 50 μm, as shown in FIG5. The first insulating resin layer 140 and the metal foil layer 141a are tightly bonded to the ceramic layer 130 by vacuum hot pressing based on vacuum lamination and pressing.

[0033] The first insulating resin layer 140 is formed using an insulating resin (such as epoxy resin or dicis-diimide-trimethylamine resin) with high thermal conductivity and high heat resistance. Furthermore, for example, alumina, aluminum nitride, or similar fillers may be incorporated into the first insulating resin layer 140 to improve its thermal conductivity. On the other hand, any rolled alloy exemplified as the material for the first heater pattern 141 and the second heater pattern 151 can be used as the material for the metal foil layer 141a. That is, the metal foil layer 141a is made of an alloy such as CN49 (constantan) (Cu-Ni-Mn-Fe alloy), Zeranin (Cu-Mn-Sn alloy), or manganese-nickel-copper (Cu-Mn-Ni alloy).

[0034] When the first insulating resin layer 140 has been provided, the metal foil layer 141a is formed, for example, by photolithography, to form a first heater pattern 141 with a desired pattern (step S103). That is, a photoresist is formed on the surface of the metal foil layer 141a, and the photoresist is exposed and developed to form a photoresist pattern covering the portion that should remain as the first heater pattern 141. Then, the exposed metal foil layer 141a not covered by the photoresist pattern is removed by etching. As a result, a first heater pattern 141 with a desired shape is formed, for example, as shown in FIG. 6. In FIG. 6, for example, a cross-section of the first heater pattern 141 formed into two concentric circles is shown.

[0035] When the first heater pattern 141 has been formed, the conductive component 170 is placed on the surface of the first heater pattern 141 (step S104). Specifically, the conductive adhesive sheet contains conductive fillers in a resin such as an acrylic resin or a urethane resin. The conductive adhesive sheet is, for example, 40 μm to 100 μm thick. The conductive component 170 is cut from the conductive adhesive sheet into the shape of a circular cylinder, each having a bottom diameter of about 0.1 mm to 3 mm. The conductive component 170 thus formed is adhesively bonded to the surface of the first heater pattern 141. Incidentally, the conductive component 170 can be formed into the shape of a circular cylinder or a rectangular cylinder, which are cut from an assembly in which a plurality of conductive adhesive sheets are bonded to each other on top.

[0036] The conductive component 170 is positioned where it can be electrically connected to the first heater pattern 141 and the second heater pattern 151, for example, as shown in FIG7. Since the conductive component 170 is cut from the conductive adhesive sheet to be formed, its position can be easily fixed when it is bonded to the first heater pattern 141. Furthermore, at the time when the conductive component 170 is bonded to the first heater pattern 141, the resin forming the conductive component 170 is in a semi-cured state, and the hardness of the semi-cured conductive component 170 is higher than that of the semi-cured insulating resin formed into the second insulating resin layer 150. Incidentally, to increase the hardness of the semi-cured conductive component 170, it can be heated and cured to a predetermined degree after it is bonded to the first heater pattern 141.

[0037] When the conductive component 170 has been placed on the first heater pattern 141, a second insulating resin layer 150 is formed to cover the first heater pattern 141 (step S105). A metal foil layer is formed on the side of the second insulating resin layer 150 opposite to the first heater pattern 141. That is, a second insulating resin layer 150 with a thickness of, for example, about 40 μm to 100 μm is formed on the surface above the first insulating resin layer 140 and the first heater pattern 141, which includes a metal foil layer 151a formed on one side of the second insulating resin layer 150 with a thickness of, for example, 25 μm to 50 μm, as shown in FIG8. The second insulating resin layer 150 and the metal foil layer 151a are tightly bonded to the first insulating resin layer 140 by vacuum hot pressing based on vacuum lamination and pressing.

[0038] The second insulating resin layer 150 is formed using an insulating resin (such as epoxy resin or dicis-butenediamine-trimethylamine resin) with high thermal conductivity and high heat resistance. Furthermore, for example, alumina, aluminum nitride, or similar fillers may be incorporated into the second insulating resin layer 150 to improve its thermal conductivity. On the other hand, any rolled alloy exemplified as the material for the first heater pattern 141 and the second heater pattern 151 can be used as the material for the metal foil layer 151a. That is, the metal foil layer 151a is made of an alloy such as CN49 (constantan) (Cu-Ni-Mn-Fe alloy), Zeranin (Cu-Mn-Sn alloy), or manganese-nickel-copper (Cu-Mn-Ni alloy).

[0039] Incidentally, instead of the heater electrode that generates heat, the second heater pattern 151 can function as a bypass electrode that forms an electrical connection between the electrodes of the first heater pattern 141 or between the first heater pattern 141 and the power feed section 161. When the second heater pattern 151 functions as a bypass electrode, a metal with low resistance (such as copper or a copper alloy) can be used as the material for the metal foil layer 151a.

[0040] When the second insulating resin layer 150 is provided, the insulating resin forming the second insulating resin layer 150 is in a semi-cured state and has a lower hardness than the conductive component 170. Therefore, the insulating resin forming the second insulating resin layer 150 is pushed out by the conductive component 170. As a result, the conductive component 170 penetrates the second insulating resin layer 150, such that the upper end of the conductive component 170 is adjacent to the lower side of the metal foil layer 151a formed on the surface of the second insulating resin layer 150. Therefore, one end of the conductive component 170 is adjacent to the upper side of the first heater pattern 141, and the other end of the conductive component 170 is adjacent to the lower side of the metal foil layer 151a. Furthermore, during the vacuum thermopress bonding performed on the second insulating resin layer 150, the second insulating resin layer 150 is cured and the conductive component 170 is also cured by heating and pressure. The second insulating resin layer 150 is pressurized during deposition and the conductive component 170 is cured. Therefore, the conductive component 170 can be securely contacted below the metal foil layer 151a, and the connection reliability between the two heater patterns is improved.

[0041] When the second insulating resin layer 150 has been provided, the metal foil layer 151a is formed, for example, by photolithography to form a second heater pattern 151 with a desired pattern (step S106). That is, a photoresist is formed on the surface of the metal foil layer 151a, and the photoresist is exposed and developed to form a photoresist pattern covering the portion that should remain as the second heater pattern 151. Then, the exposed metal foil layer 151a not covered by the photoresist pattern is removed by etching to form a first heater pattern 151 with a desired shape, for example, as shown in FIG9. As shown in FIG9, the second heater pattern 151 is placed at locations where at least some portions of the second heater pattern 151 do not overlap with the first heater pattern 141. That is, at least some portions of the second heater pattern 151 are formed at locations where, in a plan view, they overlap with areas where the first heater pattern 141 is not formed. Furthermore, the second heater pattern 151 in other parts is formed therein in the plan view at a position where it overlaps with the first heater pattern 141 in the region including the location of the conductive member 170.

[0042] FIG. 10 is a view showing a specific example of a first heater pattern 141. FIG. 11 is a view showing a specific example of a second heater pattern 151. As shown in FIG. 10, when the first heater pattern 141 is formed into two concentric circles, the conductive member 170 is formed at the position where it contacts the electrodes forming the concentric circles. When the second heater pattern 151 is formed in a plan view where some portions of the second heater pattern 151 overlap with the first heater pattern 141 and other portions of the second heater pattern 151 do not overlap, as shown in FIG. 11, the conductive member 170 is formed in the area where the second heater pattern 151 overlaps with the first heater pattern 141 in the plan view.

[0043] In this manner, in the region including the location of the conductive member 170, the first heater pattern 141 and the second heater pattern 151 overlap in the plan view, and one end of the conductive member 170 is adjacent to the upper surface of the first heater pattern 141, while the other end of the conductive member 170 is adjacent to the lower surface of the second heater pattern 151. Therefore, the first heater pattern 141 and the second heater pattern 151 are electrically connected to each other through the conductive member 170 without undergoing a through-hole forming step. In other words, the connection between the two heater patterns can be achieved through a simple step, thereby improving the manufacturing efficiency of the electrostatic chuck 120 and the substrate fixing device 100.

[0044] When the second heater pattern 151, which is connected to the first heater pattern 141 via the conductive member 170, has been formed, a third insulating resin layer 160 is formed to cover the second heater pattern 151 (step S107). Specifically, a third insulating resin layer 160 in a semi-cured state is formed to cover the second insulating resin layer 150 and the second heater pattern 151. Then, the third insulating resin layer 160 is heated and pressed to cure it. As a result, two heater layers are formed in which the first heater pattern 141 and the second heater pattern 151 are connected to each other via the conductive member 170, for example, as shown in FIG12.

[0045] Subsequently, an opening is formed in the third insulating resin layer 160 at the position corresponding to the electrode pad in the second heater pattern 151 (step S108). That is, in order to expose the second heater pattern 151 at the position of the electrode pad that will serve as the contact power feeding portion 161, an opening 161a is formed in the third insulating resin layer 160, for example, as shown in FIG13. In this way, an electrostatic chuck 120 having two layers of heater electrodes connected to each other by conductive members 170 can be obtained.

[0046] The electrostatic chuck 120 is bonded to the substrate 110 using an adhesive (step S109). Specifically, the surface of the third insulating resin layer 160 in which the opening 161a is formed is bonded to the substrate 110, for example, using a silane coupling agent and an adhesive. In this case, the position of the opening 161a is aligned with the position of the power feeding portion 161 and bonded thereto. Therefore, the power feeding portion 161 and the second heater pattern 151 are in contact with each other, so that electrical power can also be fed to the second heater pattern 151. In addition, the second heater pattern 151 is connected to the first heater pattern 141 through the conductive member 170. Therefore, electrical power can also be fed to the first heater pattern 141. When the electrostatic chuck 120 is bonded to the substrate 110, the substrate fixing device 100 is completed.

[0047] According to this specific example, as described above, an insulating resin layer is formed to cover the first heater pattern while the conductive component is placed on the surface of the first heater pattern, and the conductive component penetrates the insulating resin layer. Then, the front end of the conductive component that has penetrated the insulating resin layer is placed adjacent to the second heater pattern. Therefore, the first heater pattern and the second heater pattern can be electrically connected to each other through the conductive component without forming any through holes connecting the first heater pattern to the second heater pattern. Therefore, the steps of forming through holes in the insulating resin layer and filling the through holes with metal paste can be eliminated, thereby improving manufacturing efficiency.

[0048] Furthermore, in a prior art manufacturing method in which a through-hole is first formed in an insulating resin layer and then a metal paste is filled into the through-hole to form a through-hole that electrically connects the first heater pattern to the second heater pattern, it is believed that the metal paste cannot completely fill the through-hole. In this case, the reliability of the electrical connection between the through-hole and the heater pattern cannot be sufficiently ensured. On the other hand, according to this embodiment, the conductive member 170 is securely contacted on its upper and lower sides with the first heater pattern 141 and the second heater pattern 151. Therefore, the reliability of the electrical connection between the first heater pattern 141 and the second heater pattern 151 can be further improved by means of the conductive member 170.

[0049] Incidentally, in the aforementioned specific example, two layers of heater electrodes, namely the first heater pattern 141 and the second heater pattern 151, are provided in the electrostatic chuck 120. However, it is alternatively possible to provide three or more layers of heater patterns in the electrostatic chuck 120. Even in the case of providing three or more layers of heater patterns, conductive components are placed on the surface of each layer of heater pattern, and an insulating resin layer is deposited thereon from above, such that the conductive components penetrate the insulating resin layer and contact the upper layer of the heater pattern. Therefore, the upper and lower layers of the heater pattern can be easily electrically connected, thereby improving manufacturing efficiency.

[0050] Furthermore, in the aforementioned specific example, electrode pads are formed in the portion of the first heater pattern 141 that contacts the conductive member 170, or in the second heater pattern 151, in the portion that contacts the power supply portion 161. Each electrode pad has a specific size or larger diameter to securely connect to the conductive member 170 or the power supply portion 161. The area around the electrode pads tends to be a blank area of ​​the heater pattern. Therefore, the temperature around the electrode pads tends to decrease, which may result in reduced thermal uniformity.

[0051] Therefore, in the aforementioned specific example, the electrode pad of the heater pattern on one layer can overlap with the heater pattern on another layer, thereby preventing the temperature around the electrode pad from dropping and improving thermal uniformity.

[0052] Furthermore, in the aforementioned specific example, the conductive component 170 is formed of a material comprising resin and conductive filler in the resin, but the conductive component 170 may alternatively be formed of another electrical conductor. However, the conductive component 170 is formed of a material with a higher hardness than the insulating resin forming the second insulating resin layer 150. Therefore, when the second insulating resin layer 150 is formed to cover the first heater pattern 141 on which the conductive component 170 has been placed, the end portion of the conductive component 170 penetrates the second insulating resin layer 150 to contact the metal foil layer 151a.

[0053] Although preferred embodiments have been described in detail above, this disclosure is not limited to the aforementioned embodiments, and various modifications and substitutions may be added to the aforementioned embodiments without departing from the scope described in the claims. [Simplified Explanation of the Diagram]

[0009] Figure 1 is a perspective view showing the configuration of a substrate fixing device according to a specific example; Figure 2 is a schematic cross-sectional view showing the substrate fixing device according to the specific example; Figure 3 is a flowchart showing the manufacturing method of the substrate fixing device according to the specific example; Figure 4 is a view showing a specific example of a ceramic layer forming step; Figure 5 is a view showing a specific example of a first insulating resin layer deposition step; Figure 6 is a view showing a specific example of a first heater pattern forming step; Figure 7 is a view showing a specific example of a conductive component placement step; Figure 8 is a view showing a specific example of a second insulating resin layer deposition step; Figure 9 is a view showing a specific example of a second heater pattern forming step; Figure 10 is a view showing a specific example of a first heater pattern; Figure 11 is a view showing a specific example of a second heater pattern; Figure 12 is a view showing a specific example of a third insulating resin layer deposition step; and Figure 13 is a view showing a specific example of an opening forming step.

Claims

1. A substrate fixing device, comprising: Base plate; And an electrostatic clamp, which is fixed to the base plate and configured to attract the substrate by electrostatic force; The electrostatic chuck includes: a ceramic layer formed of ceramic and configured to adsorb the substrate in a state where the ceramic layer is in contact with the substrate; A first heater pattern is disposed on the ceramic layer and configured to generate heat; an insulating resin layer is disposed on the first heater pattern to cover the first heater pattern; a second heater pattern is disposed on the insulating resin layer and configured to generate heat; and a conductive component penetrates the insulating resin layer such that one end of the conductive component contacts the surface of the first heater pattern and the other end of the conductive component contacts the surface of the second heater pattern; the conductive component is a conductive adhesive sheet in which conductive filler is contained in resin, formed from the conductive adhesive sheet in a semi-cured state with a hardness higher than that of the insulating resin forming the insulating resin layer, and the conductive adhesive sheet has the hardness to allow the conductive component to penetrate the insulating resin layer and contact the second heater pattern when the insulating resin layer covering the first heater pattern is formed with the conductive component disposed on the surface of the first heater pattern.

2. The substrate fixing device as claimed in claim 1, wherein, The conductive component includes an upper surface and a lower surface opposite to the upper surface. The upper surface of the conductive component is flush with the surface of the first heater pattern, and the lower surface of the conductive component is flush with the surface of the second heater pattern.

3. The substrate fixing device as claimed in claim 1 or 2, wherein, The conductive component is formed of a material comprising resin and conductive filler contained in the resin.

4. The substrate fixing device as claimed in claim 1 or 2, wherein, The conductive component includes an upper surface and a lower surface opposite to the upper surface. The upper surface contacts the first heater pattern, and the lower surface contacts the second heater pattern. The diameter of each of the upper and lower surfaces is in the range of 0.1 mm to 3 mm.

5. The substrate fixing device as claimed in claim 1 or 2, wherein, The conductive component overlaps with the patterns of the first heater and the second heater in the plan view.

6. The substrate fixing device as claimed in claim 1 or 2, wherein, The ceramic layer comprises: an electrode configured to generate an electrostatic force according to a voltage applied to the electrode; and a ceramic layer surrounding the electrode.

7. An electrostatic chuck, comprising: A ceramic layer, which is formed of ceramic and configured to adsorb objects; A first heater pattern is disposed on the ceramic layer and configured to generate heat; An insulating resin layer is disposed on the first heater pattern to cover the first heater pattern; a second heater pattern is disposed on the insulating resin layer and configured to generate heat; and a conductive member penetrates the insulating resin layer such that one end of the conductive member contacts the surface of the first heater pattern and the other end of the conductive member contacts the surface of the second heater pattern; the conductive member is a conductive adhesive sheet in which conductive filler is contained in resin, formed from the conductive adhesive sheet in a semi-cured state with a hardness higher than that of the insulating resin forming the insulating resin layer, and the conductive adhesive sheet has the hardness to allow the conductive member to penetrate the insulating resin layer and contact the second heater pattern when the insulating resin layer covering the first heater pattern is formed with the conductive member disposed on the surface of the first heater pattern.

8. The electrostatic clamp as described in request item 7, wherein, The conductive component includes an upper surface and a lower surface opposite to the upper surface. The upper surface of the conductive component is flush with the surface of the first heater pattern, and the lower surface of the conductive component is flush with the surface of the second heater pattern.

9. A method of manufacturing an electrostatic chuck, the method comprising the steps of: forming a ceramic layer comprising electrodes and ceramic surrounding the electrodes; forming a first heater pattern on the ceramic layer, wherein the first heater pattern is configured to generate heat; placing a conductive component on the surface of the first heater pattern; providing an insulating resin layer on the ceramic layer to cover the conductive component and the first heater pattern, wherein a metal layer is formed on one side of the insulating resin layer; and patterning the metal layer to form a second heater pattern, wherein in the step of providing the insulating resin layer, the conductive component penetrates the insulating resin layer to contact the metal layer.

10. As in request item 9, wherein, In the step of providing the insulating resin layer, pressure and heat are applied to the insulating resin layer so that the conductive component penetrates the insulating resin layer to contact the metal layer.

11. As in request item 9 or 10, wherein, The conductive component is formed of a material with a higher hardness than the insulating resin that forms the insulating resin layer.

12. As in request item 9 or 10, wherein, The conductive component is formed of a resin containing conductive filler, and the conductive component is placed on the surface of the first heater pattern in a semi-cured state.

13. As in request item 9 or 10, wherein, The step of placing the conductive component includes heating the conductive component placed on the first heater pattern to harden the conductive component to a predetermined degree.

Images